ABSTRACT
Human T cell leukemia/T-lymphotropic virus type 1 (HTLV-1) infection occurs by cell-to-cell transmission and can induce fatal adult T cell leukemia. Vaccine development is critical for the control of HTLV-1 transmission. However, determining whether vaccine-induced anti-Env antibodies can prevent cell-to-cell HTLV-1 transmission is challenging. Here, we examined the protective efficacy of a vaccine inducing anti-Env antibodies against HTLV-1 challenge in cynomolgus macaques. Eight of 10 vaccinated macaques produced anti-HTLV-1 neutralizing antibodies (NAbs) and were protected from an intravenous challenge with 108 HTLV-1-producing cells. In contrast, the 2 vaccinated macaques without NAb induction and 10 unvaccinated controls showed HTLV-1 infection with detectable proviral load after challenge. Five of the eight protected macaques were administered with an anti-CD8 monoclonal antibody, but proviruses remained undetectable and no increase in anti-HTLV-1 antibodies was observed even after CD8+ cell depletion in three of them. Analysis of Env-specific T cell responses did not suggest involvement of vaccine-induced Env-specific T cell responses in the protection. These results indicate that anti-Env antibody induction by vaccination can result in functionally sterile HTLV-1 protection, implying the rationale for strategies aimed at anti-Env antibody induction in prophylactic HTLV-1 vaccine development.
Subject(s)
Antibodies, Neutralizing , HTLV-I Infections , Human T-lymphotropic virus 1 , Vaccination , Animals , Human T-lymphotropic virus 1/immunology , HTLV-I Infections/immunology , HTLV-I Infections/prevention & control , Antibodies, Neutralizing/immunology , Humans , Macaca fascicularis , Viral Load , CD8-Positive T-Lymphocytes/immunology , Gene Products, env/immunology , Antibodies, Viral/immunology , Viral Vaccines/immunology , Viral Vaccines/administration & dosage , Disease Models, AnimalABSTRACT
The Bovine Leukemia Virus (BLV) Envelope (Env) glycoprotein complex is instrumental in viral infectivity and shapes the host's immune response. This study presents the production and characterization of a soluble furin-mutated BLV Env ectodomain (sBLV-EnvFm) expressed in a stable S2 insect cell line. We purified a 63 kDa soluble protein, corresponding to the monomeric sBLV-EnvFm, which predominantly presented oligomannose and paucimannose N-glycans, with a high content of core fucose structures. Our results demonstrate that our recombinant protein can be recognized from specific antibodies in BLV infected cattle, suggesting its potential as a powerful diagnostic tool. Moreover, the robust humoral immune response it elicited in mice shows its potential contribution to the development of subunit-based vaccines against BLV.
Subject(s)
Antibodies, Viral , Leukemia Virus, Bovine , Recombinant Proteins , Viral Envelope Proteins , Animals , Leukemia Virus, Bovine/genetics , Leukemia Virus, Bovine/immunology , Cattle , Recombinant Proteins/genetics , Mice , Viral Envelope Proteins/genetics , Viral Envelope Proteins/immunology , Viral Envelope Proteins/metabolism , Antibodies, Viral/immunology , Enzootic Bovine Leukosis/virology , Cell Line , Gene Products, env/genetics , Gene Products, env/metabolism , Gene Products, env/immunologyABSTRACT
Binding to the receptor, CD4, drives the pretriggered, "closed" (State-1) conformation of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer ([gp120/gp41]3) into more "open" conformations. HIV-1 Env on the viral membrane is maintained in a State-1 conformation that resists binding and neutralization by commonly elicited antibodies. Premature triggering of Env before the virus engages a target cell typically leads to increased susceptibility to spontaneous inactivation or ligand-induced neutralization. Here, we showed that single amino acid substitutions in the gp41 membrane-proximal external region (MPER) of a primary HIV-1 strain resulted in viral phenotypes indicative of premature triggering of Env to downstream conformations. Specifically, the MPER changes reduced viral infectivity and globally increased virus sensitivity to poorly neutralizing antibodies, soluble CD4, a CD4-mimetic compound, and exposure to cold. In contrast, the MPER mutants exhibited decreased sensitivity to the State 1-preferring inhibitor, BMS-806, and to the PGT151 broadly neutralizing antibody. Depletion of cholesterol from virus particles did not produce the same State 1-destabilizing phenotypes as MPER alterations. Notably, State 1-stabilizing changes in Env distant from the MPER could minimize the phenotypic effects of MPER alteration but did not affect virus sensitivity to cholesterol depletion. Thus, membrane-proximal gp41 elements contribute to the maintenance of the pretriggered Env conformation. The conformationally disruptive effects of MPER changes can be minimized by distant State 1-stabilizing Env modifications, a strategy that may be useful in preserving the native pretriggered state of Env. IMPORTANCE The pretriggered shape of the human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) is a major target for antibodies that can neutralize many strains of the virus. An effective HIV-1 vaccine may need to raise these types of antibodies, but this goal has proven difficult. One reason is that the pretriggered shape of Env is unstable and dependent on interactions near the viral membrane. Here, we showed that the membrane-proximal external region (MPER) of Env plays an important role in maintaining Env in a pretriggered shape. Alterations in the MPER resulted in global changes in Env conformation that disrupted its pretriggered shape. We also found that these disruptive effects of MPER changes could be minimized by distant Env modifications that stabilized the pretriggered shape. These modifications may be useful for preserving the native shape of Env for structural and vaccine studies.
