RESUMEN

Viral infection generally induces polyclonal neutralizing antibody responses. However, how many lineages of antibody responses can fully represent the neutralization activities in sera has not been well studied. Using the newly designed stable HIV-1 Env trimer as hook, we isolated two distinct broadly neutralizing antibodies (bnAbs) from Chinese rhesus macaques infected with SHIV1157ipd3N4 for 5 years. One lineage of neutralizing antibodies (JT15 and JT16) targeted the V2-apex in the Env trimers, similar to the J038 lineage bnAbs identified in our previous study. The other lineage neutralizing antibody (JT18) targeted the V3 crown region in the Env, which strongly competed with human 447-52D. Each lineage antibody neutralized a different set of viruses. Interestingly, when the two neutralizing antibodies from different lineages isolated from the same macaque were combined, the mixture had a neutralization breath very similar to that from the cognate sera. Our study demonstrated that a minimum of two different neutralizing antibodies can fully recapitulate the serum neutralization breadth. This observation can have important implications in AIDS vaccine design.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , Macaca mulatta , Síndrome de Inmunodeficiencia Adquirida del Simio , Macaca mulatta/inmunología , Animales , VIH-1/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Humanos , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/sangre , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/sangre , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Pruebas de Neutralización

RESUMEN

We aim to develop an in vivo hematopoietic stem cell (HSC) gene therapy approach for persistent control/protection of HIV-1 infection based on the stable expression of a secreted decoy protein for HIV receptors CD4 and CCR5 (eCD4-Ig) from blood cells. HSCs in mice and a rhesus macaque were mobilized from the bone marrow and transduced by an intravenous injection of HSC-tropic, integrating HDAd5/35++ vectors expressing rhesus eCD4-Ig. In vivo HSC transduction/selection resulted in stable serum eCD4-Ig levels of ∼100 µg/mL (mice) and >20 µg/mL (rhesus) with half maximal inhibitory concentrations (IC50s) of 1 µg/mL measured by an HIV neutralization assay. After simian-human-immunodeficiency virus D (SHIV.D) challenge of rhesus macaques injected with HDAd-eCD4-Ig or a control HDAd5/35++ vector, peak plasma viral load levels were ∼50-fold lower in the eCD4-Ig-expressing animal. Furthermore, the viral load was lower in tissues with the highest eCD4-Ig expression, specifically the spleen and lymph nodes. SHIV.D challenge triggered a selective expansion of transduced CD4+CCR5+ cells, thereby increasing serum eCD4-Ig levels. The latter, however, broke immune tolerance and triggered anti-eCD4-Ig antibody responses, which could have contributed to the inability to eliminate SHIV.D. Our data will guide us in the improvement of the in vivo approach. Clearly, our conclusions need to be validated in larger animal cohorts.

Asunto(s)

Infecciones por VIH , VIH-1 , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Humanos , Animales , Ratones , Macaca mulatta , Virus de la Inmunodeficiencia de los Simios/genética , Células Madre Hematopoyéticas , Síndrome de Inmunodeficiencia Adquirida del Simio/terapia

RESUMEN

Understanding maturation pathways of broadly neutralizing antibodies (bnAbs) against HIV-1 can be highly informative for HIV-1 vaccine development. A lineage of J038 bnAbs is now obtained from a long-term SHIV-infected macaque. J038 neutralizes 54% of global circulating HIV-1 strains. Its binding induces a unique "up" conformation for one of the V2 loops in the trimeric envelope glycoprotein and is heavily dependent on glycan, which provides nearly half of the binding surface. Their unmutated common ancestor neutralizes the autologous virus. Continuous maturation enhances neutralization potency and breadth of J038 lineage antibodies via expanding antibody-Env contact areas surrounding the core region contacted by germline-encoded residues. Developmental details and recognition features of J038 lineage antibodies revealed here provide a new pathway for elicitation and maturation of V2-targeting bnAbs.

