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

Pol-Specific CD8+ T Cells Recognize Simian Immunodeficiency Virus-Infected Cells Prior to Nef-Mediated Major Histocompatibility Complex Class I Downregulation▿

Effective, vaccine-induced CD8+ T-cell responses should recognize infected cells early enough to prevent production of progeny virions. We have recently shown that Gag-specific CD8+ T cells recognize simian immunodeficiency virus-infected cells at 2 h postinfection, whereas Env-specific CD8+ T cells do not recognize infected cells until much later in infection. However, it remains unknown when other proteins present in the viral particle are presented to CD8+ T cells after infection. To address this issue, we explored CD8+ T-cell recognition of epitopes derived from two other relatively large virion proteins, Pol and Nef. Surprisingly, infected cells efficiently presented CD8+ T-cell epitopes from virion-derived Pol proteins within 2 h of infection. In contrast, Nef-specific CD8+ T cells did not recognize infected cells until 12 h postinfection. Additionally, we show that SIVmac239 Nef downregulated surface major histocompatibility complex class I (MHC-I) molecules beginning at 12 h postinfection, concomitant with presentation of Nef-derived CD8+ T-cell epitopes. Finally, Pol-specific CD8+ T cells eliminated infected cells as early as 6 h postinfection, well before MHC-I downregulation, suggesting a previously underappreciated antiviral role for Pol-specific CD8+ T cells

The high frequency Indian rhesus macaque MHC class I molecule, Mamu-B01, 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%). We first identified a preliminary binding motif by eluting and sequencing endogenously bound Mamu-B*01 ligands. We further characterized the peptide-binding characteristics using panels of single amino acid substitution analogs. Using this detailed motif, 507 peptides derived from SIV(mac)239 were identified and tested for their Mamu-B*01 binding capacity. Surprisingly, only 11 (2.2%) of these motif-containing peptides bound with IC50 values < or =500 nM. We assessed the immunogenicity of these peptides using freshly isolated PBMC from ten Mamu-B*01+ SIV-infected rhesus macaques in IFN-gamma ELISPOT and IFN-gamma/TNF-alpha intracellular cytokine staining assays. Lymphocytes from these SIV-infected macaques responded to none of these peptides. Furthermore, there was no sequence variation indicative of escape in the regions of the virus that encoded these peptides. Additionally, we could not confirm previous reports of SIV-derived Mamu-B*01-restricted epitopes in the Env and Gag proteins. Our results suggest that the high frequency MHC class I molecule, Mamu-B*01, is not involved in SIV-specific CD8+ T lymphocyte responses

Vaccination with gag, vif, and nef Gene Fragments Affords Partial Control of Viral Replication after Mucosal Challenge with SIVmac239

Made available in DSpace on 2015-05-04T17:07:28Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) myrna_bonaldoetal_IOC_2014.pdf: 6308018 bytes, checksum: 8d6762258d0dfa74834cd8870c4070d5 (MD5) Previous issue date: 2014University of Miami. Miller School of Medicine. Department of Pathology. Miami, Florida, USA.University of Wisconsin. Department of Medicine. Madison, Wisconsin, USA.University of Wisconsin. Wisconsin National Primate Research Center. Madison, Wisconsin, USA.University of Wisconsin. Wisconsin National Primate Research Center. Madison, Wisconsin, USA.University of Wisconsin. Wisconsin National Primate Research Center. Madison, Wisconsin, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Flavivírus. Rio de Janeiro, RJ, Brasil.University of Miami. Miller School of Medicine. Department of Pathology. Miami, Florida, USA.University of Wisconsin. Wisconsin National Primate Research Center. Madison, Wisconsin, USA.University of Wisconsin. Wisconsin National Primate Research Center. Madison, Wisconsin, USA.University of Alabama at Birmingham. Department of Biostatistics. Section on Statistical Genetics. Birmingham, Alabama, USA.International AIDS Vaccine Initiative. AIDS Vaccine Design and Development Laboratory. Brooklyn Army Terminal. Brooklyn, New York, USA.Leidos Biomedical Research. Inc. Frederick National Laboratory. AIDS and Cancer Virus Program. Frederick, Maryland, USA.University of Alabama at Birmingham. Department of Biostatistics. Section on Statistical Genetics. Birmingham, Alabama, USA.International AIDS Vaccine Initiative. AIDS Vaccine Design and Development Laboratory. Brooklyn Army Terminal. Brooklyn, New York, USA.Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.Leidos Biomedical Research. Inc. Frederick National Laboratory. AIDS and Cancer Virus Program. Frederick, Maryland, USA.University of Miami. Miller School of Medicine. Department of Pathology. Miami, Florida, USA.Broadly targeted cellular immune responses are thought to be important for controlling replication of human and simian immunodeficiency viruses (HIV and SIV). However, eliciting such responses by vaccination is complicated by immunodominance, the preferential targeting of only a few of the many possible epitopes of a given antigen. This phenomenon may be due to the coexpression of dominant and subdominant epitopes by the same antigen-presenting cell and may be overcome by distributing these sequences among several different vaccine constructs. Accordingly, we tested whether vaccinating rhesus macaques with “minigenes” encoding fragments of Gag, Vif, and Nef resulted in broadened cellular responses capable of controlling SIV replication.Wedelivered these minigenes through combinations of recombinant Mycobacterium bovis BCG (rBCG), electroporated recombinant DNA (rDNA) along with an interleukin-12 (IL-12)-expressing plasmid (EP rDNA plus pIL-12), yellow fever vaccine virus 17D (rYF17D), and recombinant adenovirus serotype 5 (rAd5). Although priming with EP rDNA plus pIL-12 increased the breadth of vaccine-induced T-cell responses, this effect was likely due to the improved antigen delivery afforded by electroporation rather than modulation of immunodominance. Indeed, Mamu-A*01 vaccinees mounted CD8 T cells directed against only one subdominant epitope, regardless of the vaccination regimen. After challenge with SIVmac239, vaccine efficacy was limited to a modest reduction in set point in some of the groups and did not correlate with standard T-cell measurements. These findings suggest that broad T-cell responses elicited by conventional vectors may not be sufficient to substantially contain AIDS virus replication

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. These elite controllers (ECs) mounted a broad SIV-specific CD4+ T-cell response. Here, we describe five macaque MHC-II alleles (Mamu-DRB*w606, -DRB*w2104, -DRB1*0306, -DRB1*1003, and -DPB1*06) that restricted six SIV-specific CD4+ T-cell epitopes in ECs and report the first association between specific MHC-II alleles and elite control. Interestingly, the macaque MHC-II alleles, Mamu-DRB1*1003 and -DRB1*0306, were enriched in this EC group (P values of 0.02 and 0.05, respectively). Additionally, Mamu-B*17-positive SIV-infected rhesus macaques that also expressed these two MHC-II alleles had significantly lower viral loads than Mamu-B*17-positive animals that did not express Mamu-DRB1*1003 and -DRB1*0306 (P value of <0.0001). The study of MHC-II alleles in macaques that control viral replication could improve our understanding of the role of CD4+ T cells in suppressing HIV/SIV replication and further our understanding of HIV vaccine design