scholarly journals Preexisting Infection with Human T-Cell Lymphotropic Virus Type 2 neither Exacerbates nor Attenuates Simian Immunodeficiency Virus SIVmac251 Infection in Macaques

2010 ◽  
Vol 84 (6) ◽  
pp. 3043-3058 ◽  
Author(s):  
Shari N. Gordon ◽  
Anna R. Weissman ◽  
Valentina Cecchinato ◽  
Claudio Fenizia ◽  
Zhong-Min Ma ◽  
...  

ABSTRACT Coinfection with human T-cell lymphotropic virus type 2 (HTLV-2) and human immunodeficiency virus type 1 (HIV-1) has been reported to have either a slowed disease course or to have no effect on progression to AIDS. In this study, we generated a coinfection animal model and investigated whether HTLV-2 could persistently infect macaques, induce a T-cell response, and impact simian immunodeficiency virus SIVmac251-induced disease. We found that inoculation of irradiated HTLV-2-infected T cells into Indian rhesus macaques elicited humoral and T-cell responses to HTLV-2 antigens at both systemic and mucosal sites. Low levels of HTLV-2 provirus DNA were detected in the blood, lymphoid tissues, and gastrointestinal tracts of infected animals. Exposure of HTLV-2-infected or naïve macaques to SIVmac251 demonstrated comparable levels of SIVmac251 viral replication, similar rates of mucosal and peripheral CD4+ T-cell loss, and increased T-cell proliferation. Additionally, neither the magnitude nor the functional capacity of the SIV-specific T-cell-mediated immune response was different in HTLV-2/SIVmac251 coinfected animals versus SIVmac251 singly infected controls. Thus, HTLV-2 targets mucosal sites, persists, and importantly does not exacerbate SIVmac251 infection. These data provide the impetus for the development of an attenuated HTLV-2-based vectored vaccine for HIV-1; this approach could elicit persistent mucosal immunity that may prevent HIV-1/SIVmac251 infection.

2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  

ABSTRACT The presence, at the time of challenge, of antiviral effector T cells in the vaginal mucosa of female rhesus macaques immunized with live-attenuated simian-human immunodeficiency virus 89.6 (SHIV89.6) is associated with consistent and reproducible protection from pathogenic simian immunodeficiency virus (SIV) vaginal challenge (18). Here, we definitively demonstrate the protective role of the SIV-specific CD8+ T-cell response in SHIV-immunized monkeys by CD8+ lymphocyte depletion, an intervention that abrogated SHIV-mediated control of challenge virus replication and largely eliminated the SIV-specific T-cell responses in blood, lymph nodes, and genital mucosa. While in the T-cell-intact SHIV-immunized animals, polyfunctional and degranulating SIV-specific CD8+ T cells were present in the genital tract and lymphoid tissues from the day of challenge until day 14 postchallenge, strikingly, expansion of SIV-specific CD8+ T cells in the immunized monkeys was minimal and limited to the vagina. Thus, protection from uncontrolled SIV replication in animals immunized with attenuated SHIV89.6 is primarily mediated by CD8+ T cells that do not undergo dramatic systemic expansion after SIV challenge. These findings demonstrate that despite, and perhaps because of, minimal systemic expansion of T cells at the time of challenge, a stable population of effector-cytotoxic CD8+ T cells can provide significant protection from vaginal SIV challenge.


2014 ◽  
Vol 30 (1) ◽  
pp. 97-101 ◽  
Author(s):  
Adele Caterino-de-Araujo ◽  
Mariana Cavalheiro Magri ◽  
Neuza Satomi Sato ◽  
Helena Kaminami Morimoto ◽  
Luis Fernando de Macedo Brigido ◽  
...  

2008 ◽  
Vol 82 (24) ◽  
pp. 12335-12345 ◽  
Author(s):  
Caroline Goujon ◽  
Vanessa Arfi ◽  
Thomas Pertel ◽  
Jeremy Luban ◽  
Julia Lienard ◽  
...  