Asunto(s)

Infecciones por VIH , Seropositividad para VIH , VIH-1 , Anticuerpos Neutralizantes , Anticuerpos ampliamente neutralizantes , Epítopos , Anticuerpos Anti-VIH , Humanos , Productos del Gen env del Virus de la Inmunodeficiencia Humana

RESUMEN

Chimeric simian and human immunodeficiency viruses (SHIVs) are appropriate animal models for the human immunodeficiency virus (HIV) because HIV has quite a narrow host range. Additionally, SHIVs that encode the HIV-1 Env protein and are infectious to macaques have many strains that show different pathogenesis, such as the highly pathogenic SHIV-KS661 and the less pathogenic SHIV-#64. Therefore, we used SHIVs to understand different aspects of AIDS pathogenesis. In a previous study, we established a mathematical model of in vivo early SHIV infection dynamics, which revealed the expected uninfected and infected dynamics in Rhesus macaques. In concrete, the number of uninfected CD4+ T cells in SHIV-KS661-infected Rhesus macaques decreased more significantly and rapidly than that of SHIV-#64 Rhesus macaques, and these Rhesus macaques did not any induce host immune response. In contrast, the number of uninfected CD4+ T cells in SHIV-#64-infected Rhesus macaques is maintained, and host immune response developed. Although we considered that the peak viral load might determine whether systemic CD4+ T cell depletion occurs or host immune responses develop, we could not investigate this because our model quantified only SHIV infection prior to the development of the pathogenicity or host immune responses. Therefore, we developed a new mathematical model to investigate why SHIV-#64 and SHIV-KS661 showed different long-term viral dynamics. We fitted our new model considering antibody responses to our experimental datasets that included antibody titers, CD4+ T cells, and viral load data. We performed a maximum likelihood estimation using a non-linear mixed effect model. From the results, we derived the basic reproduction numbers of SHIV-#64 and SHIV-KS661 from intravenous infection (IV) and SHIV-KS661 from intrarectal infection (IR), as well as the antiviral effects of antibodies against SHIV-#64(IV) and SHIV-KS661(IR). We found significant differences between the basic reproduction number of SHIV-#64(IV) or -KS661(IR) and that of SHIV-KS661(IV). We found no clear difference between the antiviral effects of SHIV-#64(IV) and SHIV-KS661(IR), and revealed that an antiviral effect more than 90% of that of maximum antibody responses was induced from initial antibody responses (i.e., antibody response just after its inducement). In conclusion, we found that the basic reproduction number, rather than SHIV strains determines whether systemic CD4+ T cell depletion develops, and the subsequent antibody responses occurs.

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Animales , Antivirales , Humanos , Inmunidad , Macaca mulatta , Carga Viral

RESUMEN

Non-human primates (NHP) are the only animal model suitable to evaluate the protection efficacy of HIV-1 vaccines. It is important to understand how and when neutralizing antibodies (nAbs) with specificities similar to those of human broadly neutralizing antibodies (bnAbs) develop in NHPs. To address these questions, we determined plasma neutralization specificities in two macaques which developed neutralization breadth after long-term simian/human immunodeficiency virus (SHIV) infection and identified neutralization escape mutations by analyzing the env sequences from longitudinal plasma samples. Neutralization activities targeting V2, CD4bs, V3 and gp120-gp41 interface only became detectable in week 350 plasma from macaques G1015R and G1020R using 25710 env mutants. When mapped with CAP45 env mutants, only V2 specificity was detected at week 217 and persisted until week 350 in G1015R. Neutralization escape mutations were found in CD4bs and V2 regions. However, all of them were different from those resistant mutations identified for human bnAbs. These results show that nAbs with specificities similar to human bnAbs are only detectable after long-term SHIV infection and that neutralization escape mutations in macaques are different from those found in HIV-1-infected individuals. These findings can have important implications in the best utilization of the NHP model to evaluate HIV-1 vaccines.

Asunto(s)

Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Animales , Anticuerpos Neutralizantes/biosíntesis , Genes env/genética , Genes env/inmunología , Anticuerpos Anti-VIH/biosíntesis , Seropositividad para VIH , Macaca mulatta/inmunología , Mutación , Pruebas de Neutralización , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/genética , Factores de Tiempo

