Patent Application
20220040230
The lymphocyte population in peripheral blood mononuclear cells (PBMCs) mainly constitutes T-cells, B-cells and, the natural-killer cells (NK cells). NK cells are known to play central defense against viral infection and killing tumor cells, and have been classified as effectors of innate immunity due to the lack of antigen specific cell surface receptors. T cells are known to mediate the cellular immunity mediating humoral immunity, provide adaptive immunity which work in close collaboration with the innate immune system. Human NK cells are defined phenotypically by the surface expression of CD56 and CD16, and by their lack of CD3 surface expression. About 90% of human NK cells are CD56dim CD16bright cells and found to be the major cytotoxic subset, whereas CD56bright CD16dim/-NK cells were found to secrete more cytokines. Major cytokines, secreted by NK cells are interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), TNF-β, granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin-10 (IL-10), and IL-13.
NK cells isolated from the peripheral blood of cancer patients display phenotypic and functional alterations especially during advanced stage of cancer. It has been shown that freshly isolated tumor infiltrating NK cells are not cytotoxic to autologous tumors. T cells dysfunction has also been reported in cancer patients. Moreover, NK and T cells, especially NK cells obtained from the peripheral blood of patients with cancer have significantly reduced function particularly cytotoxic activity. Suppression of NK cells is mediated by downregulation of NK receptors in the tumor microenvironment. NK cells infiltration and cytotoxic activity of peripheral-blood lymphocytes has indirect co-relation the prognosis of cancer patients.
The major T-cell subpopulations are helper (CD4+) and cytotoxic (CD8+) T cells. The cellular immune responses that protect against tumors typically have been attributed to CD8+ T cells, CD8+ T cells are associated with chemo-response against the cancer. High numbers of T cells with CD8+ memory T cells, decreased proportions of tumor-infiltrating CD4+ T cells with high percentages of T-regulatory (Tregs) and, reversed CD4/CD8 ratios at tumor site were significantly associated with overall survival in patients with solid cancers. It has been shown that CD45RA+ T cells with high expression of CD62L and CCR7 have longer active life-span and are more effective against cancers in comparison to T memory cells. CD28 co-stimulation play crucial role in T cells anti-tumor and anti-microbial activity, lower surface expression of CD28 on cancer patients' T cells indicate their lower activity of T cells to fight against the cancer and the infection in those patients. Lower surface expression of CD127 on the surface of T cells has been shown to be influenced by the presence of cancer and infections.
Natural killer (NK) cells lyse and differentiate cancer stem cells/undifferentiated tumors with lower expression of MHC class I, CD54 and B7H1 and higher expression of CD44. Medium and high cytotoxic activity of peripheral-blood lymphocytes are associated with reduced cancer risk, and high NK-cell infiltration of the tumor is associated with a better prognosis, whereas low activity is associated with increased cancer risk.
Lower MHC-class I expression on cancer stem cells (CSCs)/poorly differentiated tumors might favor their survival, and explain their limited effectiveness to T-cell based immunotherapies in cancer patients. CSCs are excellent targets of NK cell-mediated cytotoxicity, whereas their differentiated counterparts are significantly more resistant. Furthermore, de-differentiation of tumors resulted in their increased susceptibility to NK cell-mediated cytotoxicity. It is known that cytotoxic function of primary NK cells is suppressed after their interaction with CSCs/stem cells. NK cells, as a result of CD16 receptor cross-linking or interaction with CSCs/undifferentiated tumors, undergo split-anergy, a key event in which NK-cytotoxicity is lost but a greater secretion of IFN-γ is triggered which promote an increase in the differentiation antigen expression of MHC-class I, CD54 and PD-L1 on tumors which has recently been shown to correlate with effectiveness of anti-PD-1 therapy. Indeed, overall higher levels of circulating NK cells are associated with better prognosis in cancer patients. However, NK cell cytotoxic activity in peripheral blood of cancer patients is reduced, and also the expression of NK cell activating receptors were diminished even at the early stages of cancer and are further reduced in advanced disease. Defect in NK cell function is seen both at the pre-neoplastic and neoplastic stages of pancreatic cancer. Among pancreatic tumors, MiaPaCa-2 (MP2) pancreatic cancer stem cells (CSCs) were shown to have increased tumor cell growth, migration, clonogenicity, and self-renewal capacity and chemotherapy resistance.
Immunotherapy with a single type of immune cells, although effective, has not demonstrated complete eradication of tumors, because it utilizes only a specialized subset of the immune cells to target a subpopulation of cancer cells. Thus, there is a great need to identify and develop therapeutic compositions and methods for improved immunotherapies that encompass multiple immune cell types that can target cancer cells using multiple mechanisms.
The present invention is based, at least in part, on the discovery that primary NK cells mediate antibody-dependent cellular cytotoxicity (ADCC) against differentiated tumors but not against undifferentiated/stem-like tumors, and that super-charged NK cells do not mediate ADCC but can target/kill differentiated tumors directly. The present invention is also based, at least in part, on the discovery that NK cells expand CD8+ T cells preferentially, and that NK cells prevent progression of cancer through selection and differentiation of CSCs/poorly-differentiated tumors, resulting in inhibition of the tumor aggressiveness, metastatic potential, and increased susceptibility to chemotherapy.
In one aspect, the invention provides a method of treating a subject afflicted with a cancer, comprising administering to the subject an immunological composition, wherein the immunological composition comprises at least two cell types selected from: (a) allogeneic primary NK cells, (b) allogeneic super-charged NK cells, (c) autologous super-charged NK cell expanded CD8+ T cells, and (d) allogeneic super-charged NK cell expanded autologous CD8+ T cells, is provided.
Numerous embodiments are further provided that can be applied to any aspect of the present invention and/or combined with any other embodiment(s) described herein. For example, in certain embodiments, the method comprises administering to the subject an immunological composition comprising three cell types, or even four cell types. In certain embodiments, the NK cells of the subject show one or more reduced activities selected from: (a) cytokine secretion, optionally wherein the cytokine is IFN-γ, (b) cytotoxicity, (c) expansion of CD8+ T cells, (d) differentiation of stem-like/poorly differentiated tumor cells, and (e) ADCC activity. In certain embodiments, the immunological composition is administered in a pharmaceutically acceptable formulation. In certain embodiments, the method further comprises administering to the subject an antibody against at least one surface protein that is highly expressed on cancer cells, e.g., an antibody that binds MICA/MICB. The antibody may be administered in an amount sufficient to induce ADCC.
In certain embodiments, the method further comprises activating NK cells by inducing or enhancing secretion of IFN-γ in the NK cells, e.g., by administering to the subject one or more additional agents that enhance secretion of IFN-γ by the NK cells, such as IL-2, anti-CD16 antibody, anti-CD3 antibody, anti-CD28 antibody, Mekabu, and/or a composition comprising at least one bacterial strain (e.g., Streptococcus thermophiles, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, KE99, or Lactobacillus bulgaricus), optionally wherein the at least one bacterial strain is either alive or sonicated. In certain preferred embodiments, the composition comprises AJ2 bacteria. In particularly preferred embodiments, the one or more additional agents that activate NK cells are Mekabu and AJ2 bacteria.
In certain embodiments, the method further comprises administering to the subject at least one additional immunotherapy and/or cancer therapy, e.g., which may be administered before, after, or concurrently with the immunological composition. In certain such embodiments, the at least one additional immunotherapy inhibits an immune checkpoint, such as CTLA-4, PD-1, VISTA, B7-H2, B7-H3, PD-L1, B7-H4, B7-H6, ICOS, HVEM, PD-L2, CD160, gp49B, PIR-B, KIR family receptors, TIM-1, TIM-3, TIM-4, LAG-3, GITR, 4-IBB, OX-40, BTLA, SIRP, CD47, CD48, 2B4 (CD244), B7.1, B7.2, ILT-2, ILT-4, TIGIT, HHLA2, butyrophilins, IDO, CD39, CD73 or A2aR. In certain preferred embodiments, the immune checkpoint is selected from CTLA-4, PD-1, PD-L1, and PD-L2. In certain other embodiments, the cancer therapy is selected from radiation, a radiosensitizer, a chemotherapy, interferon, and an interferon-inducing agent. In certain such embodiments, the cancer therapy is a chemotherapy, optionally wherein the chemotherapy is paclitaxel and/or cisplatin.
In certain embodiments, the method further comprises administering to the subject an agent that induces differentiation of poorly differentiated cancer cells, optionally wherein the agent is N-acetylcysteine (NAC).
In certain embodiments, the cancer is pancreatic cancer, or oral cancer, e.g., oral squamous carcinoma. In certain embodiments, the cancer is highly differentiated. In other embodiments, the cancer is stem-like/poorly differentiated.
In certain embodiments, the subject is a mammal, e.g., a mouse or a human, preferably a human.
In another aspect, the invention provides a method of killing or inhibiting proliferation of cancer cells, comprising contacting the cancer cells with an immunological composition (e.g., a composition as described herein), e.g., wherein the immunological composition comprises at least two cell types selected from: (a) allogeneic primary NK cells, (b) allogeneic super-charged NK cells, (c) autologous super-charged NK cell expanded CD8+ T cells, and (d) allogeneic super-charged NK cell expanded autologous CD8+ T cells.
As described above, numerous embodiments are further provided that can be applied to any aspect of the present invention and/or combined with any other embodiment(s) described herein. For example, in certain embodiments, the method comprises contacting the cancer cells with an immunological composition comprising at least three of these cell types, or even four of these cell types. The immunological composition may be in pharmaceutically acceptable formulation.
In certain embodiments, the method further comprises contacting the cancer cells with an antibody against at least one surface protein that is highly expressed on cancer cells, e.g., an antibody that binds MICA/MICB. In certain embodiments, the antibody is provided in an amount sufficient to induce ADCC. In certain embodiments, the method further comprises activating NK cells by inducing or enhancing secretion of IFN-γ in the NK cells, e.g., by contacting the NK cells with one or more additional agents that enhance secretion of IFN-γ by the NK cells, such as IL-2, anti-CD16 antibody, anti-CD3 antibody, anti-CD28 antibody, Mekabu, and a composition comprising at least one bacterial strain (such as Streptococcus thermophiles, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, KE99, and Lactobacillus bulgaricus), optionally wherein the at least one bacterial strain is either alive or sonicated. In certain preferred embodiments, the composition comprises AJ2 bacteria. In particularly preferred embodiments, the one or more additional agents are Mekabu and AJ2 bacteria.
In certain embodiments, the method further comprises contacting the cancer cells with at least one additional immunotherapy and/or cancer therapy, e.g., which may be added before, after, or concurrently with the immunological composition. In certain embodiments, the at least one additional immunotherapy inhibits an immune checkpoint, such as CTLA-4, PD-1, VISTA, B7-H2, B7-H3, PD-L1, B7-H4, B7-H6, ICOS, HVEM, PD-L2, CD160, gp49B, PIR-B, KIR family receptors, TIM-1, TIM-3, TIM-4, LAG-3, GITR, 4-IBB, OX-40, BTLA, SIRP, CD47, CD48, 2B4 (CD244), B7.1, B7.2, ILT-2, ILT-4, TIGIT, HHLA2, butyrophilins, IDO, CD39, CD73 or A2aR. In certain preferred embodiments, the immune checkpoint is selected from CTLA-4, PD-1, PD-L1, and PD-L2. In certain embodiments, the cancer therapy is selected from radiation, a radiosensitizer, a chemotherapy, interferon, and an interferon-inducing agent. In certain such embodiments, the cancer therapy is a chemotherapy, optionally wherein the chemotherapy is a paclitaxel and/or cisplatin. In certain embodiments, the method further comprises contacting the cancer cells with an agent that induces differentiation of poorly differentiated cancer cells, optionally wherein the agent is N-acetylcysteine (NAC).
In certain embodiments, the cancer is pancreatic cancer, or oral cancer, e.g., oral squamous carcinoma. In certain embodiments, the cancer is highly differentiated. In other embodiments, the cancer is stem-like/poorly differentiated.
In certain embodiments, the subject is a mammal, e.g., a mouse or a human, preferably a human.
In another aspect, the invention provides an immunological composition capable of eliciting an immune response in a subject, comprising at least two cell types selected from: (a) allogeneic primary NK cells, (b) allogeneic super-charged NK cells, (c) autologous super-charged NK cell expanded CD8+ T cells, and (d) allogeneic super-charged NK cell expanded autologous CD8+ T cells.
In certain such embodiments, the immunological composition comprises three cell types, or even four cell types. The immunological composition may be a pharmaceutically acceptable formulation. In certain embodiments, the immunological composition further comprises an antibody against at least one surface protein that is highly expressed on cancer cells, such as an antibody that binds MICA/MICB. The antibody may be present in an amount sufficient to induce ADCC when administered to a subject.
In certain embodiments, the immunological composition further comprises one or more additional agents that enhance secretion of IFN-γ by the NK cells, such as IL-2, anti-CD16 antibody, anti-CD3 antibody, anti-CD28 antibody, Mekabu, or a composition comprising at least one bacterial strain (e.g., Streptococcus thermophiles, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, KE99, and Lactobacillus bulgaricus), optionally wherein the at least one bacterial strain is either alive or sonicated. In certain preferred embodiments, the composition comprises AJ2 bacteria. In particularly preferred embodiments, the immunological composition further comprises Mekabu and AJ2 bacteria. In certain embodiments, the immunological composition further comprises at least one additional immunotherapy and/or cancer therapy. In certain such embodiments, the at least one additional immunotherapy inhibits an immune checkpoint, such as CTLA-4, PD-1, VISTA, B7-H2, B7-H3, PD-L1, B7-H4, B7-H6, ICOS, HVEM, PD-L2, CD160, gp49B, PIR-B, KIR family receptors, TIM-1, TIM-3, TIM-4, LAG-3, GITR, 4-IBB, OX-40, BTLA, SIRP, CD47, CD48, 2B4 (CD244), B7.1, B7.2, ILT-2, ILT-4, TIGIT, HHLA2, butyrophilins, IDO, CD39, CD73 or A2aR. In yet certain preferred embodiments, the immune checkpoint is selected from CTLA-4, PD-1, PD-L1, and PD-L2. In certain embodiments, the immunological composition further comprises a cancer therapy selected from a radiosensitizer, a chemotherapy, interferon, and an interferon-inducing agent. In certain such embodiments, the cancer therapy is chemotherapy, optionally wherein the chemotherapy is paclitaxel and/or cisplatin. In certain embodiments, the immunological composition further comprises an agent that induces differentiation of poorly differentiated cancer cells, optionally wherein the agent is N-acetylcysteine (NAC).
Procedures were carried out as depicted in this figure, and disease progression was monitored (
MP2, PL12 and Capan cells were treated with or without NAC (20 nM) for 24 hours, followed by treatment with Paclitaxel (200 and 600 nM) for 18-24 hours. All samples start with the same number of cells (100,000 per well in a 24 well plate) treated with different treatment modalities. Afterwards, the viability of untreated and treated MP2, PL12 and Capan cells were determined using propidium iodide and analyzed with flow cytometry. One of the five representative experiment is shown in the figure.
MP2, PL12, and Capan tumors (1×105 tumors/well) were treated with or without Paclitaxel for 18-20 hours before the viability of cells was determined using propidium iodide staining. P-values of <0.05 were obtained for differences between MP2 vs. PL12 and Capan at the concentrations of 10 nM, 200 nM, 600 nM, 1000 nM and 10 μg of Paclitaxel (n=2 per each experimental condition) (
Hu-BLT mice were implanted with tumors and injected with NK cells, as described in Materials and Methods, before spleen and BM were harvested and single cell suspensions were prepared after mice were euthanized. CD56+NK cells were positively selected from splenocytes, and monocytes were purified from BM cells, and co-cultured at (NK:Monocytes; 2:1 ratio) and treated with IL-2 (1000U/ml) alone or in combination with LPS (100 ng/mL) for 7 days before the supernatants were harvested and IFN-γ secretion was determined using ELISA (
The present invention relates, in part, to immunological compositions and methods of using them to treat a subject afflicted with a cancer, and/or to kill or inhibit proliferation of cancer cells. The compositions comprises multiple immune cell types that can target different populations of cancer cells. Such compositions can also benefit diseases other than cancer, as they can generally strengthen the immune system of a subject.
The articles “a” and “an” are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, “an” element means one element or more than one element.
The term “administering” is intended to include routes of administration which allow an agent to perform its intended function. Examples of routes of administration for treatment of a body which can be used include injection (subcutaneous, intravenous, parenterally, intraperitoneally, intrathecal, etc.), oral, inhalation, and transdermal routes. The injection can be bolus injections or can be continuous infusion. Depending on the route of administration, the agent can be coated with or disposed in a selected material to protect it from natural conditions which may detrimentally affect its ability to perform its intended function. The agent may be administered alone, or in conjunction with a pharmaceutically acceptable carrier.
The term “activating” or “activation” refers to an enhancement of the function of a target. For example, the instant disclosure provides a method of activating a NK cell in vitro, ex vivo, and/or in vivo. In the instant disclosure, the activation of a cell refers to an enhancement of the function of such cell, including at least an enhancement of activity and/or at least one cellular function (e.g., cytotoxicity, cell division and/or growth rate, etc.). In some embodiments, the agent used herein activates at least one cell, such as NK cell(s).