ABSTRACT Human immunodeficiency virus type 2 (HIV-2)/simian immunodeficiency virus SIVSM Vpx is incorporated into virion particles and is thus present during the early steps of infection, when it has been reported to influence the nuclear import of viral DNA. We recently reported that Vpx promoted the accumulation of full-length viral DNA following the infection of human monocyte-derived dendritic cells (DCs). This positive effect was exerted following the infection of DCs with cognate viruses and with retroviruses as divergent as HIV-1, feline immunodeficiency virus, and even murine leukemia virus, leading us to suggest that Vpx counteracted an antiviral restriction present in DCs. Here, we show that Vpx is required, albeit to a different extent, for the infection of all myeloid but not of lymphoid cells, including monocytes, macrophages, and monocytoid THP-1 cells that had been induced to differentiate with phorbol esters. The intracellular localization of Vpx was highly heterogeneous and cell type dependent, since Vpx localized differently in HeLa cells and DCs. Despite these differences, no clear correlation between the functionality of Vpx and its intracellular localization could be drawn. As a first insight into its function, we determined that SIVSM/HIV-2 and SIVRCM Vpx proteins interact with the DCAF1 adaptor of the Cul4-based E3 ubiquitin ligase complex recently described to associate with HIV-1 Vpr and HIV-2 Vpx. However, the functionality of Vpx proteins in the infection of DCs did not strictly correlate with DCAF1 binding, and knockdown experiments failed to reveal a functional role for this association in differentiated THP-1 cells. Lastly, when transferred in the context of a replication-competent viral clone, Vpx was required for replication in DCs.


2005 ◽  
Vol 79 (18) ◽  
pp. 11580-11587 ◽  
Author(s):  
Laura M. J. Ylinen ◽  
Zuzana Keckesova ◽  
Sam J. Wilson ◽  
Srinika Ranasinghe ◽  
Greg J. Towers

ABSTRACT Primate lentiviruses have narrow host ranges, due in part to their sensitivities to mammalian intracellular antiviral factors such as APOBEC3G and TRIM5α. Despite the protection provided by this innate immune system, retroviruses are able to transfer between species where they can cause disease. This is true for sooty mangabey simian immunodeficiency virus, which has transferred to humans as HIV-2 and to rhesus macaques as SIVmac, where it causes AIDS. Here we examine the sensitivities of the closely related HIV-2 and SIVmac to restriction by TRIM5α. We show that rhesus TRIM5α can restrict HIV-2 but not the closely related SIVmac. SIVmac has not completely escaped TRIM5α, as shown by its sensitivity to distantly related TRIM5α from the New World squirrel monkey. Squirrel monkey TRIM5α blocks SIVmac infection after DNA synthesis and is not saturable with restriction-sensitive virus-like particles. We map the determinant for TRIM5α sensitivity to the structure in the capsid protein that recruits CypA into HIV-1 virions. We also make an SIV, mutated at this site, which bypasses restriction in all cells tested.


2004 ◽  
Vol 48 (9) ◽  
pp. 3483-3490 ◽  
Author(s):  
Michael J. Hofman ◽  
Joanne Higgins ◽  
Timothy B. Matthews ◽  
Niels C. Pedersen ◽  
Chalet Tan ◽  
...  

ABSTRACT The specificity of nonnucleoside reverse transcriptase (RT) inhibitors (NNRTIs) for the RT of human immunodeficiency virus type 1 (HIV-1) has prevented the use of simian immunodeficiency virus (SIV) in the study of NNRTIs and NNRTI-based highly active antiretroviral therapy. However, a SIV-HIV-1 chimera (RT-SHIV), in which the RT from SIVmac239 was replaced with the RT-encoding region from HIV-1, is susceptible to NNRTIs and is infectious to rhesus macaques. We have evaluated the antiviral activity of efavirenz against RT-SHIV and the emergence of efavirenz-resistant mutants in vitro and in vivo. RT-SHIV was susceptible to efavirenz with a mean effective concentration of 5.9 ± 4.5 nM, and RT-SHIV variants selected with efavirenz in cell culture displayed 600-fold-reduced susceptibility. The efavirenz-resistant mutants of RT-SHIV had mutations in RT similar to those of HIV-1 variants that were selected under similar conditions. Efavirenz monotherapy of RT-SHIV-infected macaques produced a 1.82-log-unit decrease in plasma viral-RNA levels after 1 week. The virus load rebounded within 3 weeks in one treated animal and more slowly in a second animal. Virus isolated from these two animals contained the K103N and Y188C or Y188L mutations. The RT-SHIV-rhesus macaque model may prove useful for studies of antiretroviral drug combinations that include efavirenz.