RESUMEN

Since chimeric simian and human immunodeficiency viruses (SHIVs) used here, that is, SHIV-#64 and -KS661 utilize both CCR5 and CXCR4 chemokine receptors, they have broad target cell properties. A highly pathogenic SHIV strain, SHIV-KS661, causes an infection that systemically depletes the CD4+ T cells of Rhesus macaques, while a less pathogenic strain, SHIV-#64, does not cause severe symptoms in the macaques. In our previous studies, we established in vitro quantification system for virus infection dynamics, and concluded that SHIV-KS661 effectively produces infectious virions compared with SHIV-#64 in the HSC-F cell culture. However, in vivo dynamics of SHIV infection have not been well understood. To quantify SHIV-#64 and -KS661 infection dynamics in Rhesus macaques, we developed a novel approach and analyzed total CD4+ T cells and viral load in peripheral blood, and reproduced the expected dynamics for the uninfected and infected CD4+ T cells in silico. Using our previous cell culture experimental datasets, we revealed that an infection rate constant is different between SHIV-#64 and -KS661, but the viral production rate and the death rate are similar for the both strains. Thus, here, we assumed these relations in our in vivo data and carried out the data fitting. We performed Bayesian estimation for the whole dataset using MCMC sampling, and simultaneously fitted our novel model to total CD4+ T cells and viral load of SHIV-#64 and -KS661 infection. Our analyses explained that the Malthusian parameter (i.e., fitness of virus infection) and the basic reproduction number (i.e., potential of virus infection) for SHIV-KS661 are significantly higher than those of SHIV-#64. In addition, we demonstrated that the number of uninfected CD4+ T cells in SHIV-KS661 infected Rhesus macaques decreases to the significantly lower value than that before the inoculation several days earlier compared with SHIV-#64 infection. Taken together, the differences between SHIV-#64 and -KS661 infection before the peak viral load might determine the subsequent destiny, that is, whether the systemic CD4+ T cell depletion occurs or the host immune response develop.

Asunto(s)

Infecciones por VIH/virología , VIH/patogenicidad , Macaca mulatta/virología , Virus de la Inmunodeficiencia de los Simios/patogenicidad , Animales , Teorema de Bayes , Recuento de Linfocito CD4 , Humanos , Macaca mulatta/sangre , Linfocitos T/virología , Carga Viral , Virión , Replicación Viral

RESUMEN

Improved vaccine-mediated protection against HIV-1 requires a thorough understanding of the mode of HIV-1 transmission and how various immune responses control transmission. Cell-associated HIV-1 is infectious and contributes to HIV-1 transmission in humans. Non-human primate models of cell-associated SIV infection demonstrate that cell-associated SIV is more infectious than cell-free SIV. In a recently described chimeric simian⁻human immunodeficiency virus (SHIV) macaque model, it was demonstrated that an occult infection with cell-associated SHIV can be established that evades passive protection with a broadly neutralizing antibody (bnAb). Indeed, considerable in vitro data shows that bnAbs have less efficacy against cell-associated HIV-1 than cell-free HIV-1. Optimizing the protective capacity of immune responses such as bnAbs against cell-associated infections may be needed to maximize their protective efficacy.

Asunto(s)

Anticuerpos Neutralizantes/inmunología , Transmisión de Enfermedad Infecciosa/prevención & control , Anticuerpos Anti-VIH/inmunología , Infecciones por VIH/prevención & control , Infecciones por VIH/transmisión , VIH-1/inmunología , Animales , Modelos Animales de Enfermedad , Inmunización Pasiva , Macaca

RESUMEN

A preventive human immunodeficiency virus type 1 (HIV-1) vaccine is an essential part of the strategy to eradicate AIDS. A critical question is whether antibodies that do not neutralize primary isolate (tier 2) HIV-1 strains can protect from infection. In this study, we investigated the ability of an attenuated poxvirus vector (NYVAC) prime-envelope gp120 boost to elicit potentially protective antibody responses in a rhesus macaque model of mucosal simian-human immunodeficiency virus (SHIV) infection. NYVAC vector delivery of a group M consensus envelope, trivalent mosaic envelopes, or a natural clade B isolate B.1059 envelope elicited antibodies that mediated neutralization of tier 1 viruses, cellular cytotoxicity, and phagocytosis. None of the macaques made neutralizing antibodies against the tier 2 SHIV SF162P3 used for mucosal challenge. Significant protection from infection was not observed for the three groups of vaccinated macaques compared to unvaccinated macaques, although binding antibody to HIV-1 Env correlated with decreased viremia after challenge. Thus, NYVAC Env prime-gp120 boost vaccination elicited polyfunctional, nonneutralizing antibody responses with minimal protective activity against tier 2 SHIV mucosal challenge.IMPORTANCE The antibody responses that confer protection against HIV-1 infection remain unknown. Polyfunctional antibody responses correlated with time to infection in previous macaque studies. Determining the ability of vaccines to induce these types of responses is critical for understanding how to improve upon the one efficacious human HIV-1 vaccine trial completed thus far. We characterized the antibody responses induced by a NYVAC-protein vaccine and determined the protective capacity of polyfunctional antibody responses in an R5, tier 2 mucosal SHIV infection model.