The terms “cancer” or “tumor” or “hyperproliferative” refer to the presence of cells possessing characteristics typical of cancer-causing cells, such as uncontrolled proliferation, immortality, metastatic potential, rapid growth and proliferation rate, and certain characteristic morphological features. Unless otherwise stated, the terms include metaplasias. In some embodiments, such cells exhibit such characteristics in part or in full due to at least one genetic mutations. Cancer cells are often in the form of a tumor, but such cells may exist alone within an animal, or may be a non-tumorigenic cancer cell, such as a leukemia cell. As used herein, the term “cancer” includes premalignant as well as malignant cancers. Cancers include, but are not limited to, B cell cancer, e.g., multiple myeloma, Waldenstrom's macroglobulinemia, the heavy chain diseases, such as, for example, alpha chain disease, gamma chain disease, and mu chain disease, benign monoclonal gammopathy, and immunocytic amyloidosis, melanomas, breast cancer, lung cancer, bronchus cancer, colorectal cancer, prostate cancer, pancreatic cancer, stomach cancer, ovarian cancer, urinary bladder cancer, brain or central nervous system cancer, peripheral nervous system cancer, esophageal cancer, cervical cancer, uterine or endometrial cancer, cancer of the oral cavity or pharynx, liver cancer, kidney cancer, testicular cancer, biliary tract cancer, small bowel or appendix cancer, salivary gland cancer, thyroid gland cancer, adrenal gland cancer, osteosarcoma, chondrosarcoma, cancer of hematologic tissues, and the like. Other non-limiting examples of types of cancers applicable to the methods encompassed by the present invention include human sarcomas and carcinomas, e.g., fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, colorectal cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, liver cancer, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, bone cancer, brain tumor, testicular cancer, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma; leukemias, e.g., acute lymphocytic leukemia and acute myelocytic leukemia (myeloblastic, promyelocytic, myelomonocytic, monocytic and erythroleukemia); chronic leukemia (chronic myelocytic (granulocytic) leukemia and chronic lymphocytic leukemia); and polycythemia vera, lymphoma (Hodgkin's disease and non-Hodgkin's disease), multiple myeloma, Waldenstrom's macroglobulinemia, and heavy chain disease. In some embodiments, cancers are epithlelial in nature and include but are not limited to, bladder cancer, breast cancer, cervical cancer, colon cancer, gynecologic cancers, renal cancer, laryngeal cancer, lung cancer, oral cancer, head and neck cancer, ovarian cancer, pancreatic cancer, prostate cancer, or skin cancer. In other embodiments, the cancer is oral cancer, oral squamous carcinoma, breast cancer, prostate cancer, lung cancer, or colon cancer. In still other embodiments, the epithelial cancer is non-small-cell lung cancer, nonpapillary renal cell carcinoma, cervical carcinoma, ovarian carcinoma (e.g., serous ovarian carcinoma), or breast carcinoma. The epithelial cancers may be characterized in various other ways including, but not limited to, serous, endometrioid, mucinous, clear cell, Brenner, or undifferentiated.
The term “control” refers to any suitable reference standard, such as a normal patient, cultured primary cells/tissues isolated from a subject such as a normal subject, adjacent normal cells/tissues obtained from the same organ or body location of the patient, a tissue or cell sample isolated from a normal subject, or a primary cells/tissues obtained from a depository. In other preferred embodiments, the control may comprise an expression level, numbers of a certain cell type (e.g., NK cells or monocytes), and/or a cellular function of a certain cell type for a set of subject, such as a normal or healthy subject.
The term “immune cell” refers to cells that play a role in the immune response. Immune cells are of hematopoietic origin, and include lymphocytes, such as B cells and T cells; natural killer cells; myeloid cells, such as monocytes, macrophages, eosinophils, mast cells, basophils, and granulocytes.
The term “cytokine” refers to a broad and loose category of small proteins (˜5-20 kDa) that are important in cell signaling. Their release has an effect on the behaviour of cells around them. cytokines are involved in autocrine signaling, paracrine signaling and endocrine signaling as immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, and may additionally include hormones or growth factors in the instant disclosure. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells. Preferred cytokines are exemplified in the specification and the Figures of the instant disclosure.
The term “cytokine/chemokine activity,” includes the ability of a cytokine or a chemokine to modulate at least on of cellular functions. Generally, cytokines or chemokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Thus, the term “cytokine/chemokine activity” includes the ability of a cytokine or chemokine to bind its natural cellular receptor(s), the ability to modulate cellular signals, and the ability to modulate the immune response.
The term “immune response” includes NK-mediated, T cell mediated, and/or B cell mediated immune responses. Exemplary immune responses include T cell responses, e.g., cytokine production and cellular cytotoxicity. In addition, the term immune response includes immune responses that are indirectly affected by NK cell or T cell activation, e.g., antibody production (humoral responses) and activation of cytokine responsive cells, e.g., macrophages.
The term “immunotherapeutic agent” can include any molecule, peptide, antibody or other agent which can stimulate a host immune system to generate an immune response to a tumor or cancer in the subject. Various immunotherapeutic agents are useful in the compositions and methods described herein.
The instant disclosure provides methods to activate NK cells. The term “activate”, “activation,” or “activating” refers to activating NK cell functions. The term “NK cell function(s)” refers to any function of NK cells, such as cytotoxicity and/or cytokine/chemokine production/secretion activities, especially secretion of IFN-γ.
The terms “prevent,” “preventing,” “prevention,” “prophylactic treatment,” and the like refer to reducing the probability of developing a disease, disorder, or condition in a subject, who does not have, but is at risk of or susceptible to developing a disease, disorder, or condition.
The term “inhibit” includes the reduce, decrease, limitation, or blockage, of, for example a particular action, function, or interaction. In some embodiments, cancer is “inhibited” if at least one symptom of the cancer is alleviated, terminated, slowed, or prevented. As used herein, cancer is also “inhibited” if recurrence or metastasis of the cancer is reduced, slowed, delayed, or prevented.
The term “subject” refers to any healthy animal, mammal or human, or any animal, mammal or human afflicted with a cancer, e.g., brain metastasis, oral cancer, lung, ovarian, pancreatic, liver, breast, prostate, colon carcinomas, melanoma, multiple myeloma, and the like. The term “subject” is interchangeable with “patient.”
The term “therapeutic effect” refers to a local or systemic effect in animals, particularly mammals, and more particularly humans, caused by a pharmacologically active substance. The term thus means any substance intended for use in the diagnosis, cure, mitigation, treatment or prevention of disease or in the enhancement of desirable physical or mental development and conditions in an animal or human. The phrase “therapeutically-effective amount” means that amount of such a substance that produces some desired local or systemic effect at a reasonable benefit/risk ratio applicable to any treatment. In certain embodiments, a therapeutically effective amount of a compound will depend on its therapeutic index, solubility, and the like. For example, certain compounds discovered by the methods of the present invention may be administered in a sufficient amount to produce a reasonable benefit/risk ratio applicable to such treatment.
Unless otherwise specified here within, the terms “antibody” and “antibodies” refers to antigen-binding portions adaptable to be expressed within cells as “intracellular antibodies.” (Chen et al. (1994) Human Gene Ther. 5:595-601). Methods are well-known in the art for adapting antibodies to target (e.g., inhibit) intracellular moieties, such as the use of single-chain antibodies (scFvs), modification of immunoglobulin VL domains for hyperstability, modification of antibodies to resist the reducing intracellular environment, generating fusion proteins that increase intracellular stability and/or modulate intracellular localization, and the like. Intracellular antibodies can also be introduced and expressed in one or more cells, tissues or organs of a multicellular organism, for example for prophylactic and/or therapeutic purposes (e.g., as a gene therapy) (see, at least PCT Publs. WO 08/020079, WO 94/02610, WO 95/22618, and WO 03/014960; U.S. Pat. No. 7,004,940; Cattaneo and Biocca (1997) Intracellular Antibodies: Development and Applications (Landes and Springer-Verlag publs.); Kontermann (2004) Methods 34:163-170; Cohen et al. (1998) Oncogene 17:2445-2456; Auf der Maur et al. (2001) FEBS Lett. 508:407-412; Shaki-Loewenstein et al. (2005) J. Immunol. Meth. 303:19-39).
Antibodies may be polyclonal or monoclonal; xenogeneic, allogeneic, or syngeneic; or modified forms thereof (e.g., humanized, chimeric, etc.). Antibodies may also be fully human. Preferably, antibodies of the present invention bind specifically or substantially specifically to a biomarker polypeptide or fragment thereof. The terms “monoclonal antibodies” and “monoclonal antibody composition”, as used herein, refer to a population of antibody polypeptides that contain only one species of an antigen binding site capable of immunoreacting with a particular epitope of an antigen, whereas the term “polyclonal antibodies” and “polyclonal antibody composition” refer to a population of antibody polypeptides that contain multiple species of antigen binding sites capable of interacting with a particular antigen. A monoclonal antibody composition typically displays a single binding affinity for a particular antigen with which it immunoreacts.
Antibodies may also be “humanized”, which is intended to include antibodies made by a non-human cell having variable and constant regions which have been altered to more closely resemble antibodies that would be made by a human cell. For example, by altering the non-human antibody amino acid sequence to incorporate amino acids found in human germline immunoglobulin sequences. The humanized antibodies of the present invention may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo), for example in the CDRs. The term “humanized antibody”, as used herein, also includes antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences.
The term “immune cell” refers to cells that play a role in the immune response. Immune cells are of hematopoietic origin, and include lymphocytes, such as B cells and T cells; natural killer cells; myeloid cells, such as monocytes, macrophages, eosinophils, mast cells, basophils, and granulocytes.
Since it is well-known in the art that antibody heavy and light chain CDR3 domains play a particularly important role in the binding specificity/affinity of an antibody for an antigen, the recombinant monoclonal antibodies of the present invention prepared as set forth above preferably comprise the heavy and light chain CDR3s of variable regions of the antibodies described herein and well-known in the art. Similarly, the antibodies can further comprise the CDR2s of variable regions of said antibodies. The antibodies can further comprise the CDR1s of variable regions of said antibodies. In other embodiments, the antibodies can comprise any combinations of the CDRs.
The CDR1, 2, and/or 3 regions of the engineered antibodies described above can comprise the exact amino acid sequence(s) as those of variable regions of the present invention described herein. However, the ordinarily skilled artisan will appreciate that some deviation from the exact CDR sequences may be possible while still retaining the ability of the antibody, especially an introbody, to bind a desired target, either alone or in combination with an immunotherapy, such as the one or more biomarkers, the binding partners/substrates of such biomarkers, or an immunotherapy effectively (e.g., conservative sequence modifications). Accordingly, in other embodiments, the engineered antibody may be composed of one or more CDRs that are, for example, 50%, 60%, 70%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.5% identical to one or more CDRs of the present invention described herein or otherwise publicly available.
For example, the structural features of non-human or human antibodies (e.g., a rat anti-mouse/anti-human antibody) can be used to create structurally related human antibodies, especially introbodies, that retain at least one functional property of the antibodies of the present invention, such as an immune checkpoint. Another functional property includes inhibiting binding of the original known, non-human or human antibodies in a competition ELISA assay.
Antibodies, immunoglobulins, and polypeptides of the invention can be used in an isolated (e.g., purified) form or contained in a vector, such as a membrane or lipid vesicle (e.g. a liposome). Moreover, amino acid sequence modification(s) of the antibodies described herein are contemplated. For example, it may be desirable to improve the binding affinity and/or other biological properties of the antibody. It is known that when a humanized antibody is produced by simply grafting only CDRs in VH and VL of an antibody derived from a non-human animal in FRs of the VH and VL of a human antibody, the antigen binding activity is reduced in comparison with that of the original antibody derived from a non-human animal. It is considered that several amino acid residues of the VH and VL of the non-human antibody, not only in CDRs but also in FRs, are directly or indirectly associated with the antigen binding activity. Hence, substitution of these amino acid residues with different amino acid residues derived from FRs of the VH and VL of the human antibody would reduce binding activity and can be corrected by replacing the amino acids with amino acid residues of the original antibody derived from a non-human animal.
Similarly, modifications and changes may be made in the structure of the antibodies described herein, and in the DNA sequences encoding them, and still obtain a functional molecule that encodes an antibody and polypeptide with desirable characteristics. For example, antibody glycosylation patterns can be modulated to, for example, increase stability. By “altering” is meant deleting one or more carbohydrate moieties found in the antibody, and/or adding one or more glycosylation sites that are not present in the antibody. Glycosylation of antibodies is typically N-linked. “N-linked” refers to the attachment of the carbohydrate moiety to the side chain of an asparagine residue. The tripeptide sequences asparagine-X-serine and asparagines-X-threonine, where X is any amino acid except proline, are the recognition sequences for enzymatic attachment of the carbohydrate moiety to the asparagine side chain. Thus, the presence of either of these tripeptide sequences in a polypeptide creates a potential glycosylation site. Addition of glycosylation sites to the antibody is conveniently accomplished by altering the amino acid sequence such that it contains one or more of the above-described tripeptide sequences (for N-linked glycosylation sites). Another type of covalent modification involves chemically or enzymatically coupling glycosides to the antibody. These procedures are advantageous in that they do not require production of the antibody in a host cell that has glycosylation capabilities for N- or O-linked glycosylation. Depending on the coupling mode used, the sugar(s) may be attached to (a) arginine and histidine, (b) free carboxyl groups, (c) free sulfhydryl groups such as those of cysteine, (d) free hydroxyl groups such as those of serine, threonine, orhydroxyproline, (e) aromatic residues such as those of phenylalanine, tyrosine, or tryptophan, or (f) the amide group of glutamine. For example, such methods are described in WO87/05330.
Similarly, removal of any carbohydrate moieties present on the antibody may be accomplished chemically or enzymatically. Chemical deglycosylation requires exposure of the antibody to the compound trifluoromethanesulfonic acid, or an equivalent compound. This treatment results in the cleavage of most or all sugars except the linking sugar (N-acetylglucosamine or N-acetylgalactosamine), while leaving the antibody intact. Chemical deglycosylation is described by Sojahr et al. (1987) and by Edge et al. (1981). Enzymatic cleavage of carbohydrate moieties on antibodies can be achieved by the use of a variety of endo- and exo-glycosidases as described by Thotakura et al. (1987).
The term “immunotherapy” or “immunotherapies” refer to any treatment that uses certain parts of a subject's immune system to fight diseases such as cancer. The subject's own immune system is stimulated (or suppressed), with or without administration of one or more agent for that purpose. Immunotherapies that are designed to elicit or amplify an immune response are referred to as “activation immunotherapies.” Immunotherapies that are designed to reduce or suppress an immune response are referred to as “suppression immunotherapies.” Any agent believed to have an immune system effect on the genetically modified transplanted cancer cells can be assayed to determine whether the agent is an immunotherapy and the effect that a given genetic modification has on the modulation of immune response. In some embodiments, the immunotherapy is cancer cell-specific. In some embodiments, immunotherapy can be “untargeted,” which refers to administration of agents that do not selectively interact with immune system cells, yet modulates immune system function. Representative examples of untargeted therapies include, without limitation, chemotherapy, gene therapy, and radiation therapy.
Immunotherapy is one form of targeted therapy that may comprise, for example, the use of cancer vaccines and/or sensitized antigen presenting cells. For example, an oncolytic virus is a virus that is able to infect and lyse cancer cells, while leaving normal cells unharmed, making them potentially useful in cancer therapy. Replication of oncolytic viruses both facilitates tumor cell destruction and also produces dose amplification at the tumor site. They may also act as vectors for anticancer genes, allowing them to be specifically delivered to the tumor site. The immunotherapy can involve passive immunity for short-term protection of a host, achieved by the administration of pre-formed antibody directed against a cancer antigen or disease antigen (e.g., administration of a monoclonal antibody, optionally linked to a chemotherapeutic agent or toxin, to a tumor antigen). For example, anti-VEGF and mTOR inhibitors are known to be effective in treating renal cell carcinoma. Immunotherapy can also focus on using the cytotoxic lymphocyte-recognized epitopes of cancer cell lines. Alternatively, antisense polynucleotides, ribozymes, RNA interference molecules, triple helix polynucleotides and the like, can be used to selectively modulate biomolecules that are linked to the initiation, progression, and/or pathology of a tumor or cancer.
Immunotherapy can involve passive immunity for short-term protection of a host, achieved by the administration of pre-formed antibody directed against a cancer antigen or disease antigen (e.g., administration of a monoclonal antibody, optionally linked to a chemotherapeutic agent or toxin, to a tumor antigen). Immunotherapy can also focus on using the cytotoxic lymphocyte-recognized epitopes of cancer cell lines. Alternatively, antisense polynucleotides, ribozymes, RNA interference molecules, triple helix polynucleotides and the like, can be used to selectively modulate biomolecules that are linked to the initiation, progression, and/or pathology of a tumor or cancer.
The term “immunogenic chemotherapy” refers to any chemotherapy that has been demonstrated to induce immunogenic cell death, a state that is detectable by the release of one or more damage-associated molecular pattern (DAMP) molecules, including, but not limited to, calreticulin, ATP and HMGB1 (Kroemer et al. (2013), Annu. Rev. Immunol., 31:51-72). In addition, the term “immunogenic chemotherapy” further refers to any chemotherapy that results in priming the immune system such that it leads to enhanced immune activity towards cancer. Specific representative examples of consensus immunogenic chemotherapies include 5′-fluorouracil, anthracyclines, such as doxorubicin, and the platinum drug, oxaliplatin, among others.
In some embodiments, immunotherapy comprises inhibitors of one or more immune checkpoints. The term “immune checkpoint” refers to a group of molecules on the cell surface of CD4+ and/or CD8+ T cells that fine-tune immune responses by down-modulating or inhibiting an anti-tumor immune response. Immune checkpoint proteins are well-known in the art and include, without limitation, CTLA-4, PD-1, VISTA, B7-H2, B7-H3, PD-L1, B7-H4, B7-H6, ICO S, HVEM, PD-L2, CD160, gp49B, PIR-B, KIR family receptors, TIM-1, TIM-3, TIM-4, LAG-3, GITR, 4-IBB, OX-40, BTLA, SIRP, CD47, CD48, 2B4 (CD244), B7.1, B7.2, ILT-2, ILT-4, TIGIT, HHLA2, butyrophilins, IDO, CD39, CD73 and A2aR (see, for example, WO 2012/177624). The term further encompasses biologically active protein fragments, as well as nucleic acids encoding full-length immune checkpoint proteins and biologically active protein fragments thereof. In some embodiments, the term further encompasses any fragment according to homology descriptions provided herein. In certain embodiments, the immune checkpoint is PD-1.
Immune checkpoints and their sequences are well-known in the art and representative embodiments are described below. For example, the term “PD-1” refers to a member of the immunoglobulin gene superfamily that functions as a coinhibitory receptor having PD-L1 and PD-L2 as known ligands. PD-1 was previously identified using a subtraction cloning based approach to select for genes upregulated during TCR-induced activated T cell death. PD-1 is a member of the CD28/CTLA-4 family of molecules based on its ability to bind to PD-L1. Like CTLA-4, PD-1 is rapidly induced on the surface of T-cells in response to anti-CD3 (Agata et al. 25 (1996) Int. Immunol. 8:765). In contrast to CTLA-4, however, PD-1 is also induced on the surface of B-cells (in response to anti-IgM). PD-1 is also expressed on a subset of thymocytes and myeloid cells (Agata et al. (1996) supra; Nishimura et al. (1996) Int. Immunol. 8:773).