Subject(s)
HIV Infections , HIV-1 , Antibodies, Neutralizing , Gene Products, env/chemistry , Gene Products, env/immunology , Glycoproteins/chemistry , HIV Antibodies/immunology , HIV Envelope Protein gp120/immunology , HIV Envelope Protein gp41/chemistry , HIV Envelope Protein gp41/immunology , HIV Infections/immunology , HIV Infections/virology , HIV-1/chemistry , HIV-1/immunology , HumansABSTRACT
Antibodies are principal immune components elicited by vaccines to induce protection from microbial pathogens. In the Thai RV144 HIV-1 vaccine trial, vaccine efficacy was 31% and the sole primary correlate of reduced risk was shown to be vigorous antibody response targeting the V1V2 region of HIV-1 envelope. Antibodies against V3 also were inversely correlated with infection risk in subsets of vaccinees. Antibodies recognizing these regions, however, do not exhibit potent neutralizing activity. Therefore, we examined the antiviral potential of poorly neutralizing monoclonal antibodies (mAbs) against immunodominant V1V2 and V3 sites by passive administration of human mAbs to humanized mice engrafted with CD34+ hematopoietic stem cells, followed by mucosal challenge with an HIV-1 infectious molecular clone expressing the envelope of a tier 2 resistant HIV-1 strain. Treatment with anti-V1V2 mAb 2158 or anti-V3 mAb 2219 did not prevent infection, but V3 mAb 2219 displayed a superior potency compared to V1V2 mAb 2158 in reducing virus burden. While these mAbs had no or weak neutralizing activity and elicited undetectable levels of antibody-dependent cellular cytotoxicity (ADCC), V3 mAb 2219 displayed a greater capacity to bind virus- and cell-associated HIV-1 envelope and to mediate antibody-dependent cellular phagocytosis (ADCP) and C1q complement binding as compared to V1V2 mAb 2158. Mutations in the Fc region of 2219 diminished these effector activities in vitro and lessened virus control in humanized mice. These results demonstrate the importance of Fc functions other than ADCC for antibodies without potent neutralizing activity.
Subject(s)
Gene Products, env/immunology , HIV Antibodies/pharmacology , HIV Infections , Viral Load/drug effects , Animals , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/pharmacology , HIV Antibodies/immunology , HIV-1/immunology , Humans , Immunization, Passive , Immunoglobulin Constant Regions , Mice , Mucous MembraneSubject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , Gene Products, env/blood , Gene Products, env/immunology , Pregnancy Proteins/blood , Pregnancy Proteins/immunology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology , Abortion, Spontaneous , Amino Acids , Antibodies, Monoclonal/chemistry , Cross Reactions , Female , HEK293 Cells , Humans , Patient Safety , PregnancyABSTRACT
Following curative immunotherapy of B16F10 tumors, ~60% of mice develop a strong antibody response against cell-surface tumor antigens. Their antisera confer prophylactic protection against intravenous challenge with B16F10 cells, and also cross-react with syngeneic and allogeneic tumor cell lines MC38, EL.4, 4T1, and CT26. We identified the envelope glycoprotein (env) of a murine endogenous retrovirus (ERV) as the antigen accounting for the majority of this humoral response. A systemically administered anti-env monoclonal antibody cloned from such a response protects against tumor challenge, and prophylactic vaccination against the env protein protects a majority of naive mice from tumor establishment following subcutaneous inoculation with B16F10 cells. These results suggest the potential for effective prophylactic vaccination against analogous HERV-K env expressed in numerous human cancers.
