scholarly journals Simian-Human Immunodeficiency Virus Containing a Human Immunodeficiency Virus Type 1 Subtype-E Envelope Gene: Persistent Infection, CD4+ T-Cell Depletion, and Mucosal Membrane Transmission in Macaques

2000 ◽  
Vol 74 (17) ◽  
pp. 7851-7860 ◽  
Author(s):  
Sunee Himathongkham ◽  
Nancy S. Halpin ◽  
Jinling Li ◽  
Michael W. Stout ◽  
Christopher J. Miller ◽  
...  

ABSTRACT The envelope (env) glycoprotein of human immunodeficiency virus type 1 (HIV-1) determines several viral properties (e.g., coreceptor usage, cell tropism, and cytopathicity) and is a major target of antiviral immune responses. Most investigations on env have been conducted on subtype-B viral strains, prevalent in North America and Europe. Our study aimed to analyze env genes of subtype-E viral strains, prevalent in Asia and Africa, with a nonhuman primate model for lentivirus infection and AIDS. To this end, we constructed a simian immunodeficiency virus/HIV-1 subtype-E (SHIV) recombinant clone by replacing the env ectodomain of the SHIV-33 clone with theenv ectodomain from the subtype-E strain HIV-1CAR402, which was isolated from an individual in the Central African Republic. Virus from this recombinant clone, designated SHIV-E-CAR, replicated efficiently in macaque peripheral blood mononuclear cells. Accordingly, juvenile macaques were inoculated with cell-free SHIV-E-CAR by the intravenous or intravaginal route; virus replicated in these animals but did not produce hematological abnormalities. In an attempt to elicit the pathogenic potential of the recombinant clone, we serially passaged this viral clone via transfusion of blood and bone marrow through juvenile macaques to produce SHIV-E-P4 (fourth-passage virus). The serially passaged virus established productive infection and CD4+ T-cell depletion in juvenile macaques inoculated by either the intravenous or the intravaginal route. Determination of the coreceptor usage of SHIV-E-CAR and serially passaged SHIV-E-P4 indicated that both of these viruses utilized CXCR4 as a coreceptor. In summary, the serially passaged SHIV subtype-E chimeric virus will be important for studies aimed at developing a nonhuman primate model for analyzing the functions of subtype-E env genes in viral transmission and pathogenesis and for vaccine challenge experiments with macaques immunized with HIV-1 env antigens.

2006 ◽  
Vol 80 (12) ◽  
pp. 5984-5991 ◽  
Author(s):  
Bärbel Schröfelbauer ◽  
Tilo Senger ◽  
Gerard Manning ◽  
Nathaniel R. Landau

ABSTRACT Human APOBEC3F (hA3F) and APOBEC3G (hA3G) are antiretroviral cytidine deaminases that can be encapsidated during virus assembly to catalyze C→U deamination of the viral reverse transcripts in the next round of infection. Lentiviruses such as human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) have evolved the accessory protein Vif to induce their degradation before packaging. HIV type 1 (HIV-1) Vif counteracts hA3G but not rhesus macaque APOBEC3G (rhA3G) or African green monkey (AGM) APOBEC3G (agmA3G) because of a failure to bind the nonhuman primate proteins. The species specificity of the interaction is controlled by amino acid 128, which is aspartate in hA3G and lysine in rhA3G. With the objective of overcoming this species restriction, mutations were introduced into HIV-1 Vif at amino acid positions that differed in charge between HIV-1 Vif and SIV Vif. The mutant proteins were tested for the ability to counteract hA3G, rhA3G, and agmA3G. Alteration of the conserved sequence at positions 14 to 17 from DRMR to SERQ, which is the sequence in AGM Vif, caused HIV-1 Vif to functionally interact with rhA3G and agmA3G. Mutation of three residues to the sequence SEMQ allowed interaction with rhA3G. SEMQ Vif also counteracted D128K mutant hA3G and wild-type hA3G. Introduction of the sequence into an infectious molecular HIV-1 clone allowed the virus to replicate productively in human cells that expressed rhA3G or hA3G. These findings provide insight into the interaction of Vif with A3G and are a step toward the development of a novel primate model for AIDS.