The nucleic acid and amino acid sequences of a representative human PD-1 biomarker is available to the public at the GenBank database under NM_005018.2 and NP_005009.2 and is shown in Table 1 (see also Ishida et al. (1992) 20 EMBO J 11:3887; Shinohara et al. (1994) Genomics 23:704; U.S. Pat. No. 5,698,520). PD-1 has an extracellular region containing immunoglobulin superfamily domain, a transmembrane domain, and an intracellular region including an immunoreceptor tyrosine-based inhibitory motif (ITIM) (Ishida et al. (1992) EMBO J. 11:3887; Shinohara et al. (1994) Genomics 23:704; and U.S. Pat. No. 5,698,520) and an immunoreceptor tyrosine-based switch motif (ITSM). These features also define a larger family of polypeptides, called the immunoinhibitory receptors, which also includes gp49B, PIR-B, and the killer inhibitory receptors (KIRs) (Vivier and Daeron (1997) Immunol. Today 18:286). It is often assumed that the tyrosyl phosphorylated ITIM and ITSM motif of these receptors interacts with SH2-domain containing phosphatases, which leads to inhibitory signals. A subset of these immunoinhibitory receptors bind to MHC polypeptides, for example the KIRs, and CTLA4 binds to B7-1 and B7-2. It has been proposed that there is a phylogenetic relationship between the MHC and B7 genes (Henry et al. (1999) Immunol. Today 20(6):285-8).
The term “response to immunotherapy” or “response to inhibitor(s) of one or more biomarkers listed in Table 1, in combination with an immunotherapy” relates to any response of the hyperproliferative disorder (e.g., cancer) to an anti-cancer agent, such as an inhibitor of one or more biomarkers listed in Table 1, and an immunotherapy, preferably to a change in tumor mass and/or volume after initiation of neoadjuvant or adjuvant therapy. Hyperproliferative disorder response may be assessed, for example for efficacy or in a neoadjuvant or adjuvant situation, where the size of a tumor after systemic intervention can be compared to the initial size and dimensions as measured by CT, PET, mammogram, ultrasound or palpation. Responses may also be assessed by caliper measurement or pathological examination of the tumor after biopsy or surgical resection. Response may be recorded in a quantitative fashion like percentage change in tumor volume or in a qualitative fashion like “pathological complete response” (pCR), “clinical complete remission” (cCR), “clinical partial remission” (cPR), “clinical stable disease” (cSD), “clinical progressive disease” (cPD) or other qualitative criteria. Assessment of hyperproliferative disorder response may be done early after the onset of neoadjuvant or adjuvant therapy, e.g., after a few hours, days, weeks or preferably after a few months. A typical endpoint for response assessment is upon termination of neoadjuvant chemotherapy or upon surgical removal of residual tumor cells and/or the tumor bed. This is typically three months after initiation of neoadjuvant therapy. In some embodiments, clinical efficacy of the therapeutic treatments described herein may be determined by measuring the clinical benefit rate (CBR). The clinical benefit rate is measured by determining the sum of the percentage of patients who are in complete remission (CR), the number of patients who are in partial remission (PR) and the number of patients having stable disease (SD) at a time point at least 6 months out from the end of therapy. The shorthand for this formula is CBR=CR+PR+SD over 6 months. In some embodiments, the CBR for a particular cancer therapeutic regimen is at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or more. Additional criteria for evaluating the response to cancer therapies are related to “survival,” which includes all of the following: survival until mortality, also known as overall survival (wherein said mortality may be either irrespective of cause or tumor related); “recurrence-free survival” (wherein the term recurrence shall include both localized and distant recurrence); metastasis free survival; disease free survival (wherein the term disease shall include cancer and diseases associated therewith). The length of said survival may be calculated by reference to a defined start point (e.g., time of diagnosis or start of treatment) and end point (e.g., death, recurrence or metastasis). In addition, criteria for efficacy of treatment can be expanded to include response to chemotherapy, probability of survival, probability of metastasis within a given time period, and probability of tumor recurrence. For example, in order to determine appropriate threshold values, a particular cancer therapeutic regimen can be administered to a population of subjects and the outcome can be correlated to biomarker measurements that were determined prior to administration of any cancer therapy. The outcome measurement may be pathologic response to therapy given in the neoadjuvant setting. Alternatively, outcome measures, such as overall survival and disease-free survival can be monitored over a period of time for subjects following cancer therapy for which biomarker measurement values are known. In certain embodiments, the doses administered are standard doses known in the art for cancer therapeutic agents. The period of time for which subjects are monitored can vary. For example, subjects may be monitored for at least 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, or 60 months. Biomarker measurement threshold values that correlate to outcome of a cancer therapy can be determined using well-known methods in the art, such as those described in the Examples section.
The term “resistance” refers to an acquired or natural resistance of a cancer sample or a mammal to a cancer therapy (i.e., being nonresponsive to or having reduced or limited response to the therapeutic treatment), such as having a reduced response to a therapeutic treatment by 25% or more, for example, 30%, 40%, 50%, 60%, 70%, 80%, or more, to 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 15-fold, 20-fold or more. The reduction in response can be measured by comparing with the same cancer sample or mammal before the resistance is acquired, or by comparing with a different cancer sample or a mammal that is known to have no resistance to the therapeutic treatment. A typical acquired resistance to chemotherapy is called “multidrug resistance.” The multidrug resistance can be mediated by P-glycoprotein or can be mediated by other mechanisms, or it can occur when a mammal is infected with a multi-drug-resistant microorganism or a combination of microorganisms. The determination of resistance to a therapeutic treatment is routine in the art and within the skill of an ordinarily skilled clinician, for example, can be measured by cell proliferative assays and cell death assays as described herein as “sensitizing.” In some embodiments, the term “reverses resistance” means that the use of a second agent in combination with a primary cancer therapy (e.g., chemotherapeutic or radiation therapy) is able to produce a significant decrease in tumor volume at a level of statistical significance (e.g., p<0.05) when compared to tumor volume of untreated tumor in the circumstance where the primary cancer therapy (e.g., chemotherapeutic or radiation therapy) alone is unable to produce a statistically significant decrease in tumor volume compared to tumor volume of untreated tumor. This generally applies to tumor volume measurements made at a time when the untreated tumor is growing log rhythmically.
The terms “response” or “responsiveness” refers to an anti-cancer response, e.g. in the sense of reduction of tumor size or inhibiting tumor growth. The terms can also refer to an improved prognosis, for example, as reflected by an increased time to recurrence, which is the period to first recurrence censoring for second primary cancer as a first event or death without evidence of recurrence, or an increased overall survival, which is the period from treatment to death from any cause. To respond or to have a response means there is a beneficial endpoint attained when exposed to a stimulus. Alternatively, a negative or detrimental symptom is minimized, mitigated or attenuated on exposure to a stimulus. It will be appreciated that evaluating the likelihood that a tumor or subject will exhibit a favorable response is equivalent to evaluating the likelihood that the tumor or subject will not exhibit favorable response (i.e., will exhibit a lack of response or be non-responsive).
As used herein, the term “unresponsiveness” includes refractivity of cancer cells to therapy or refractivity of therapeutic cells, such as immune cells, to stimulation, e.g., stimulation via an activating receptor or a cytokine. Unresponsiveness can occur, e.g., because of exposure to immunosuppressants or exposure to high doses of antigen. As used herein, the term “anergy” or “tolerance” includes refractivity to activating receptor-mediated stimulation. Such refractivity is generally antigen-specific and persists after exposure to the tolerizing antigen has ceased. For example, anergy in T cells (as opposed to unresponsiveness) is characterized by lack of cytokine production, e.g., IL-2. T cell anergy occurs when T cells are exposed to antigen and receive a first signal (a T cell receptor or CD-3 mediated signal) in the absence of a second signal (a costimulatory signal). Under these conditions, reexposure of the cells to the same antigen (even if reexposure occurs in the presence of a costimulatory polypeptide) results in failure to produce cytokines and, thus, failure to proliferate. Anergic T cells can, however, proliferate if cultured with cytokines (e.g., IL-2). For example, T cell anergy can also be observed by the lack of IL-2 production by T lymphocytes as measured by ELISA or by a proliferation assay using an indicator cell line. Alternatively, a reporter gene construct can be used. For example, anergic T cells fail to initiate IL-2 gene transcription induced by a heterologous promoter under the control of the 5′ IL-2 gene enhancer or by a multimer of the AP1 sequence that can be found within the enhancer (Kang et al. (1992) Science 257:1134).
Natural killer cells or NK cells are a type of cytotoxic lymphocyte critical to the innate immune system. The role NK cells play is analogous to that of cytotoxic T cells in the vertebrate adaptive immune response. NK cells provide rapid responses to viral-infected cells, acting at around 3 days after infection, and respond to tumor formation. Typically, immune cells detect major histocompatibility complex (MHC) presented on infected cell surfaces, triggering cytokine release, causing lysis or apoptosis. NK cells are unique, however, as they have the ability to recognize stressed cells in the absence of antibodies and MHC, allowing for a much faster immune reaction. They were named “natural killers” because of the initial notion that they do not require activation to kill cells that are missing “self” markers of MHC class 1. This role is especially important because harmful cells that are missing MHC I markers cannot be detected and destroyed by other immune cells, such as T lymphocyte cells.
NK cells (belonging to the group of innate lymphoid cells) are defined as large granular lymphocytes (LGL) and constitute the third kind of cells differentiated from the common lymphoid progenitor-generating B and T lymphocytes. NK cells are known to differentiate and mature in the bone marrow, lymph nodes, spleen, tonsils, and thymus, where they then enter into the circulation. NK cells differ from natural killer T cells (NKTs) phenotypically, by origin and by respective effector functions; often, NKT cell activity promotes NK cell activity by secreting IFNγ. In contrast to NKT cells, NK cells do not express T-cell antigen receptors (TCR) or pan T marker CD3 or surface immunoglobulins (Ig) B cell receptors, but they usually express the surface markers CD16 (FcγRIII) and CD56 in humans, NK1.1 or NK1.2 in C57BL/6 mice. The NKp46 cell surface marker constitutes, at the moment, another NK cell marker of preference being expressed in both humans, several strains of mice (including BALB/c mice) and in three common monkey species.
NK cells are negatively regulated by major histocompatibility complex (MHC) class I-specific inhibitory receptors (Karre et al., 1986; Ohlen et al, 1989). These specific receptors bind to polymorphic determinants of MHC class I molecules or HLA present on other cells and inhibit NK cell lysis. In humans, certain members of a family of receptors termed killer Ig-like receptors (KIRs) recognize groups of HLA class I alleles.
KIRs are a large family of receptors present on certain subsets of lymphocytes, including NK cells. The nomenclature for KIRs is based upon the number of extracellular domains (KIR2D or KIR3D) and whether the cytoplasmic tail is either long (KIR2DL or KIR3DL) or short (KIR2DS or KIR3DS). Within humans, the presence or absence of a given KIR is variable from one NK cell to another within the NK population present in a single individual. Within the human population there is also a relatively high level of polymorphism of the KIR molecules, with certain KIR molecules being present in some, but not all individuals. Certain KIR gene products cause stimulation of lymphocyte activity when bound to an appropriate ligand. The confirmed stimulatory KIRs all have a short cytoplasmic tail with a charged transmembrane residue that associates with an adapter molecule having an immunostimulatory motif (ITAM). Other KIR gene products are inhibitory in nature.
Natural killer cells constitute about 10% of peripheral blood mononuclear cells in human blood, and are identified by their lack of surface expression of CD3 and expressions of CD16 and CD56. NK cells mediate both direct and antibody-dependent cellular cytotoxicity (ADCC) against tumor cells and virally infected cells. They can recognize these cells without prior sensitization. NK cells mediate direct cytotoxicity by releasing pre-formed granules known as perforin and granzyme B, which can induce necrosis and apoptosis. When NK cell recognize its target cells and forms the lytic immunological synapse, the secretory lysosome polarizes towards the synapse and move into close proximity to the plasma membrane. Perforin, a membrane-disrupting protein, facilitates delivery of the Granzyme, a serine protease, which cleaves a variety of targets, such as caspases, resulting in cell death. NK cells can also mediate direct cytotoxicity via death receptors on the target cells through surface expression of their ligands such as Fas Ligand, Trail and TNF-alpha. Fas (CD95/AP0-1/TNFRSF6), a cell surface protein that belongs to the tumor necrosis factor receptor family, can mediate apoptosis when bound to its natural ligand, CD95L (CD178/TNFSF6) or stimulated with agonistic antibodies. NK cells can mediate antibody dependent cellular cytotoxicity (ADCC) against tumors and regulate the function of other cells through the secretion of cytokines and chemokines.
Two major subsets of NK cells have been identified, one with the surface expression of CD16+++CD56+, which is the predominant subset in the circulating blood with high cytotoxicity, whereas the other is CD16−CD56+++ subset residing in the mucosa known as the regulatory subset. Our Laboratory has established four different stages of NK cell maturation. Stage one NK cells are CD16+++, CD56+, CD69−, and CD107a− found to select and kill cancer stem-like cells/undifferentiated tumors. Upon IL-2 activation and CD16 receptor triggering NK cells express CD16+/−CD56++CD69+CD107a+ and increase secretion of IFN-γ and TNF-α while exhibiting decreased cytotoxicity. This is the second stage and NK cells in this stage are known as split-anergized NK cells. Without further activation NK cells move towards stage three where they become non-functional and lose their cytotoxicity and cytokine secretion ability. Finally, NK cells may undergo apoptosis giving rise to stage 4.
In some embodiments, the instant invention is drawn to a composition comprising at least one probiotic bacterial strain, capable of regulating NK cell function. Such probiotic bacteria induce significant split anergy in activated NK cells, leading to a significant induction of IFN-γ and TNF-α. In addition, such probiotic bacteria induce significant expansion of NK cells. Exemplary probiotic bacteria useful for this purpose are disclosed in International Patent Application WO18/112366, hereby incorporated herein by reference, in particular for the probiotic bacteria it discloses.
Many commercial probiotics are available, having various effects of reducting gastrointestinal discomfort or strengthening of the immune system. Preferred probiotic bacteria species for use in the compositions and methods described herein include those commercially available strains of probiotic bacteria (such as AJ2 bacteria), especially those from the Streptococcus (e.g., S. thermophiles), Bifidobacterium (e.g., B. longum, B. breve, B. infantis, B. breve, B. infantis), and Lactobacillus genera (e.g., L. acidophilus, L. helveticus, L. bulgaricus, L. rhamnosus, L. plantarum, and L. casei). The instant disclosure comprising methods of administering at least one probiotic bacterial strain, preferably a combination of two or more different bacterial strains, to a subject, preferably a mammal (e.g., a human). Such administration may be systemically or locally (e.g., directly to intestines) performed. A preferably administration route is oral administration. Other routes (e.g., rectal) may be also used. For administration, either the bacteria (e.g., in a wet, sonicated, grounded, or dried form or formula), the bacterial culture medium containing the bacteria, or the bacterial culture medium supernatant (not containing the bacteria), may be administered.
AJ2 is a combination of eight strains of gram positive probiotic bacteria with the ability to induce synergistic production of IFN-γ when added to IL-2-treated or IL-2+anti-CD16 monoclonal antibody-treated NK cells (anti-CD16mAb). The combination of strains was used to provide bacterial diversity in addition to synergistic induction of a balanced pro and anti-inflammatory cytokine and growth factor release NK cells. Moreover, the quantity of each bacteria within the combination of strains was adjusted to yield a closer ratio of IFN-γ to IL-10 to that obtained when NK cells are activated with IL-2+anti-CD16mAb in the absence of bacteria. The rationale behind such selection was to obtain a ratio similar to that obtained with NK cells activated with IL-2+anti-CD16mAb in the absence of bacteria since such treatment provided significant differentiation of the cells.
Antibody-dependent cellular-cytotoxicity (ADCC), is a mechanism by which immune cells bearing the Fc receptor can kill the cells coated with the antibody upon binding of the Fc receptor to the Fc portion of the antibody. NK cells are one the subset of immune cells that can mediate ADCC through FcγRIIIA receptor also known as CD16. The mechanism by which NK cells mediate ADCC is not fully understood. When the effector cell recognizes the target by cross-linking of the Fc receptor and the antibody coating the target cell, the immunoreceptor tyrosine-based activation motifs (ITAMs) gets phosphorylated in the effector cells and leading to triggering of main downstream signaling pathways in the effector cell to kill the target cell. One of the mechanisms by which NK cells mediated ADCC can be through perforin-granzyme mediate cytotoxicity. The role of FAS ligand in ADCC is unknown but It has been shown that cross-linking of the CD16 receptor on NK cells can upregulate FAS ligand on them which may be indicative an important role of Fas/Fas-L in ADCC.
Fucoidan is a sulfated polysaccharide found on different species of brown algae and brown seaweed such as Mozuko, Mekabue, Limi moui, bladderwrack, and hijiki. Based on the source of extraction, Fucoidan may have different chemical compositions. For example, beside the polysaccharide and the sulfate, they might also contain other monosaccharides (mannose, galactose, glucose, xylose, etc.) uranic acids, acetyl groups, and protein. Undaria pinnatifida, also known as Mekabue seaweed is another source of Fucoidan composing fucose, galactose, and sulfate.
Split anergy is a maturation stage of NK cells, wherein NK cells show reduced cytotoxicity andaugmented secretion of IFN-γ. Split-anergized NK cells promote differentiation of target cells via secreted and membrane-bound factors, increase tumor cell resistance to NK cell-mediated cytotoxicity, as well as inhibit inflammation due to the reduction of cytokine and chemokine production after tumor differentiation.
Cancer stem cells (CSCs) are stem cells which can create various populations of differentiated cells that define the tumor mass. CSCs are like normal stem cells, and have self-renewal capacity and also can be differentiated, but in a dysregulated manner. The existence of CSCs is described in many tumors including, but not limited to, acute myeloid leukemia, breast, prostate, melanoma, lung, colon, brain, liver, gastric and pancreatic cancer.
Osteoclast are the bone cells responsible for the bone homeostasis by resorbing the bone. Osteoclast matures via RANKL stimulation and the process is regulated by ICAM-1. Proinflammatory signals can induce expression of ICAM-1 and RANKL on osteoclasts. These signals are mediated by subsets of immune cells. It has been shown that osteoclasts express multiple ligands for both activating and inhibitory NK cell receptors.
Major Histocompatibility Complex Class I-Related Chains A and B (MICA/MICB) are proteins known to be induced upon stress, damage, viral infection or transformation of cells which act as a ‘kill me’ signal through the cytotoxic lymphocytes. In contrast to classical MHC class-I molecules, this protein is not involved in antigen presenting but they are known to be a ligand for a natural killer group 2D (NKG2D) receptor, a receptor on cytotoxic cells. Engagement of NKG2D receptors triggers natural killer (NK) cell-mediated cytotoxicity and provides a costimulatory signal for CD8 T cells and γδ T cells. MICAS were not thought to be constitutively expressed by healthy normal cells, but recently studies have shown that this protein is also expressed on surface of healthy cells such as breast, colon, liver, pancreas, stomach, bronchus, bladder and ureter in smooth muscle cells and/or myofibroblasts within stomach, small intestine, colon, bladder, cervix, fallopian tube, prostate and ureter. The differential expression of MICA/MICB based on the differentiation status of the tumor cells have not be studied. In this study, we will evaluate the expression of MICA/MICB on the undifferentiated/stem-like and differentiated oral and pancreatic tumors.
