Patent Application
20230338465
The present specification comprises a sequence listing in computer readable format, submitted together with the application. The sequence listing forms part of the disclosure and is incorporated in the specification in its entirety.
The present invention relates to the use of phosphotidylserine or pathogenic sugar targeted therapeutics for the management and treatment of microbial infections, including Zika, Dengue, Respiratory Syncytial Virus, West Nile, Ebola, H1N1, Mycobacterium Leprae, Mycobacterium tuberculosis, Enteroviruses, Leishmaniasis, Malaria and Coronaviruses SARS-CoV.
Provided are compositions related to novel, therapeutic proteins including pathogen neutralizing proteins that may be conjugated to furin protease inhibitors, T cell engagers, platforms with cytotoxic functions, mono and multivalent molecules, drug conjugates and adjuvants, carriers and methods of administration, in particular subcutaneous, oral or nasal administration. This invention further relates to a companion diagnostic as a method of selection of subjects that may benefit from such therapies and a blood biomarker for rapid and easy monitoring of response of treatment.
According to WHO, the Arborviruses Zika Virus (ZIKV), Chikungunya (CHIKV), Dengue (DENV), West Nile (WNV), as well as Ebola (EBLV) and SARS are relatively recent, life-threatening, rare diseases prone to pandemic spread that pose a high global public health risk (WHO report 2020).
There are no FDA approved therapies for these diseases. A live, recombinant vaccine consisting of the envelope glycoprotein of one of the Ebola strains, Zaire Ebolavirus (Ervebo, 2019) was recently approved by the FDA for adult use only, although the duration of protection is still not entirely known. Another recombinant vaccine consisting of the pre-M and E proteins for all 4 strains of Dengue (Dengvaxia, 2019) has also been approved however Lim et al 2019 reported new mutations in DENV with different antigenic properties.
ZIKV, WNV and DENV are flaviviruses (family Flaviviridae) primarily transmitted by mosquito vectors (i.e. arboviruses). Zika is a positive single stranded RNA flaviviridae virus mainly transmitted by the Aedes mosquito and an increasing number of strains in two phylogenetic lineages (Asian and African) have been identified since its first isolation in Uganda in 1947 (Ramos da Silva 2016). According to WHO outbreaks in 2015-2017 resulted in more than 30,000 cases worldwide (Worlds Health Organization Zika Epidemiology update July 2019, Website: www_who.int/emergencies/diseases/zika/zika-epidemiology-update-july-2019.pdf?ua=1, accessed 5 Aug. 2020).
According to Musso 2015, Zika is also spread through sexual contact (Musso 2015) and according to Rasmussen 2016, Zika is also spread from maternal to fetal blood (Rasmussen 2016).
An expanding spectrum of neurological sequelae has been reported. According to Rasmussen 2016 a particularly serious co-morbidity of Zika infection in pregnant women is severe congenital microcephaly to their progeny (Rasmussen 2016). According to Barbi 2018, in adults, Guillain-Barré syndrome (GBS), an auto-immune disease that destroys the myelin sheath and causes progressive ascending paralysis has been estimated to affect 1.23% of patients (Barbi 2018). Other reported ZIKV neurological complications include encephalitis/meningoencephalitis, acute disseminated encephalomyelitis, myelitis, cerebrovascular complications, seizures and encephalopathy, sensory polyneuropathy and sensory neuropathy.
Primary hosts of ZIKV include human, monkey, and mosquito. According to Hou 2017 neural stem cells, fibroblasts, epithelial and blood cells are permissive to ZIKV infection (Hou 2017).
Dengue virus (DEGV) is a negative RNA strand flavivirus that causes the most prevalent arthropod-born viral disease in the world (1 million cases/year). DENV infection causes human diseases with a wide spectrum of clinical symptoms, ranging from asymptomatic infection or self-limited febrile illness named Dengue fever (DF) to life-threatening diseases including Dengue hemorrhagic fever (DHF) and Dengue shock syndrome (DSS). There are currently no therapies for Dengue nor a vaccine for individuals not previously infected by Dengue or travelling from non-endemic areas. Dengvaxia is a vaccine approved for individuals 9 through 16 years of age with laboratory-confirmed previous dengue infection and living in endemic areas.
The Pat. Application US2009175865A1 describes antibodies that are engineered by replacing one or more amino acids of a parent antibody with non-cross-linked, highly reactive cysteine amino acids. Among other mutations, the patent application mentions A339C and S337C.
The patent application WO2015157595 describes conjugate compounds comprising antibodies and fragments thereof engineered with one or more reactive cysteine residues. Among other mutations, the patent application mentions K340C.
According to Wenwen Bi et al. (IgG Fc-binding mortif-conjugated HIV-1 fusion inhibitor exhibits improved potency and in vivo half-life: Potential application in combination with broad neutralizing antibodies, PLOS Pathogens, Dec. 5, 2019.) a strategy have been developed to extend the in vivo half-life of a short HIV-1 fusion inhibitory peptide, CP24, by fusing it with the human IgG Fc-binding peptide (IBP).
There is an unmet need for new technologies to manage emerging as well as re-emerging infectious diseases prone to genetic variability.
Similarities in the way viruses bind to permissive human cells, are activated in the endosomal-lysosomal compartments and become infectious, offer insights towards a potential pan-therapeutic approach to their treatment.
Glycans are essential structural and functional components of microbes. Among these, glucans, polysaccharide moieties derived from D-glucose, are prominent constituents of the cell walls of fungi, plants, and mycobacteria. High mannose containing structures (mannans) are expressed by many viruses, fungi, and bacteria, and fucose structures (fucans) are found on the surface of helminths and some bacteria (Geijtenbeek and Gringhuis, 2009; Robinson et al., 2006).
The human immune system has evolved innate pattern-recognition receptors that discern self from non-self-glycans. Binding of C-type lectins to pathogen sugars triggers both innate and adaptive immune events that lead to pathogen clearance however this interaction may also be exploited to enhance pathogenicity.
The myeloid, dendritic and macrophage cell specific C-type lectin receptor CD209 (also known as DC-SIGN), (Zelensky and Gready, 2005) is an important host cell receptor for entry of ZIKV (Perera Lecoin, 2013, Osorio and Sousa 2011), Influenza (Gillespie 2016), DENV (Cruz-Oliveira, 2015), WNV (Davis 2006), Ebola (Alvarez 2002), enterovirus (REN 2014), mycobacterium tuberculosis (Tailleux 2003) and mycobacterium Leprae (Barreiro 2006) and SARS-COV2/COVID19 (Amraei 2020, Cai 2020, Jeffers 2004). The protozoan vector borne disease Leshmaniasis and Malaria are non-viral pathogens that may exploit CD209 for host entry (Colmenares 2002, Morenikeji 2020). CD209 binds to both mannan (high-mannose N-linked oligosaccharides) and fucan moieties that comprise viral signatures or “pathogen associated molecular patterns (PAMPs). The binding occurs within a compact protein region with a unique structural fold that became known as the “C-type carbohydrate recognition domain” or “C-type lectin domain (CTLD)” (Weis and Drick- Amer, 1996).