Asunto(s)

Vacunas contra el SIDA/inmunología , VIH-1/inmunología , Inmunización Secundaria , Inmunogenicidad Vacunal , Virus de la Inmunodeficiencia de los Simios/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Animales , Humanos , Macaca mulatta

RESUMEN

HIV vaccine development is focused on designing immunogens and delivery methods that elicit protective immunity. We evaluated a combination of adenovirus (Ad) vectors expressing HIV 1086.C (clade C) envelope glycoprotein (Env), SIV Gag p55, and human pegivirus GBV-C E2 glycoprotein. We compared replicating simian (SAd7) with nonreplicating human (Ad4) adenovirus-vectored vaccines paired with recombinant proteins in a novel prime-boost regimen in rhesus macaques, with the goal of eliciting protective immunity against SHIV challenge. In both vaccine groups, plasma and buccal Env-specific IgG, tier 1 heterologous neutralizing antibodies, and antibody-dependent cell-mediated viral inhibition were readily generated. High Env-specific T cell responses elicited in all vaccinees were significantly greater than responses targeting Gag. After three intrarectal exposures to heterologous tier 1 clade C SHIV, all 10 sham-vaccinated controls were infected, whereas 4/10 SAd7- and 3/10 Ad4-vaccinated macaques remained uninfected or maintained tightly controlled plasma viremia. Time to infection was significantly delayed in SAd7-vaccinated macaques compared to the controls. Cell-associated and plasma virus levels were significantly lower in each group of vaccinated macaques compared to controls; the lowest plasma viral burden was found in animals vaccinated with the SAd7 vectors, suggesting superior immunity conferred by the replicating simian vectors. Furthermore, higher V1V2-specific binding antibody titers correlated with viral control in the SAd7 vaccine group. Thus, recombinant Ad plus protein vaccines generated humoral and cellular immunity that was effective in either protecting from SHIV acquisition or significantly reducing viremia in animals that became infected, consequently supporting additional development of replicating Ad vectors as HIV vaccines.IMPORTANCE There is a well-acknowledged need for an effective AIDS vaccine that protects against HIV infection and limits in vivo viral replication and associated pathogenesis. Although replicating virus vectors have been advanced as HIV vaccine platforms, there have not been any direct comparisons of the replicating to the nonreplicating format. The present study directly compared the replicating SAd7 to nonreplicating Ad4 vectors in macaques and demonstrated that in the SAd7 vaccine group, the time to infection was significantly delayed compared to the control group, and V1V2 Env-specific binding antibodies correlated with viral outcomes. Viral control was significantly enhanced in vaccinated macaques compared to controls, and in infected SAd7-vaccinated macaques compared to Ad4-vaccinated macaques, suggesting that this vector may have conferred more effective immunity. Because blocking infection is so difficult with current vaccines, development of a vaccine that can limit viremia if infection occurs would be valuable. These data support further development of replicating adenovirus vectors.

Asunto(s)

Adenoviridae , Vectores Genéticos , Vacunas contra el SIDAS/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunas Sintéticas , Adenoviridae/genética , Adenoviridae/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Especificidad de Anticuerpos/inmunología , Recuento de Linfocito CD4 , Línea Celular , Vectores Genéticos/genética , Vectores Genéticos/inmunología , Genotipo , VIH/inmunología , Humanos , Inmunidad Humoral , Inmunización/métodos , Estimación de Kaplan-Meier , Macaca mulatta , Masculino , Unión Proteica/inmunología , Vacunas contra el SIDAS/administración & dosificación , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/genética , Linfocitos T/inmunología , Linfocitos T/metabolismo , Proteínas del Envoltorio Viral/inmunología , Carga Viral

RESUMEN

HIV infection not only destroys CD4+ T cells but also inflicts serious damage to the B-cell compartment, such as lymphadenopathy, destruction of normal B-cell follicle architecture, polyclonal hypergammaglobulinemia, increased apoptosis of B cells, and irreversible loss of memory B-cell responses with advanced HIV disease. Subepithelial B cells and plasma cells are also affected, which results in loss of mucosal IgG and IgA antibodies. This leaves the mucosal barrier vulnerable to bacterial translocation. The ensuing immune activation in mucosal tissues adds fuel to the fire of local HIV replication. We postulate that compromised mucosal antibody defenses also facilitate superinfection of HIV-positive individuals with new HIV strains. This in turn sets the stage for the generation of circulating recombinant forms of HIV. What can the mucosal B-cell compartment contribute to protect a healthy, uninfected host against mucosal HIV transmission? Here, we discuss proof-of-principle studies we have performed using passive mucosal immunization, i.e., topical administration of preformed anti-HIV monoclonal antibodies (mAbs) as IgG1, dimeric IgA1 (dIgA1), and dIgA2 isotypes, alone or in combination. Our data indicate that mucosally applied anti-HIV envelope mAbs can provide potent protection against mucosal transmission of simian-human immunodeficiency virus. Our review also discusses the induction of mucosal antibody defenses by active vaccination and potential strategies to interrupt the vicious cycle of bacterial translocation, immune activation, and stimulation of HIV replication in individuals with damaged mucosal barriers.

