The present invention relates to the field of cellular immunology and immunotherapy. More specifically, the present invention relates to a method for inducing an immune response in a human or animal subject, as well as to a pharmaceutical composition and a kit of parts comprising such compositions for inducing an immune response. Furthermore, the present invention concerns a method for producing the pharmaceutical composition in vitro and the use of primed dendritic cells in a pharmaceutical composition or in a method for inducing an immune response. The present invention more specifically relates to a vaccine against the SARS Coronavirus 2 (SARS-CoV-2).
Pathogens, such as viruses, bacteria, fungi and parasites are organisms that can cause a disease, while some pathogens have be found to be responsible for severe effects and casualties in afflicted hosts.
Vaccination or administration of antibiotics can be useful in preventing or fighting disease arising from pathogens. The immune system of the human body provides defense against some common pathogens. Pathogens comprise proteins, so-called antigens that can be recognized by the immune system of the host. Antigens can belong to many different chemical classes and can derive from viral or bacterial proteins, lipids, carbohydrates, or combinations of these, such as lipoproteins or glycoproteins.
The adaptive immune system comprises two main mechanisms of immunity: Firstly, in humoral immunity, in which the immune system deals with freely circulating pathogenic antigens outside of infected cells, B-cells, by the aid of helper T cells and antigen presenting cells, differentiate into antibody-producing plasma B-cells against a specific antigen. These antibodies then bind to and neutralize the pathogenic antigens or cause lysis or phagocytosis. Secondly, in cellular immunity, which occurs inside infected cells, pathogenic antigens are expressed on the infected cell's surface or on an antigen presenting cell (APC). Helper T cells release cytokines that help activated CD8+ T cells bind to the infected cells' MHC-antigen complex and cause the CD8+ T cells to differentiate into cytotoxic T lymphocytes (CTL)—white blood cells that have the ability to kill other cells of the body in a highly specific manner. CTLs are CD8+ T cells that have been stimulated by peptides presented by the major histocompatibility complex class I (MHC I) on affected cells. After stimulation, they migrate through the tissues of the body to find and kill the target cells that are bearing the specific antigen. Antigen-specific CTLs proliferate to produce daughter cells with the same antigen specificity as the parent cells. The total number of those antigen-specific CTLs in the body is increased by the cell division of the activated CTLs. More importantly, some cells from both humoral (plasma cells) and cellular immunity (CTLs) will go on to differentiate into memory plasma cells or memory T cells. These are long lived cells that patrol the body and are on the look out for any subsequent invasion by the same pathogen. Memory cells are the basis of protective immunity or vaccination.
Dendritic cells (DCs) provide the signals that are required for the activation of T cells and they are potent APCs in the immune system. Interaction between the antigen presented by a MHC I or II protein or peptide that is present on the APCs and the T-cell receptor/CD3 complex is responsible for the specificity of the immune response. This interaction is necessary for T cell activation, but not sufficient. Interaction between receptor-ligand pairs of APCs and T cells generates costimulatory signals that can lead to induction of effector T cell functions and to the full proliferation of T cells.
T cells have the antigen-specific receptor, TCR, that recognizes a physical complex between host MHC proteins and small peptide fragments derived from protein antigens. The interaction between the peptide and MHC molecule is highly specific. MHC I molecules present peptide antigens to CD8+ T cells and MHCII molecules present peptides in CD4+ helper T cells. The size of those peptides that can be bound is 8 to 10 amino acids.
Immune recognition of pathogen-associated antigens is performed by specific CD8+ cytotoxic T lymphocytes that interact with the peptides that are bound to MHC I molecules. The in vitro stimulation of that interaction can be performed with the presentation of those molecules by APCs and especially the DCs. “Priming” or “pulsing” is the in vitro step, in which dendritic cells first contact the antigen and are then “primed or “loaded” with the respective antigen, i.e. present the antigenic peptide on their MHC I molecules. This is an essential step in the subsequent antigen presentation to the CD4+ or CD8+ T cells, i.e. T cell activation. CD8+ T cells that have been activated by the APCs (said activated CD8+ T cells are termed CTLs in the scope of this application) can recognize the same MHC/peptide complex on the target cells, i.e. pathogen-infected cells, and be triggered to kill them.