There is no cure for COVID-19, currently a worldwide pandemic, however the FDA has granted emergency use authorization for the antiviral Remdesivir, although their effectiveness against Covid-19 has yet to be demonstrated in large-scale, randomized clinical trials. Among approaches in early preclinical development are ACE2 decoy proteins to block viral attachment to host cells, and off-label use of dexamethasone to reduce inflammation in patients on ventilators but not patients with early stage symptoms. Thus, there is an urgent need for effective and safe means for treating and alleviating COVID-19 and related symptoms. Thus, there is an urgent need for a diagnostic that can precisely select patients that may benefit from a particular treatment.
The outer virus membrane layer of several viruses is rich in phospholipid phosphatidylserine (PS) whereas in the host cell membrane, PS is normally restricted to the inner membrane layer.
The T-cell immunoglobulin and mucin domain 1 (TIM-1) human membrane receptor functions as a potent co-stimulatory molecule for T-cell activation.
TIM1 (also known as HAVCR1) is a type I transmembrane glycoprotein that contains an extracellular domain composed of an N-terminal immunoglobulin variable (IgV)-like domain followed by a glycosylated mucin domain, a single transmembrane domain, and a short cytoplasmic tail with tyrosine phosphorylation motifs. The Ig V domain of TIM1 is predicted to contain a conserved PS binding site (Santiago et al., 2007).
TIM-1 is expressed preferentially on T-helper 2 (Th2) cells in the brain, gastrointestinal tract, liver and gallbladder, kidney, testis and lymphoid tissue. According to Freeman 2010 TIM-1 recognizes and attaches to exposed PS with high specificity in dying, apoptotic cells and triggers their phagocytosis by the immune system (Freeman 2010). TIM-1 promotes apoptotic clearance by binding to PS through its metal ion-dependent ligand binding site (MILIBS) within the IgV domain.
It has also been shown that TIM1 is an entry factor for highly divergent viruses (Jemielity, 2013), including Zika (Lee 2018), Ebola (Brunton 2019), Dengue (Chu 2019, Amara 2015), West Nile (Richard 2015), Hepatitis A and possibly Malaria (Nuchnoi 2020).
These studies indicate that TIM-1, functions as a common attachment factor for a range of enveloped viruses through direct interaction with PS of the viral envelope independent of glycoproteins.
TIM1 is the most well-known PS receptor although other PS receptors have been described to a lesser extent such as Tyro3, Axl and Mer of the TAM family of proteins.
According to Angiari et al. 2014, TIM-1 plays a role in autoimmune and inflammatory disease development by controlling T cell adhesion through binding to P-selectin proteins via the TIM-1 mucin and IgV domains (Angiari 2014).
Kuroda et al. 2015 reported that filovirus infection and GP-mediated membrane fusion were significantly suppressed by treatment with a TIM-1-specific monoclonal antibody that interfered with the interaction between TIM-1 and Niemann-Pick C1 Protein (NPC1). This study suggested that TIM-1 may also participate in viral membrane fusion.
According to Yuan et al. 2015, human TIM-1 directly binds to EBOV glycoprotein (GP) and the authors determined the crystal structures of the Ig V domains of hTIM-1 and hTIM-4 as well as the binding region.
According to Kondratowicza et al. 2010, TIM-1 on host epithelial cells of the trachea, cornea, and conjunctiva, binds directly to the receptor binding domain of the Zaire Ebola virus (EBOV) glycoprotein and enhances airborne and hand-to-eye infection. Blockage of this interaction with antibodies inhibited binding and Ebola infection.
Thus, TIM-1 may have both protein dependent and independent functions in viral infection.
Furin cleavage sites are present in entry proteins of Zika, Dengue, COVID-19 (Coutard 2020), Ebola, HIV, and Hepatitis B viruses among others (Braun 2019).
Decanoyl-Arg-Val-Lys-Arg-chloromethylketone (dec-RVKR-cmk) comprising SEQ ID NO. 81 and hexa-D-arginine (D6R) are small synthetic furin inhibitors that have been used to show reduction of viral infectivity in vitro (Owczarek, 2019, Imran 2019, Remacle 2010, Couture 2015). CMK is more effective than D6R in the reduction of Hepatitis replication by inhibiting furin-mediated processing of the hepatitis B e-antigen (HBeAg) precursor into mature HBeAg. Dec-RVKR-cmk is a small, synthetic, irreversible, and cell-permeable competitive inhibitor of all proprotein convertases (PC1, PC2, PC4, PACE 4, PC5, PC7, and furin). CMK is reported to inhibit furin-mediated cleavage and fusion activity of viral glycoproteins, and acts as an antiviral agent against different viruses, including human immunodeficiency virus, Chikungunya virus, chronic hepatitis B virus, influenza A, Ebola virus infection and papilloma virus. Smith et al. and Steinmetzer et al. also patented a peptidomimetic furin inhibitor by modifying the C-terminal of dec-RVKR-cmk with decarboxylated arginine mimetics, resulting in highly potent furin inhibitors (Couture 2015).
Wide-range furin/proprotein inhibitors are thought to have minimal off-pathogen, on-target effects in the host given that proprotein convertases are highly redundant, as shown by furin knockout mice.
CMK has been shown to have anti-flavivirus activity at non-cytotoxic concentration (Imran 2019).
Zika virus contains 3 structural (capsid-pC, envelope-pE and membrane-prM) and 7 non-structural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5). Zika virus replication occurs in the permissive host cell after internalization via clathrin-mediated pH dependent endocytosis and maturation of viral proteins in the lysosomal compartment (Owczarek, 2019). In the lysosome, furin or furin-like proteases cleave viral surface glycoprotein prM into its active form destabilizing the viral membrane and promoting release of the viral RNA for replication in mitochondria and endoplasmatic reticulum.
There is no vaccine for ZIKV although there are investigational agents in clinical development.
It has been shown that furin inhibition causes the immature virion to be transported to late compartments where it undergoes proteolytic degradation. The degradation products are ejected from the cell via slow recycling vesicles (Owczarek, 2019).