RESUMEN

BACKGROUND: The host range of human immunodeficiency virus (HIV) is quite narrow. Therefore, analyzing HIV-1 pathogenesis in vivo has been limited owing to lack of appropriate animal model systems. To overcome this, chimeric simian and human immunodeficiency viruses (SHIVs) that encode HIV-1 Env and are infectious to macaques have been developed and used to investigate the pathogenicity of HIV-1 in vivo. So far, we have many SHIV strains that show different pathogenesis in macaque experiments. However, dynamic aspects of SHIV infection have not been well understood. To fully understand the dynamic properties of SHIVs, we focused on two representative strains-the highly pathogenic SHIV, SHIV-KS661, and the less pathogenic SHIV, SHIV-#64-and measured the time-course of experimental data in cell culture. METHODS: We infected HSC-F with SHIV-KS661 and -#64 and measured the concentration of Nef-negative (target) and Nef-positive (infected) HSC-F cells, the total viral load, and the infectious viral load daily for 9 days. The experiments were repeated at two different multiplicities of infection, and a previously developed mathematical model incorporating the infectious and non-infectious viruses was fitted to the full dataset of each strain simultaneously to characterize the infection dynamics of these two strains. RESULTS AND CONCLUSIONS: We quantified virological indices including virus burst sizes and basic reproduction number of both SHIV-KS661 and -#64. Comparing the burst size of total and infectious viruses (viral RNA copies and TCID50, respectively), we found that there was a statistically significant difference between the infectious virus burst size of SHIV-KS661 and -#64, while there was no significant difference between the total virus burst size. Furthermore, our analyses showed that the fraction of infectious virus among the produced SHIV-KS661 viruses, which is defined as the infectious viral load (TCID50/ml) divided by the total viral load (RNA copies/ml), is more than 10-fold higher than that of SHIV-#64 during overall infection (i.e., for 9 days). Taken together, we conclude that the highly pathogenic SHIV produces infectious virions more effectively than the less pathogenic SHIV in cell culture.

Asunto(s)

VIH-1/fisiología , Modelos Teóricos , Virus de la Inmunodeficiencia de los Simios/fisiología , Carga Viral/fisiología , Virión/fisiología , Animales , Línea Celular , Humanos

RESUMEN

Since the discovery of the first inhibitors of HIV replication, drug resistance has been a major problem in HIV therapy due in part to the high mutation rate of HIV. Therefore, the development of a predictive animal model is important to identify impending resistance mutations and to possibly inform treatment decisions. Significant advances have been made possible through use of nonhuman primates infected by SIV, SHIV, and simian-tropic HIV-1 (stHIV-1), and use of humanized mouse models of HIV-1 infections. In this review, we describe some of the findings from animal models used for the preclinical testing of integrase strand transfer inhibitors. These models have led to important findings about the potential role of integrase strand transfer inhibitors in both the prevention and treatment of HIV-1 infection.

RESUMEN

Marginal zone (MZ) B cells generate T-independent antibody responses to pathogens before T-dependent antibodies arise in germinal centers. They have been identified in cynomolgus monkeys and monitored during acute SIV infection, yet have not been well-studied in rhesus macaques. Here we characterized rhesus macaque MZ B cells, present in secondary lymphoid tissue but not peripheral blood, as CD19(+), CD20(+), CD21(hi), IgM(+), CD22(+), CD38(+), BTLA(+), CD40(+), CCR6(+) and BCL-2(+). Compared to healthy macaques, SHIVSF162P4-infected animals showed decreased total B cells and MZ B cells and increased MZ B cell Ki-67 expression early in chronic infection. These changes persisted in late chronic infection, despite viremia reductions to low or undetectable levels. Expression levels of additional phenotypic markers and RNA PCR array analyses were in concert with continued low-level activation and diminished function of MZ B cells. We conclude that MZ B-cell dysregulation and dysfunction associated with SIV/HIV infection are not readily reversible.