1990 ◽  
Vol 11 (6) ◽  
pp. 314-318 ◽  
Author(s):  
Julie Larkin ◽  
John T. Sinnott ◽  
Joshua Weiss ◽  
Douglas A. Holt

Human T-cell lymphotropic virus type-1 (HTLV-I) is a recently recognized retrovirus identified as the cause of adult T-cell leukemia-lymphoma (ATLL) and HTLV-I-associated myelopathy (TSPI HAM). HTLV-I, a member of theRetroviridaefamily of viruses, was first described in 1980 after the isolation of the virus from a patient with a T-cell lymphoma. These pathogenic retroviruses are typically divided into theOncovirinaeandLentivirinae. The oncovirus group, including HTLV-I, HTLV-II and bovine leukemia virus (BLV), is generally associated with tumors. The lentiviruses are associated with immune deficiency and/or neurologic disease, and include agents such as the visna virus of sheep and the human immunodeficiency virus type-1 and -2 HIV-1 and HIV-2).


2015 ◽  
Vol 89 (21) ◽  
pp. 10802-10820 ◽  
Author(s):  
Mauricio A. Martins ◽  
Damien C. Tully ◽  
Michael A. Cruz ◽  
Karen A. Power ◽  
Marlon G. Veloso de Santana ◽  
...  

ABSTRACTCertain major histocompatibility complex class I (MHC-I) alleles (e.g.,HLA-B*27) are enriched among human immunodeficiency virus type 1 (HIV-1)-infected individuals who suppress viremia without treatment (termed “elite controllers” [ECs]). Likewise,Mamu-B*08expression also predisposes rhesus macaques to control simian immunodeficiency virus (SIV) replication. Given the similarities between Mamu-B*08 and HLA-B*27, SIV-infectedMamu-B*08+animals provide a model to investigate HLA-B*27-mediated elite control. We have recently shown that vaccination with three immunodominant Mamu-B*08-restricted epitopes (Vif RL8, Vif RL9, and Nef RL10) increased the incidence of elite control inMamu-B*08+macaques after challenge with the pathogenic SIVmac239 clone. Furthermore, a correlate analysis revealed that CD8+T cells targeting Nef RL10 was correlated with improved outcome. Interestingly, this epitope is conserved between SIV and HIV-1 and exhibits a delayed and atypical escape pattern. These features led us to postulate that a monotypic vaccine-induced Nef RL10-specific CD8+T-cell response would facilitate the development of elite control inMamu-B*08+animals following repeated intrarectal challenges with SIVmac239. To test this, we vaccinatedMamu-B*08+animals withnefinserts in which Nef RL10 was either left intact (group 1) or disrupted by mutations (group 2). Although monkeys in both groups mounted Nef-specific cellular responses, only those in group 1 developed Nef RL10-specific CD8+T cells. These vaccine-induced effector memory CD8+T cells did not prevent infection. Escape variants emerged rapidly in the group 1 vaccinees, and ultimately, the numbers of ECs were similar in groups 1 and 2. High-frequency vaccine-induced CD8+T cells focused on a single conserved epitope and therefore did not prevent infection or increase the incidence of elite control inMamu-B*08+macaques.IMPORTANCESince elite control of chronic-phase viremia is a classic example of an effective immune response against HIV/SIV, elucidating the basis of this phenomenon may provide useful insights into how to elicit such responses by vaccination. We have previously established that vaccine-induced CD8+T-cell responses against three immunodominant epitopes can increase the incidence of elite control in SIV-infectedMamu-B*08+rhesus macaques—a model of HLA-B*27-mediated elite control. Here, we investigated whether a monotypic vaccine-induced CD8+T-cell response targeting the conserved “late-escaping” Nef RL10 epitope can increase the incidence of elite control inMamu-B*08+monkeys. Surprisingly, vaccine-induced Nef RL10-specific CD8+T cells selected for variants within days after infection and, ultimately, did not facilitate the development of elite control. Elite control is, therefore, likely to involve CD8+T-cell responses against more than one epitope. Together, these results underscore the complexity and multidimensional nature of virologic control of lentivirus infection.


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