Characterization of Mauritian Cynomolgus Macaque FcγR Alleles Using Long-Read Sequencing.

The FcγRs are immune cell surface proteins that bind IgG and facilitate cytokine production, phagocytosis, and Ab-dependent, cell-mediated cytotoxicity. FcγRs play a critical role in immunity; variation in these genes is implicated in autoimmunity and other diseases. Cynomolgus macaques are an excellent animal model for many human diseases, and Mauritian cynomolgus macaques (MCMs) are particularly useful because of their restricted genetic diversity.

High Reproducibility of ELISPOT Counts from Nine Different Laboratories.

The primary goal of immune monitoring with ELISPOT is to measure the number of T cells, specific for any antigen, accurately and reproducibly between different laboratories. In ELISPOT assays, antigen-specific T cells secrete cytokines, forming spots of different sizes on a membrane with variable background intensities. Due to the subjective nature of judging maximal and minimal spot sizes, different investigators come up with different numbers.

Simian immunodeficiency virus-specific CD4+ T cells from successful vaccinees target the SIV Gag capsid.

We recently demonstrated that vaccinated rhesus macaques controlled viral replication of a heterologous SIV challenge. Here, we analyzed anamnestic SIV-specific CD4+ T-cell responses expanding immediately after challenge and show that successful vaccinees consistently targeted a short region of the Gag-p27 Capsid (amino acids 249-291). We have also defined the major histocompatibility complex class II (MHC-II) restricting alleles for several of these responses and show that DQ-restricted CD4+ T-cells depend on unique combinations of both the DQA and DQB alleles.

Simian immunodeficiency virus-specific CD8+ T cells recognize Vpr- and Rev-derived epitopes early after infection.

The kinetics of CD8(+) T cell epitope presentation contribute to the antiviral efficacy of these cells yet remain poorly defined. Here, we demonstrate presentation of virion-derived Vpr peptide epitopes early after viral penetration and prior to presentation of Vif-derived epitopes, which required de novo Vif synthesis. Two Rev epitopes exhibited differential presentation kinetics, with one Rev epitope presented within 1 h of infection.

High viremia is associated with high levels of in vivo major histocompatibility complex class I Downregulation in rhesus macaques infected with simian immunodeficiency virus SIVmac239.

Human and simian immunodeficiency viruses (HIV and SIV) downregulate major histocompatibility complex class I (MHC-I) molecules from the surface of infected cells. Although this activity is conserved across viral isolates, its importance in AIDS pathogenesis is not clear. We therefore developed an assay to detect the level of MHC-I expression of SIV-infected cells directly ex vivo.

Effective simian immunodeficiency virus-specific CD8+ T cells lack an easily detectable, shared characteristic.

The immune correlates of human/simian immunodeficiency virus control remain elusive. While CD8(+) T lymphocytes likely play a major role in reducing peak viremia and maintaining viral control in the chronic phase, the relative antiviral efficacy of individual virus-specific effector populations is unknown. Conventional assays measure cytokine secretion of virus-specific CD8(+) T cells after cognate peptide recognition.

Infection with "escaped" virus variants impairs control of simian immunodeficiency virus SIVmac239 replication in Mamu-B*08-positive macaques.

An understanding of the mechanism(s) by which some individuals spontaneously control human immunodeficiency virus (HIV)/simian immunodeficiency virus replication may aid vaccine design. Approximately 50% of Indian rhesus macaques that express the major histocompatibility complex (MHC) class I allele Mamu-B*08 become elite controllers after infection with simian immunodeficiency virus SIVmac239. Mamu-B*08 has a binding motif that is very similar to that of HLA-B27, a human MHC class I allele associated with the elite control of HIV, suggesting that SIVmac239-infected Mamu-B*08-positive (Mamu-B*08+) animals may be a good model for the elite control of HIV.

Two MHC class I molecules associated with elite control of immunodeficiency virus replication, Mamu-B*08 and HLA-B*2705, bind peptides with sequence similarity.

HLA-B27- and -B57-positive HIV-infected humans have long been associated with control of HIV replication, implying that CD8(+) T cell responses contribute to control of viral replication. In a similar fashion, 50% of Mamu-B*08-positive Indian rhesus macaques control SIVmac239 replication and become elite controllers with chronic-phase viremia <1000 viral RNA copies/ml. Interestingly, Mamu-B*08-restricted SIV-derived epitopes appeared to match the peptide binding profile for HLA-B*2705 in humans.