Immunotherapy therefore activates the subject's own immune system to recognize and kill the cells presenting antigens. The development of a successful strategy for treating a human disease requires an understanding of the responses of the immune cells that participate in the control of the pathogenic condition. The immune cells can be nonspecific effector cells, such as natural killer cells and macrophages, effector cells with limited diversity for antigen recognition, like γδ T cells, and highly specific effector cells that have enormous diversity in antigen recognition such as antibody-producing B cells and αβ T cells.
Epitope identification often involves derivation and testing of overlapping peptide libraries from the pathogen proteins that are based on known protein databases. Development and refinement of algorithms that predict pathogen-associated epitopes as well as the definition of preferred peptide-binding characteristics for MHC proteins that are associated with susceptibility to autoimmune disease or infection has been an important tool for the selection of epitopes with high immunogenicity.
The challenge has been the administration of an antigen to induce an immune response and keep it over time. In vitro, e.g. MHC I molecules can be loaded externally (ex vivo, in vitro) with a synthetic peptide to elicit CTL response, such as disclosed e.g. in EP1448229A2. In the same manner, MHCII molecules can also be loaded externally with a synthetic peptide to elicit B cell differentiation into plasma cells and antibody generation.
Due to the current Covid-19 pandemic, it has become an urgent need to find a vaccine against the SARS-CoV-2 virus. The present invention provides a vaccine comprising three doses with each one peptide of SARS-CoV-2 presented on dendritic cells, administered sequentially at three different points in time.
The present invention concerns a vaccine against SARS-CoV-2, by stimulating immune cells to recognize specific peptides of SARS-CoV-2, which eventually results in memory cell formation, i.e. formation of both memory plasma cell and central/effector memory T cell. The vaccine contains three populations of activated autologous dendritic cells (DCs) generated from mononuclear cells. For activation, each population of DCs is “pulsed” in vitro with a different SARS-CoV-2 peptide. Thus, this DC-based vaccine is administered in three doses, wherein dose 1 contains activated autologous DCs which have been activated with a first SARS-CoV-2 peptide, and is administered in week 1. Dose 2 contains activated autologous DCs which have been activated with a second SARS-CoV-2 peptide, the second peptide having been selected from a group of four different peptides, and is administered in week 2. Dose 3 contains activated autologous DCs which have been activated with a third SARS-CoV-2 peptide, and is administered in week 3.
The present invention concerns a pharmaceutical product comprising a first composition, a second composition and a third composition, wherein each of the first, second, and third compositions comprise one of three different populations of activated autologous DCs from a single human or animal subject. The activated autologous DCs in each of the three populations present a different peptide of a spike protein or of an envelope protein of SARS-CoV-2.
According to a first preferred embodiment, the first composition comprises a first population of activated autologous DCs which have been activated with a first peptide of a spike protein of SARS-CoV-2 or of an envelope protein of SARS-CoV-2, preferably of a spike protein of SARS-CoV-2. The second composition of the respective pharmaceutical product comprises a second population of activated autologous DCs which have been activated with a second peptide of a spike protein of SARS-CoV-2 or of an envelope protein of SARS-CoV-2, wherein the second peptide is different from the first peptide. The third composition of the respective pharmaceutical product comprises a third population of activated autologous DCs which have been activated with a third peptide of a spike protein of SARS-CoV-2 or of an envelope protein of SARS-CoV-2, preferably of a spike protein of SARS-CoV-2, wherein the third peptide is different from the first peptide and the second peptide.
The present invention further concerns the above mentioned pharmaceutical product for use as a vaccine, preferably for use as a vaccine against a viral disease caused by SARS-CoV-2 in a human or animal subject.
