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. We recently reported that transient in vivo CD8(+) cell depletion in simian immunodeficiency virus (SIV)-infected elite controller (EC) macaques resulted in a brief period of viral recrudescence. SIV replication was rapidly controlled with the reappearance of CD8(+) cells, implicating that these cells actively suppress viral replication in ECs. Methods and Findings. Here we show that three ECs in that study made at least seven robust CD8(+) T cell responses directed against novel epitopes in Vif, Rev, and Nef restricted by the MHC class I molecule Mamu-B*08. Two of these Mamu-B*08-positive animals subsequently lost control of SIV replication. Their breakthrough virus harbored substitutions in multiple Mamu-B*08-restricted epitopes. Indeed, we found evidence for selection pressure mediated by Mamu-B*08-restricted CD8(+) T cells in all of the newly identified epitopes in a cohort of chronically infected macaques. Conclusions. Together, our data suggest that Mamu-B*08-restricted CD8(+) T cell responses effectively control replication of pathogenic SIV(mac)239. All seven regions encoding Mamu-B*08-restricted CD8(+) T cell epitopes also exhibit amino acid replacements typically seen only in the presence of Mamu-B*08, suggesting that the variation we observe is indeed selected by CD8(+) T cell responses. SIVmac239 infection of Indian rhesus macaques expressing Mamu-B*08 may therefore provide an animal model for understanding CD8(+) T cell-mediated control of HIV replication in humans.National Institutes of Health (NIH)National Center for Research Resources (NCRR)Japan Health Sciences FoundationKent State University Research CouncilOhio Board of Regents Research ChallengeResearch Facilities ImprovementUniv Wisconsin, WNPRC, Madison, WI 53706 USAUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilUniv Wisconsin, Dept Pathol & Lab Med, Madison, WI USALa Jolla Inst Allergy & Immunol, Div Vaccine Discovery, La Jolla, CA USAUniv Oxford, John Radcliffe Hosp, Weatherall Inst Mol Med, Oxford OX3 9DU, EnglandKent State Univ, Dept Biol Sci, Kent, OH 44242 USAUniv S Carolina, Dept Biol Sci, Columbia, SC 29208 USAUniversidade Federal de São Paulo, Div Infect Dis, São Paulo, BrazilNational Institutes of Health (NIH): HHSN266200400088CNational Institutes of Health (NIH): R01 AI049120National Institutes of Health (NIH): R01 AI052056National Institutes of Health (NIH): R24 RR015371National Institutes of Health (NIH): R24 RR016038National Institutes of Health (NIH): R21 AI068586National Center for Research Resources (NCRR): P51 RR000167Japan Health Sciences Foundation: GM43940Research Facilities Improvement: RR15459-01Research Facilities Improvement: RR020141-01Web of Scienc

Measurement of the asymmetries in 3He→ \overrightarrow{\sf He}(¯e, e′p)d and 3He→ \overrightarrow{\sf He}(¯e, e′p)np

Abstract.: The electron target asymmetries A || and A⊥ with target spin parallel and perpendicular to the momentum transfer \ensuremath{\boldsymbol{q}} were measured for both the two- and three-body breakup of 3He in the 3 $\overrightarrow{\rm He}$ (¯e, e'p)-reaction. Polarized electrons were scattered off polarized 3He in the quasielastic regime in parallel kinematics with the scattered electron and the knocked-out proton detected using the Three-Spectrometer Facility at MAMI. The results are compared to Faddeev calculations which take into account Final-State Interactions as well as Meson Exchange Currents. The experiment confirms the prediction of a large effect of Final-State Interactions in the asymmetry of the three-body breakup and of an almost negligible one for the two-body breaku

Functional analysis of frequently expressed Chinese rhesus macaque MHC class I molecules Mamu-A1*02601 and Mamu-B*08301 reveals HLA-A2 and HLA-A3 supertypic specificities

The Simian immunodeficiency virus (SIV)-infected Indian rhesus macaque (Macaca mulatta) is the most established model of HIV infection and AIDS-related research, despite the potential that macaques of Chinese origin is a more relevant model. Ongoing efforts to further characterize the Chinese rhesus macaques’ major histocompatibility complex (MHC) for composition and function should facilitate greater utilization of the species. Previous studies have demonstrated that Chinese-origin M. mulatta (Mamu) class I alleles are more polymorphic than their Indian counterparts, perhaps inferring a model more representative of human MHC, human leukocyte antigen (HLA). Furthermore, the Chinese rhesus macaque class I allele Mamu-A1*02201, the most frequent allele thus far identified, has recently been characterized and shown to be an HLA-B7 supertype analog, the most frequent supertype in human populations. In this study, we have characterized two additional alleles expressed with high frequency in Chinese rhesus macaques, Mamu-A1*02601 and Mamu-B*08301. Upon the development of MHC–peptide-binding assays and definition of their associated motifs, we reveal that these Mamu alleles share peptide-binding characteristics with the HLA-A2 and HLA-A3 supertypes, respectively, the next most frequent human supertypes after HLA-B7. These data suggest that Chinese rhesus macaques may indeed be a more representative model of HLA gene diversity and function as compared to the species of Indian origin and therefore a better model for investigating human immune responses

The most common Chinese rhesus macaque MHC class I molecule shares peptide binding repertoire with the HLA-B7 supertype

Of the two rhesus macaque subspecies used for AIDS studies, the Simian immunodeficiency virus-infected Indian rhesus macaque (Macaca mulatta) is the most established model of HIV infection, providing both insight into pathogenesis and a system for testing novel vaccines. Despite the Chinese rhesus macaque potentially being a more relevant model for AIDS outcomes than the Indian rhesus macaque, the Chinese-origin rhesus macaques have not been well-characterized for their major histocompatibility complex (MHC) composition and function, reducing their greater utilization. In this study, we characterized a total of 50 unique Chinese rhesus macaques from several varying origins for their entire MHC class I allele composition and identified a total of 58 unique complete MHC class I sequences. Only nine of the sequences had been associated with Indian rhesus macaques, and 28/58 (48.3%) of the sequences identified were novel. From all MHC alleles detected, we prioritized Mamu-A1*02201 for functional characterization based on its higher frequency of expression. Upon the development of MHC/peptide binding assays and definition of its associated motif, we revealed that this allele shares peptide binding characteristics with the HLA-B7 supertype, the most frequent supertype in human populations. These studies provide the first functional characterization of an MHC class I molecule in the context of Chinese rhesus macaques and the first instance of HLA-B7 analogy for rhesus macaques

The thermal stability of oligonucleotide duplexes is sequence independent in tetraalkylammonium salt solutions: application to identifying recombinant DNA clones.

In solutions of tetraalkylammonium salts the melting temperature of oligonucleotide duplexes is independent of nucleotide sequence and thus GC content. Data quantitating the destabilizing effects of various mismatches in these solvents are also presented. The results are in accord with theories on DNA melting and establish conditions under which oligonucleotides can be used as hybridization probes with predictable and controllable specificity