Like ZIKV, DENV binding of viral protein E with cellular receptors allows viral particles to internalize into the permissible cell via the chlathrin mediated endocytosis pathway. To release the viral RNA genome, DENV virions undergo an acid-induced conformational change and membrane fusion. Newly synthesized viral proteins generated near the endoplasmic reticulum (ER) promote replication of the viral RNA genome, induction of membrane rearrangement, and assembly of new viral particles. To facilitate the process of DENV replication, DENV not only interacts with various cellular components, but also triggers various host responses, such as autophagy.
CD3 is a protein complex and T cell co-receptor that is involved in activating T cells. CD3 is selectively expressed on T cells in blood, bone marrow and lymphoid tissues, but not on other normal tissues and with no cross reactivity to other animals except for chimpanzee. Recently, human CD3 transgenic mice have been engineered, facilitating the study of anti-CD3 immunotherapies.
Anti-CD3 based therapies such as muromomab-CD3 (Janssen, Orthoclone, OKT3) have been extensively studied in humans both systemically and orally to block reactive T cells and ameliorate ulcerative cholitis and metabolic syndrome (da Cunha 2011, Ilan 2010-NCT01287195, NCT01205087). Anti-CD3 bispecific antibody platforms that bridge tumors and engage T cells such as blinatumomab and catumaxomab have been approved for the treatment of cancer and several others CD3 bispecifics are in clinical development (Suurs, 2019).
According to an aspect, the invention concerns a fusion construct comprising an Ig-Fc domain or other protein scaffold, such as albumin, and
PAMP refers to Pathogen-associated molecular pattern: conserved molecular structures produced by microbial pathogens, but not by the host organism that are recognized by the host innate immune system.
According to another aspect, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to another aspect, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
ADCC may be defined as Antibody-Dependent Cellular Cytotoxicity. ADCP may be defined as Antibody-Dependent Cellular Phagocytosis. CDC may be defined as Complement-dependent cytotoxicity.
According to another aspect, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to another aspect, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
Preferably the Furin inhibitor is selected among chloromethylketone and D-arginine derivatives such as hexa-D-arginine and dec-RVKR-cmk (comprising SEQ ID NO. 81).
The linker and spacers may be conjugated to furin, see Table 7.
According to another aspect, the invention concerns a fusion construct, wherein said fusion construct is an IgG3 construct, and wherein said IgG3 construct comprises a hinge region, wherein said hinge region has been modified.
According to another aspect, the invention concerns a fusion construct, a fusion protein or an antibody comprising the constant region(s) of IgG3 and a hinge, wherein said hinge preferably is selected among an IgG1 or IgG4 hinge.
According to another aspect, the invention concerns IgG3 homodimer comprising a hinge region, wherein said hinge region comprises a sequence selected among SEQ ID No.: 6, 8 and 68.
According to another aspect, the invention concerns IgG3 heterodimer comprising a hinge region, wherein said hinge region comprises a sequence selected among SEQ ID No.: 6, 8 and 68.
According to another aspect, the invention concerns IgG3, wherein said IgG3 comprises a mutation at position 405 and/or position 409. According to another aspect, the invention concerns IgM heterodimers obtainable by changing the charge pairs of the CH2 and/or CH4 domains.
According to another aspect, the invention concerns IgM heterodimers, comprising one or more of the mutations of Table 8.
According to another aspect, the invention concerns a fusion construct, wherein said fusion construct comprises an IgG3 homodimer, an IgG3 heterodimer and/or an IgM heterodimer according to the invention.
According to another aspect, the invention concerns use of a fusion construct according to the invention for the treatment of an infection.
According to another aspect, the invention concerns use, wherein said infections are selected among viral, bacterial, and protozoan infections.
According to another aspect, the invention concerns use, wherein the treatment comprising administration of the fusion construct with an administration form selected among subcutaneous, intradermal, intramuscular, oral and nasal.
According to another aspect, the invention concerns use of IgG4 or a part of IgG4 for payload delivery, wherein said IgG4 has been modified to comprise no Fc or wherein the activity of the Fc of said IgG4 has been nullified or diminished by one or more mutations.
According to another aspect, the invention concerns a vaccine comprising a fusion construct according to the invention.
According to another aspect, the invention concerns a vaccine comprising a mannan, a high mannose containing structure, a fucan and/or a phospholipid phosphatidylserine (PS).
According to another aspect, the invention concerns a composition comprising a fusion construct according to the invention, optionally comprising one or more excipients such as diluents, binders or carriers.
According to another aspect, the invention concerns a method of treating and/or preventing an infection in a subject, comprising a step of administration of a fusion construct and/or a vaccine and/or a composition according to the invention.
According to another aspect, the invention concerns a method of screening and/or monitoring progression of a disease in a subject, wherein said method comprises the following steps:
According to another aspect, the invention concerns an isolated nucleic acid molecule encoding a fusion construct according to the invention.
According to another aspect, the invention concerns a recombinant vector comprising the nucleic acid molecule of the invention.
According to another aspect, the invention concerns a host cell comprising the recombinant vector of the invention.
According to another aspect, the invention concerns a method to produce a fusion construct according to the invention comprising a step of culturing the host cell according to the invention in a culture medium under conditions allowing the expression of the fusion construct and separating the fusion construct from the culture medium.
According to an embodiment, the invention concerns a fusion construct comprising an Ig-Fc domain or other protein scaffold, such as albumin, and
PAMP refers to Pathogen-associated molecular pattern: conserved molecular structures produced by microbial pathogens, but not by the host organism that are recognized by the host innate immune system.
The term “protein scaffold” refers to a protein structure on which the active elements defined in a. and b. above can be bound. The protein scaffold should preferably be soluble in plasma and preferably have a high residence time in plasma, which typically can be provided if the complete fusion protein has a size above the renal clearance limit, such as above 60 kDa, or by selecting a protein scaffold that is subject to an active retention system e.g. proteins binding and recycled to the plasma via the FcRn receptor. Examples of suitable protein scaffolds include plasma proteins or fragments thereof, such as constant regions of immunoglobulins, albumin, albumin domain I, II, or III, transferrin and lactoferrin.
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to an embodiment, the invention concerns a fusion construct comprising
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
ADCC may be defined as Antibody-Dependent Cellular Cytotoxicity. ADCP may be defined as Antibody-Dependent Cellular Phagocytosis. CDC may be defined as Complement-dependent cytotoxicity.
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
According to an embodiment, the invention concerns a fusion construct comprising an IgG-Fc domain or other protein scaffold and
Preferably the Furin inhibitor is selected among chloromethylketone and D-arginine derivatives such as hexa-D-arginine and dec-RVKR-cmk (comprising SEQ ID NO. 81).