The present invention further concerns the above mentioned pharmaceutical product for use in treatment of a viral disease caused by SARS-CoV-2, preferably for use in treatment of COVID-19, wherein the three compositions described above are administered to the human or animal subject separately from each other and sequentially at three different points in time. Preferably, the first composition is administered to the human or animal subject in week 1, preferably on day 1, of a vaccination schedule, preferably by injection, wherein the second composition is administered to the human or animal subject in week 2, preferably on day 8, of the vaccination schedule, preferably by injection, and wherein the third composition is administered to the human or animal subject in week 3, preferably on day 15, of the vaccination schedule, preferably by injection. Advantageously, each composition is administered to the human or animal subject partially by intravenous and partially by subcutaneous injection. This is to be understood in that a part of the respective dose to be administered, comprising the respective composition to be injected is injected first intravenously, and the rest of the respective dose comprising the respective composition is injected subcutaneously.
The present invention furthermore concerns a kit of parts for use as a vaccine in a human or animal subject, comprising the pharmaceutical product as described above.
Said kit of parts is intended especially for use as a vaccine against a viral disease caused by SARS-CoV-2, more preferably for use as a vaccine against COVID-19. Said kit of parts comprises a first composition, a second composition and a third composition, wherein each of the first, second, and third compositions comprise one of three different populations of activated autologous DCs from a single human or animal subject, wherein the activated autologous DCs in each of the three populations present, preferably on one or more cell surface molecules, preferably on an MHC-complex, a different peptide of a spike protein of SARS-CoV-2 or an envelope protein of SARS-CoV-2.
The kit of parts according to a further preferred embodiment of the present invention comprises a first composition, a second composition and a third composition, wherein
Preferably, the first composition comprises a first population of activated autologous DCs of the human or animal subject, which present on their cell surface a SARS-CoV-2 spike protein (84-92) LPFNDGVYF peptide (SEQ ID NO: 1).
The second composition preferably comprises a second population of activated autologous DCs of the human or animal subject which present on their cell surface one peptide selected from the group consisting of SARS-CoV-2 spike protein (326-340) IVRFPNITNLCPFGE peptide (SEQ ID NO: 2), SARS-CoV-2 spike protein (718-726) FTISVTTEI peptide (SEQ ID NO: 3), SARS-CoV-2 spike protein (449-463) YNYLYRLFRKSNLKP (SEQ ID NO: 4), and SARS-CoV-2 envelope protein (2-10) YSFVSEETG peptide (SEQ ID NO: 5).
The third composition preferably comprises a third population of activated autologous DCs of the human or animal subject, which present on their cell surface a SARS-CoV-2 spike protein (1185-1200) RLNEVAKNLNESLIDL peptide (SEQ ID NO: 6).
The administration sequence of the doses/compositions can also be altered.
The three compositions of a kit of parts according to a further preferred embodiment of the present invention are administered to the human or animal subject separately from each other and sequentially at three different points in time. Preferably, the three compositions are administered to the human or animal subject by injection, more preferably by a combination of intravenous and subcutaneous injections. Preferably 50-90% of each dose/composition are injected intravenously and the remaining 10-50% of each respective dose/composition are injected subcutaneously.
Preferably, the first composition is administered to the human or animal subject in week 1, preferably on day 1, of a vaccination schedule, wherein the second composition is administered to the same human or animal subject in week 2, preferably on day 8, of the vaccination schedule, and wherein the third composition is administered to the same human or animal subject in week 3, preferably on day 15 of the vaccination schedule.
The present invention further concerns a method of treating or preventing a viral disease caused by SARS-CoV-2 in a human or animal subject, comprising the followings steps:
In a preferred method of treating a viral disease caused by SARS-CoV-2 in a human or animal subject,
According to a further preferred method of treating a viral disease caused by SARS-CoV-2 in a human or animal subject, the first, second and third composition are administered to the human or animal subject, i.e. the same human or animal subject, separately from each other and sequentially at three different points in time. Preferably, the first composition is administered to the human or animal subject in week 1, preferably on day 1 of a vaccination schedule, the second composition is administered to the same human or animal subject in week 2, preferably on day 8 of the vaccination schedule, and the third composition is administered to the same human or animal subject in week 3, preferably on day 15 of the vaccination schedule.