Subject(s)
Antibodies, Neoplasm/immunology , Endogenous Retroviruses/immunology , Gene Products, env/immunology , Immunotherapy/methods , Neoplasms , Animals , Cell Line, Tumor , Mice , Mice, Inbred C57BL , Neoplasms/immunology , Neoplasms/therapySubject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Pregnancy Complications, Infectious/prevention & control , Abortion, Spontaneous/epidemiology , Clinical Trials as Topic , Communication , Cross Reactions/immunology , Female , Fertility , Gene Products, env/immunology , Humans , Immunity, Maternally-Acquired , Pregnancy , Pregnancy Proteins/immunology , Pregnancy, Unplanned , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunologyABSTRACT
The role of vaccine-induced anti-V2 Abs was tested in three protection experiments in rhesus macaques. In an experiment using immunogens similar to those in the RV144 vaccine trial (Anti-envelope [Env]), nine rhesus macaques were coimmunized with gp16092TH023 DNA and SIV gag and gp120A244 and gp120MN proteins. In two V2-focused experiments (Anti-V2 and Anti-V2 Mucosal), nine macaques in each group were immunized with V1V292TH023 DNA, V1V2A244 and V1V2CasaeA2 proteins, and cyclic V2CaseA2 peptide. DNA and protein immunogens, formulated in Adjuplex, were given at 0, 4, 12, and 20 weeks, followed by intrarectal SHIVBaL.P4 challenges. Peak plasma viral loads (PVL) of 106-107 copies/ml developed in all nine sham controls. Overall, PVL was undetectable in one third of immunized macaques, and two animals tightly controlled the virus with the Anti-V2 Mucosal vaccine strategy. In the Anti-Env study, Abs that captured or neutralized SHIVBaL.P4 inversely correlated with PVL. Conversely, no correlation with PVL was found in the Anti-V2 experiments with nonneutralizing plasma Abs that only captured virus weakly. Titers of Abs against eight V1V2 scaffolds and cyclic V2 peptides were comparable between controllers and noncontrollers as were Ab-dependent cellular cytotoxicity and Ab-dependent cell-mediated virus inhibition activities against SHIV-infected target cells and phagocytosis of gp120-coated beads. The Anti-Env experiment supports the role of vaccine-elicited neutralizing and nonneutralizing Abs in control of PVL. However, the two V2-focused experiments did not support a role for nonneutralizing V2 Abs alone in controlling PVL, as neither Ab-dependent cellular cytotoxicity, Ab-dependent cell-mediated virus inhibition, nor phagocytosis correlated inversely with heterologous SHIVBaL.P4 infection.
Subject(s)
AIDS Vaccines/immunology , HIV Infections/prevention & control , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/immunology , AIDS Vaccines/administration & dosage , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Antibody-Dependent Cell Cytotoxicity/immunology , Disease Models, Animal , Female , Gene Products, env/immunology , HIV Infections/blood , HIV Infections/immunology , HIV Infections/virology , Humans , Immunogenicity, Vaccine , Macaca mulatta , Male , Phagocytosis/immunology , Simian Acquired Immunodeficiency Syndrome/blood , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Acquired Immunodeficiency Syndrome/virology , Viral LoadABSTRACT
Several HIV-1 and SIV vaccine candidates have shown partial protection against viral challenges in rhesus macaques. However, the protective efficacy of vaccine-elicited polyclonal antibodies has not previously been demonstrated in adoptive transfer studies in nonhuman primates. In this study, we show that passive transfer of purified antibodies from vaccinated macaques can protect naive animals against SIVmac251 challenges. We vaccinated 30 rhesus macaques with Ad26-SIV Env/Gag/Pol and SIV Env gp140 protein vaccines and assessed the induction of antibody responses and a putative protective signature. This signature included multiple antibody functions and correlated with upregulation of interferon pathways in vaccinated animals. Adoptive transfer of purified immunoglobulin G (IgG) from the vaccinated animals with the most robust protective signatures provided partial protection against SIVmac251 challenges in naive recipient rhesus macaques. These data demonstrate the protective efficacy of purified vaccine-elicited antiviral antibodies in this model, even in the absence of virus neutralization.