The linker and spacers may be conjugated to furin, see Table 7.
According to an embodiment, the invention concerns the fusion construct, wherein said peptide, protein or antibody fragment is capable of binding to and/or stimulating an immune cell.
According to an embodiment, the invention concerns the fusion construct, wherein said TIM1 fragment has a sequence length selected from the group consisting of 40-200 amino acid residues, 50-180 amino acid residues, 60-160 amino acid residues, 70-140 amino acid residues, 80-130 amino acid residues, 90-120 amino acid residues, 100-120 amino acid residues and 100-110 amino acid residues.
According to an embodiment, the invention concerns the fusion construct, wherein said CD209 fragment has a sequence length selected from the group consisting of 40-200 amino acid residues, 40-190 amino acid residues, 50-180 amino acid residues, 60-170 amino acid residues, 70-160 amino acid residues, 80-150 amino acid residues, 90-150 amino acid residues, 100-150 amino acid residues, 110-150 amino acid residues, 120-150 amino acid residues and 130-140 amino acid residues.
According to an embodiment, the invention concerns the fusion construct, wherein said TIM1 and/or CD209 fragment has a sequence homology of at least 70%, alternatively 75%, alternatively 80%, alternatively 85%, alternatively 90%, alternatively 95% to wildtype TIM1 or CD209.
According to an embodiment, the invention concerns the fusion construct, wherein said TIM1 and/or CD209 fragment has intact TIM1 and/or CD209 function.
According to an embodiment, the invention concerns the fusion construct, wherein said IgG-Fc domain is an IgG3-Fc domain.
According to an embodiment, the invention concerns the fusion construct, comprising additionally at least one of the following:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a sequence according to SEQ ID No.: 1 and/or SEQ ID No.: 2.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a sequence according to SEQ ID No.: 3 and/or SEQ ID No.: 4.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7 or preferably at least 8 disulfide bonds.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is capable of binding to a target, and wherein said target is a mannan, a high-mannose containing structure, a fucan, a phospholipid phosphatidylserine and/or CD3.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a linker.
According to an embodiment, the invention concerns the fusion construct, wherein said linker is selected among a (GGGGS)3 linker (SEQ ID NO. 41), a (GGGGS)4 linker (SEQ ID NO. 70), a (GGGGS)5 linker (SEQ ID NO. 71) and a (GGGGS)6 linker (SEQ ID NO. 72).
A (GGGGS) linker may be defined as a Gly-Gly-Gly-Gly-Ser linker (SEQ ID NO. 69).
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises at least one free cysteine residue, at least two free cysteine residues, at least three free cysteine residues, at least four free cysteine residues, at least five free cysteine residues or preferably at least six free cysteine residues.
According to an embodiment, the invention concerns the fusion construct, wherein said free cysteine allows interaction with a drug and/or a payload.
According to an embodiment, the invention concerns the fusion construct, wherein said payload is a furin inhibitor.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a A339C mutation, a S337C mutation and/or a K340C mutation.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a sequence selected among any of the sequences SEQ ID No.: 36, 37, SEQ ID No.: 38, 39, 40, 42, 44 or 46.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is an IgG1, IgG2, IgG3 or an IgG4.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is an IgG, IgM, IgA, IgD or an IgE.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a null fc.
According to an embodiment, the invention concerns the fusion construct, wherein said null fc comprises an Ala substitution at position 234 and/or Ala substitution at 235, and/or N297A, and/or a K322A mutation.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a heterodimerization domain.
According to an embodiment, the invention concerns the fusion construct, wherein said heterodimerization domain comprises a sequence according to SEQ ID No.: 48, 49 or 50.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a heterodimerization mutation.
According to an embodiment, the invention concerns the fusion construct, wherein said heterodimerization mutation is an F405L and/or K409R mutation.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises:
According to an embodiment, the invention concerns the fusion construct, wherein the ratio of fusion construct to said drug and/or payload is selected among 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a kappa light chain according to SEQ ID No.: 51 or a lambda light chain according to SEQ ID No.: 52 or 53.
According to an embodiment, the invention concerns a fusion construct, wherein said fusion construct is an IgG3 construct, and wherein said IgG3 construct comprises a hinge region, wherein said hinge region has been modified.
According to an embodiment, the invention concerns the fusion construct, wherein said hinge region comprises a sequence having a total of at least 10% identity, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 99% identity to the sequence according to SEQ ID No.: 6 or SEQ ID No.: 8.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises the sequence according to SEQ ID No.: 5, 7, 9, 10, 11, 12 and/or 13.
According to an embodiment, the invention concerns the fusion construct, wherein said hinge region comprises at least one free cysteine residue, at least two free cysteine residues or preferably at least three free cysteine residues.
According to an embodiment, the invention concerns the fusion construct, wherein said hinge region comprises a S228P mutation.
According to an embodiment, the invention concerns the fusion construct, wherein said hinge region comprises a sequence according to SEQ ID No.: 6 and/or SEQ ID No.: 8 and/or SEQ ID No.: 68.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is used to detect phosphatidylserine.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is used to detect phosphatidylserine in the blood of a subject.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a sequence according to SEQ ID No.: 1, and/or a sequence according to SEQ ID No.: 2.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is used to detect C-type lectin binding mannan or fucan moieties.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is used to detect C-type lectin binding mannan or fucan moieties in the blood of a subject.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct comprises a sequence according to SEQ ID No.: 3 and/or a sequence according to SEQ ID No.: 4.
According to an embodiment, the invention concerns a fusion construct, a fusion protein or an antibody comprising the constant region(s) of IgG3 and a hinge, wherein said hinge preferably is selected among an IgG1 or IgG4 hinge.
According to an embodiment, the invention concerns the fusion construct, fusion protein or antibody, comprising one or more heterodimerization mutations.
According to an embodiment, the invention concerns the fusion construct, fusion protein or antibody, comprising heterodimerization mutations involve positions 405 and/or 409 (EU numbering).
According to an embodiment, the invention concerns IgG3 homodimer comprising a hinge region, wherein said hinge region comprises a sequence selected among SEQ ID No.: 6, 8 and 68.
According to an embodiment, the invention concerns IgG3 heterodimer comprising a hinge region, wherein said hinge region comprises a sequence selected among SEQ ID No.: 6, 8 and 68.
According to an embodiment, the invention concerns IgG3, wherein said IgG3 comprises a mutation at position 405 and/or position 409.