The present invention furthermore concerns a method for obtaining a population of human or animal autologous dendritic cells (DCs) presenting a viral antigenic peptide, preferably a SARS-CoV-2 peptide. Preferably, the respective peptide is selected from the following group consisting of SARS-CoV-2 spike protein (84-92) LPFNDGVYF peptide (SEQ ID NO: 1), SARS-CoV-2 spike protein (326-340) IVRFPNITNLCPFGE peptide (SEQ ID NO: 2), SARS-CoV-2 spike protein (718-726) FTISVTTEI peptide (SEQ ID NO: 3), SARS-CoV-2 spike protein (449-463) YNYLYRLFRKSNLKP (SEQ ID NO: 4), SARS-CoV-2 envelope protein (2-10) YSFVSEETG peptide (SEQ ID NO: 5), and SARS-CoV-2 spike protein (1185-1200) RLNEVAKNLNESLIDL peptide (SEQ ID NO: 6), for the preparation of a pharmaceutical product or for the preparation of a kit of parts as described above, comprising the following steps:
In case the loaded DCs obtained in step c.) present the viral antigenic peptide on their MHC I, in optional step e.), the maturing step is carried out with a cytokine cocktail preferably including IL-6, preferably IL-6 at a concentration of 10 ng/ml, IL-1β, preferably IL-1β at a concentration of 25 ng/ml, TNF-α, preferably TNF-α at a concentration of 50 ng/ml, and PGE2, preferably PGE2 at a concentration of 10−6 M. In this case, the loaded DCs activate T cells in the subject's body, which are turned into CTL, which then kill infected cells.
In case the loaded DCs obtained in step c.) present the viral antigenic peptide on their MHC II, in optional step e.), the maturing step is carried out with a cytokine cocktail preferably including GM-CSF, IL-4, TNF-α, sCD40L, IL-6, IL-21, IL-10 and anti-human IgM. In this case, preferably the following concentration ranges are used: 1-200 ng/ml GM-CSF, 1-200 ng/ml IL-4, 1-200 ng/ml TNF-α, 1-100 μg/ml sCD40L, 1-200 ng/ml IL-6, 1-200 ng/ml IL-21, 1-200 ng/ml IL-10, 1-100 μg/ml anti-human IgM. In this case, the loaded DCs activate T helper cells which then activate B cells to turn into antibody-secreting plasma cells.
Preferably, the loaded DCs are contained in the pharmaceutical product according to the invention and injected in an immature form, i.e. after step c.) or after step d.) in case cryopreservation is desired or necessary. In this case, the maturation of the loaded DCs takes place inside the body of the vaccinated human or animal subject. Alternatively, the loaded DCs are contained in the pharmaceutical product according to the invention and injected in a mature form after going through a maturation process described in step e.) above.
In the production of a vaccine or kit of parts, comprising three compositions comprising loaded dendritic cells, the method described above for obtaining a population of human or animal autologous dendritic cells presenting an viral antigenic peptide, i.e. the method for obtaining a population of loaded dendritic cells, is conducted separately with each selected individual peptide in step b.), thereby yielding three separate compositions of autologous loaded dendritic cells, wherein in each of the three compositions, the loaded DCs present a different peptide.
The present invention therefore furthermore concerns a method for the production of a medicament, comprising the following steps:
Preferably, step c.) and, if necessary, the following incubation, is followed by
The terms “vaccine” or “vaccine treatment” in the context of this application is to be understood as a prophylactic treatment, in which an immune response, especially against a viral disease caused by SARS-CoV-2, is activated in the body of the human or animal subject after following a specific vaccination schedule. By the inventive vaccine comprising the pharmaceutical product according to the invention, the immune response is triggered to be produced. In case the subject already produced an immune response, but an insufficient response to eliminate the virus, this response can be increased by the inventive vaccine.