Asunto(s)

Linfocitos B/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/inmunología , Animales , Antígenos CD/análisis , Linfocitos B/química , Linfocitos B/clasificación , Enfermedad Crónica , Perfilación de la Expresión Génica , Inmunoglobulina M/análisis , Inmunofenotipificación , Antígeno Ki-67/análisis , Recuento de Linfocitos , Tejido Linfoide/patología , Macaca mulatta , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Síndrome de Inmunodeficiencia Adquirida del Simio/patología , Viremia

RESUMEN

HIV research has made rapid progress and led to remarkable achievements in recent decades, the most important of which are combination antiretroviral therapies (cART). However, in the absence of a vaccine, the pandemic continues, and additional strategies are needed. The 'towards an HIV cure' initiative aims to eradicate HIV or at least bring about a lasting remission of infection during which the host can control viral replication in the absence of cART. Cases of spontaneous and treatment-induced control of infection offer substantial hope. Here, we describe the scientific knowledge that is lacking, and the priorities that have been established for research into a cure. We discuss in detail the immunological lessons that can be learned by studying natural human and animal models of protection and spontaneous control of viraemia or of disease progression. In particular, we describe the insights we have gained into the immune mechanisms of virus control, the impact of early virus-host interactions and why chronic inflammation, a hallmark of HIV infection, is an obstacle to a cure. Finally, we enumerate current interventions aimed towards improving the host immune response.

Asunto(s)

Síndrome de Inmunodeficiencia Adquirida/prevención & control , Infecciones por VIH/inmunología , Interacciones Huésped-Patógeno/inmunología , Inflamación/inmunología , Investigación/tendencias , Replicación Viral/inmunología , Síndrome de Inmunodeficiencia Adquirida/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos

RESUMEN

Human immunodeficiency virus (HIV)-1 subtype CRF01_AE is one of the major HIV-1 subtypes that dominate the global epidemic. However, its drug resistance, associated mutations, and viral fitness have not been systemically studied, because available chimeric simian-HIVs (SHIVs) usually express the HIV-1 reverse transcriptase (rt) gene of subtype B HIV-1, which is different from subtype CRF01_AE HIV-1. In this study, a recombinant plasmid, pRT-SHIV/AE, was constructed to generate a chimeric RT-SHIV/AE by replacing the rt gene of simian immunodeficiency virus (SIVmac239) with the counterpart of Chinese HIV-1 subtype CRF01_AE. The infectivity, replication capacity, co-receptor tropism, drug sensitivity, and genetic stability of RT-SHIV/AE were characterized. The new chimeric RT-SHIV/AE effectively infected and replicated in human T cell line and rhesus peripheral blood mononuclear cells (rhPBMC). The rt gene of RT-SHIV/AE lacked the common mutation (T215I) associated with drug resistance. RT-SHIV-AE retained infectivity and immunogenicity, similar to that of its counterpart RT-SHIV/TC virus following intravenous inoculation in Chinese rhesus macaque. RT-SHIV-AE was more sensitive to nucleoside reverse transcriptase inhibitors (NRTIs) than the RT-SHIV/TC. RT-SHIV/AE was genetically stable in Chinese rhesus macaque. The new chimeric RT-SHIV/AE may be a valuable tool for evaluating the efficacy of the rt-based antiviral drugs against the subtype CRF01_AE HIV-1.

Asunto(s)

Transcriptasa Inversa del VIH/genética , VIH/genética , Virus Reordenados/genética , Virus de la Inmunodeficiencia de los Simios/genética , Secuencia de Aminoácidos , Animales , Fármacos Anti-VIH/farmacología , Línea Celular , China , Clonación Molecular , Modelos Animales de Enfermedad , Sistemas de Liberación de Medicamentos , Células HEK293 , VIH/fisiología , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Macaca mulatta/virología , Datos de Secuencia Molecular , Plásmidos/genética , ARN Viral/sangre , Virus Reordenados/fisiología , Inhibidores de la Transcriptasa Inversa/farmacología , Virus de la Inmunodeficiencia de los Simios/fisiología , Linfocitos T/citología , Linfocitos T/virología , Replicación Viral

RESUMEN

BACKGROUND: A rhesus macaque developed chronic anemia, lymphocytic leukocytopenia, fever, and anorexia while immunodeficient following inoculation with a simian-human immunodeficiency virus. METHODS: A complete blood count, peripheral blood smear, polymerase chain reaction and gene sequence were performed. RESULTS: Blood smears demonstrated persistent intraerythrocytic piroplasms with rare Maltese cross forms. Babesia microti-like protozoa were confirmed by polymerase chain reaction and sequencing of the 18S ribosomal RNA gene. CONCLUSION: With continued use of non-human primates as models for human diseases, infection and complications from babesiosis should be monitored.