In certain embodiments, the subject suitable for the compositions and methods disclosed herein is a mammal (e.g., mouse, rat, primate, non-human mammal, domestic animal, such as a dog, cat, cow, horse, and the like), and is preferably a human.
In certain embodiments, the subject is an animal model of cancer. For example, the animal model can be an orthotopic xenograft animal model of a human-derived cancer.
In various embodiments of the methods of the present invention, the subject has not undergone treatment, such as chemotherapy, radiation therapy, targeted therapy, and/or immunotherapies. In other embodiments, the subject has undergone treatment, such as chemotherapy, radiation therapy, targeted therapy, and/or immunotherapies.
In certain embodiments, the subject has had surgery to remove cancerous or precancerous tissue. In other embodiments, the cancerous tissue has not been removed, e.g., the cancerous tissue may be located in an inoperable region of the body, such as in a tissue that is essential for life, or in a region where a surgical procedure would cause considerable risk of harm to the patient.
In one aspect, other anti-cancer therapies and/or immunotherapies combination or combinations of therapies (e.g., one or more PI3Kbeta-selective inhibitors, such as KIN193, in combination with one or more immune checkpoint inhibitors, such as an anti-PD-1 antibody, either alone or in combination with yet additional anti-cancer therapies, such as targeted therapy) can be administered (e.g., conjointly).
The phrases “conjoint administration” and “administered conjointly” refer to any form of administration of two or more different therapeutic compounds such that the second compound is administered while the previously administered therapeutic compound is still effective in the body (e.g., the two compounds are simultaneously effective in the patient, which may include synergistic effects of the two compounds). For example, the different therapeutic compounds can be administered either in the same formulation or in separate formulations, either concomitantly or sequentially. In certain embodiments, the different therapeutic compounds can be administered within one hour, 12 hours, 24 hours, 36 hours, 48 hours, 72 hours, or a week of one another. Thus, an individual who receives such treatment can benefit from a combined effect of different therapeutic compounds.
Combination therapies are also contemplated and can comprise, for example, one or more chemotherapeutic agents and radiation, one or more chemotherapeutic agents and immunotherapy, or one or more chemotherapeutic agents, radiation and chemotherapy, each combination of which can be with a therapy as disclosed herein. As described below, agents can be administered in combination therapy with, e.g., chemotherapeutic agents, hormones, antiangiogens, radiolabelled compounds, or with surgery, cryotherapy, and/or radiotherapy. The preceding treatment methods can be administered in conjunction with other forms of conventional therapy (e.g., standard-of-care treatments for cancer well-known to the skilled artisan), either consecutively with, pre- or post-conventional therapy. For example, these modulatory agents can be administered with a therapeutically effective dose of chemotherapeutic agent. In other embodiments, these modulatory agents are administered in conjunction with chemotherapy to enhance the activity and efficacy of the chemotherapeutic agent. The Physicians' Desk Reference (PDR) discloses dosages of chemotherapeutic agents that have been used in the treatment of various cancers. The dosing regimen and dosages of these aforementioned chemotherapeutic drugs that are therapeutically effective will depend on the particular melanoma, being treated, the extent of the disease and other factors familiar to the physician of skill in the art and can be determined by the physician.
The term “targeted therapy” refers to administration of agents that selectively interact with a chosen biomolecule to thereby treat cancer. One example includes immunotherapies such as immune checkpoint inhibitors, which are well-known in the art. For example, anti-PD-1 pathway agents, such as therapeutic monoclonal blocking antibodies, which are well-known in the art and described above, can be used to target tumor microenvironments and cells expressing unwanted components of the PD-1 pathway, such as PD-1, PD-L1, and/or PD-L2.
For example, the term “PD-1 pathway” refers to the PD-1 receptor and its ligands, PD-L1 and PD-L2. “PD-1 pathway inhibitors” block or otherwise reduce the interaction between PD-1 and one or both of its ligands such that the immunoinhibitory signaling otherwise generated by the interaction is blocked or otherwise reduced. Anti-immune checkpoint inhibitors can be direct or indirect. Direct anti-immune checkpoint inhibitors block or otherwise reduce the interaction between an immune checkpoint and at least one of its ligands. For example, PD-1 inhibitors can block PD-1 binding with one or both of its ligands. Direct PD-1 combination inhibitors are well-known in the art, especially since the natural binding partners of PD-1 (e.g., PD-L1 and PD-L2), PD-L1 (e.g., PD-1 and B7-1), and PD-L2 (e.g., PD-1 and RGMb) are known.
For example, agents which directly block the interaction between PD-1 and PD-L1, PD-1 and PD-L2, PD-1 and both PD-L1 and PD-L2, such as a bispecific antibody, can prevent inhibitory signaling and upregulate an immune response (i.e., as a PD-1 pathway inhibitor). Alternatively, agents that indirectly block the interaction between PD-1 and one or both of its ligands can prevent inhibitory signaling and upregulate an immune response. For example, B7-1 or a soluble form thereof, by binding to a PD-L1 polypeptide indirectly reduces the effective concentration of PD-L1 polypeptide available to bind to PD-1. Exemplary agents include monospecific or bispecific blocking antibodies against PD-1, PD-L1, and/or PD-L2 that block the interaction between the receptor and ligand(s); a non-activating form of PD-1, PD-L1, and/or PD-L2 (e.g., a dominant negative or soluble polypeptide), small molecules or peptides that block the interaction between PD-1, PD-L1, and/or PD-L2; fusion proteins (e.g. the extracellular portion of PD-1, PD-L1, and/or PD-L2, fused to the Fc portion of an antibody or immunoglobulin) that bind to PD-1, PD-L1, and/or PD-L2 and inhibit the interaction between the receptor and ligand(s); a non-activating form of a natural PD-1, PD-L2, and/or PD-L2 ligand, and a soluble form of a natural PD-1, PD-L2, and/or PD-L2 ligand.
Indirect anti-immune checkpoint inhibitors block or otherwise reduce the immunoinhibitory signaling generated by the interaction between the immune checkpoint and at least one of its ligands. For example, an inhibitor can block the interaction between PD-1 and one or both of its ligands without necessarily directly blocking the interaction between PD-1 and one or both of its ligands. For example, indirect inhibitors include intrabodies that bind the intracellular portion of PD-1 and/or PD-L1 required to signal to block or otherwise reduce the immunoinhibitory signaling. Similarly, nucleic acids that reduce the expression of PD-1, PD-L1, and/or PD-L2 can indirectly inhibit the interaction between PD-1 and one or both of its ligands by removing the availability of components for interaction. Such nucleic acid molecules can block PD-L1, PD-L2, and/or PD-L2 transcription or translation.
Immunotherapies that are designed to elicit or amplify an immune response are referred to as “activation immunotherapies.” Immunotherapies that are designed to reduce or suppress an immune response are referred to as “suppression immunotherapies.” Any agent believed to have an immune system effect on the genetically modified transplanted cancer cells can be assayed to determine whether the agent is an immunotherapy and the effect that a given genetic modification has on the modulation of immune response. In some embodiments, the immunotherapy is cancer cell-specific. In some embodiments, immunotherapy can be “untargeted,” which refers to administration of agents that do not selectively interact with immune system cells, yet modulates immune system function. Representative examples of untargeted therapies include, without limitation, chemotherapy, gene therapy, and radiation therapy.
Immunotherapy can involve passive immunity for short-term protection of a host, achieved by the administration of pre-formed antibody directed against a cancer antigen or disease antigen (e.g., administration of a monoclonal antibody, optionally linked to a chemotherapeutic agent or toxin, to a tumor antigen). Immunotherapy can also focus on using the cytotoxic lymphocyte-recognized epitopes of cancer cell lines. Alternatively, antisense polynucleotides, ribozymes, RNA interference molecules, triple helix polynucleotides and the like, can be used to selectively modulate biomolecules that are linked to the initiation, progression, and/or pathology of a tumor or cancer.
In certain embodiments, immunotherapy comprises adoptive cell-based immunotherapies. Well-known adoptive cell-based immunotherapeutic modalities, including, without limitation, Irradiated autologous or allogeneic tumor cells, tumor lysates or apoptotic tumor cells, antigen-presenting cell-based immunotherapy, dendritic cell-based immunotherapy, adoptive T cell transfer, adoptive CAR T cell therapy, autologous immune enhancement therapy (MET), cancer vaccines, and/or antigen presenting cells. Such cell-based immunotherapies can be further modified to express one or more gene products to further modulate immune responses, such as expressing cytokines like GM-CSF, and/or to express tumor-associated antigen (TAA) antigens, such as Mage-1, gp-100, patient-specific neoantigen vaccines, and the like.
In other embodiments, immunotherapy comprises non-cell-based immunotherapies. In certain such embodiments, compositions comprising antigens with or without vaccine-enhancing adjuvants are used. Such compositions exist in many well-known forms, such as peptide compositions, oncolytic viruses, recombinant antigen comprising fusion proteins, and the like. In still other embodiments, immunomodulatory interleukins, such as IL-2, IL-6, IL-7, IL-12, IL-17, IL-23, and the like, as well as modulators thereof (e.g., blocking antibodies or more potent or longer lasting forms) are used. In yet other embodiments, immunomodulatory cytokines, such as interferons, G-CSF, imiquimod, TNFalpha, and the like, as well as modulators thereof (e.g., blocking antibodies or more potent or longer lasting forms) are used. In other embodiments, immunomodulatory chemokines, such as CCL3, CCL26, and CXCL7, and the like, as well as modulators thereof (e.g., blocking antibodies or more potent or longer lasting forms) are used. In other embodiments, immunomodulatory molecules targeting immunosuppression, such as STAT3 signaling modulators, NFkappaB signaling modulators, and immune checkpoint modulators, are used. The terms “immune checkpoint” and “anti-immune checkpoint therapy” are described above.
In still other embodiments, immunomodulatory drugs, such as immunocytostatic drugs, glucocorticoids, cytostatics, immunophilins and modulators thereof (e.g., rapamycin, a calcineurin inhibitor, tacrolimus, ciclosporin (cyclosporin), pimecrolimus, abetimus, gusperimus, ridaforolimus, everolimus, temsirolimus, zotarolimus, etc.), hydrocortisone (cortisol), cortisone acetate, prednisone, prednisolone, methylprednisolone, dexamethasone, betamethasone, triamcinolone, beclometasone, fludrocortisone acetate, deoxycorticosterone acetate (doca) aldosterone, a non-glucocorticoid steroid, a pyrimidine synthesis inhibitor, leflunomide, teriflunomide, a folic acid analog, methotrexate, anti-thymocyte globulin, anti-lymphocyte globulin, thalidomide, lenalidomide, pentoxifylline, bupropion, curcumin, catechin, an opioid, an IMPDH inhibitor, mycophenolic acid, myriocin, fingolimod, an NF-xB inhibitor, raloxifene, drotrecogin alfa, denosumab, an NF-xB signaling cascade inhibitor, disulfiram, olmesartan, dithiocarbamate, a proteasome inhibitor, bortezomib, MG132, Prol, NPI-0052, curcumin, genistein, resveratrol, parthenolide, thalidomide, lenalidomide, flavopiridol, non-steroidal anti-inflammatory drugs (NSAIDs), arsenic trioxide, dehydroxymethylepoxyquinomycin (DHMEQ), I3C (indole-3-carbinol)/DIM (di-indolmethane) (13C/DIM), Bay 11-7082, luteolin, cell permeable peptide SN-50, IKBa.-super repressor overexpression, NFKB decoy oligodeoxynucleotide (ODN), or a derivative or analog of any thereo, are used. In yet other embodiments, immunomodulatory antibodies or protein are used. For example, antibodies that bind to CD40, Toll-like receptor (TLR), OX40, GITR, CD27, or to 4-1BB, T-cell bispecific antibodies, an anti-IL-2 receptor antibody, an anti-CD3 antibody, OKT3 (muromonab), otelixizumab, teplizumab, visilizumab, an anti-CD4 antibody, clenoliximab, keliximab, zanolimumab, an anti-CD11 a antibody, efalizumab, an anti-CD18 antibody, erlizumab, rovelizumab, an anti-CD20 antibody, afutuzumab, ocrelizumab, ofatumumab, pascolizumab, rituximab, an anti-CD23 antibody, lumiliximab, an anti-CD40 antibody, teneliximab, toralizumab, an anti-CD40L antibody, ruplizumab, an anti-CD62L antibody, aselizumab, an anti-CD80 antibody, galiximab, an anti-CD147 antibody, gavilimomab, a B-Lymphocyte stimulator (BLyS) inhibiting antibody, belimumab, an CTLA4-Ig fusion protein, abatacept, belatacept, an anti-CTLA4 antibody, ipilimumab, tremelimumab, an anti-eotaxin 1 antibody, bertilimumab, an anti-a4-integrin antibody, natalizumab, an anti-IL-6R antibody, tocilizumab, an anti-LFA-1 antibody, odulimomab, an anti-CD25 antibody, basiliximab, daclizumab, inolimomab, an anti-CD5 antibody, zolimomab, an anti-CD2 antibody, siplizumab, nerelimomab, faralimomab, atlizumab, atorolimumab, cedelizumab, dorlimomab aritox, dorlixizumab, fontolizumab, gantenerumab, gomiliximab, lebrilizumab, maslimomab, morolimumab, pexelizumab, reslizumab, rovelizumab, talizumab, telimomab aritox, vapaliximab, vepalimomab, aflibercept, alefacept, rilonacept, an IL-1 receptor antagonist, anakinra, an anti-IL-5 antibody, mepolizumab, an IgE inhibitor, omalizumab, talizumab, an IL12 inhibitor, an IL23 inhibitor, ustekinumab, and the like.
Nutritional supplements that enhance immune responses, such as vitamin A, vitamin E, vitamin C, and the like, are well-known in the art (see, for example, U.S. Pat. Nos. 4,981,844 and 5,230,902 and PCT Publ. No. WO 2004/004483) can be used in the methods described herein.
Similarly, agents and therapies other than immunotherapy or in combination thereof can be used with in combination with inhibitors of one or more biomarkers listed in Table 1, with or without immunotherapies to stimulate an immune response to thereby treat a condition that would benefit therefrom. For example, chemotherapy, radiation, epigenetic modifiers (e.g., histone deacetylase (HDAC) modifiers, methylation modifiers, phosphorylation modifiers, and the like), targeted therapy, and the like are well-known in the art.
Alternatively, immunotherapy may comprise, for example, the use of cancer vaccines and/or sensitized antigen presenting cells. For example, an oncolytic virus is a virus that is able to infect and lyse cancer cells, while leaving normal cells unharmed, making them potentially useful in cancer therapy. Replication of oncolytic viruses both facilitates tumor cell destruction and also produces dose amplification at the tumor site. They may also act as vectors for anticancer genes, allowing them to be specifically delivered to the tumor site. The immunotherapy can involve passive immunity for short-term protection of a host, achieved by the administration of pre-formed antibody directed against a cancer antigen or disease antigen (e.g., administration of a monoclonal antibody, optionally linked to a chemotherapeutic agent or toxin, to a tumor antigen). Immunotherapy can also focus on using the cytotoxic lymphocyte-recognized epitopes of cancer cell lines. Alternatively, antisense polynucleotides, ribozymes, RNA interference molecules, triple helix polynucleotides and the like, can be used to selectively modulate biomolecules that are linked to the initiation, progression, and/or pathology of a tumor or cancer.
The term “untargeted therapy” refers to administration of agents that do not selectively interact with a chosen biomolecule yet treat cancer. Representative examples of untargeted therapies include, without limitation, chemotherapy, gene therapy, and radiation therapy.
In certain embodiments, chemotherapy is used. Chemotherapy includes the administration of a chemotherapeutic agent. Such a chemotherapeutic agent may be, but is not limited to, those selected from among the following groups of compounds: platinum compounds, cytotoxic antibiotics, antimetabolites, anti-mitotic agents, alkylating agents, arsenic compounds, DNA topoisomerase inhibitors, taxanes, nucleoside analogues, plant alkaloids, and toxins; and synthetic derivatives thereof. Exemplary compounds include, but are not limited to, alkylating agents: cisplatin, treosulfan, and trofosfamide; plant alkaloids: vinblastine, paclitaxel, docetaxol; DNA topoisomerase inhibitors: teniposide, crisnatol, and mitomycin; anti-folates: methotrexate, mycophenolic acid, and hydroxyurea; pyrimidine analogs: 5-fluorouracil, doxifluridine, and cytosine arabinoside; purine analogs: mercaptopurine and thioguanine; DNA antimetabolites: 2′-deoxy-5-fluorouridine, aphidicolin glycinate, and pyrazoloimidazole; and antimitotic agents: halichondrin, colchicine, and rhizoxin. Compositions comprising one or more chemotherapeutic agents (e.g., FLAG, CHOP) may also be used. FLAG comprises fludarabine, cytosine arabinoside (Ara-C) and G-CSF. CHOP comprises cyclophosphamide, vincristine, doxorubicin, and prednisone. In certain embodiments, PARP (e.g., PARP-1 and/or PARP-2) inhibitors are used and such inhibitors are well-known in the art (e.g., Olaparib, ABT-888, BSI-201, BGP-15 (N-Gene Research Laboratories, Inc.); INO-1001 (Inotek Pharmaceuticals Inc.); PJ34 (Soriano et al., 2001; Pacher et al., 2002b); 3-aminobenzamide (Trevigen); 4-amino-1, 8-naphthalimide; (Trevigen); 6(5H)-phenanthridinone (Trevigen); benzamide (U.S. Pat. Re. 36,397); and NU1025 (Bowman et al.). The mechanism of action is generally related to the ability of PARP inhibitors to bind PARP and decrease its activity. PARP catalyzes the conversion of .beta.-nicotinamide adenine dinucleotide (NAD+) into nicotinamide and poly-ADP-ribose (PAR). Both poly (ADP-ribose) and PARP have been linked to regulation of transcription, cell proliferation, genomic stability, and carcinogenesis (Bouchard V. J. et. al. Experimental Hematology, Volume 31, Number 6, June 2003, pp. 446-454(9); Herceg Z.; Wang Z.-Q. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, Volume 477, Number 1, 2 Jun. 2001, pp. 97-110(14)). Poly(ADP-ribose) polymerase 1 (PARP1) is a key molecule in the repair of DNA single-strand breaks (SSBs) (de Murcia J. et al. 1997. Proc Natl Acad Sci USA 94:7303-7307; Schreiber V, Dantzer F, Ame J C, de Murcia G (2006) Nat Rev Mol Cell Biol 7:517-528; Wang Z Q, et al. (1997) Genes Dev 11:2347-2358). Knockout of SSB repair by inhibition of PARP1 function induces DNA double-strand breaks (DSBs) that can trigger synthetic lethality in cancer cells with defective homology-directed DSB repair (Bryant H E, et al. (2005) Nature 434:913-917; Farmer H, et al. (2005) Nature 434:917-921). The foregoing examples of chemotherapeutic agents are illustrative, and are not intended to be limiting.