Subject(s)
Immunization, Passive/methods , SAIDS Vaccines/immunology , Simian Immunodeficiency Virus/immunology , AIDS Vaccines/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Formation/immunology , Gene Products, env/immunology , Gene Products, gag/immunology , Gene Products, pol/immunology , HIV-1/immunology , Immunoglobulin G/immunology , Macaca mulatta/immunology , Simian Acquired Immunodeficiency Syndrome/immunologyABSTRACT
Studies have shown that vaccine vectors and route of immunization can differentially activate different arms of the immune system. However, the effects of different HIV vaccine immunogens on mucosal inflammation have not yet been studied. Because mucosal sites are the primary route of HIV infection, we evaluated the cervico-vaginal inflammatory cytokine and chemokine levels of Mauritian cynomolgus macaques following immunization and boost using two different SIV vaccine immunogens. The PCS vaccine delivers 12 20-amino acid peptides overlapping the 12 protease cleavage sites, and the Gag/Env vaccine delivers the full Gag and full Env proteins of simian immunodeficiency virus. We showed that the PCS vaccine prime and boosts induced short-lived, lower level increases of a few pro-inflammatory/chemotactic cytokines. In the PCS-vaccine group only the levels of MCP-1 were significantly increased above the baseline (P = 0.0078, Week 6; P = 0.0078, Week 17; P = 0.0234; Week 51) following multiple boosts. In contrast, immunizations with the Gag/Env vaccine persistently increased the levels of multiple cytokines/chemokines. In the Gag/Env group, higher than baseline levels were consistently observed for IL-8 (P = 0.0078, Week 16; P = 0.0078, Week 17; P = 0.0156, Week 52), IL-1ß (P = 0.0234, Week 16; P = 0.0156, Week 17; P = 0.0156, Week 52), and MIP-1α (P = 0.0313, Week 16; P = 0.0156, Week 17; P = 0.0313, Week 52). Over time, repeated boosts altered the relative levels of these cytokines between the Gag/Env and PCS vaccine group. 18 weeks after final boost with a higher dosage, IP-10 levels (P = 0.0313) in the Gag/Env group remained higher than baseline. Thus, the influence of vaccine immunogens on mucosal inflammation needs to be considered when developing and evaluating candidate HIV vaccines.
Subject(s)
Cervix Uteri/drug effects , Cytokines/metabolism , Gene Products, env/administration & dosage , Gene Products, gag/administration & dosage , Inflammation Mediators/metabolism , SAIDS Vaccines/administration & dosage , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/immunology , Vagina/drug effects , Animals , Cervix Uteri/immunology , Cervix Uteri/metabolism , Female , Gene Products, env/genetics , Gene Products, env/immunology , Gene Products, env/toxicity , Gene Products, gag/genetics , Gene Products, gag/immunology , Gene Products, gag/toxicity , Macaca fascicularis , Mucous Membrane/drug effects , Mucous Membrane/immunology , Mucous Membrane/metabolism , SAIDS Vaccines/genetics , SAIDS Vaccines/immunology , SAIDS Vaccines/toxicity , Simian Acquired Immunodeficiency Syndrome/immunology , Simian Acquired Immunodeficiency Syndrome/virology , Time Factors , Vaccination , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Vaccines, Synthetic/toxicity , Vagina/immunology , Vagina/metabolismABSTRACT
INTRODUCTION: Temelimab (formerly called GNbAC1) is an immunoglobulin (Ig) G4 monoclonal antibody that targets the human endogenous retroviral envelope protein HERV-W-Env, shown to be associated with the pathogenesis of certain autoimmune disorders such as multiple sclerosis (MS) and type 1 diabetes mellitus (T1D). By neutralizing HERV-W-Env, temelimab could act as a disease-modifying therapy for these disorders. It is currently in clinical development for MS and T1D. METHODS: The safety information on temelimab (including potential infusion-related reactions, malignancies, pregnancies and antidrug antibodies) collected during three phase I and four phase II clinical trials was reviewed and is summarized in this article. RESULTS: In the entire development program, 54 healthy volunteers received single doses of temelimab in three phase I studies, and 334 MS or T1D patients received temelimab for a total estimated exposure of 465 patient-years in four phase II trials. No differences were observed between numbers of treatment-emergent adverse events (TEAEs) or serious adverse events (SAEs) between treatment groups (including placebo), and the number of SAEs was limited. Furthermore, no differences were observed in laboratory evaluations, vital signs, electrocardiogram (ECG), or physical examinations between treatment groups. Rare potential infusion-related reactions were reported. Temelimab treatment was not associated with an increased risk of infections or infestations. CONCLUSION: These results suggest that treatment with temelimab was not associated with any particular type of AE. Overall, temelimab was safe and very well tolerated over the tested dose range after repeated monthly administrations.
Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal/therapeutic use , Multiple Sclerosis/drug therapy , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized/adverse effects , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Drug-Related Side Effects and Adverse Reactions/etiology , Gene Products, env/immunology , Humans , Immunoglobulin G/immunologyABSTRACT
The V1V2 loop of the Env protein is a major target for HIV-1 vaccine development because in multiple studies antibodies to this region correlated with protection. Although SAPNs expressed in E. coli elicited anti-V1V2 antibodies, the Env protein is heavily glycosylated. In this study the technology has been adapted for expression in mammalian cells. SAPNs containing a V1V2 loop from a B-subtype transmitter/founder virus were expressed in E. coli, ExpiCHO, and Expi293 cells. Independent of the expression host, particles were well-formed. All SAPNs raised high titers of V1V2-specific antibodies, however, SAPNE.coli induced a mainly anti-V1 response, while SAPNExpiCHO and SAPNExpi293 induced a predominantly anti-V2 response. In an ADCP assay, sera from animals immunized with the SAPNExpiCHO or SAPNExpi293 induced a significant increase in phagocytic activity. This novel way of producing SAPNs displaying glycosylated epitopes could increase the antibody titer, functional activity, and shift the immune response towards the desired pathway.
Subject(s)
HIV Infections/genetics , HIV-1/genetics , Immunity/genetics , Nanoparticles/chemistry , Animals , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/drug effects , Antibodies, Neutralizing/immunology , Epitopes/drug effects , Epitopes/immunology , Escherichia coli/genetics , Gene Products, env/genetics , Gene Products, env/immunology , HIV Infections/immunology , HIV Infections/virology , HIV-1/immunology , HIV-1/pathogenicity , Humans , Immunity/immunology , ImmunizationABSTRACT
Lentiviruses harbour high genetic variability for efficient evasion from host immunity. An attenuated equine infectious anaemia (EIA) vaccine was developed decades ago in China and presented remarkably robust protection against EIA. The vaccine was recently proven to have high genomic diversity, particular in env. However, how and to what extent the high env diversity relates to immune protection remains unclear. In this study, we compared immune protections and responses of three groups of horses stimulated by the high-diversity vaccine EIAV_HD, a single molecular clone of the vaccine EIAV_LD with low env diversity, as well as a constructed vaccine strain EIAV_MD with moderate env diversity. The disparity of virus-host interactions between three env diversity-varied groups (5 horses in each group) was evaluated using clinical manifestation, pathological scores, and env-specific antibody. We found the highest titres of env antibodies (Abs) or neutralizing Abs (nAbs) in the EIAV_HD group, followed by the EIAV_MD group, and the lowest titres in the EIAV_LD group (P<0.05). The occurrence of disease/death was different between EIAV_HD group (1/0), EIAV_MD (2/2), and EIAV_LD group (4/2). A similar env diversity-related linear relationship was observed in the clinical manifestations and pathological changes. This diversity-dependent disparity in changes between the three groups was more distinct after immunosuppression, suggesting that env diversity plays an important role in protection under low host immunocompetence. In summary, inoculation with vaccines with higher genetic diversity could present broader and more efficient protection. Our findings strongly suggest that an abundance of Env antigens are required for efficient protection against lentiviruses.