According to an embodiment, the invention concerns IgM heterodimers obtainable by changing the charge pairs of the CH2 and/or CH4 domains.
According to an embodiment, the invention concerns IgM heterodimers, comprising one or more of the mutations of Table 8.
According to an embodiment, the invention concerns the IgM, wherein said IgM comprises a sequence according to SEQ ID No.: 64 and/or 65.
According to an embodiment, the invention concerns a fusion construct, wherein said fusion construct comprises an IgG3 homodimer, an IgG3 heterodimer and/or an IgM heterodimer according to the invention.
According to an embodiment, the invention concerns the fusion construct, wherein said fusion construct is for use in the treatment of an infection.
According to an embodiment, the invention concerns the fusion construct, wherein said infection is an infection caused by a virus, a parasite, a bacterium, a fungi or a protozoan.
According to an embodiment, the invention concerns the fusion construct, wherein said virus is selected among an arborvirus, Zika virus, Dengue virus, West Nile virus, Ebola virus, influenza virus, influenza virus H1N1, Chikungunya virus, Enterovirus and Coronaviruses SARS-COV.
According to an embodiment, the invention concerns the fusion construct, wherein said bacteria is selected among mycobacterium tuberculosis and mycobacterium leprae.
According to an embodiment, the invention concerns the fusion construct, wherein said parasite is selected among Leishmaniasis and Malaria.
According to an embodiment, the invention concerns use of a fusion construct according to the invention for the treatment of an infection.
According to an embodiment, the invention concerns use, wherein said infections are selected among viral, bacterial and protozoan infections.
According to an embodiment, the invention concerns use, wherein the treatment comprising administration of the fusion construct with an administration form selected among subcutaneous, intradermal, intramuscular, oral and nasal.
According to an embodiment, the invention concerns use of IgG4 or a part of IgG4 for payload delivery, wherein said IgG4 has been modified to comprise no Fc or wherein the activity of the Fc of said IgG4 has been nullified or diminished by one or more mutations.
According to an embodiment, the invention concerns the use, wherein said IgG4 comprises one or more heterodimerization mutations.
According to an embodiment, the invention concerns the use, wherein said IgG4 comprises one or more Cys mutations, preferably thereby allowing site specific conjugation.
According to an embodiment, the invention concerns the use, wherein said IgG4 comprises a Cys at position 339 (EU numbering).
According to an embodiment, the invention concerns a vaccine comprising a fusion construct according to the invention.
According to an embodiment, the invention concerns a vaccine comprising a mannan, a high mannose containing structure, a fucan and/or a phospholipid phosphatidylserine (PS).
According to an embodiment, the invention concerns the vaccine further comprising a β -glucan adjuvant to potentiate immune response.
According to an embodiment, the invention concerns the vaccine, for the prevention and/or treatment of an infection.
According to an embodiment, the invention concerns the vaccine, wherein said infection is caused by a virus, a parasite, a bacterium, a fungus or a protozoan.
According to an embodiment, the invention concerns the fusion construct and/or vaccine, wherein said fusion construct and/or vaccine allows administration through a route selected among subcutaneous administration, intradermal administration, intramuscular administration, oral administration and/or nasal administration.
According to an embodiment, the invention concerns a composition comprising a fusion construct according to the invention, optionally comprising one or more excipients such as diluents, binders or carriers.
According to an embodiment, the invention concerns a method of treating and/or preventing an infection in a subject, comprising a step of administration of a fusion construct and/or a vaccine and/or a composition to the invention.
According to an embodiment, the invention concerns a method of screening and/or monitoring progression of a disease in a subject, wherein said method comprises the following steps:
According to an embodiment, the invention concerns an isolated nucleic acid molecule encoding a fusion construct according to the invention.
According to an embodiment, the invention concerns a recombinant vector comprising the nucleic acid molecule according to the invention.
According to an embodiment, the invention concerns a host cell comprising the recombinant vector according to the invention.
According to an embodiment, the invention concerns a method to produce a fusion construct according to the invention comprising a step of culturing the host cell according to the invention in a culture medium under conditions allowing the expression of the fusion construct and separating the fusion construct from the culture medium.
Additional embodiments of the invention are described below.
According to an embodiment, the invention concerns a fusion construct, wherein said fusion construct comprises a hinge region, wherein said hinge region comprises any of the sequences as described below:
According to an embodiment, the invention concerns a fusion construct, wherein said fusion construct comprises an Fc heterodimerization sequence at residue 405-409, wherein said Fc heterodimerization sequence comprises a sequence according to SEQ ID No.: 48, 49 or 50.
Immunoglobulins are glycoproteins composed of one or more units, each containing four polypeptide chains: two identical heavy chains (HCs) and two identical light chains (LCs). The amino terminal ends of the polypeptide chains show considerable variation in amino acid composition and are referred to as the variable (V) regions to distinguish them from the relatively constant (C) regions. Each light chain consists of one variable domain, VL, and one constant domain, CL. The heavy chains consist of a variable domain, VH, and three constant domains CH1, CH2 and CH3. Heavy and light chains are held together by a combination of non-covalent interactions and covalent interchain disulfide bonds, forming a bilaterally symmetric structure. The V regions of H and L chains comprise the antigen-binding sites of the immunoglobulin (Ig) molecules. Each Ig monomer contains two antigen-binding sites and is said to be bivalent.
The Fab contains one complete L chain in its entirety and the V and CH1 portion of one H chain. The Fab can be further divided into a variable fragment (Fv) composed of the VH and VL domains, and a constant fragment (Fb) composed of the CL and CH1 domains.
The H chain constant domain is generally defined as CH1-CH2-CH3 (IgG, IgA, IgD) with an additional domain (CH4) for IgM and IgE. As described above, the CH1 domain is located within the F(ab) region whereas the remaining CH domains (CH2—CH3 or CH2—CH4) comprise the Fc fragment. This Fc fragment defines the isotype and subclass of the immunoglobulin.
CH3 domain: The terms CH3 domain and CH3 region are used interchangeable herein.
CH1 domain: The terms CH1 domain and CH1 region are used interchangeable herein.
Hinge region: The hinge region is the area of the heavy chains between the first and second C region domains and is held together by disulfide bonds. A hinge region typically comprises between 10 and 30 amino acid residues.
Linker: A linker might be a peptide linker or a non-peptide linker. An example of a peptide linker is a Gly/Ser peptide linker comprising a five amino acid residue unit, GGGGS (SEQ ID NO:71), that can be repeated a suitable amount of times. A linker might be a naturally occurring linker or a synthetically produced linker. A linker might occur naturally in a molecule or might be synthetically added to a molecule.