In other embodiments, radiation therapy is used. The radiation used in radiation therapy can be ionizing radiation. Radiation therapy can also be gamma rays, X-rays, or proton beams. Examples of radiation therapy include, but are not limited to, external-beam radiation therapy, interstitial implantation of radioisotopes (1-125, palladium, iridium), radioisotopes such as strontium-89, thoracic radiation therapy, intraperitoneal P-32 radiation therapy, and/or total abdominal and pelvic radiation therapy. For a general overview of radiation therapy, see Hellman, Chapter 16: Principles of Cancer Management: Radiation Therapy, 6th edition, 2001, DeVita et al., eds., J. B. Lippencott Company, Philadelphia. The radiation therapy can be administered as external beam radiation or teletherapy wherein the radiation is directed from a remote source. The radiation treatment can also be administered as internal therapy or brachytherapy wherein a radioactive source is placed inside the body close to cancer cells or a tumor mass. Also encompassed is the use of photodynamic therapy comprising the administration of photosensitizers, such as hematoporphyrin and its derivatives, Vertoporfin (BPD-MA), phthalocyanine, photosensitizer Pc4, demethoxy-hypocrellin A; and 2BA-2-DMHA.
In yet other embodiments, surgical intervention can physically remove cancerous cells and/or tissues.
In still other embodiments, hormone therapy is used. Hormonal therapeutic treatments can comprise, for example, hormonal agonists, hormonal antagonists (e.g., flutamide, bicalutamide, tamoxifen, raloxifene, leuprolide acetate (LUPRON), LH-RH antagonists), inhibitors of hormone biosynthesis and processing, and steroids (e.g., dexamethasone, retinoids, deltoids, betamethasone, cortisol, cortisone, prednisone, dehydrotestosterone, glucocorticoids, mineralocorticoids, estrogen, testosterone, progestins), vitamin A derivatives (e.g., all-trans retinoic acid (ATRA)); vitamin D3 analogs; antigestagens (e.g., mifepristone, onapristone), or antiandrogens (e.g., cyproterone acetate).
In yet other embodiments, hyperthermia, a procedure in which body tissue is exposed to high temperatures (up to 106° F.) is used. Heat may help shrink tumors by damaging cells or depriving them of substances they need to live. Hyperthermia therapy can be local, regional, and whole-body hyperthermia, using external and internal heating devices. Hyperthermia is almost always used with other forms of therapy (e.g., radiation therapy, chemotherapy, and biological therapy) to try to increase their effectiveness. Local hyperthermia refers to heat that is applied to a very small area, such as a tumor. The area may be heated externally with high-frequency waves aimed at a tumor from a device outside the body. To achieve internal heating, one of several types of sterile probes may be used, including thin, heated wires or hollow tubes filled with warm water; implanted microwave antennae; and radiofrequency electrodes. In regional hyperthermia, an organ or a limb is heated. Magnets and devices that produce high energy are placed over the region to be heated. In another approach, called perfusion, some of the patient's blood is removed, heated, and then pumped (perfused) into the region that is to be heated internally. Whole-body heating is used to treat metastatic cancer that has spread throughout the body. It can be accomplished using warm-water blankets, hot wax, inductive coils (like those in electric blankets), or thermal chambers (similar to large incubators). Hyperthermia does not cause any marked increase in radiation side effects or complications. Heat applied directly to the skin, however, can cause discomfort or even significant local pain in about half the patients treated. It can also cause blisters, which generally heal rapidly.
In still other embodiments, photodynamic therapy (also called PDT, photoradiation therapy, phototherapy, or photochemotherapy) is used for the treatment of some types of cancer. It is based on the discovery that certain chemicals known as photosensitizing agents can kill one-celled organisms when the organisms are exposed to a particular type of light. PDT destroys cancer cells through the use of a fixed-frequency laser light in combination with a photosensitizing agent. In PDT, the photosensitizing agent is injected into the bloodstream and absorbed by cells all over the body. The agent remains in cancer cells for a longer time than it does in normal cells. When the treated cancer cells are exposed to laser light, the photosensitizing agent absorbs the light and produces an active form of oxygen that destroys the treated cancer cells.
In yet other embodiments, laser therapy is used to harness high-intensity light to destroy cancer cells. This technique is often used to relieve symptoms of cancer such as bleeding or obstruction, especially when the cancer cannot be cured by other treatments. It may also be used to treat cancer by shrinking or destroying tumors. The term “laser” stands for light amplification by stimulated emission of radiation. Ordinary light, such as that from a light bulb, has many wavelengths and spreads in all directions. Laser light, on the other hand, has a specific wavelength and is focused in a narrow beam. This type of high-intensity light contains a lot of energy. The laser light then raises the temperature of the tumor, which damages or destroys cancer cells.
The duration and/or dose of treatment with therapies may vary according to the particular therapeutic agent or combination thereof. An appropriate treatment time for a particular cancer therapeutic agent will be appreciated by the skilled artisan. The present invention contemplates the continued assessment of optimal treatment schedules for each cancer therapeutic agent, where the phenotype of the cancer of the subject as determined by the methods of the present invention is a factor in determining optimal treatment doses and schedules.
In other embodiments, recombinant biomarker polypeptides, and fragments thereof, can be administered to subjects. In some embodiments, fusion proteins can be constructed and administered which have enhanced biological properties. In addition, the biomarker polypeptides, and fragment thereof, can be modified according to well-known pharmacological methods in the art (e.g., pegylation, glycosylation, oligomerization, etc.) in order to further enhance desirable biological activities, such as increased bioavailability and decreased proteolytic degradation.
The therapeutic compositions described herein can be used in a variety of in vitro and in vivo therapeutic applications using the formulations and/or combinations described herein. In various embodiments, the therapeutic agents can be used to treat cancers determined to be responsive thereto.
Modulatory methods of the present invention involve contacting a cell, such as an immune cell with an agent that inhibits or blocks the expression and/or activity of such one or more biomarkers and an immunotherapy, such as an immune checkpoint inhibitor (e.g., PD-1). Exemplary agents useful in such methods are described above. Such agents can be administered in vitro or ex vivo (e.g., by contacting the cell with the agent) or, alternatively, in vivo (e.g., by administering the agent to a subject). As such, the present invention provides methods useful for treating an individual afflicted with a condition that would benefit from an increased immune response, such as an infection or a cancer like colorectal cancer.
Agents that upregulate immune responses can be in the form of enhancing an existing immune response or eliciting an initial immune response. Thus, enhancing an immune response using the subject compositions and methods is useful for treating cancer, but can also be useful for treating an infectious disease (e.g., bacteria, viruses, or parasites), a parasitic infection, and an immunosuppressive disease.
Exemplary infectious disorders include viral skin diseases, such as Herpes or shingles, in which case such an agent can be delivered topically to the skin. In addition, systemic viral diseases, such as influenza, the common cold, and encephalitis might be alleviated by systemic administration of such agents. For example, agents that upregulate the immune response described herein are useful for modulating the arginase/iNOS balance during Trypanosoma cruzi infection in order to facilitate a protective immune response against the parasite.
Immune responses can also be enhanced in an infected patient through an ex vivo approach, for instance, by removing immune cells from the patient, contacting immune cells in vitro with an agent described herein and reintroducing the in vitro stimulated immune cells into the patient.
In certain instances, it may be desirable to further administer other agents that upregulate immune responses, for example, forms of other B7 family members that transduce signals via costimulatory receptors, in order to further augment the immune response. Such additional agents and therapies are described further below.
Agents that upregulate an immune response can be used prophylactically in vaccines against various polypeptides (e.g., polypeptides derived from pathogens). Immunity against a pathogen (e.g., a virus) can be induced by vaccinating with a viral protein along with an agent that upregulates an immune response, in an appropriate adjuvant.
Additionally, upregulation or enhancement of an immune response function, as described herein, is useful in the induction of tumor immunity.
Furthermore, the immune response can be stimulated by the methods described herein, such that preexisting tolerance, clonal deletion, and/or exhaustion (e.g., T cell exhaustion) is overcome. For example, immune responses against antigens to which a subject cannot mount a significant immune response, e.g., to an autologous antigen, such as a tumor specific antigens can be induced by administering appropriate agents described herein that upregulate the immune response. Similarly, an autologous antigen, such as a tumor-specific antigen, can be coadministered. In addition, the subject compositions can be used as adjuvants to boost responses to foreign antigens in the process of active immunization.
In certain embodiments, immune cells are obtained from a subject and cultured ex vivo in the presence of an agent as described herein, to expand the population of immune cells and/or to enhance immune cell activation. The immune cells may then be administered to a subject. Immune cells can be stimulated in vitro by, for example, providing to the immune cells a primary activation signal and a costimulatory signal, as is known in the art. Various agents can also be used to costimulate proliferation of immune cells. Immune cells may be cultured ex vivo according to the method described in PCT Application No. WO 94/29436. The costimulatory polypeptide can be soluble, attached to a cell membrane, or attached to a solid surface, such as a bead.
The immune modulating agents of the invention are administered to subjects in a biologically compatible form suitable for pharmaceutical administration in vivo, to enhance immune cell mediated immune responses. By “biologically compatible form suitable for administration in vivo” is meant a form to be administered in which any toxic effects are outweighed by the therapeutic effects. The term “subject” is intended to include living organisms in which an immune response can be elicited, e.g., mammals. Examples of subjects include humans, dogs, cats, mice, rats, and transgenic species thereof. Administration of an agent as described herein can be in any pharmacological form including a therapeutically active amount of an agent alone or in combination with a pharmaceutically acceptable carrier.
Administration of a therapeutically active amount of the therapeutic composition of the present invention is defined as an amount effective, at dosages and for periods of time necessary, to achieve the desired result. For example, a therapeutically active amount of an agent may vary according to factors such as the disease state, age, sex, and weight of the individual, and the ability of peptide to elicit a desired response in the individual. Dosage regimens can be adjusted to provide the optimum therapeutic response. For example, several divided doses can be administered daily or the dose can be proportionally reduced as indicated by the exigencies of the therapeutic situation.
The therapeutic agents described herein can be administered in a convenient manner such as by injection (subcutaneous, intravenous, etc.), oral administration, inhalation, transdermal application, or rectal administration. Depending on the route of administration, the active compound can be coated in a material to protect the compound from the action of enzymes, acids and other natural conditions which may inactivate the compound. For example, for administration of agents, by other than parenteral administration, it may be desirable to coat the agent with, or co-administer the agent with, a material to prevent its inactivation.
An agent can be administered to an individual in an appropriate carrier, diluent or adjuvant, co-administered with enzyme inhibitors or in an appropriate carrier such as liposomes. Pharmaceutically acceptable diluents include saline and aqueous buffer solutions. Adjuvant is used in its broadest sense and includes any immune stimulating compound such as interferon. Adjuvants contemplated herein include resorcinols, non-ionic surfactants such as polyoxyethylene oleyl ether and n-hexadecyl polyethylene ether. Enzyme inhibitors include pancreatic trypsin inhibitor, diisopropylfluorophosphate (DEEP) and trasylol. Liposomes include water-in-oil-in-water emulsions as well as conventional liposomes (Sterna et al. (1984) J. Neuroimmunol. 7:27).
As described in detail below, the pharmaceutical compositions of the present invention may be specially formulated for administration in solid or liquid form, including those adapted for the following: (1) oral administration, for example, drenches (aqueous or non-aqueous solutions or suspensions), tablets, boluses, powders, granules, pastes; (2) parenteral administration, for example, by subcutaneous, intramuscular or intravenous injection as, for example, a sterile solution or suspension; (3) topical application, for example, as a cream, ointment or spray applied to the skin; (4) intravaginally or intrarectally, for example, as a pessary, cream or foam; or (5) aerosol, for example, as an aqueous aerosol, liposomal preparation or solid particles containing the compound.
The phrase “pharmaceutically acceptable” is employed herein to refer to those agents, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.
The phrase “pharmaceutically-acceptable carrier” as used herein means a pharmaceutically-acceptable material, composition or vehicle, such as a liquid or solid filler, diluent, excipient, solvent or encapsulating material, involved in carrying or transporting the subject chemical from one organ, or portion of the body, to another organ, or portion of the body. Each carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and not injurious to the subject. Some examples of materials which can serve as pharmaceutically-acceptable carriers include: (1) sugars, such as lactose, glucose and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose, and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxic compatible substances employed in pharmaceutical formulations.
Wetting agents, emulsifiers and lubricants, such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, release agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the compositions.
Examples of pharmaceutically-acceptable antioxidants include: (1) water soluble antioxidants, such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite and the like; (2) oil-soluble antioxidants, such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, alpha-tocopherol, and the like; and (3) metal chelating agents, such as citric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, and the like.
Formulations useful in the methods of the present invention include those suitable for oral, nasal, topical (including buccal and sublingual), rectal, vaginal, aerosol and/or parenteral administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well-known in the art of pharmacy. The amount of active ingredient which can be combined with a carrier material to produce a single dosage form will vary depending upon the host being treated, the particular mode of administration. The amount of active ingredient, which can be combined with a carrier material to produce a single dosage form will generally be that amount of the compound which produces a therapeutic effect. Generally, out of one hundred percent, this amount will range from about 1 percent to about ninety-nine percent of active ingredient, preferably from about 5 percent to about 70 percent, most preferably from about 10 percent to about 30 percent.
Pharmaceutical compositions of this invention suitable for parenteral administration comprise one or more therapeutic agents in combination with one or more pharmaceutically-acceptable sterile isotonic aqueous or nonaqueous solutions, dispersions, suspensions or emulsions, or sterile powders which may be reconstituted into sterile injectable solutions or dispersions just prior to use, which may contain antioxidants, buffers, bacteriostats, solutes which render the formulation isotonic with the blood of the intended recipient or suspending or thickening agents.
Examples of suitable aqueous and nonaqueous carriers which may be employed in the pharmaceutical compositions of the present invention include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils, such as olive oil, and injectable organic esters, such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials, such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.
These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents, such as sugars, sodium chloride, and the like into the compositions. In addition, prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin.
When the therapeutic agents of the present invention are administered as pharmaceuticals, to humans and animals, they can be given per se or as a pharmaceutical composition containing, for example, 0.1 to 99.5% (more preferably, 0.5 to 90%) of active ingredient in combination with a pharmaceutically acceptable carrier.
Actual dosage levels of the active ingredients in the pharmaceutical compositions of this invention may be determined by the methods of the present invention so as to obtain an amount of the active ingredient, which is effective to achieve the desired therapeutic response for a particular subject, composition, and mode of administration, without being toxic to the subject.
In certain embodiments, a component of the compositions of the invention is an antibody. As defined herein, a therapeutically effective amount of antibody (i.e., an effective dosage) ranges from about 0.001 to 30 mg/kg body weight, preferably about 0.01 to 25 mg/kg body weight, more preferably about 0.1 to 20 mg/kg body weight, and even more preferably about 1 to 10 mg/kg, 2 to 9 mg/kg, 3 to 8 mg/kg, 4 to 7 mg/kg, or 5 to 6 mg/kg body weight. The skilled artisan will appreciate that certain factors may influence the dosage required to effectively treat a subject, including but not limited to the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present. Moreover, treatment of a subject with a therapeutically effective amount of an antibody can include a single treatment or, preferably, can include a series of treatments. In a preferred example, a subject is treated with antibody in the range of between about 0.1 to 20 mg/kg body weight, one time per week for between about 1 to 10 weeks, preferably between 2 to 8 weeks, more preferably between about 3 to 7 weeks, and even more preferably for about 4, 5, or 6 weeks. It will also be appreciated that the effective dosage of antibody used for treatment may increase or decrease over the course of a particular treatment. Changes in dosage may result from the results of diagnostic assays.
The therapeutic compositions of the present invention may also include known antioxidants, buffering agents, and other agents such as coloring agents, flavorings, vitamins or minerals.
RPMI 1640 supplemented with 10% fetal bovine serum (FBS) (Gemini Bio-Products, CA, USA) was used for the cultures of human NK cells and monocytes. OSCCs and stem-like OSCSCs were isolated from oral cancer patient tongue tumors at UCLA, and cultured in RPMI 1640 supplemented with 10% FBS (Gemini Bio-Products, CA, USA), 1.4% antibiotic antimycotic, 1% sodium pyruvate, 1.4% non-essential amino acids, 1% L-glutamine, 0.2% gentamicin (Gemini Bio-Products, CA, USA), and 0.15% sodium bicarbonate (Fisher Scientific, PA, USA). Mia-Paca-2 (MP2) were cultured in DMEM with 10% FBS and 1% penicillin and streptomycin (Gemini Bio-Products, CA, USA). Recombinant IL-2 was obtained from NIH-BRB. Recombinant TNF-α and IFN-γ were obtained from BioLegend (San Diego, Calif., USA). Anti-MHC class I was prepared and 1:100 dilution was found to be the optimal concentration to use. PE conjugated anti-CD54, anti-CD44, anti-B7H1, anti-MICA/MICB antibody were obtained from BioLegend (San Diego, Calif., USA). Antibody against MICA/MICB was a generous gift from Dr. Jennifer Wu from Feinberg school of medicine. The human NK and monocyte purification kits were obtained from Stem Cell Technologies (Vancouver, BC, Canada).
Purification of NK Cells and T Cells from the Human Peripheral Blood
Written informed consents, approved by UCLA Institutional Review Board (IRB), were obtained from healthy blood donors, and all procedures were approved by the UCLA-IRB. Peripheral blood was separated using Ficoll-Hypaque centrifugation, after which the white, cloudy layer, containing peripheral blood mononuclear cells (PBMC), was harvested, washed and resuspended in RPMI 1640 (Invitrogen by Life Technologies, CA) supplemented with 10% FBS and plated on plastic tissue culture dishes. After 1-2 hours of incubation, non-adherent, human peripheral blood lymphocytes (PBL) were collected. NK cells were negatively selected and isolated from PBLs using the EasySep® Human NK cell enrichment kit and T cells isolation kit, respectively purchased from Stem Cell Technologies (Vancouver, BC, Canada). Isolated NK cells were stained with anti-CD16 and anti-CD3 antibody, respectively, to measure the cell purity using flow cytometric analysis. Purified NK cells were cultured in RPMI Medium 1640 supplemented with 10% FBS (Gemini Bio-Products, CA), 1% antibiotic/antimycotic, 1% sodium pyruvate, and 1% MEM non-essential amino acids (Invitrogen, Life Technologies, CA).