Subject(s)
Equine Infectious Anemia/prevention & control , Gene Products, env/immunology , Infectious Anemia Virus, Equine/physiology , Polymorphism, Single Nucleotide , Viral Vaccines/administration & dosage , Animals , Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , Equine Infectious Anemia/immunology , Gene Products, env/genetics , High-Throughput Nucleotide Sequencing , Horses , Vaccines, Attenuated , Viral Vaccines/immunology , Viral Vaccines/pharmacology , Virus Replication/drug effectsABSTRACT
Syncytin-1 is the envelope protein of the human endogenous retrovirus W (HERV-W). It has been related to multiple sclerosis (MS) but its role in cellular immunity and its pathogenic mechanism in the autoimmune context are not fully understood. We analyzed syncytin-1 levels in peripheral blood mononuclear cells (PBMC) subsets from healthy donors, MS patients in relapse or remission, and patients with acute infections by flow cytometry. PBMC cultures were also prepared to analyze protein expression kinetics. MS patients had higher levels of syncytin-1 levels than controls. We found that syncytin-1 is elevated in monocytes during MS relapses and infections. Cells expressing syncytin-1, including monocytes, T and B lymphocytes, and NKs presented mainly an activated phenotype and, upon stimulation with LPS, its levels increased rapidly on antigen-presenting cells. Syncytin-1 ligation promoted the activation of monocytes, as demonstrated by the upregulation of CD80 and the nonclassical subset CD14low CD16+ . Our results suggest an important role for syncytin-1 in the activation of leukocytes. Given that the expression of syncytin-1 is upregulated in MS patients, this protein might be contributing to the autoimmune cascade in the disease.
Subject(s)
Endogenous Retroviruses/immunology , Gene Products, env/genetics , Monocytes/virology , Multiple Sclerosis/genetics , Multiple Sclerosis/virology , Pregnancy Proteins/genetics , Adult , B-Lymphocytes/drug effects , B-Lymphocytes/immunology , B-Lymphocytes/virology , B7-1 Antigen/genetics , B7-1 Antigen/immunology , Case-Control Studies , Endogenous Retroviruses/genetics , Female , GPI-Linked Proteins/genetics , GPI-Linked Proteins/immunology , Gene Expression Regulation , Gene Products, env/immunology , Humans , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , Killer Cells, Natural/virology , Lipopolysaccharide Receptors/genetics , Lipopolysaccharide Receptors/immunology , Lipopolysaccharides/pharmacology , Male , Middle Aged , Monocytes/drug effects , Monocytes/immunology , Multiple Sclerosis/immunology , Multiple Sclerosis/pathology , Pregnancy Proteins/immunology , Primary Cell Culture , Receptors, IgG/genetics , Receptors, IgG/immunology , Recurrence , Remission Induction , Signal Transduction , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/virologyABSTRACT
Increased expression of the retroviruses of HERV-W family has been linked to multiple sclerosis (MS) pathophysiology; nothing is known at the moment about MOG-IgG associated disorders. We compared antibody response against HERV-W peptides among patients with MOG-IgG associated disorders, multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG positive neuromyelitis optica spectrum disorder (NMOSD). A total of 102 serum samples were retrospectively analyzed. Antibody reactivity against HERV-W env peptides was similar in MOG-IgG associated disorders and MS, but different from AQP4-IgG positive NMOSD. Our findings expand the diagnostic role of HERV-W antibodies to the spectrum of demyelinating disorders associated with MOG-IgG.
Subject(s)
Autoantibodies/blood , Gene Products, env/immunology , Immunoglobulin G/blood , Multiple Sclerosis/immunology , Myelin-Oligodendrocyte Glycoprotein/immunology , Neuromyelitis Optica/immunology , Pregnancy Proteins/immunology , Adult , Aged , Aged, 80 and over , Aquaporin 4/immunology , Female , Humans , Male , Middle Aged , Retrospective StudiesABSTRACT
SHIV variants KB9 and 89.6 show differential pathogenesis in primate models with KB9 causing rapid CD4 decline while 89.6 failing to induce disease. We attempted to determine whether the differential pathogenicity of KB9 versus 89.6 was a result of differential bystander apoptosis inducing potential (AIP) of the Env glycoproteins from these viruses. We find that the KB9 Env was highly potent at inducing bystander apoptosis in CD4+ target cells compared to 89.6 Env. Cell death induction by KB9 showed classical signs of apoptosis including mitochondrial depolarization, caspase activation and PARP cleavage. Inhibiting Env mediated fusion by T20 peptide inhibited KB9 mediated bystander apoptosis. KB9 and 89.6 differed in terms of co-receptor usage with 89.6 preferring CXCR4 while KB9 using both CXCR4 and CCR5 with equal efficiency. Our study suggests that higher bystander AIP of KB9 Env compared to 89.6 may be the basis for the differential pathogenesis of these viruses.