Vaccine-induced cellular responses control simian immunodeficiency virus replication after heterologous challenge.

All human immunodeficiency virus (HIV) vaccine efficacy trials to date have ended in failure. Structural features of the Env glycoprotein and its enormous variability have frustrated efforts to induce broadly reactive neutralizing antibodies. To explore the extent to which vaccine-induced cellular immune responses, in the absence of neutralizing antibodies, can control replication of a heterologous, mucosal viral challenge, we vaccinated eight macaques with a DNA/Ad5 regimen expressing all of the proteins of SIVmac239 except Env.

Mauritian cynomolgus macaques share two exceptionally common major histocompatibility complex class I alleles that restrict simian immunodeficiency virus-specific CD8+ T cells.

Vaccines that elicit CD8(+) T-cell responses are routinely tested for immunogenicity in nonhuman primates before advancement to clinical trials. Unfortunately, the magnitude and specificity of vaccine-elicited T-cell responses are variable in currently utilized nonhuman primate populations, owing to heterogeneity in major histocompatibility (MHC) class I genetics. We recently showed that Mauritian cynomolgus macaques (MCM) have unusually simple MHC genetics, with three common haplotypes encoding a shared pair of MHC class IA alleles, Mafa-A*25 and Mafa-A*29.

Comprehensive immunological evaluation reveals surprisingly few differences between elite controller and progressor Mamu-B*17-positive simian immunodeficiency virus-infected rhesus macaques.

The association between particular major histocompatibility complex class I (MHC-I) alleles and control of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication implies that certain CD8(+) T-lymphocyte (CD8-TL) responses are better able than others to control viral replication in vivo. However, possession of favorable alleles does not guarantee improved prognosis or viral control. In rhesus macaques, the MHC-I allele Mamu-B*17 is correlated with reduced viremia and is overrepresented in macaques that control SIVmac239, termed elite controllers (ECs).

Patterns of CD8+ immunodominance may influence the ability of Mamu-B*08-positive macaques to naturally control simian immunodeficiency virus SIVmac239 replication.

Certain major histocompatibility complex (MHC) class I alleles are strongly associated with control of human immunodeficiency virus and simian immunodeficiency virus (SIV). CD8(+) T cells specific for epitopes restricted by these molecules may be particularly effective. Understanding how CD8(+) T cells contribute to control of viral replication should yield important insights for vaccine design.

CD8+ T cells from SIV elite controller macaques recognize Mamu-B*08-bound epitopes and select for widespread viral variation.

Background: It is generally accepted that CD8+ T cell responses play an important role in control of immunodeficiency virus replication. The association of HLA-B27 and -B57 with control of viremia supports this conclusion. However, specific correlates of viral control in individuals expressing these alleles have been difficult to define.

The major histocompatibility complex class II alleles Mamu-DRB1*1003 and -DRB1*0306 are enriched in a cohort of simian immunodeficiency virus-infected rhesus macaque elite controllers.

The role of CD4(+) T cells in the control of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) replication is not well understood. Even though strong HIV- and SIV-specific CD4(+) T-cell responses have been detected in individuals that control viral replication, major histocompatibility complex class II (MHC-II) molecules have not been definitively linked with slow disease progression. In a cohort of 196 SIVmac239-infected Indian rhesus macaques, a group of macaques controlled viral replication to less than 1,000 viral RNA copies/ml.

Molecular typing of major histocompatibility complex class I alleles in the Indian rhesus macaque which restrict SIV CD8+ T cell epitopes.

The utility of the rhesus macaque as an animal model in both HIV vaccine development and pathogenesis studies necessitates the development of accurate and efficient major histocompatibility complex (MHC) genotyping technologies. In this paper, we describe the development and application of allele-specific polymerase chain reaction (PCR) amplification for the simultaneous detection of eight MHC class I alleles from the rhesus macaque (Macaca mulatta) of Indian descent. These alleles were selected, as they have been implicated in the restriction of CD8(+) T cell epitopes of simian immunodeficiency virus (SIV).

Mamu-B*08-positive macaques control simian immunodeficiency virus replication.

