Distinct host cell proteins incorporated by SIV replicating in CD4+ T Cells from natural disease resistant versus non-natural disease susceptible hosts

<p>Abstract</p> <p>Background</p> <p>Enveloped viruses including the simian immunodeficiency virus (SIV) replicating within host cells acquire host proteins upon egress from the host cells. A number of studies have catalogued such host proteins, and a few have documented the potential positive and negative biological functions of such host proteins. The studies conducted herein utilized proteomic analysis to identify differences in the spectrum of host proteins acquired by a single source of SIV replicating within CD4⁺T cells from disease resistant sooty mangabeys and disease susceptible rhesus macaques.</p> <p>Results</p> <p>While a total of 202 host derived proteins were present in viral preparations from CD4⁺T cells from both species, there were 4 host-derived proteins that consistently and uniquely associated with SIV replicating within CD4⁺T cells from rhesus macaques but not sooty mangabeys; and, similarly, 28 host-derived proteins that uniquely associated with SIV replicating within CD4⁺T cells from sooty mangabeys, but not rhesus macaques. Of interest was the finding that of the 4 proteins uniquely present in SIV preparations from rhesus macaques was a 26 S protease subunit 7 (MSS1) that was shown to enhance HIV-1 'tat" mediated transactivation. Among the 28 proteins found in SIV preparations from sooty mangabeys included several molecules associated with immune function such as CD2, CD3ε, TLR4, TLR9 and TNFR and a bioactive form of IL-13.</p> <p>Conclusions</p> <p>The finding of 4 host proteins that are uniquely associated with SIV replicating within CD4⁺T cells from disease susceptible rhesus macaques and 28 host proteins that are uniquely associated with SIV replicating within CD4⁺T cells from disease resistant sooty mangabeys provide the foundation for determining the potential role of each of these unique host-derived proteins in contributing to the polarized clinical outcome in these 2 species of nonhuman primates.</p

Comparative AMS radiocarbon dating of pretreated versus non-pretreated tropical wood samples

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 268 (2010): 910-913, doi:10.1016/j.nimb.2009.10.062.Several wood samples collected from Dorslandboom, a large African baobab (Adansonia digitata L.) from Namibia, were investigated by AMS radiocarbon dating subsequent to pretreatment and, alternatively, without pretreatment. The comparative statistical evaluation of results showed that there were no significant differences between fraction modern values and radiocarbon dates of the samples analyzed after pretreatment and without pretreatment, respectively. The radiocarbon date of the oldest sample was 993 ± 20 BP. Dating results also revealed that Dorslandboom is a multi-generation tree, with several stems showing different ages.This material is based on work supported by U.S. National Science Foundation under Cooperative Agreement OCE-022828996. Part of the research was supported by grants from the Romanian Academy and the Romanian National University Research Council (PN II – ID 2354) and also by Nova Research Inc

Beyond outputs: pathways to symmetrical evaluations of university sustainable development partnerships

As the United Nations Decade of Education for Sustainable Development (2005–2014) draws to a close, it is timely to review ways in which the sustainable development initiatives of higher education institutions have been, and can be, evaluated. In their efforts to document and assess collaborative sustainable development program outcomes and impacts, universities in the North and South are challenged by similar conundrums that confront development agencies. This article explores pathways to symmetrical evaluations of transnationally partnered research, curricula, and public-outreach initiatives specifically devoted to sustainable development. Drawing on extensive literature and informed by international development experience, the authors present a novel framework for evaluating transnational higher education partnerships devoted to sustainable development that addresses design, management, capacity building, and institutional outreach. The framework is applied by assessing several full-term African higher education evaluation case studies with a view toward identifying key limitations and suggesting useful future symmetrical evaluation pathways. University participants in transnational sustainable development initiatives, and their supporting donors, would be well-served by utilizing an inclusive evaluation framework that is infused with principles of symmetry

Dysregulation of the Polo-Like Kinase Pathway in CD4(+) T Cells Is Characteristic of Pathogenic Simian Immunodeficiency Virus Infection

CD4(+) T-cell dysfunction highlighted by defects within the intracellular signaling cascade and cell cycle has long been characterized as a direct and/or indirect consequence of human immunodeficiency virus (HIV) infection in humans and simian immunodeficiency virus (SIV) infection in rhesus macaques (RM). Dysregulation of the M phase of the cell cycle is a well-documented effect of HIV or SIV infection both in vivo and in vitro. In this study the effect of SIV infection on the modulation of two important regulators of the M phase—polo-like kinases Plk3 and Plk1—was investigated. We have previously shown that Plk3 is markedly downregulated in CD4(+) T cells from SIV-infected disease-susceptible RM but not SIV-infected disease-resistant sooty mangabeys (SM), denoting an association of downregulation with disease progression. Here we show that, in addition to the downregulation, Plk3 exhibits aberrant activation patterns in the CD4(+) T cells from SIV-infected RM following T-cell receptor stimulation. Interestingly, in vitro SIV infection of CD4(+) T cells leads to the upregulation, rather than downregulation, of Plk3, suggesting that different mechanisms operate in vitro and in vivo. In addition, CD4(+) T cells from RM with high viral loads exhibited consistent and significant upregulation of Plk1, concurrent with an aberrant activation-induced Plk1 response, suggesting complex mechanisms of SIV-induced M-phase abnormalities in vivo. Altogether this study presents a novel mechanism underlying M-phase defects observed in CD4(+) T cells from HIV or SIV-infected disease-susceptible humans and RM which may contribute to aberrant T-cell responses and disease pathogenesis

Phenotypic and Functional Characterization of Monoclonal Antibodies with Specificity for Rhesus Macaque CD200, CD200R and Mincle.