Asunto(s)

Animales de Laboratorio , Babesia microti/aislamiento & purificación , Babesiosis/diagnóstico , Macaca mulatta , Enfermedades de los Monos/diagnóstico , Síndrome de Inmunodeficiencia Adquirida del Simio/complicaciones , Animales , Babesia microti/genética , Babesiosis/parasitología , ADN Protozoario/genética , Femenino , VIH-1/fisiología , Datos de Secuencia Molecular , Enfermedades de los Monos/parasitología , Enfermedades de los Monos/virología , Reacción en Cadena de la Polimerasa , ARN Ribosómico 18S/genética , Análisis de Secuencia de ADN , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/fisiología

RESUMEN

BACKGROUND: Long-acting, hormonal contraception may increase HIV risk. Copper intrauterine devices (IUDs) could serve as non-hormonal alternatives. We pilot a pigtail macaque model for evaluating HIV susceptibility factors during copper IUD use. METHODS: Frameless and flexible GyneFix(®) copper IUDs were surgically implanted into three SHIVSF 162p3 -positive macaques via hysterotomy and monitored for up to 4 months. Four macaques served as non-IUD controls. RESULTS: All animals retained the devices without complications. No consistent change in vaginal viral RNA or inflammatory cytokines was seen. Two animals had altered menstrual cycles and experienced marked thinning of vaginal epithelium after IUD insertion. Histological examination of uterine tissue at necropsy revealed endometrial ulceration and lymphocytic inflammation with glandular loss at sites of direct IUD contact. CONCLUSIONS: Although the need for insertion surgery could limit its usefulness, this model will allow studies on copper IUDs and SHIV shedding, disease progression, and HIV susceptibility factors.

Asunto(s)

Infecciones por VIH/prevención & control , Dispositivos Intrauterinos de Cobre/efectos adversos , Macaca nemestrina , Síndrome de Inmunodeficiencia Adquirida del Simio/prevención & control , Animales , Anticoncepción , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades/inmunología , Susceptibilidad a Enfermedades/fisiopatología , Susceptibilidad a Enfermedades/virología , Femenino , VIH/fisiología , Infecciones por VIH/inmunología , Infecciones por VIH/fisiopatología , Infecciones por VIH/virología , Humanos , Macaca nemestrina/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/fisiopatología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Virus de la Inmunodeficiencia de los Simios/aislamiento & purificación , Útero/inmunología , Esparcimiento de Virus

RESUMEN

The mucosal epithelia together with adaptive immune responses, such as local production and secretion of dimeric and polymeric immunoglobulin A (IgA), are a crucial part of the first line of defense against invading pathogens. IgA is primarily secreted as SIgA and plays multiple roles in mucosal defense. The study of SIgA-mediated protection is an important area of research in mucosal immunity but an easy, fast and reproducible method to generate pathogen-specific SIgA in vitro has not been available. We report here a new method to produce SIgA by co-purification of dimeric IgA, containing J chain, and recombinant human SC expressed in CHO cells. We previously reported the generation, production and characterization of the human recombinant monoclonal antibody IgA2 b12. This antibody, derived from the variable regions of the neutralizing anti-HIV-1 mAb IgG1 b12, blocked viral attachment and uptake by epithelial cells in vitro. We used a cloned CHO cell line that expresses monomeric, dimeric and polymeric species of IgA2 b12 for large-scale production of dIgA2 b12. Subsequently, we generated a CHO cell line to express recombinant human secretory component (rhSC). Here, we combined dIgA2 b12 and CHO-expressed rhSC via column chromatography to produce SIgA2 b12 that remains fully intact upon elution with 0.1M citric acid, pH 3.0. We have performed biochemical analysis of the synthesized SIgA to confirm the species is of the expected size and retains the functional properties previously described for IgA2 b12. We show that SIgA2 b12 binds to the HIV-1 gp120 glycoprotein with similar apparent affinity to that of monomeric and dimeric forms of IgA2 b12 and neutralizes HIV-1 isolates with similar potency. An average yield of 6 mg of SIgA2 b12 was achieved from the combination of 20mg of purified dIgA2 b12 and 2L of rhSC-containing CHO cell supernatant. We conclude that synthesized production of stable SIgA can be generated by co-purification. This process introduces a simplified means of generating a variety of pathogen-specific SIgA antibodies for research and clinical applications.