The term “week 1/2/3”, respectively, is to be understood in that dose 1 of the vaccine, preferably comprising DCs loaded with a first peptide (Seq.ID 1), is administered on day 1 of a vaccination schedule. Approximately one week after dose 1, preferably on day 8 of the vaccination schedule, dose 2, comprising DCs loaded with a second peptide selected from a group of four peptides (Seq.ID 2-5), is administered to the same subject, and approximately one week after dose 2, preferably on day 15 of the vaccination schedule, dose 3, comprising DCs loaded with a third peptide (Seq.ID 6), is administered. However, the time between the days of administration may vary, depending on the status of the individual subject's immune system. The sequence of administration of the doses 1-3 can also be altered, such as for example dose 1-2-3, 1-3-2, 2-1-3, 2-3-1, 3-1-2, or 3-2-1.
The terms “primed/pulsed/loaded/activated dendritic cells” are to be understood as dendritic cells which present the respective peptide on a cell surface molecule, i.e. MHC I/II.
Further embodiments of the invention are laid down in the dependent claims.
Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,
The peptides were selected according to their ability to activate the immune system. For the peptide sequence design, a number of publically available T-cell epitope prediction tools were used. These tools were selected according to Sanchez-Trincado et al, 2017 (J. L. Sanchez-Trincado, M. Gomez-Perosanz, P. A. Reche, “Fundamentals and Methods for T- and B-Cell Epitope Prediction”, Journal of Immunology Research, vol. 2017, Article ID 2680160).
Dose 1 of the vaccine, comprising a first composition comprising SARS-CoV-2 spike protein (84-92) LPFNDGVYF peptide (SEQ ID NO: 1), to be administered in week 1, and dose 3 of the vaccine, comprising a third composition comprising SARS-CoV-2 spike protein (1185-1200) RLNEVAKNLNESLIDL peptide (SEQ ID NO: 6), to be administered in week 3, were designed to activate cellular, i.e. CTL-mediated immunity. Dose 2 of the vaccine, comprising a second composition comprising one peptide selected from the group consisting of SARS-CoV-2 spike protein (326-340) IVRFPNITNLCPFGE peptide (SEQ ID NO: 2), SARS-CoV-2 spike protein (718-726) FTISVTTEI peptide (SEQ ID NO: 3), SARS-CoV-2 spike protein (449-463) YNYLYRLFRKSNLKP (SEQ ID NO: 4), and SARS-CoV-2 envelope protein (2-10) YSFVSEETG peptide (SEQ ID NO: 5), was designed to activate humoral, i.e. antibody-mediated immunity. All four peptides for dose 2 were found to be immunogenic for the activation of immunity via MHC II by the algorithm used for immunogenicity determination.
Dendritic Cell Generation
The initial sample consisted of 50 ml of peripheral blood of a human subject. 40 ml of whole blood were lysed with NH4Cl. Cells were then washed with PBS. Supernatant was discarded and cell pellet was re-suspended in 100 μl Monocyte Enrichment Cocktail from Monocyte Enrichment Set (558454, BD), containing magnetic beads conjugated with an antibody specific for the selection of monocytes. Cells were incubated for 15 minutes. After the incubation period, the cell pellet was resuspended in 5 ml PBS and washed by centrifugation for 5 minutes, 200×g, wherein ×g” stands for times gravity (unit of relative centrifugal force (RCF)). The supernatant was discarded and the cell pellet was incubated with 100 μl of Streptavidin Particles Plus from the same Monocyte Enrichment Set. The cell pellet was then incubated for 30 minutes. After the incubation period, 1 ml of PBS was added and the tube was positioned in a magnetic separation rack for eppendorf tubes for 10 minutes. After incubation, the supernatant, i.e. the negative fraction containing mononuclear cells, was collected, added in 10 ml PBS and washed by centrifugation for 5 minutes at 200×g. The supernatant was discarded and the cell pellet was resuspended in 15 ml RPMI supplemented with 10% FBS, 200 mM L-glutamine, GM-CSF and IL-4, preferably 1-200 ng/ml of GM-CSF and 1-200 ng/ml of IL-4. The 15 ml of medium containing the cells were divided into three T-25 culture flasks (one for production of each dose/activation with one of the separate peptides) for 6 days at 37° C., at 5% CO2. Half way through the culture period, medium was replenished.