Subject(s)
Apoptosis , CD4-Positive T-Lymphocytes/virology , Simian Immunodeficiency Virus/immunology , Caspases , Cell Death , Gene Products, env/immunology , HEK293 Cells , HIV-1 , HeLa Cells , Humans , Receptors, CXCR4 , Virulence , Virus SheddingABSTRACT
Immunization vectors based on cytomegalovirus (CMV) have attracted a lot of interest in recent years because of their high efficacy in the simian immunodeficiency virus (SIV) macaque model, which has been attributed to their ability to induce strong, unusually broad, and unconventionally restricted CD8+ T cell responses. To evaluate the ability of CMV-based vectors to mediate protection by other immune mechanisms, we evaluated a mouse CMV (MCMV)-based vector encoding Friend virus (FV) envelope (Env), which lacks any known CD8+ T cell epitopes, for its protective efficacy in the FV mouse model. When we immunized highly FV-susceptible mice with the Env-encoding MCMV vector (MCMV.env), we could detect high frequencies of Env-specific CD4+ T cells after a single immunization. While the control of an early FV challenge infection was highly variable, an FV infection applied later after immunization was tightly controlled by almost all immunized mice. Protection of mice correlated with their ability to mount a robust anamnestic neutralizing antibody response upon FV infection, but Env-specific CD4+ T cells also produced appreciable levels of interferon γ. Depletion and transfer experiments underlined the important role of antibodies for control of FV infection but also showed that while no Env-specific CD8+ T cells were induced by the MCMV.env vaccine, the presence of CD8+ T cells at the time of FV challenge was required. The immunity induced by MCMV.env immunization was long-lasting, but was restricted to MCMV naïve animals. Taken together, our results demonstrate a novel mode of action of a CMV-based vaccine for anti-retrovirus immunization that confers strong protection from retrovirus challenge, which is conferred by CD4+ T cells and antibodies.
Subject(s)
Friend murine leukemia virus/immunology , Muromegalovirus/immunology , Viral Vaccines/immunology , Adoptive Transfer , Animals , Antibodies, Viral/biosynthesis , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/virology , Female , Friend murine leukemia virus/genetics , Friend murine leukemia virus/pathogenicity , Gene Products, env/genetics , Gene Products, env/immunology , Genetic Vectors , Immunization , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Muromegalovirus/genetics , Retroviridae Infections/immunology , Retroviridae Infections/prevention & control , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology , Viral Vaccines/geneticsABSTRACT
A study in nonhuman primates reported that infusions of an antibody against α4ß7 integrin, in combination with antiretroviral therapy, showed consistent, durable control of simian immunodeficiency virus (SIV) in rhesus macaques. The antibody used has pleiotropic effects, so we set out to gain insight into the underlying mechanism by comparing this treatment to treatment with non-neutralizing monoclonal antibodies against the SIV envelope glycoprotein that only block α4ß7 binding to SIV Env but have no other host-directed effects. Similar to the initial study, we used an attenuated strain of SIV containing a stop codon in nef. The study used 30 macaques that all began antiretroviral therapy and then were divided into five groups to receive different antibody treatments. Unlike the published report, we found no sustained virologic control by these treatments in vivo.