Certain major histocompatibility complex (MHC) class I alleles are associated with the control of human immunodeficiency virus and simian immunodeficiency virus (SIV) replication. We have designed sequence-specific primers for detection of the rhesus macaque MHC class I allele Mamu-B*08 by PCR and screened a cohort of SIV-infected macaques for this allele. Analysis of 196 SIV(mac)239-infected Indian rhesus macaques revealed that Mamu-B*08 was significantly overrepresented in elite controllers; 38% of elite controllers were Mamu-B*08 positive compared to 3% of progressors (P = 0.

Gag-specific CD8+ T lymphocytes recognize infected cells before AIDS-virus integration and viral protein expression.

CD8(+) T cells are a key focus of vaccine development efforts for HIV. However, there is no clear consensus as to which of the nine HIV proteins should be used for vaccination. The early proteins Tat, Rev, and Nef may be better CD8(+) T cell targets than the late-expressed structural proteins Gag, Pol, and Env.

The antiviral efficacy of simian immunodeficiency virus-specific CD8+ T cells is unrelated to epitope specificity and is abrogated by viral escape.

CD8(+) T lymphocytes appear to play a role in controlling human immunodeficiency virus (HIV) replication, yet routine immunological assays do not measure the antiviral efficacy of these cells. Furthermore, it has been suggested that CD8+ T cells that recognize epitopes derived from proteins expressed early in the viral replication cycle can be highly efficient. We used a functional in vitro assay to assess the abilities of different epitope-specific CD8+ T-cell lines to control simian immunodeficiency virus (SIV) replication.

Not all cytokine-producing CD8+ T cells suppress simian immunodeficiency virus replication.

Current assays of CD8+ T-lymphocyte function measure cytokine production rather than the ability of these lymphocytes to suppress viral replication. Here we show that CD8+ T-cell clones recognizing the same epitope vary enormously in the ability to suppress simian immunodeficiency virus SIVmac239 replication in an in vitro suppression assay. However, all Nef(165-173)IW9- and Vif(66-73)HW8-specific clones from elite controllers effectively suppressed SIV replication.

Repeated intravaginal inoculation with cell-associated simian immunodeficiency virus results in persistent infection of nonhuman primates.

The goal of the present study was to develop a nonhuman primate model of intravaginal human immunodeficiency virus (HIV) transmission with cell-associated virus. Reproductively mature, cycling cynomolgus macaques with or without chemically induced, transient ulcers of the lower female reproductive tract repeatedly received challenge with a variable amount of in vitro simian immunodeficiency virus mac239-infected peripheral blood mononuclear cells. Persistent viremia was established with surprisingly few infectious lymphocytes containing physiologically relevant quantities of cell-associated virus.

Tat(28-35)SL8-specific CD8+ T lymphocytes are more effective than Gag(181-189)CM9-specific CD8+ T lymphocytes at suppressing simian immunodeficiency virus replication in a functional in vitro assay.

Epitope-specific CD8+ T lymphocytes may play an important role in controlling human immunodeficiency virus (HIV)/simian immunodeficiency virus replication. Unfortunately, standard cellular assays do not measure the antiviral efficacy (the ability to suppress virus replication) of CD8+ T lymphocytes. Certain epitope-specific CD8+ T lymphocytes may be better than others at suppressing viral replication.

The high frequency Indian rhesus macaque MHC class I molecule, Mamu-B*01, does not appear to be involved in CD8+ T lymphocyte responses to SIVmac239.

Although the SIV-infected Indian rhesus macaque (Macaca mulatta) is the animal model most widely used for studying HIV infection, our current understanding of the functional macaque MHC class I molecules is limited. To date, SIV-derived CD8+ T lymphocyte epitopes from only three high frequency macaque MHC class I molecules have been extensively characterized. In this study, we defined the peptide-binding properties of the high frequency Indian rhesus macaque class I molecule, Mamu-B*01 ( approximately 26%).

Identification of seventeen new simian immunodeficiency virus-derived CD8+ T cell epitopes restricted by the high frequency molecule, Mamu-A*02, and potential escape from CTL recognition.

MHC class I-restricted CD8+ T cells play an important role in controlling HIV and SIV replication. In SIV-infected Indian rhesus macaques (Macaca mulatta), comprehensive CD8+ T cell epitope identification has only been undertaken for two alleles, Mamu-A*01 and Mamu-B*17. As a result, these two molecules account for virtually all known MHC class I-restricted SIV-derived CD8+ T cell epitopes.