Alternatively to the dendritic cell generation of example 1, peripheral blood mononuclear cells (PBMCs) were isolated from freshly collected blood samples in vacutainers containing EDTA. PBMCs were isolated using density gradient centrifugation (e.g. Biocoll or Ficoll separation). The cell pellet was resuspended in RPMI supplemented with 10% FBS and 200 mM L-glutamine and left for 2 hours until monocyte adherence. The rest of the cells was discarded and adhered cells were cultured in the presence of 10 ml fresh RPMI (e.g. RPMI 1640) supplemented with 10% FBS, 200 mM L-glutamine, GM-CSF and IL-4, preferably 1-200 ng/ml of GM-CSF, and preferably 1-200 ng/ml of IL-4.
As in example 1, the 15 ml of medium containing the cells were divided into three T-25 culture flasks (one for production of each dose/activation with one of the separate peptides) for 6 days at 37° C., at 5% CO2. Half way through the culture period, medium was replenished.
Pulsing of the DCs
After 6 days, the DCs were isolated and cultured according to one of the methods described in examples 1 or 2 above, and then pulsed with the addition of 10 μg/ml of one of the following peptides for 4 to 24 hours.
Peptide 1 is to be used for pulsing DCs in the preparation of dose 1 of the vaccine. Peptide 2 was selected for pulsing DCs in the preparation of dose 2 of the vaccine, and peptide 6 was used for pulsing DCs in the preparation of dose 3 of the vaccine.
In the case of peptides 1 and 6, in each case 1-10 μg/ml b2 microglobulin were added to the DCs for the pulsing step. This is due to the fact that peptides 1 and 5, respectively, are presented by the MHC I complex on the cell surface of DCs, which results in an activation of T cells (cellular immunity). Peptides 2, 3 and 4 are presented by the MHC II complex of DCs, which results in an activation of B cells (humoral immunity). Microglobulin was only added for the peptides presented by the MHC I complex.
The pulsed DCs were still immature, i.e. the maturation occurs in vivo after injection.
After pulsing, DCs from each flask were collected and cryo-preserved until further use.
Injection of Doses 1/2/3 of Vaccine
For use, i.e. for injection, DCs of the selected first, second or third dose were thawed and washed with PBS. The cell pellet was resuspended in 6 ml of 0.45% NaCl prior to injection. Thus, each dose had a volume of 6 ml. Of this volume, in each case, for each dose, 1 ml of the respective composition was injected in the human subject (individuals 1-10) subcutaneously, and the remaining 5 ml of the injection volume of the composition were subsequently injected to the same respective subject intravenously.
All three doses of the vaccine, each comprising one composition comprising a population of activated autologous DCs, were injected into the same human subject with in each case approximately 1 week in between the doses of administration. In total, feedback data is available of 16 vaccinated individuals for Day 76 and of 13 vaccinated individuals for day 38.
Follow-Ups
Follow up blood samples were collected from each of the 10 individual human subjects on day 38 and day 76 after the first injection to assess immunity. Preferably, follow up blood samples are to be collected at days 38, 76, 180, 364 (approx. after 1 month, 2-3 months, 6 months, and 12 months) after the first injection to assess immunity. Analysis of the blood samples collected at the specified points in time provides information about immune status after the vaccination. Performed tests include the following:
Analysis of Follow-Ups:
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Number | Date | Country | Kind |
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20201323.1 | Oct 2020 | EP | regional |
21159603.6 | Feb 2021 | EP | regional |
This application is a continuation of U.S. patent application Ser. No. 17/349,462, filed on Jun. 16, 2021, which claims priority from European Patent Application No. 20201323.1, filed on Oct. 12, 2020, and European Patent Application No. 21159603.6, filed on Feb. 26, 2021, in the European Patent Office, the disclosures of which are incorporated herein by reference in their respective entireties.
Number | Date | Country | |
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Parent | 17349462 | Jun 2021 | US |
Child | 17401584 | US |