Subject(s)
Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/therapeutic use , Integrin alpha4/immunology , Integrin beta Chains/immunology , Simian Acquired Immunodeficiency Syndrome/therapy , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/genetics , Simian Immunodeficiency Virus/immunology , Animals , Antibodies, Monoclonal/administration & dosage , Antibodies, Viral/administration & dosage , DNA, Viral/blood , Gene Products, env/immunology , HIV Infections/therapy , Macaca mulatta , RNA, Viral/blood , Simian Acquired Immunodeficiency Syndrome/blood , Simian Acquired Immunodeficiency Syndrome/drug therapy , Simian Immunodeficiency Virus/physiology , T-Lymphocytes/immunology , Viral Load , Viral Regulatory and Accessory Proteins/genetics , Viral Regulatory and Accessory Proteins/immunology , Virus ReplicationABSTRACT
Rationale: Antiretroviral therapy can effectively suppress HIV-1 replication in the peripheral blood to an undetectable level. However, elimination of the latent virus in reservoirs remains a challenge and is a major obstacle in the treatment of HIV-1-infected patients. Exosomes exhibit huge promise as an endogenous drug delivery nanosystem for delivering drugs to solid tissues given their unique properties, including low immunogenicity, innate stability, high delivery efficiency, and most importantly the ability to penetrate solid tissues due to their lipophilic properties. Methods: We engineered and expressed the scFv of a high affinity HIV-1-specific monoclonal antibody, 10E8, on the exosomal surface (10E8scFv-exos). Subsequently, the 10E8scFv-exos were loaded with curcumin (Cur), a chemical that kills HIV-1-infected cells, or miR-143, an apoptosis-inducing miRNA. We tested the ability of 10E8scFv-exos to deliver cargo to Env+ target cells and tissues, as well as their ability to suppress HIV-1 infection. Results: 10E8scFv-exos efficiently targeted CHO cells expressing a trimeric gp140 on their surface (Env+ cells) in vitro, as demonstrated by confocal imaging and flow cytometry. 10E8scFv-exos loaded with Cur or miR-143 showed specific killing of Env+ cells. In addition, 10E8scFv-exos loaded with Cur or miR-143 could suppress p24 expression in an HIV-1 latency cell line ACH2 and in PBMCs from an ART-treated HIV-1-infected patient. In an NCG mouse model grafted with tumorigenic Env+ CHO cells and which had developed solid tissue tumors, intravenously injected 10E8scFv-exos targeted the Env-expressing tissues and delivered Cur to induce a strong suppression of the Env+ tumor growth with low toxicity. Conclusion: In principle, engineered exosomes can deliver anti-HIV agents to solid tissues by specifically targeting cells expressing viral envelop proteins and inducing cell killing, suggesting that such an approach could be developed for eradicating virus-infected cells in tissue reservoirs.
Subject(s)
Anti-HIV Agents/administration & dosage , Drug Delivery Systems , Extracellular Vesicles/metabolism , HIV Antibodies/genetics , HIV Infections/drug therapy , HIV-1/immunology , Animals , Antibodies, Monoclonal/administration & dosage , CHO Cells , Cricetulus , Curcumin/administration & dosage , Exosomes/immunology , Exosomes/metabolism , Extracellular Vesicles/immunology , Feasibility Studies , Female , Gene Products, env/immunology , HIV Infections/virology , HIV-1/drug effects , HIV-1/physiology , Humans , Mice , MicroRNAs/administration & dosage , RNAi Therapeutics , Single-Chain Antibodies/genetics , Virus Latency/drug effectsABSTRACT
Cytomegalovirus (CMV) is a ubiquitous ß-herpesvirus that establishes life-long latent infection in a high percentage of the population worldwide. CMV induces the strongest and most durable CD8+ T cell response known in human clinical medicine. Due to its unique properties, the virus represents a promising candidate vaccine vector for the induction of persistent cellular immunity. To take advantage of this, we constructed a recombinant murine CMV (MCMV) expressing an MHC-I restricted epitope from influenza A virus (IAV) H1N1 within the immediate early 2 (ie2) gene. Only mice that were immunized intranasally (i.n.) were capable of controlling IAV infection, despite the greater potency of the intraperitoneally (i.p.) vaccination in inducing a systemic IAV-specific CD8+ T cell response. The protective capacity of the i.n. immunization was associated with its ability to induce IAV-specific tissue-resident memory CD8+ T (CD8TRM) cells in the lungs. Our data demonstrate that the protective effect exerted by the i.n. immunization was critically mediated by antigen-specific CD8+ T cells. CD8TRM cells promoted the induction of IFNγ and chemokines that facilitate the recruitment of antigen-specific CD8+ T cells to the lungs. Overall, our results showed that locally applied MCMV vectors could induce mucosal immunity at sites of entry, providing superior immune protection against respiratory infections.