Human purified and hu-BLT enriched NK cells were activated with rh-IL-2 (1000 U/ml) and anti-CD16mAb (3 ug/ml) for 18-20 hours before they were co-cultured with feeder cells and sAJ2. The culture media was refreshed with rh-IL-2 every three days [43].
As described above, human NK cells were purified from PBMCs of healthy donors. NK cells were treated with a combination of anti-CD16mAb (3 μg/mL) and IL-2 (1,000 U/mL) for 18 hours before supernatants were removed and used for differentiation experiments. The amounts of IFN-γ produced by activated NK cells were assess with IFN-γ ELISA (BioLegend, CA, USA). OSCSCs were differentiated with gradual daily addition of increasing amounts of NK cell supernatants. On average, to induce differentiation, a total of 3,500 pg. of IFN-γ containing supernatants were added for 5 days to induce differentiation and resistance of OSCSCSs to NK cell-mediated cytotoxicity and a total of 7000 pg. of IFN-γ containing supernatants were added for 7 days to induce differentiation and resistance of MP2 to NK cell-mediated cytotoxicity. Afterwards, target cells were washed with PBS, detached and used for experiments.
Treating NK Cell with Mekabue
The Fucoidan extracted from the Mekabue seaweed was purchased from NatureMedic. 12.5 g of the Mekabue extracted fucoidan (Mekabue) was solubilized in 1 ml of PBS.1 and then added to cultures.
AJ2 was weighed and resuspended in RPMI Medium 1640 containing 10% FBS at a concentration of 10 mg/mL. The bacteria were thoroughly vortexed, then sonicated on ice for 15 seconds, at 6 to 8 amplitudes. Sonicated samples were then incubated for 30 seconds on ice. After every five pulses, a sample was taken to observe under the microscope until at least 80 percent of cell walls were lysed. It was determined that approximated 20 rounds of sonication/incubation on ice, were conducted to achieve complete sonication. Finally, the sonicated samples (sAJ2) were aliquoted and stored in a −80° C. freezer.
Osteoclasts were generated from PBMC-purified monocytes and cultured in alpha-MEM medium, containing M-CSF (25 ng/mL) and RANK Ligand (RANKL) (25 ng/mL), for 21 days. 14 Medium was refreshed every 3 days with fresh alpha-MEM, containing M-CSF (25 ng/mL) and RANKL (25 ng/mL).
The target cells (5×105) were labeled with 50 μCi 51Cr (Perkin Elmer, Santa Clara, Calif.) and chromated for 1 hour. Following incubation, target cells were washed once to remove excess unbound 51Cr. Cells were resuspended in 1×106/mL and the treated with the anti-MICA/MICB antibody or Cetaximab (3 μg/mL) and incubated for 30 minutes. Following incubation, target cells were washed again to remove excess unbound antibody and 51Cr. Labeled target cells were culture with effector cells and the cytotoxicity against target cells were assessed using 51Cr release cytotoxicity assay.
51Cr Release Cytotoxicity Assay 51Cr was purchased from Perkin Elmer (Santa Clara, Calif.). Standard 51Cr release cytotoxicity assays were used to determine NK cell cytotoxic function in the experimental cultures. The effector cells (1×105 cells/well) were aliquoted into 96-well round-bottom micro-well plates (Fisher Scientific, Pittsburgh, Pa.) and titrated at 4 to 8 serial dilutions. Target cells (5×105) were labeled with 50 μCi 51Cr (Perkin Elmer, Santa Clara, Calif.) and chromated for 1 hour. Following incubation, target cells were washed twice to remove excess unbound 51Cr. 51Cr-labeled target cells were aliquoted into the 96-well round bottom microwell plates containing effector cells at a concentration of 1×104 cells/well at a top effector:target (E:T) ratio of 5:1. Plates were centrifuged and incubated for a period of 4 hours. After a 4-hour incubation period, the supernatants were harvested from each sample and counted for released radioactivity using the gamma counter. Total (containing 51Cr labeled target cells) and spontaneous (supernatants of target cells alone) release values were measured and used to calculate the percentage specific cytotoxicity. The percentage specific cytotoxicity was calculated using the following formula:
% Cytotoxicity=[Experimental cpm−spontaneous cpm]/[Total cpm−spontaneous cpm]
Lu30/106 is calculated by using the inverse of the number of effector cells needed to lyse 30% of target cells×100.
ELISA kit for IFN-γ was purchased from BioLegend (San Diego, Calif.). ELISA was performed to detect the level of IFN-γ produced from cell cultures. The assay was conducted as described in the manufacturer's protocol. Briefly, 96-well EIA/RIA plates were coated with diluted capture antibody corresponding to target cytokine and incubated overnight at 4° C. After 16-18 hours of incubation, the plates were washed 4 times with wash 18 buffer (0.05% Tween in 1×PBS) and blocked with assay diluent (1% BSA in 1×PBS). The plates were incubated for 1 hour at room temperature, on a plate shaker at 200 rpm; plates were washed 4 times following incubation. Then, 100 μL of standards and samples collected from each culture were added to the wells and incubated for 2 hours at room temperature, on the plate shaker at 200 rpm. After incubation, plates were washed 4 times, loaded with detection antibody, and incubated for 1 hour at room temperature, on the plate shaker at 200 rpm. After 1 hour of incubation, the plates were washed 4 times; wells were loaded with Avidin-HRP solution and incubated for 30 minutes at room temperature, on the plate shaker at 200 rpm. After washing the plates 5 times with wash buffer; 100 uL of TMB substrate solution was added to the wells and plates were incubated in the dark until they developed a desired blue color (or up to 30 minutes). Then, 100 μL of stop solution (2N H2SO4) was added per well to stop the reaction. Finally, plates were read in a microplate reader, at 450 nm to obtain absorbance values (BioLegend, ELISA manual).
1×105 cells from each condition were stained in 100 μL of cold 1% BSA-PBS with predetermined optimal concentration of PE conjugated antibodies, as detailed in the experiments, and incubated at 4° C. for 30 minutes. Then, cells were washed and resuspended in 1% BSA-PBS. The Epics C (Coulter) flow cytometer was used for cellular surface analysis.
An unpaired or paired two-tailed Student's t-test were performed to compare different groups depending on the experimental design. The p-values were expressed within the figures as follows: ***p-value<0.001, **p-value: 0.001-0.01, *p-value: 0.01-0.05. The GraphPad Prism software was used to analyze the data.
OSCSCs and MP2 displayed higher expression of CD44, and lower expression of MHC-I, MICA and CD54, while the reverse profile was seen in their differentiated compartments. To differentiate the OSCSCs, and MP2 the tumor cells were treated with supernatants from split-anergized NK cells as described in Example 1. Treatment of OSCSCs and MP2 with split-anergized NK cells supernatant decreased the CD44 surface expression and increased the MHC-I, MICA and CD54 surface expression (
OSCSCs and MP2 displayed lower expression of MICA/MICB, while the reverse profile was seen in their differentiated compartments, OSCCs and PL12. Treatment of OSCSCs and MP2 with split-anergized NK cells supernatant increase the MICA/MICB surface expression showing that well-differentiated tumors express higher level of MICA/MICB in comparison to undifferentiated/stem-like oral and pancreatic tumors (
To study the antibody dependent mediated cytotoxicity (ADCC) in NK cells, against differentiated tumor cells expressing high level of MICA/MICB and their undifferentiated compartments expressing low level of MICA/MICB, NK cells were purified from healthy donors. NK cells were left untreated, treated with IL-2, or the combination of IL-2 and anti-CD16mAb. Their cytotoxicity against the OSCSCs and OSCCs untreated or treated with the antibody against MICA/MICB was determined using the 51Cr release assay. Untreated and IL-2 treated NK cells mediated higher cytotoxicity against anti-MICAS treated OSCCS in comparison to untreated OSCCS (
To further confirm that the same observation can be seen in pancreatic tumor, the same experiment in Example 4 was conducted with MP2 and PL12. The cytotoxicity against anti-MICA/MICB treated PL12 was 55-fold higher in untreated and 4.3-fold higher in IL-2 treated NK than untreated PL12. (
Treatment of OSCSCs and MP2 with split-anergized NK cells supernatant increases the surface expression of differentiation markers including MICA/MICB. To determine if differentiating oral and pancreatic tumors with split-anergized NK cells supernatants make them susceptible to NK cell mediated ADCC, OSCSCs, and MP2 were differentiated as described in Example 1, and cytotoxicity of untreated and IL-2 treated NK cells against untreated and MICA/MICB treated undifferentiated, split-anergized NK cells supernatant-differentiated, and undifferentiated/stem-like oral and pancreatic tumors were measured. The untreated and IL-2 treated NK cells mediated ADCC against OSCCSs and PL12 (
To determine whether anti-MICA/MICB antibody can increase the secretion of IFN-γ, NK cells were cultured with untreated or antiMICA/MCB treated OSCCs and OSCSCs. Untreated NK cells did not induce IFN-γ secretion without or with being co-cultured with tumor cells. As we shown previously combination of IL-2 and anti-CD16 mAb induced the highest level of IFN-γ by NK cells. When IL-2 treated NK cells were co-cultured with OSCCs and OSCSCs they secreted higher level of IFN-γ in comparison to the control groups (NK cells alone, with no tumor), and OSCSCs caused more secretion of IFN-γ than OSCCs. When IL-2 treated NK cells were cultured with antiMICA/MICB treated OSCCs they secreted more IFN-γ than NK cells cultured with untreated OSCCs while secreted IFN-γ in NK cells co-cultured with untreated OSCSCs and antiMICA/MICB treated OSCCs was not significantly different. The same trend was seen in three different separate experiment (
Super-charged NK cells (“expanded NK cells”) have both high cytotoxicity and cytokine secretion abilities. When comparing the function and surface expression of primary and supercharged NK cells, they show different characteristics. Super-charged NK cells have high cytotoxicity against undifferentiated tumor cells, but their function against differentiated tumors was not studied. To compare the cytotoxicity of primary NK and expanded NK against differentiated and undifferentiated tumor cells, NK cells were expanded for 15 days and their cytotoxicity against OSCCs, OSCSCS, PL12 and MP2 was measured. While undifferentiated tumor cells were more susceptible to primary NK cell-mediated lysis, in comparison to differentiated compartments, expanded NK cells from the same donor were able to significantly target both differentiated and undifferentiated tumor cells. The cytotoxicity of expanded NK cells was 3 to 15-fold higher against OSCCs and 4.7-fold higher against PL12 in comparison to primary NK cells.
A stage of NK cells maturation named “split anergy” that indicate reduced NK cell cytotoxicity in the presence of significant secretion of cytokines. Treatment of NK cells with IL-2 and anti-CD16 mAb, can induce split anergy in primary NK cells. To determine whether combination of IL-2 and anti-CD16 mAb treatment will decrease the cytotoxicity in expanded NK, freshly purified NK from healthy donors were expanded. After being in culture for 15 days, NK cells were purified from the same donors and primary and expanded NK cells were treated with IL-2 and the combination of IL-2 and anti-CD16 mAb for 18 hours and their cytotoxicity against OSCSCs was measured using standard 4-hours 51Cr release assay. The cytotoxicity of IL-2 and anti-CD16 treated primary NK cells against OSCSCs decrease 2.4 to 4.9-fold while the cytotoxicity in Expanded of IL-2 and anti-CD16 treated Expanded NK cells were almost the same as IL-2 treated expanded NK (
CD16 gets downmodulated on expanded NK cells. To study the ability of expanded NK cells in mediating ADCC, cytotoxicity of primary NK cells and expanded NK cells on day 15, from the same donor were measured against untreated, anti-MICA/MICB antibody, and Cetaximab treated OSCCs. While untreated and IL-2 treated primary NK cells mediated higher levels of cytotoxicity against anti-MICA/MICB antibody and Cetaximab treated OSCCs, than untreated tumors, expanded NK and IL2-reactivated NK expanded NK cells did not mediate ADCC against anti-MICA/MICB antibody or Cetaximab treated OSCCs. (
IFN-γ secreted by NK cells have a significant role in differentiation of tumor cells. To look at the strategy to increase the increase NK cell mediated production of IFN-γ, the effect of Fucoidan and AJ2 probiotic bacteria on function of NK cells was studied. To study the effect of Fucoidan on NK cells function, purified NK cells form healthy donors were treated with IL-2 and different concentrations of D-fucoidan extracted from Undaria pinnatifida known as Mekabue for 24 hours. Treatment of NK cells with Mekabue for 24 hours significantly increased their ability to secrete IFN-γ but a decreased their cytotoxicity, pushing the NK cells to a stage known as split-anergy (
To study the effect of AJ2 probiotic bacteria on the function of NK cells, purified NK cells were treated with IL-2 for 18 hours and they were treated with the AJ2 probiotic bacteria for 24 hours. Activated NK cells with AJ2 induced higher level of IFN-γ, while their ability to mediated cytotoxicity was not changed. (
To study the synergistic effect of AJ2 and Mekabue on IFN-γ induction by NK cells, purified NK cells form healthy donors were treated with IL-2 for 18 hours and then they were left untreated, treated with AJ2, or Mekabue, or both. The supernatant from the cultures was collected after 24 hours and IFN-γ as measured. NK cells treated with AJ2 or Mekabue induce significantly higher level of IFN-γ in comparison to control group (
NK cells target poorly differentiated cells or stem cells with lower expression of key differentiation antigens. The link between the stage of maturation and differentiation of tumors and their sensitivity to NK cell-mediated lysis is discovered in this study. It is demonstrated herein that stem-like/poorly differentiated oral and pancreatic tumor cells were significantly more susceptible to NK cell-mediated cytotoxicity whereas, their differentiated counterparts were significantly more resistant. Furthermore, it is demonstrated herein that differentiated oral, pancreatic tumor cells, and cancer stem cells/poorly differentiated tumor cells differentiated in vitro with supernatants from split-anergized NK cells became resistant to NK cell-mediated cytotoxicity. Unlike the cancer stem cells (CSCs)/poorly differentiated tumor cells, both patient-derived differentiated tumor cells and split-anergized NK supernatant-differentiated tumor cells exhibited upregulated CD54, B7H1, and MHC class I surface expression and demonstrated decreased CD44 expression.
When it comes to NK cells immunity, MICA/MICB antigen plays an important role since it is a well-known ligand for NKG2D and it gets expressed upon stress, damage, viral infection or transformation of cells which act as a ‘kill me’ signal through the cytotoxic lymphocytes. It is demonstrated herein that MICA/MICB does not get upregulated on all tumor cells, but it is correlated with the differentiation stages of the cells. It is presented herein for the first time that differentiated oral, pancreatic tumor cells, and cancer stem cells/poorly differentiated tumor cells differentiated in vitro with supernatants from split-anergized NK cells express a higher level of MICA/MICB in comparison to their stem-like/undifferentiated counterpart. Primary NK cells preferentially target stem-like/undifferentiated cells. Accordingly, the surprising observation that well-differentiated cells express a higher level of MICA/MICB, which is a ligand for an activator receptor on NK cells, indicates the novel roles of MICA/MICB ligands and its receptors. Since there was a difference in the pattern of MICA/MICB expression in stem-like/undifferentiated and well-differentiated oral and pancreatic tumor, it was studied whether NK cells mediate ADCC differentially against these tumors based on the antibody specific to MICA/MICB. It is demonstrated herein that antibodies specific to MICA/MICB increased NK cell-mediated ADCC against well-differentiated and cancer stem cells/poorly differentiated tumor cells differentiated in vitro with supernatants from split-anergized NK cells while stem-like/undifferentiated were not targeted by untreated and IL-2 treated primary NK cells through ADCC which correlated with the expression level of MICA/MICB. When NK cells were treated with antiCD16 mAb, NK cells were not able to mediate ADCC since the CD16 receptor was masked by the antibody. It is further presented herein that antibody specific to MICA/MICB increased IFN-γ secretion by NK cells when cultured with differentiated Oral tumors expressing MICA/MICB but not stem-like/undifferentiated Oral tumor cells. When NK cells were cultured with target cells and the antibody specific to the antigen they present, the cytokines such as TNFα, IL-6, IFN-γ or chemokines such as IL-8 and MCP-1 were found to be significantly enhanced.
It was also delineated herein the underlying differences between the functions of primary and Expanded NK cells in direct cytotoxicity and ADCC. NK cells were expanded by IL-2, antiCD16 mAb, and AJ2 probiotic bacteria activation and using Osteoclast as feeder cells. This strategy leads to NK cells called “Super Charged NK cell”, having high cytotoxicity and high level of IFN-γ secretion. When the cytotoxicity of NK cells against stem-like/undifferentiated oral and pancreatic tumors with their well-differentiated counterpart were compared, it was discovered that Expanded NK cells target both undifferentiated and differentiated tumor cells while primary NK cells preferentially target undifferentiated/Stem-like population. The cytotoxicity of expanded NK cells was 3 to 15-fold higher against OSCCs and 4.7-fold higher against PL12 in comparison to primary NK cells showing that the extend well-differentiated tumor cells can become sensitive to Expanded NK cell-mediated cytotoxicity can be different based on the biology of these cells and maybe their resistance to primary NK cells mediated cytotoxicity. Expanded NK cells express a higher level of NKG2D than primary NK cells. As presented above, MICA/MICB, one of the NKG2D ligands, expresses highly on well-differentiated cells, which also express a high level of MHC-I. Therefore, since Expanded NK cells express a higher level of NKG2D, the NKG2D-MICA/MICB mediated lysis become the dominant mechanism of cytotoxicity in expanded NK cells leading to targeting both undifferentiated and differentiated tumor cells.
The stage of maturation in NK cells called split anergy can be initiated by targeting different receptors on NK cells including the CD16 receptor. As described above, when NK cells were treated with the combination of IL-2 and antiCD16 mAb, their cytotoxicity decrease but their ability to secrete IFN-γ significantly increase in comparison to IL-2 treated NK cells. Furthermore, it is presented herein that spilt anergy occurs in the primary NK cells, but not in the Expanded NK cells. Treating Expanded NK cells with the combination of IL-2 and antiCD16 did not result in a decrease in their cytotoxicity. CD16 gets downregulated on the surface of expanded NK cells and this explains why antiCD16 treatment in Expanded NK cells cannot push them towards the split anergy stage. Since the level of CD16 is different on primary and Expanded NK cells, ADCC in primary and Expanded NK cells was compared. When the level of ADCC was measured in untreated and IL-2 treated NK cells against well-differentiated Oral tumors treated with antiMICA/MICB antibody and also Cetaximab (antibody against EGFR receptor), despite primary NK cells, Expanded NK cells were not able to mediate ADCC and even some levels of inhibition was seen in antibody treated tumor cells in comparison to the untreated cells. The lower level of ADCC of Expanded NK cells is due to the downmodulation of CD16 receptor on their surface. Although Expanded NK cells express some levels of CD16, a higher level of CD16 is required for NK cells to be able to mediate ADCC as it is known that during HIV-1 infection, NK cells are known to express low levels of CD16 and exhibit reduced ADCC.