Asunto(s)

Anticuerpos Neutralizantes/biosíntesis , Inmunoglobulina A Secretora/biosíntesis , Animales , Anticuerpos Neutralizantes/aislamiento & purificación , Células CHO , Cromatografía de Afinidad , Cricetinae , Cricetulus , Proteína gp120 de Envoltorio del VIH/inmunología , VIH-1/inmunología , Humanos , Inmunoglobulina A Secretora/aislamiento & purificación , Unión Proteica , Ingeniería de Proteínas , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación

RESUMEN

BACKGROUND: The CRF08_BC strain is one of the most predominant circulating Human immunodeficiency virus type 1 (HIV-1) strains in the Chinese pandemic. A simian-human immunodeficiency virus (SHIV) encoding HIV-1 CRF08_BC env is highly desirable to evaluate candidate AIDS vaccines in non-human primates. METHODS: SHIV-KBQJ-12, which carries the envelope glycoprotein from QJ001, an infectious molecular clone of HIV-1 CRF08_BC, was generated. The replication capacity of SHIV-KBQJ-12 was determined both in human and rhesus macaque (Macaca mulatta) peripheral blood mononuclear cells (PBMCs) and in Chinese rhesus macaques. RESULTS: SHIV-KBQJ-12 replicated efficiently in human and macaque PBMCs and displayed a preference for CCR5 as an entry coreceptor. Productive infection of two macaques by intravenous inoculation with SHIV-KBQJ-12 was confirmed. CONCLUSIONS: SHIV-KBQJ-12 is an R5-tropic chimeric virus that can establish productive infection both in vitro and in vivo in Chinese rhesus macaques and will be useful to assess candidate HIV-1 CRF08_BC vaccines in China.

Asunto(s)

Vacunas contra el SIDA/inmunología , Modelos Animales de Enfermedad , Infecciones por VIH/virología , VIH-1/genética , Macaca mulatta , Virus de la Inmunodeficiencia de los Simios/genética , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Animales , Recuento de Linfocito CD4 , China , Femenino , Citometría de Flujo , Genoma Viral , Infecciones por VIH/inmunología , VIH-1/fisiología , Humanos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/virología , Masculino , Datos de Secuencia Molecular , Filogenia , Receptores CCR5 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Virus de la Inmunodeficiencia de los Simios/metabolismo , Transfección , Carga Viral , Replicación Viral , Productos del Gen env del Virus de la Inmunodeficiencia Humana/metabolismo

RESUMEN

Interleukin-21 (IL-21) is produced primarily by CD4+ T cells and regulates immunity against human/simian immunodeficiency virus (HIV/SIV) infection. Activated CD8+ cells and their secreted interferon-gamma (IFN-γ) are crucial for the control of acute HIV/SIV infection. However, whether IL-21 can regulate IFN-γ production by CD8+ cells remains controversial. Rhesus macaques (RMs, n = 8) were infected with SHIV and the levels of plasma IL-21, IFN-γ and the frequency of peripheral blood activated T cells were measured longitudinally. Following infection with SHIV, the levels of plasma IL-21 and IFN-γ increased, peaked at 17 days postinfection and declined later. Furthermore, IL-21 induced IL-21 receptor (IL-21R) and IFN-γ, perforin, but not granmyze B, expression in CD8+ cells from four selected SHIV-infected RMs. The regulatory effect of IL-21 on CD8+ cell function appeared to be associated with increased levels of STAT3, but not STAT5, phosphorylation in CD8+ cells from SHIV-infected RMs. In parallel, treatment with soluble IL-21R/Fc, an inhibitor of IL-21-induced activation of JAK1/3 and STAT3, abrogated IL-21-induced STAT3 activation and IFN-γ production in CD8+ cells from SHIV-infected RMs in vitro. Our data indicated that IL-21 was a positive regulator of IFN-γ-secreting CD8+ cells and increased the STAT3 phosphorylation, regulating T-cell immunity against acute SHIV infection in RMs. Our findings may provide a new basis for the development of immunotherapies for the control of SHIV/HIV infection.

Asunto(s)

Linfocitos T CD8-positivos/metabolismo , VIH , Interferón gamma/metabolismo , Interleucinas/farmacología , Enfermedades de los Monos/virología , Receptores de Interleucina-21/metabolismo , Virus de la Inmunodeficiencia de los Simios , Regulación hacia Arriba/efectos de los fármacos , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/patología , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Infecciones por VIH/metabolismo , Infecciones por VIH/patología , Infecciones por VIH/veterinaria , Técnicas In Vitro , Macaca mulatta , Masculino , Enfermedades de los Monos/metabolismo , Enfermedades de los Monos/patología , Perforina/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Recombinantes/farmacología , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Síndrome de Inmunodeficiencia Adquirida del Simio/metabolismo , Síndrome de Inmunodeficiencia Adquirida del Simio/patología