Antibody fragment: As used herein, an “antibody fragment” includes a portion of an intact antibody, such as, for example, the antigen-binding or variable region of an antibody. Examples of antibody fragments include Fab, Fab′, F(ab′)2, and Fv fragments; triabodies; tetrabodies; linear antibodies; single-chain antibody molecules; and multi specific antibodies formed from antibody fragments. For example, antibody fragments include isolated fragments, “Fv” fragments, consisting of the variable regions of the heavy and light chains, recombinant single chain polypeptide molecules in which light and heavy chain variable regions are connected by a peptide linker (“ScFv proteins”), and minimal recognition units consisting of the amino acid residues that mimic the hypervariable region. In many embodiments, an antibody fragment contains sufficient sequence of the parent antibody of which it is a fragment that it binds to the same antigen as does the parent antibody; in some embodiments, a fragment binds to the antigen with a comparable affinity to that of the parent antibody and/or competes with the parent antibody for binding to the antigen. Examples of antigen binding fragments of an antibody include, but are not limited to, Fab fragment, Fab′ fragment, F(ab′)2 fragment, scFv fragment, Fv fragment, dsFv diabody, dAb fragment, Fd′ fragment, Fd fragment, and an isolated complementarity determining region (CDR) region. An antigen-binding fragment of an antibody may be produced by any means. For example, an antigen-binding fragment of an antibody may be enzymatically or chemically produced by fragmentation of an intact antibody and/or it may be recombinantly produced from a gene encoding the partial antibody sequence. Alternatively, or additionally, antigen-binding fragment of an antibody may be wholly or partially synthetically produced. An antigen-binding fragment of an antibody may optionally comprise a single chain antibody fragment. Alternatively, or additionally, an antigen-binding fragment of an antibody may comprise multiple chains that are linked together, for example, by disulfide linkages. An antigen-binding fragment of an antibody may optionally comprise a multi-molecular complex. A functional antibody fragment typically comprises at least about 50 amino acids and more typically comprises at least about 200 amino acids.
Antibody or fragment thereof: As used herein, an “antibody or fragment thereof” refers to an antibody or antibody fragment as defined above.
Humanized antibodies: Humanized antibodies are antibodies from non-human species whose protein sequences have been modified to increase their similarity to antibody variants produced naturally in humans.
IMGT: the international ImMunoGeneTics information system, is an international reference in immunogenetics and immunoinformatics.
Single-chain Fv (scFv): Single-chain Fvs (scFvs) are widely known and used in the art. A single-chain Fv is a fusion protein of the variable regions of the heavy (VH) and light chains (VL) of immunoglobulins, often connected by a short linker peptide (see, e.g., see, e.g., Benny K. C. Lo (ed.), Antibody Engineering - Methods and Protocols, Humana Press 2004, and references cited therein).
All cited references are incorporated by reference.
The accompanying Figures and Examples are provided to explain rather than limit the present invention. It will be clear to the person skilled in the art that aspects, embodiments, claims and any items of the present invention may be combined.
Unless otherwise mentioned, all percentages are in weight/weight. Unless otherwise mentioned, all measurements are conducted under standard conditions (ambient temperature and pressure). Unless otherwise mentioned, test conditions are according to European Pharmacopoeia 8.0.
Construct V-TIM1-1 was selected as residues 21-125 of the full length TIM-1 sequence (https://www.uniprot.org/uniprot/Q96D42), and V-TIM1-2 was selected as residues 21-127. V-TIM1-2 contains an extra two Pro residues at the C-terminal domain boundary.
Construct V-CTLD-1 was selected as residues 250-385 of the full length DC-SIGN sequence (https://www.uniprot.org/uniprot/Q9NNX6), and V-CTLD-2 was selected as residues 254-383. V-CTLD-1 contains 4 internal disulfide bonds, whereas V-CTLD-2 contains 3 internal disulfide bonds.
Among all human IgG subclasses, IgG3 has the highest effector functions in terms of ADCC, ADCP and CDC (https://www.frontiersin.org/articles/10.3389/fimmu.2014.00520/full). IgG3 has not typically been used for therapeutics because of the short serum half-life due to proteolytic cleavage of the prolonged hinge region between the CH1 and CH2 domains. To utilize the strong effector functions of the IgG3 subclass, the V-IGG3 construct was designed where the IgG3 hinge (LKTPLGDTTHTPEPKSCDTPPPCPRCPAP) (SEQ ID NO. 6) was replaced with an IgG4 hinge sequence containing an IgG4 hinge S228P mutation to prevent Fab arm exchange (SKYGPPCPPCPAP) (SEQ ID NO. 8) or an IgG1-like hinge (KTGDTTHTCPRCPAP) (SEQ ID NO. 68).
Heterodimeric V-IGG3 constructs were designed based on including K409R (on one half-antibody) and F405L (on second antibody) mutation in the CH3 domains (https://www.nature.com/articles/nprot.2014.169). Each half antibody is first generated as a single homodimer, then mixed together and allowed to recombine as heterodimers under reducing and oxidizing conditions. The resulting sequences are noted as V-IGG3-A and V-IGG3-B and pair together, or V-IGG3-D and V-IGG3-E that pair together. Sequences are found in Table 3, including truncated version that include a (GGGGS)3 linker (SEQ ID NO. 41) to replace the CH1 domains.
TIM1 and CTLD fusion proteins were designed with the modified IgG3-Fc domains and are depicted in
Additional constructs were designed to engage T cell effector functions by fusing the TIM-1 and CTLD with a single anti-CD3 scFv. The designs are shown in
Site specific addition of drug payloads to the antibody Fc region was devised by analysis of the co-crystal structure of a human IgG1 Fc with the 3-helix bundle of bacterial protein A (PDB structure 5U4Y https://www.rcsb.org/sequence/5U4Y). Computational modelling revealed that A339C would have a stabilizing effect to the structure and S337C or K340C would have a neutral effect to the stability of the Fc domain. A339C was chosen as the site for site specific conjugation.
TIM1 and CTLD fusion proteins with Fc domain with payload conjugation sites were designed and are shown in
Decanoyl-Arg-Val-Lys-Arg-chloromethylketone (dec-RVKR-cmk) (SEQ ID NO. 81) or hexa-D-arginine (D6R) were linked to TIM-1 and CTLD constructs using cleavable linkers such as acid sensitive N-acyl-hydrazone or enzyme sensitive malemeide-conjugated dipeptides, valine-alanine, valine-citrulline, or phenylalanine-Lysine.