Lectin-like molecules and their receptors are cell surface molecules that have been shown to play a role in either facilitating infection or serving as transporters of HIV/SIV in vivo. The role of these lectin-like molecules in the pathogenesis of HIV/SIV infection continues to be defined. In efforts to gain further insight on the potential role of these lectin-like molecules, our laboratory generated monoclonal antibodies (mAb) against the human analogs of rhesus macaque CD200, CD200R and Mincle, since the rhesus macaques are accepted as the most reliable animal model to study human HIV infection. The characterization of the cell lineages from the blood and various tissues of rhesus macaques that express these lectin-like molecules are described herein. Among the mononuclear cells, the cells of the myeloid lineage of rhesus macaques are the predominant cell lineages that express readily detectable levels of CD200, CD200R and Mincle that is similar to the expression of Siglec-1 and Siglec-3 reported by our laboratory earlier. Subset analysis revealed that a higher frequency of the CD14+/CD16- subset from normal rhesus macaques express CD200, CD200R and Mincle. Differences in the frequencies and density of expression of these molecules by the gated population of CD14+ cells from various tissues are noted with PBMC and bone marrow expressing the highest and the mononuclear cells isolated from the colon and ileum expressing the lowest levels. While a significant frequency of pDCs and mDCs express Siglec-1/Siglec-3, a much lower frequency expresses CD200, CD200R and Mincle in PBMCs from rhesus macaques. The mAb against CD200 and CD200R but not Mincle appear to inhibit the infection of macrophage tropic SIV/SHIV in vitro. We conclude that these mAbs may have potential to be used as adjunctive therapeutic agents to control/inhibit SIV/HIV infection

Evidence for Antibody-Mediated Enhancement of Simian Immunodeficiency Virus (SIV) Gag Antigen Processing and Cross Presentation in SIV-Infected Rhesus Macaques

By using the dominant simian immunodeficiency virus (SIV) Gag Mamu-A01 restricted major histocompatibility complex (MHC) class I epitope p11CM, we demonstrate antibody-mediated enhanced MHC class I cross presentation of SIV Gag. In vitro restimulation of peripheral blood mononuclear cells from SIV-infected rhesus macaques with recombinant full-length SIV Gag p55 plus p55 affinity-purified immunoglobulin G (p55 Gag/p55-IgG) led to the generation of markedly higher frequencies of p11CM specific precursor cytotoxic T lymphocytes (p-CTLs) compared with restimulation with (i) SIV Gag p55 alone or (ii) optimal concentrations of the p11CM peptide alone. These results, along with the finding that CD4 depletion abrogated the enhancement, suggest a prominent role for CD4(+) T cells. Testing for p-CTLs against other Mamu-A01-restricted SIV Gag epitopes suggested that this mechanism favored recognition of the dominant p11CM peptide, potentially further skewing of the CTL response. The p-CTL enhancing effect was also decreased or abrogated by pepsin digestion of the p55-specific IgG or by the addition of monoclonal antibodies to Fc receptor (FcR) II/III, suggesting that the effect was dependent on FcR-mediated uptake of the immune-complexed antigen. Finally, incubation of antigen-presenting cells with SIV Gag p55 immune complexes in the presence of lactacystin or of bafilomycin indicated that the mechanism of antibody-mediated enhancement of cross presentation required both the proteasomal and the endosomal pathways. These data demonstrate for the first time the cross presentation of antigens via immune complexes in lentiviral infection and indicate a heretofore-unrecognized role for antibodies in modulating the magnitude and potentially also the breadth of MHC class I-restricted antigen processing and presentation and CTL responses

Effect of anti-CD200/CD200R/Mincle monoclonal antibodies on the in vitro replication of macrophage tropic SHIV.

<p>Monocytes were isolated using a procedure outlined in the methods section. A 48 well plate was seeded with 10⁴ monocytes/well and cultured for 7 days and aliquots infected with either SHIV-Bo159N4 (A) or SIVmac251Desi#4 in the presence of normal mouse Ig (10 μg/ml) or 10 μg/ml of the monoclonal antibodies against either CD200, CD200R, or Mincle. Culture supernatants were collected at various time points as shown and the p27 levels quantitated using a commercial ELISA kit. NS = non-significant and the notation * reflects a ‘p’ value of <0.05 noted for data obtained with the addition of mAb against CD200 or CD200R.</p

Comparative analysis of the frequencies of CD200, CD200R, Mincle, Siglec-1 and Siglec-3 expressing cells by the gated population of CD14⁺ cells from the PBMC samples from normal adult rhesus macaques (n = 19, black bars) and sooty mangabeys (n = 18, grey bars) (A) and similar analysis on infant (< 3 months) rhesus macaques (n = 10) and sooty mangabeys (n = 4) (B).

<p>The notations * represents p < 0.05 and *** represents p < 0.001.</p

The net frequencies (background using isotype control Ig deducted) of CD200, CD200R, Mincle, Siglec-1 and Siglec-3 expressing Lin^-, HLA-DR⁺, CD123⁺ plasmacytoid dendritic cells (pDCs, panel A) and Lin^-, HLA-DR⁺, CD11c⁺ myeloid dendritic cells (mDCs, panel B) in the peripheral blood samples from 3 normal rhesus macaques and 3 normal sooty mangabeys are displayed.

<p>The absolute numbers of mDCs noted in the blood of rhesus macaques were 355 +/- 42 and pDCs were 48 +/- 17. The data reflect the Mean +/- SD values and * reflects p< 0.05, ** reflects p< 0.01.</p