Induction of split anergy in NK cell effector function drives differentiation of healthy, as well as transformed stem-like cells. Differentiation of tumor cells is one of the important role of NK cells since the differentiated tumor micro environment become less invasive and more susceptible to chemotherapeutics. Cytokines that are secreted by NK cells, primarily IFN-γ and TNF-α, are responsible for the differentiation of cancer stem cells (CSCs) and result in the increase in differentiation antigens such as MHC class I, CD54, B7H1, and MICA and decrease in CD44. Accordingly, exposing oral and pancreatic cancer stem cells to IFN-γ secreted by NK cells activated with IL-2 and CD16, resulted in upregulation of differentiation the same differentiation markers a respectively the differentiated tumor cells, lose their cytotoxicity against NK cells. These results and the work on AJ2 probiotic bacteria illustrate the profound capability probiotic bacteria has on NK cells to induce a significant increase in cytokine secretion, known as split anergy. AJ2 is a combination of 8 strains of probiotic bacteria for their ability to induce significant secretion of IFN-γ when added to IL-2 or IL-2+anti-CD16mAb treated NK cells. The ratio of bacteria added to create sAJ2 was adjusted to yield a ratio of IFN-γ to IL-10 for when cells are activated with IL-2 or IL-2+anti-CD16mAb without bacteria. This ratio was established to obtain a similar ratio when NK cells are activated with IL-2+anti-CD16mAb without bacteria since this NK treatment provided increased differentiation of stem cells. IL-10, an anti-inflammatory cytokine, was taken into consideration to balance the significant amount of IFN-γ secreted by cells during the process of differentiation. This combination of bacterial strains was selected due to its optimal induction of pro- and anti-inflammatory cytokine and growth factors by the NK cells.
Fucoidan is a sulfated polysaccharide, can be extracted from different species of brown algae and brown seaweed. This compound has been known to have immunomodulatory effects on immune cells. Although studies have shown that Fucoidan can decrease tumor size, have antitumor activities, and lead to higher survival in tumor-induced mouse, the exact role of Fucoidan on NK cells function has not been well studied. It is presented herein that Mekabue extracted Fucoidan increased NK cells IFN-γ secretion ability but decreased NK cell-mediated cytotoxicity which is a profile of split anergized NK cells. Seeking strategies to push NK cells to secrete the highest level of IFN-γ, it was investigated herein the synergistic effect of Mekabue and AJ2 probiotic bacteria on NK cell-mediated IFN-γ secretion. NK cells treated with AJ2 or Mekabue induce significantly higher level of IFN-γ in comparison to untreated, sAJ2, or Mekabue treated IL-2 treated NK cells. NK cells express different families of Toll-like receptors (TLRs). The gram-positive bacteria in the probiotic bacteria can trigger NK cells TLRs via their cell wall components. A study showed that cytokine induction by both B. breve and the lactobacilli is strongly dependent on TLR9 since blocking of TLR9 resulted in decreased production of IL-10 and IFN-γ in PBMCs. Fucoidan from seaweeds is independent ligands for TLR-2 and TLR-4. Accordingly, NK cells produce a higher level of IFN-γ in presence of both AJ2 probiotic bacteria and Mekabue because these compound target different family of TLRs on NK cells.
In conclusion, differentiation stages of pancreatic cancer cells correlated directly with the resistance to NK cell-mediated cytotoxicity and expression of key surface antigens. Differentiation by NK cells is very important in effective targeting of cancer stem cells/undifferentiated tumor cells. As IFN-γ plays a critical rule in differentiation, treatment strategy to push NK cells to produce higher levels of IFN-γ is a critical step in eliminating tumors. Combination of probiotic AJ2 bacteria with fucoidan extracted from Mekabue seaweed can cause higher secretion of IFN-γ by NK cells. Oral and pancreatic tumor cells have a specific pattern of MICA/MICB antigen expression as differentiated tumor cells express higher levels of MICA/MICB than stem-like/undifferentiated tumor cells. Since well differentiated cells express higher levels of MICA/MICB, NK cells mediate higher levels of ADCC through antibody specific to MICA/MICB against these cells than their undifferentiated compartments. Furthermore, Primary and Expanded NK cells have very different characteristic and biological functions. Accordingly, all diverse functions of different subsets NK cells provide a novel way of developing NK cell-immunotherapeutic approaches.
RPMI 1640 supplemented with 10% Fetal Bovine Serum (FBS) (Gemini Bio-Products, CA) was used for the cultures of human NK cells, and oral squamous carcinoma stem-like cells (OSCSCs). RPMI 1640 supplemented with 10% Fetal Bovine Serum (FBS) (Gemini Bio-Products, CA) was used for the cultures the cells isolated from hu-BLT mice tissues. MiaPaCa-2 (MP2), PL12, BXPC3, HPAF, and Capan were cultured with DMEM supplemented with 10% FBS. DMEM supplemented with 10% FBS was used to culture pancreatic tumor cells isolated from hu-BLT mice pancreas. Recombinant IL-2 (rhlL-2) was obtained from NIH-BRB. Flow cytometry and other antibodies used in the study were obtained from Biolegend (San Diego, Calif.). Monoclonal antibodies to TNF-α and IFN-γ were prepared and 1:100 dilutions were found to be the optimal concentration to use for blocking experiments. NAC at 20 mM was prepared using sterilized distilled water at pH 7-7.2 and, was diluted using DMEM media to have final concentration of 20 nM.
Human pancreatic cancer cell lines Panc-1, MIA PaCa-2 (MP2), BXPC3, HPAF, Capan were generously provided by Dr. Guido Eibl (UCLA David Geffen School of Medicine) and PL12 was provided by Dr. Nicholas Cacalano (UCLA Jonsson Comprehensive Cancer Center). Panc-1, MP2 and BXPC3 were cultured with DMEM in supplement with 10% FBS and 2% Penicillin-Streptomycin (Gemini Bio-Products, CA). HPAF, Capan and PL12 were cultured in RMPI 1640 medium supplemented with 10% FBS and 2% Penicillin-Streptomycin. Recombinant human IL-2 was obtained from NIH-BRB. Recombinant human TNF-α rand IFN-γ were obtained from Biolegend (San Diego, Calif.). Antibodies to CD16 were purchased from Biolegend (San Diego, Calif.). Anti-MHC class I was prepared and 1:100 dilution was found to be the optimal concentration to use. Fluorochrome-conjugated human and mouse antibodies for flow cytometry were obtained from Biolegend (San Diego, Calif.). Monoclonal antibodies to TNF-α were prepared from ascites of mice injected with TNF-α hybridomas, after which the antibodies were purified and specificity determined by both ELISA and functional assays against rh TNF-α. Monoclonal IFN-γ antibodies were prepared in rabbits, purified and specificity determined with ELISA and functional assays against rIFN-γ. 1:100 dilution of anti-TNF-α and anti-IFN-γ antibodies was found to be the optimal concentration to block rhTNF-α and rhIFN-γ function. The human NK, CD3+ T cells and monocytes purification kits were obtained from Stem Cell Technologies (Vancouver, Canada). Propidium iodide and N-Acetyl Cysteine (NAC) were purchased from Sigma Aldrich (St. Louis, Mo.). Cisplatin and paclitaxel were purchased from Ronald Reagan UCLA Medical Center Pharmacy (Los Angeles, Calif.).
Written informed consents approved by UCLA Institutional Review Board (IRB) were obtained and all procedures were approved by the UCLA-IRB. NK cells and monocytes were negatively selected and isolated from PBMCs using the EasySep® Human NK cell enrichment kit and monocyte isolation kit, respectively purchased from Stem Cell Technologies (Vancouver, BC, Canada). Isolated NK cells and monocytes were stained with anti-CD16 and anti-CD14 antibody, respectively, to measure the cell purity using flow cytometric analysis.
Animal research was performed under the written approval of the UCLA Animal Research Committee (ARC). Humanized-BLT (hu-BLT; human bone marrow/liver/thymus) mice were prepared as previously described.
In vivo growth of pancreatic tumors were done by orthotopic cell implantation into 8-10 week-old NSG mice or hu-BLT mice pancreas. To establish orthotopic tumors, mice were anesthetized using isoflurane followed by 2 cm of the incision on the lower right abdomen. Once the spleen was exposed, spleen was pulled out as pancreas in lying under the spleen. Spleen was holded using sterilized forceps and the pancreas was exposed (laparotomy). Tumor cells were then transferred by direct injection with 10 μl HC Matrigel (Corning, N.Y., USA) using insulin syringe with 28 G needle in the pancreas. Mice were monitored for tumor growth by palpating the abdominal site. 7 to 10 days after the surgery mice received 1.5×106 super-charged NK cells via tail vein injection. Mice were fed AJ2 (5 billion/dose) orally, similar to how humans ingest probiotics. The first dose of AJ2 was given one or two weeks before tumor implantation and was continued throughout the experiment every 48 hours. Mice were euthanized when signs of morbidity were evident. Pancreas, pancreatic tumors, bone marrow, spleen, and peripheral blood were harvested from mice at the end of the experiment or when tumor size reached 2 cm diameter.
To establish orthotopic tumors, mice were anesthetized using isoflurane and oral tumor cells were then injected in oral floor by direct injection with 10 μl HC Matrigel (Corning, N.Y., USA). 7 to 10 days after the oral tumor injections, mice received 1.5×106 super-charged NK cells via tail vein injection. Mice were fed AJ2 (5 billion/dose) orally, similar to how humans ingest probiotics. The first dose of AJ2 was given one or two weeks before tumor implantation and was continued throughout the experiment every 48 hours. Mice were euthanized when signs of morbidity were evident. Peripheral blood was harvested from mice at the end of the experiment or when tumor size reached 2 cm diameter.
Cell Dissociation and Cell Culture of Tissues from Hu-BLT and NSG Mice
The pancreas and/or pancreatic tumor harvested from NSG and hu-BLT mice were immediately cut into 1 mm3 pieces and placed into a digestion buffer containing 1 mg/ml collagenase IV, 10 U/ml DNAse I, and 1% bovine serum albumin (BSA) in DMEM media, and incubated for 20 minutes at 37° C. oven on a 150 rpm shaker. After digestion, the sample was filtered through a 40 mm cell strainer and centrifuged at 1500 rpm for 10 minutes at 4° C. The pellet was re-suspended in DMEM media and cells were counted. To obtain single-cell suspensions from BM, femurs were cut from both ends and were flushed from one end to other using RPMI media, BM cells was filtered through a 40 mm cell. To obtain single-cell suspensions from spleen, spleen was smashed until no big piece was left and sample was filtered through a 40 mm cell and centrifuged at 1500 rpm for 5 minutes at 4° C. The pellet was re-suspended in ACK buffer to remove the red blood cells for 2-5 mins followed re-suspension in RMPI media and centrifuged at 1500 rpm for 5 minutes at 4° C. Peripheral blood mononuclear cells (PBMCs) were isolated using ficoll-hypaque centrifugation of heparinized blood specimens. The buffy coat containing PBMCs were harvested, washed and re-suspended in RPMI 1640 medium.
Purification of NK Cells, CD3+ T Cells, and Monocytes from Hu-BLT Mice
NK cells from hu-BLT mice splenocytes were isolated using the human CD56+ selection kit (Stem Cells Technologies, Canada). Monocytes from hu-BLT mice BM cells were positively selected from BM using human CD14 isolation kit (eBioscience, San Diego, Calif.). Isolated NK cells and monocytes were stained with anti-CD16 and anti-CD14 antibody, respectively, to measure the cell purity using flow cytometric analysis.
Purified monocytes both form human peripheral blood and hu-BLT mice BM cells were cultured in alpha-MEM medium containing M-CSF (25 ng/mL) and RANKL (25 ng/mL) for 21 days, or otherwise specified. The medium was refreshed every 3 days with fresh alpha-MEM containing M-CSF and RANKL. Human purified and hu-BLT NK cells were activated with rh-IL-2 (1000 U/ml) and anti-CD16mAb (3 ug/ml) for 18-20 hours before they were co-cultured with osteoclasts and sonicated AJ2 for NK cells expansion. The medium was refreshed every 3 days with RMPI containing rh-IL-2 (1500 U/ml).
Human ELISA kits for IFN-γ were purchased from Biolegend (San Diego, Calif.). The assay was conducted as described in the manufacturer's protocol. The plates were read in a microplate reader, at 450 nm to obtain absorbance values (Biolegend, ELISA manual). To analyze and obtain the cytokine and chemokine concentration, a standard curve was generated by either two or three-fold dilution of recombinant cytokines provided by the manufacturer.
The levels of cytokines and chemokines were examined by multiplex assay, which was conducted as described in the manufacturer's protocol for each specified kit. Analysis was performed using a Luminex multiplex instrument (MAGPIX, Millipore, Billerica, Mass.) and data was analyzed using the proprietary software (xPONENT 4.2, Millipore, Billerica, Mass.).
Staining was performed by labeling the cells with antibodies as described previously. Briefly, the cells were washed twice with ice-cold PBS/1% BSA. Predetermined optimal concentrations of specific human flow cytometric antibodies were added to 1×104 cells in 50 μl of cold-PBS/1% BSA and cells were incubated on ice for 30 min. Thereafter cells were washed in cold PBS/1% BSA and brought to 500 μl with PBS/1% BSA. Flow cytometry analysis was performed using Beckman Coulter Epics XL cytometer (Brea, Calif.) and results were analyzed in FlowJo vX software (Ashland, Oreg.).
The 51Cr release assay was performed as described previously. OSCSCs were used as target cells to assess NK cell-mediated cytotoxicity because these cells are the most susceptible cells to NK cell-mediated cytotoxicity. Briefly, different numbers of effector cells were incubated with 51Cr-labeled target cells. After a 4-hour incubation period the supernatants were harvested from each sample and counted for released radioactivity using the gamma counter. The percentage specific cytotoxicity was calculated using the following formula:
Lytic unit 30/106 is calculated by using the inverse of the number of effector cells needed to lyse 30% of tumor target cells×100.
Differentiation of MP2 tumors was conducted as described previously. NK cells were treated with a combination of anti-CD16mAb (3 μg/mL) and IL-2 (1,000 U/mL) for 18 hours before supernatants were removed and used for differentiation experiments. The amounts of IFN-γ produced by activated NK cells were assess with IFN-γ ELISA (Biolegend, CA, USA). MP2 cells were differentiated with gradual daily addition of increasing amounts of NK cell supernatants (of corresponding treatments). On average, to induce differentiation, a total of 3,500 pg of IFN-γ containing supernatants were added for 4 days to induce differentiation and resistance of MP2 tumor cells to NK cell-mediated cytotoxicity. Afterwards, target cells were washed with 1×PBS, detached and used for experiments.
An unpaired, two-tailed student t-test was performed for the statistical analysis. One-way ANOVA using Prism-7 software was used to compare different groups. (n) denotes the number of mice used for each condition in the experiment. The following symbols represent the levels of statistical significance within each analysis, ***(p-value<0.001), **(p-value 0.001-0.01), *(p-value 0.01-0.05).
Six pancreatic tumor cells were used to determine surface expression, susceptibility to NK cell mediated cytotoxicity and secretion of cytokines when cultured with NK cells. Poorly differentiated MP-2 and Panc-1 expressed higher amounts of CD44 and moderate or low levels of MHC class I and CD54. Moderately differentiated BXPC3 and HPAF expressed moderate to high levels of CD44 and CD54 and higher levels of MHC-class I. Well differentiated Capan and PL12 had much lower levels of CD44 and higher levels of CD54 and MHC class I (
Among six different pancreatic tumor types (
NK-differentiated MP2 tumors exhibited similar surface phenotype to well-differentiated PL12 and Capan tumors, and they too were resistant to NK cell mediated cytotoxicity (
MP2 tumors (3×105 tumors) implanted in the pancreas of NSG mice grew within 3-4 weeks and metastasized to liver and caused death of the mice (
Stem-like/undifferentiated MP2 and well differentiated Capan pancreatic tumor cells were treated with rhTNF-α and rhIFN-γ and their susceptibility to NK cell mediated lysis was assessed in a standard 4-hour 51Cr release assay. As shown in
Hu-BLT mice that were reconstituted with the human immune system, exhibited greater than 90% reconstitution with huCD45+ immune cells in different tissue compartments (
Hu-BLT mice (
The majority of infiltrating human immune cells in the pancreas was CD3+ T (54%) and B cells (43.3%), with CD8+ T cells constituting the larger proportions of the T cells (approximately 80%) than CD4+ T cells (approximately 20%) (Table 2;
Mice implanted with MP2 tumors and injected with 1 to 1.5×106 super-charged NK cells with potent cytotoxic and cytokine secretion capabilities (
Unlike tumor-bearing mice, when mice were fed AJ2 1-2 weeks before tumor implantation, and injected with allogeneic or autologous super-charged NK cells (
When pancreas were removed, dissociated and equal numbers of cells were cultured from tumor-bearing mice which did not receive NK injection, attached colonies of tumors could be seen in 24-48 hours and they grew rapidly thereafter, whereas those injected with allogeneic NK cells (
On average a decrease in secreted IFN-γ from the pancreatic cell cultures could be observed in mice implanted with MP2 tumors, as compared to control mice with no tumors (
The expression of B7H1 (PD-L1), MHC-class I and CD54 were higher on MP2 tumors cultured from the pancreas of NK-injected mice when compared to tumor-bearing mice in the absence of NK injection (
PBMCs from tumor-bearing mice (
Similar to those seen with the pancreatic tumors, implantation of oral tumors in the oral cavity of hu-BLT mice resulted in similar profiles of cytotoxicity and secretion of IFN-γ from PBMCs isolated from oral tumor bearing mice in the presence and absence of NK injection and feeding with AJ2 (
Since NK mediated inhibition of tumor growth in the pancreas was very strong, no tumor growth either in NK injected tumor-bearing mice or those receiving both NK and anti-PD1 antibody can be seen when compared to tumor-bearing mice (
Unlike MP2 tumors, treatment of well-differentiated PL12 and Capan tumors with paclitaxel (
Purified NK cells from different groups of mice were cultured with their respective autologous monocytes (
Finally, when the same amount of IFN-γ from the supernatants of NK cells were used to differentiate OSCSC tumors, those from pancreatic cancer patients' NK cells were less effective in differentiating OSCSC tumors as compared to those from healthy donors' NK cells. (
NK cells limit growth and expansion of CSCs/poorly differentiated pancreatic tumors by tumor lysis and differentiation. MP2 tumors being stem-like/poorly differentiated, form large tumors in NSG and hu-BLT mice, and they have the ability to metastasize to other organs/tissues, whereas their NK-differentiated MP2 tumors or patient-derived well-differentiated PL-12 tumors form no or very small tumors respectively in the pancreas without metastatic potential. Indeed, the growth potential of MP2 tumors in vitro is found to be 10-15 fold, whereas those of the NK-differentiated counterparts are between 1.5-4 fold when the same numbers of tumors are cultured at the same time period, and no or slight cell death could be seen in the cultures of either undifferentiated MP2 tumors or those differentiated by the NK cells.