Acid sensitive linkers are cleaved in the lysosome acidic environment after internalization of the construct. This strategy has been used in two approved ADCs, Gemtuzumab ozogamicin and Inotuzumab ozogamicin. Lysosomal protease sensitive dipeptides release the drug after cleavage by proteases such as cathepsin B- lysosomal protease. This type of linker chemistry has been used for FDA approved Brentuximab vedotin.
Linkage to the polypeptide of antibodies is done through the nucleophilic groups of lysine or cysteine by random conjugation, generating a heterogeneous mixture of conjugates, or by site-directed conjugation to engineered cysteines, reducing the heterogeneity of the product to an antibody-drug ratio (ADR) of 1 or 2.
The nucleophilic reactivity of the thiol functionality of a Cys residue to a maleimide group is about 1000 times higher compared to any other amino acid functionality in a protein, such as amino group of lysine residues or the N-terminal amino group. Thiol specific functionality in maleimide reagents may react with amine groups, but higher pH (>9.0) and longer reaction times are required (Garman, 1997, Non-Radioactive Labelling: A Practical Approach, Academic Press, London).
The first FDA approved site-directed ADC through engineered cysteines was vadastuximab talirine (Seattle Genetics).
IgM molecules have robust Fc effector functions, particularly with CDC. IgM molecules naturally homodimerize and then covalently associate into pentamers or hexamers. IgM do not contain hinge regions like IgG molecules and instead contain an extra CH domain (CH1-CH2-CH3-CH4). The homodimeric heavy chains come together at the CH2 and CH4 domains. Based on visual analyses of the crystal structure of the murine IgM CH2 domain (pdb 4JVU), the crystal structure of the murine IgM CH4 domain (pdb 4JVW), and a sequence alignment of the human IgM CH2 and CH4 sequences with the homologous mouse sequences, mutations were designed to induce IgM heavy chain heterodimerization by inducing charge differences at the homodimerization interfaces.
Sequence of human IgM constant region, numbered residues 1-453 by uniprot (www_uniprot.org/uniprot/P01871):
Sequence of IgM CH2-CH3-CH4 which can used for fusing to antibody fragments (Fab, scFv, VHH, etc) or targeting proteins (TIM-1, CTLD/DC-SIGN) for adding IgM effector functions (residues 105-453): V-IGM
Based on the structural analysis, the underlined residues K131 and Q135 were found to be in close proximity in the CH2:CH2 interface, and residues T354 and E385 were found to be in close proximity in the CH4:CH4 interface. The following mutations were made to alter the charge pattern in V-IGM-A and V-IGM-B to induce heterodimer formation of A:B and repel the formations of A:A or B:B.
TIM1 and CTLD fusion proteins with IgM effector functions were designed and shown in
The 10 proteins from [Table 1 and
Larger scale preps were done in ExpiCHO cells for VP011 (100 mL), VP012 (100 mL), VP013 (100 mL), VP014 (100 mL), VP019 (1L) and VP020 (250 mL). VP011, VP019 and VP020 were purified by MabSelect SuRe protein A resin column chromatography. VP012, VP013 and VP014 were purified by HiTrap Protein G resin column chromatography. Expression yields and % monomeric purity are shown in Table 13.
∗multimer peak
The sequences of the expressed recombinant proteins are shown in table 14.
SEC-HPLC analysis of VP019 (
The protein product VP025, which is a heterodimer of VP019 and VP020, was generated by co-expressing Genes TM-G4-A-DC and CT-G4-B-DC in ExpiCHO cells and purified by MabSelect SuRe protein A resin column chromatography. The resulting co-transfected sample product was named VP025-CT.
Two additional bispecific molecules containing the TIM-1 and CTLD domains on a single polypeptide chain (Table 15) were generated in 100 mL ExpiCHO cells and purified by MabSelect SuRe protein A resin column chromatography. The schematics and purity by SEC-HPLC are shown in
The sequences of the expressed recombinant proteins are shown in table 14.
The binding of VP019-F2, VP020 and VP025-CT to SARS-Cov-2 S D614G was investigated by ELISA. This protein is representative of the dominant SARS-COV-2 strain in early 2020. All ELISA assays in this and subsequent examples were done in the presence of 2.5 mM CaCl2 since DC-SIGN is known to use calcium at the binding site. Binding curves are shown in
The binding of VP025-CT to many diverse viral surface protein antigens was investigated by ELISA. Binding curves are shown in
The binding of VP019, VP020, VP025-CT (heterodimer mixture) and VP025-F4 (78% pure heterodimer) to a biotin-phosphatidyl serine and a select group of viral antigens (Influenza A H1N1 HA, Human RSV Glycoprotein G, Zika Virus Envelope Protein and SARS-Cov-2 S D614G) was investigated by ELISA. Binding curves are shown in
Solvents and reagents were purchased from Sigma-Aldrich, VWR, or Fisher Scientific, and used without further purification. Reactions were monitored either by thin-layer chromatography (TLC) or by analytical liquid chromatography-mass spectrometry (LC-MS) employing a Waters Acquity Ultra Performance LC system and a Synapt high-definition mass spectrometer. 1H NMR spectra were recorded on a Varian Unity INOVA spectrometer (500 MHz). All chemical shifts are reported in ppm and coupling constants, J, are reported in hertz (Hz). NMR solvent peaks were referenced as follows: (1H NMR) CDCl3: 7.27 ppm, DMSO-d6: 2.50 ppm. Compounds were purified by flash column chromatography on a Teledyne ISCO Combi-Flash system using normal phase silica gel (SiliCycle Inc.) or reverse phase (Teledyne Gold- C18 or C18-Aq) pre-packed columns. The purity of compounds was determined by analytical HPLC (Waters Acquity Ultra Performance) using an Acquity UPLC CSH C18 1.7 µm (50 mm x 2.1 mm) column and flow rate of 0.3 mL/min. Gradient conditions: solvent A (0.05% formic acid in water) and solvent B (0.05% formic acid in acetonitrile): 0-0.1 min 95% A, 0.1-4.0 min 5-95% B (linear gradient), 4.0-5.0 min 95% B, UV detection at 254 nm and 220 nm.
The reaction scheme is shown in
N-methyl morpholine (13.8 µlL, 0.126 mmol) was added to a solution of hexa-D-Arg (D-Argininamide D-arginyl-D-arginyl-D-arginyl-D-arginyl-D-arginyl-D-alanine; Ambeed, cat# A333458) (30 mg, 0.0314 mmol), MC-Val-Cit-PAB-PNP (BroadPharm Cat#: BP-23292, CAS: 159857-81-5) (46.4 mg, 0.0629 mmol) and HOBt.H2O (1-hydroxybenzotriazole monohydrate; 5.3 mg, 0.0345) in anhydrous DMF (1 mL) under argon atmosphere. The solution was stirred at r.t. for 18 hours. The reaction was diluted with 1:1 ACN/water (0.05% HCO2H) (10 mL) and purified by reverse phase C18-Aq flash chromatography (gradient elution; 100% water -100% ACN with 0.05% HCO2H as mobile phase additive) to afford MC-VC-PAB-(D-Arg)6-NH2 (12 mg, 0.00773 mmol, 25%) as a white solid after lyophilization. 1H NMR (500 MHz, DMSO-d6) d 10.09 (s, 1H), 8.65 (br. s, 6H), 8.47 (s, 6H), 8.32 - 8.45 (m, 4H), 8.12 - 8.20 (m, 1H), 7.84 (d, J = 7.8 Hz, 1H), 7.50 - 7.80 (m, 18H), 7.29 (d, J = 7.8 Hz, 2H), 7.17 (s, 1H), 7.01 (s, 2H), 6.08 - 6.10 (m, 1H), 5.43 - 5.50 (s, 2H), 4.89 - 5.01 (m, 2H), 4.36 - 4.41 (m, 1H), 4.12 - 4.30 (m, 6H), 4.01 - 4.09 (m, 1H), 3.35 - 3.40 (m, 2H), 2.91- 3.12 (m, 12H), 2.09 - 2.21 (m, 2H), 1.93 - 2.00 (m, 1H), 1.65 -1.75 (m, 6H), 1.40 -1.62 (m, 28H), 1.30 -1.40 (m, 1H), 1.15 - 1.25 (m, 2H), 0.80 - 0.89 (m, 6H); MS (ESI) m/z: 1552.4 [M+H]+.
The structure is shown in
A test conjugation of Hexa-D-arginine linker-compound to VP020 was performed by reacting VP025 with 4 equivalents of TCEP and incubating at 37° C. for 1 hour to reduce the free cysteines. The sample was run through a Zeba column to remove TCEP and buffer exchanged into 1x PBS containing 1 mM DTPA pH 6.5. The sample was then reacted with 2.5 equivalents of the payload (Mc-VC-PAB-(D-Arg6)-CONH2 at Room temperature for 1 hour. The final product was analyzed by mass spectrometry (see
A microneutralization assay was done to determine the antiviral properties of three compounds (VP019-F2, VP020 and VP025-F4) against RSV. Each virus was incubated with each antibody for 1 hour, after which the mix was added to A549 cells (human lung cancer cell line). Antiviral activity was determined 24 h later using an immunofluorescence-based assay. After 24 h, the infection plates were washed with PBS, fixed for 30 mins with 4% formaldehyde, washed again with PBS, and stored in PBS at 4° C. until staining. Any residual formaldehyde was quenched with 50 mM ammonium chloride, after which cells were permeabilized (0.1% Triton X100) and stained with an antibody recognizing RSV fusion protein (GeneTex GTX40697). The primary antibody was detected with an Alexa-488 conjugate secondary antibody (Life Technologies, A21244 and A11001), and nuclei were stained with Hoechst. Images were acquired on an Celllnsight CX5 high content platform (Thermo Scientific), and percentage infection calculated using CellInsight CX5 software (infected cells/total cells x 100).
The test articles were used in concentrations of 0.5 µM and samples were tested in triplicate. The resulting data are shown in
A second neutralization assay was done for Zika virus using VP025-F4 using the following procedures.
Vero E6 cells were maintained with DMEM supplemented with 2% FBS and (1% pen-strep -need to confirm with Allen) and stored at 37° C. with 5% CO2. Cells were seeded onto 48-well plates at a concentration of 8.0*104 cells per well and allowed to adhere overnight. On the morning of infection cell monolayers were examined to ensure 90-95% confluency.
VP025-F4 was serially diluted in triplicate using infection media at a ratio of 1:3 for a total of eight dilutions (220 to 0.1 µg/mL).). Zika virus (ZIKV), strain MEX-I-44, at a MOI of 1.0 (8.0*104 FFU) was added to each dilution, mixed, and incubated at 37° C. and 5% CO2 for one hour.
Simultaneous to the VP025:ZIKV incubation, positive control samples were also incubated. Mouse α-ZIKV MIAF (mouse immune ascitic fluid antibody) was diluted 1:500, 1:1000, and 1:1500 and combined with ZIKV, in triplicate, using the same concentration of virus as the test wells.
Following incubation of VP025-F4:ZIKV and α-ZIKV MIAF:ZIKV, the Vero E6 well plate was removed from the incubator. Media was aspirated from the cells and the test and positive control samples were transferred to the Vero E6 plate and returned to the incubator to allow non-neutralized virus to infect cells for one hour.
Simultaneous to the Plate Infection incubation, ZIKV was serially diluted (10-2 to 10-5) and samples were allowed to infect Vero E6 cells in triplicate.
Following the one hour incubation on Vero E6 cells an overlay of 0.8% methylcellulose was added to all wells and they were maintained at 37° C. and 5% CO2 for approximately 60 hours.
Plates were removed from the incubator, overlay was aspirated, and cells were gently washed twice with phosphate buffered saline. Virus was inactivated with a 1:1 fixative mixture of methanol and acetone which was allowed to fix plates for 30 minutes. Following inactivation, fixative was removed, and plates were allowed to air dry until no fixative remained.
All incubations and washes were performed at room temperature and plate was placed on a plate rocker. Cells were permeabilized with 0.5% Triton in PBS and washed with 0.02% Tween 20 in PBS (PBST). Blocking solution of PBST with BSA and normal goat serum was prepared and incubated on all wells for one hour. Primary antibody, mouse α-ZIKV MIAF, was diluted in PBST with BSA and stored on ice until used. Blocking solution was removed and 1° antibody was incubated for one hour. Antibody was removed and plates were washed with PBST. Secondary antibody, goat α-mouse IgG (high and low chain) HRP conjugated, was diluted in PBST with BSA. Antibody was incubated on wells for one hour and then wells were washed with PBST with BSA. Vector labs ImmPACT AMEC developing solution was prepared according to kit instructions and added to each well. Plate was incubated in the dark but checked regularly for staining. After foci were clearly developed (~15 minutes), wells were rinsed with deionized water and the plate was allowed to dry.
No foci were observed in the VP025-F4 test wells or the positive control wells (see
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/046713 | 8/19/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16997639 | Aug 2020 | US |
| Child | PCT/US2021/046713 | WO |