Patient-derived PL12 tumors or NK-differentiated tumors, although were not killed by primary NK cells, they were however, susceptible to chemo-drugs and were killed by paclitaxel (
Hu-BLT monocyte derived osteoclasts expanded hu-BLT NK cells similar to human NK cells expanded by autologous osteoclasts. In addition, both autologous and allogeneic osteoclasts were able to expand hu-BLT NK cells with hu-BLT osteoclasts having slightly higher NK expansion potential (
Similar in NSG mice, NK-differentiated MP2 tumors did not grow to the levels which could form visible tumors in hu-BLT mice, and when tumor differentiation was prevented using antibodies to IFN-γ and TNF-α, tumors grew substantially (
When the pancreas was dissociated and cultured from tumor-bearing mice injected with NK cells and fed with/without AJ2, very few tumors grew and those which grew were of differentiated phenotype, whereas tumors from tumor-bearing mice in the absence of NK cell injection grew rapidly and remained undifferentiated. Moreover, tumors dissociated and cultured from NK-injected tumor-bearing hu-BLT mice contained about 18-22 fold more huCD45+ immune cells when compared to those cultured from dissociated tumors from tumor-bearing mice in the absence of NK injection. In addition, there were substantial increases in IFN-γ secretion but much lower IL-6 secretion in pancreatic cell cultures from tumor-bearing mice injected with NK cells, and the highest increases in IFN-γ secretion were seen in tumor-bearing mice fed with AJ2 and injected with NK cells, whereas tumor bearing mice in the absence of NK injection had higher secretion of IL-6 in the presence of lower IFN-γ secretion from pancreatic cell cultures. Increased IL-6 secretion is likely due to the growing tumors in tumor-bearing mice. NK cells in different tissues of hu-BLT mice implanted with tumor and injected with NK cells in the presence/absence of feeding with AJ2 mediated significant cytotoxicity and secreted increased amounts of IFN-γ, whereas those from tumor-bearing mice in the absence of NK injection mediated much less cytotoxicity or IFN-γ secretion.
The single injection of super-charged NK cells to tumor-bearing mice resulted in increased surface receptor expression of PD-L1, CD54 and MHC-class I on implanted tumor cells, decreased growth, and mediated loss of susceptibility of tumor cells to NK cell-mediated cytotoxicity (
Similar to cancer patients' monocytes and osteoclasts, those from tumor-bearing mice had much lower ability to expand autologous or allogeneic NK cells or increase their functional potential. More severe inhibition of NK cell expansion and function is seen when both NK and monocytes are from tumor-bearing mice due to the combined defects in both NK cells and monocytes. These experiments not only highlight similarities between the tumor-bearing hu-BLT mouse model and human cancers but also indicate a severe deficiency in the function of NK cell activating effectors in tumor-bearing hu-BLT mice similar to cancer patients. It is also important to note that the highest activation of NK cells from hu-BLT mice was achieved by implantation of NK-differentiated tumors, suggesting that optimal differentiation of tumors can indeed promote and maintain intact monocyte/osteoclast function.
To understand underlying mechanisms which govern inhibition of NK cell function, the surface expression of osteoclasts was determined from cancer patients in comparison to healthy donors' osteoclasts. The findings indicated that not only inhibitory MHC-class I expression is down-regulated but also activating CD54, KLRG1 and MICAS surface expressions were decreased, suggesting an overall decrease in NK ligand expression. Loss of activating ligands could clearly be a reason for decreased activation of NK cells. However, loss of inhibitory receptors provides a more complex picture. Loss of expression of activating and inhibitory NK cell ligands was also seen on osteoclasts from KC mice with pancreatic KRAS mutation correlating with the loss of NK cell function and generation of pancreatic tumors.
Supernatants from patient's NK cells were less able to differentiate tumors indicating that the function of secreted IFN-γ from patient NK cells is also severely compromised. Thus, pancreatic tumor induction and progression in patients is due to not only combined defects in NK expansion, decreased NK-cell mediated cytotoxicity and lower secretion of IFN-γ, and much lower ability of secreted IFN-γ to differentiate tumors but also due to the defects in other subsets of immune cells which support NK cell expansion and function.
Sera Collection from Human and Hu BLT Mice Peripheral Blood
Peripheral blood (200 μl) was collected in 1.5 ml eppendorf with no heparin was left in room temperature for 15-20 minutes before it was centrifuged at 2000 rpm for 10 mins, sera layer was then harvested.
Human Single-Color Enzymatic ELISPOT Assay for IFN-γ 80 μl of anti-human IFN-γ capture antibody was added to each well of a 96-well high-protein-binding PVDF filter plate and incubated overnight at 4° C. The plate was washed with 150 μl of PBS once before adding samples into the plate. 50,000 cells in 200 μl of RPMI were added into each well and incubate at 37° C., 5% CO2 overnight. After incubation, the plate was washed twice with 200 μl PBS followed by 0.05% 200 μl Tween-PBS twice. 80 μl of anti-human IFN-γ detection antibody was added into each well and incubated at room temperature for 2 hours and the plate was washed three times with 200 μl/well of 0.05% Tween-PBS. 80 μl/well of tertiary solution which was made from 1:1000 diluted Strep-AP was added in the plate and incubated for 30 minutes. The plate was washed twice with 200 μl/well of 0.05% Tween-PBS followed by 200 μl/well distilled water twice. Then, 80 μl/well of blue development solution was added, and the plate was incubated at room temperature for 15 minutes. The reaction was stopped by gently rinsing membrane with tap water for 3 times. Air-dried the plate for 2 hours and was scanned to count IFN-γ release using CTL machine with immunoSpot® Software. (Cellular Technology Limited, OH, USA).
RPMI 1640 (Life Technologies, CA) supplemented with 10% fetal bovine serum (FBS) (Gemini Bio-Product) was used to culture human NK cells, human T cells and hu-BLT mice immune cells. Oral squamous carcinoma stem cells (OSCSCs) were isolated from patients with tongue tumors at UCLA, RPMI 1640 supplemented with 10% FBS was used for the OSCSCs cultures. Alpha-MEM (Life Technologies, CA) with 10% FBS was used for osteoclast and dendritic cell cultures. M-CSF, anti-CD16mAb and flow cytometric antibodies were purchased from Biolegend, CA. RANKL, GM-CSF and IL-4 were purchased from PeproTech, NJ, and recombinant human IL-2 was obtained from NIH-BRB. Human anti-CD3 was purchased from Stem Cell Technologies. Propidium iodide (PI) was purchased from Sigma, MO.
Written informed consents approved by UCLA Institutional Review Board (IRB) were obtained from healthy donors and cancer patients and all procedures were approved by the UCLA-IRB. NK cells, CD3+ T cells, CD4+ T cells, and CD8+ T were isolated from PBMCs using the EasySep® Human NK cell enrichment kit, EasySep® Human T cell enrichment kit, EasySep® Human CD4 T cell enrichment kit, and EasySep® Human CD8 T cell enrichment kit respectively purchased from Stem Cell Technologies (Vancouver, BC, Canada). Isolated NK cells and T cells were stained with anti-CD16, anti-CD3, anti-CD4 and anti-CD8 to measure the cell purity using flow cytometric analysis.
Purification of Human Monocytes and, Generation of Osteoclasts and Dendritic Cells
Monocytes were negatively selected and isolated from PBMCs using the EasySep® Human monocyte isolation kit purchased from Stem Cell Technologies (Vancouver, BC, Canada). Isolated monocytes were stained with anti-CD14 antibody to measure the cell purity using flow cytometric analysis, greater than 95% purity was achieved. Monocytes were differentiated to osteoclasts by treating with M-CSF (25 ng/mL) and RANKL (25 ng/mL) for 21 days. To generate dendritic cells (DCs), monocytes were treated with GM-CSF (150 ng/mL) and IL-4 (50 ng/mL) for 7 days.
AJ2 is a combination of 8 different strains of gram-positive probiotic bacteria (Streptococcus thermophiles, Bifidobacterium longum, Bifidobacterium breve, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus bulgaricus) are selected for their superior ability to induce optimal secretion of both pro-inflammatory and anti-inflammatory cytokines in NK cells [56]. For sonication, AJ2 bacteria were weighed and re-suspended in RPMI 1640 medium containing 10% FBS at a concentration of 10 mg/ml. The bacteria were thoroughly vortexed, then sonicated on ice for 15 seconds, at 6 to 8 amplitudes. Sonicated samples were then incubated for 30 seconds on ice. After every five pulses, a sample was taken to observe under the microscope until at least 80 percent of bacteria walls were lysed. It was determined that approximated 20 rounds of sonication/incubation on ice, were conducted to achieve complete sonication. Finally, the sonicated AJ2 (sAJ2) were aliquoted and stored in a −80 degrees Celsius until use.
Human purified NK cells were activated with rh-IL-2 (1000 U/ml) and anti-CD16mAb (3 μg/ml) for 18-20 hours before they were co-cultured with feeder cells (osteoclasts or dendritic cells) and sAJ2 (NK:OCs or DCs:sAJ2; 2:1:4). The medium was refreshed every 3 days with RMPI containing rh-IL-2 (1500 U/ml). Human purified T cells were activated with rh-IL-2 (100 U/ml) and anti-CD3 (1 μg/ml) for 18-20 hours before they were co-cultured with/without osteoclasts and with/without sAJ2 (T:OCs:sAJ2; 2:1:4). The culture media was refreshed with rh-IL-2 (150 U/ml) every three days.
Animal research was performed under the written approval of the UCLA Animal Research Committee (ARC) in accordance to all federal, state, and local guidelines. Combined immunodeficient NOD.CB17-Prkdcscid/J and NOD.Cg-Prkdcscid Il2rgtm1Wj1/SzJ (NSG lacking T, B, and natural killer cells) were purchased from Jackson Laboratory. Humanized-BLT (hu-BLT; human bone marrow/liver/thymus) mice were prepared on NSG background as described previously. To establish orthotopic tumors, mice were first anesthetized with isoflurane in combination with oxygen, and human OSCSCs tumor cells were then directly injected in the floor of mouth in suspension with 10 μl HC Matrigel (Corning, N.Y., USA) (1×106 cells). Four to five weeks after the tumor injections, mice were euthanized, and bone marrow, spleen, and peripheral blood were harvested.
Cell Isolations from Hu-BLT Mice BM, Spleen and Peripheral Blood
To obtain single-cell suspensions from BM, femurs were cut from both ends and were flushed from one end to other using RPMI 1640 media, afterward BM cells was filtered through a 40 μm cell strainer. To obtain single-cell suspensions from spleen, spleen was smashed until no big piece was left and sample was filtered through a 40 μm cell strainer and centrifuged at 1500 rpm for 5 minutes at 4° C. The pellet was re-suspended in ACK buffer to remove the red blood cells for 2-5 mins followed re-suspension in RMPI media and centrifuged at 1500 rpm for 5 minutes at 4° C. Peripheral blood mononuclear cells (PBMCs) were isolated using ficoll-hypaque centrifugation of heparinized blood specimens. The buffy coat containing PBMCs were harvested, washed and re-suspended in RPMI 1640 medium.
Single ELISAs and multiplex assays were performed as described previously. To analyze and obtain the cytokine and chemokine concentration, a standard curve was generated by either two or three-fold dilution of recombinant cytokines provided by the manufacturer. For multiple cytokine array, the levels of cytokines and chemokines were examined by multiplex assay, which was conducted as described in the manufacturer's protocol for each specified kit. Analysis was performed using a Luminex multiplex instrument (MAGPIX, Millipore, Billerica, Mass.) and data was analyzed using the proprietary software (xPONENT 4.2, Millipore, Billerica, Mass.).
For surface staining, the cells were washed twice using ice-cold PBS+1% BSA (Bovine serum albumin). Predetermined optimal concentrations of specific human monoclonal antibodies were added to 1×104 cells in 50 μl of cold PBS+1% BSA and cells were incubated on ice for 30 min. Thereafter cells were washed in cold PBS+1% BSA and brought to 500 μl with PBS+1% BSA. Flow cytometric analysis was performed using Beckman Coulter Epics XL cytometer (Brea, Calif.) and results were analyzed in FlowJo vX software (Ashland, Oreg.).
The 51Cr release assay was performed as described previously. Briefly, different numbers of effector cells were incubated with 51Cr-labeled target cells. After a 4-hour incubation period the supernatants were harvested from each sample and counted for released radioactivity using the gamma counter. The percentage specific cytotoxicity was calculated as follows:
LU 30/106 is calculated by using the inverse of the number of effector cells needed to lyse 30% of tumor target cells×100.
Target cells were incubated with TVATM dye at 370 C for 15 mins, afterwards effector cells were cultured with target cells for 4 hours. After a 4-hour incubation period the target cells were counted with immunospot at 525 nm emission wavelengths. The percentage specific cytotoxicity was calculated as follows:
LU 30/107 is calculated by using the inverse of the number of effector cells needed to lyse 30% of tumor target cells×100.
The prism-7 software is used for the statistical analysis. An unpaired or paired, two-tailed student t-test was performed for the statistical analysis. One-way ANOVA with a Bonferroni post-test was used to compare different groups. (n) denotes the number of human donors or mice. For in-vitro studies either duplicate or triplicate samples were used for assessment. The following symbols represent the levels of statistical significance within each analysis, ***(p value<0.001), **(p value 0.001-0.01), *(p value 0.01-0.05).
Lower numbers of PBMCs were recovered from the peripheral blood of cancer patients when compared to those isolated from healthy individuals (
Purified NK cells from cancer patients and healthy individuals were cultured with healthy allogeneic OCs, and the levels of NK cell expansion, cytotoxicity and IFN-γ secretion were assessed. NK cells from cancer patients had significantly lower expansion (
Higher percentages of CD45RO expressing T cells in the presence of lower percentages of CD45RA were observed in PBMCs isolated from cancer patients, whereas T cells from healthy individuals exhibited the inverse relationship CD45RA>CD45RO (
Next, purified NK cells and T cells were each cultured with OCs and determined the fractions of CD4+ and CD8+ T cells within both the NK and T cell co-cultures with OCs. Purified T cells cultured with OCs increased the percentages of CD8+ T cells and the ratio of CD4/CD8 decreased from 2.4 in T cells in the absence of OCs to 1.2 in those cultured with OCs (
Higher secretion of cytokines, chemokines, soluble Fas-Ligand and perforin except GM-CSF and IL-13 were seen in OCs expanded NK cells compared to CD3+ T, CD4+ T or CD8+ T cells those purified from day 12 OCs expanded NK cells culture (
When purified NK cells from healthy individuals with no/few T cells contaminants were cultured with either OCs or DCs, there was significantly higher NK cell expansion in the presence of OCs (
Hu-BLT mice were implanted with OSCSCs in the oral cavity and injected with super-charged NK cells with potent cytotoxic and cytokine secretion capabilities. After several weeks, mice were sacrificed and tissues were removed, dissociated and the cells were analyzed (
The purified CD4+ T cells and CD8+ T cells were treated with anti-CD3/CD28 in the presence of IL-2 to assess the degree of expansion (
When the levels of cytokines and chemokines were assessed in OC expanded NK cells and compared to OC expanded T cells, NK cells secreted higher levels of cytokines and chemokines (
CD4+ and CD8+ T cells were positively selected and they were further activated with anti-CD3 and IL-2 (
NK functional inactivation and loss of numbers occurs at the pre-neoplastic stage of pancreatic cancer due to the effects of both the KRAS mutation and high fat calorie diet. It is demonstrated herein that patients with pancreatic cancer have severely suppressed NK function. Both cytotoxicity and the ability to secrete the IFN-γ are suppressed in the patients. In addition, the numbers of peripheral blood mononuclear cells are also severely decreased in cancer patients. Interestingly, the percentages of both NK cells and monocyte are significantly increased whereas the percentage of CD3+ T cells and B cells is significantly decreased and the percentage of CD11b+ cells in increased. Furthermore, the majority of cytokines secreted by the NK cells or detected in the sera of the cancer patients are also severely decreased indicating a profound suppression of the immune function in cancer patients. Moreover, OC-modulated expansion of cancer patient NK cells is severely inhibited and the expanded patient NK cells mediated significantly low cytotoxicity and IFN-γ secretion. In cancer patients, both primary and expanded NK cells are defective in the function. Expansion of T cells as well as IFN-γ secretion is also decreased in cancer patients under different activation conditions. Cancer patients demonstrated high CD45RO and decreased CD62L indicating the increased activation in vivo. This is also evident for the increased percentage of CD8+ T cells and declined ratio of CD4/CD8 (
Interestingly, significant differences are observed between DC-modulated expansion of NK cells and OC-modulated NK cells expansion. When OC-modulated expansion resulted in the secondary expansion of NK cells modulated expansion of CD8+ T cells, DC-modulated expansion on NK cells resulted in secondary expansion of CD4+ T cells. There is larger increase in CD45RO and decrease in CD62L in T cells expanded by OC expanded NK cells than DC expanded NK cells indicating increased activation of T cells by the NK cells (
It is demonstrated herein that injection of OC-expanded NK cells to tumor-bearing hu-BLT mice increased the numbers of CD8+ T cells in bone marrow, spleen, and peripheral blood resulting in the increased levels of NK cell-mediated cytotoxicity as well as increased secretion of IFN-γ (
All publications, patents, and patent applications mentioned herein are hereby incorporated by reference in their entirety as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference. In case of conflict, the present application, including any definitions herein, will control.
Also incorporated by reference in their entirety are any polynucleotide and polypeptide sequences which reference an accession number correlating to an entry in a public database, such as those maintained by The Institute for Genomic Research (TIGR) on the world wide web at tigr.org and/or the National Center for Biotechnology Information (NCBI) on the World Wide Web at ncbi.nlm.nih.gov.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.
This application claims the benefit of U.S. Provisional Application No. 62/778,189, filed on Dec. 11, 2018, the entire contents of which are incorporated herein in their entirety by this reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US19/65381 | 12/10/2019 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62778189 | Dec 2018 | US |