2006 ◽  
Vol 81 (4) ◽  
pp. 1619-1631 ◽  
Author(s):  
Xu G. Yu ◽  
Mathias Lichterfeld ◽  
Senica Chetty ◽  
Katie L. Williams ◽  
Stanley K. Mui ◽  
...  

ABSTRACT The relative contributions of HLA alleles and T-cell receptors (TCRs) to the prevention of mutational viral escape are unclear. Here, we examined human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T-cell responses restricted by two closely related HLA class I alleles, B*5701 and B*5703, that differ by two amino acids but are both associated with a dominant response to the same HIV-1 Gag epitope KF11 (KAFSPEVIPMF). When this epitope is presented by HLA-B*5701, it induces a TCR repertoire that is highly conserved among individuals, cross-recognizes viral epitope variants, and is rarely associated with mutational escape. In contrast, KF11 presented by HLA-B*5703 induces an entirely different, more heterogeneous TCR β-chain repertoire that fails to recognize specific KF11 escape variants which frequently arise in clade C-infected HLA-B*5703+ individuals. These data show the influence of HLA allele subtypes on TCR selection and indicate that extensive TCR diversity is not a prerequisite to prevention of allowable viral mutations.


2005 ◽  
Vol 86 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Eva K. L. Nordström ◽  
Mattias N. E. Forsell ◽  
Christina Barnfield ◽  
Eivor Bonin ◽  
Tomas Hanke ◽  
...  

With the human immunodeficiency virus type 1 (HIV-1) epidemic expanding at increasing speed, development of a safe and effective vaccine remains a high priority. One of the most central vaccine platforms considered is plasmid DNA. However, high doses of DNA and several immunizations are typically needed to achieve detectable T-cell responses. In this study, a Semliki Forest virus replicon DNA vaccine designed for human clinical trials, DREP.HIVA, encoding an antigen that is currently being used in human trials in the context of a conventional DNA plasmid, pTHr.HIVA, was generated. It was shown that a single immunization of DREP.HIVA stimulated HIV-1-specific T-cell responses in mice, suggesting that the poor immunogenicity of conventional DNA vaccines may be enhanced by using viral replicon-based plasmid systems. The results presented here support the evaluation of Semliki Forest virus replicon DNA vaccines in non-human primates and in clinical studies.


2003 ◽  
Vol 77 (1) ◽  
pp. 291-300 ◽  
Author(s):  
L. Musey ◽  
Y. Ding ◽  
J. Cao ◽  
J. Lee ◽  
C. Galloway ◽  
...  

ABSTRACT Induction of adaptive immunity to human immunodeficiency virus type 1 (HIV-1) at the mucosal site of transmission is poorly understood but crucial in devising strategies to control and prevent infection. To gain further understanding of HIV-1-specific T-cell mucosal immunity, we established HIV-1-specific CD8+ cytotoxic T-lymphocyte (CTL) cell lines and clones from the blood, cervix, rectum, and semen of 12 HIV-1-infected individuals and compared their specificities, cytolytic function, and T-cell receptor (TCR) clonotypes. Blood and mucosal CD8+ CTL had common HIV-1 epitope specificities and major histocompatibility complex restriction patterns. Moreover, both systemic and mucosal CTL lysed targets with similar efficiency, primarily through the perforin-dependent pathway in in vitro studies. Sequence analysis of the TCRβ VDJ region revealed in some cases identical HIV-1-specific CTL clones in different compartments in the same HIV-1-infected individual. These results clearly establish that a subset of blood and mucosal HIV-1-specific CTL can have a common origin and can traffic between anatomically distinct compartments. Thus, these effectors can provide immune surveillance at the mucosa, where rapid responses are needed to contain HIV-1 infection.


2001 ◽  
Vol 75 (16) ◽  
pp. 7621-7628 ◽  
Author(s):  
Julianna Lisziewicz ◽  
Dmitry I. Gabrilovich ◽  
Georg Varga ◽  
Jianqing Xu ◽  
Philip D. Greenberg ◽  
...  

ABSTRACT A novel technology combining replication- and integration-defective human immunodeficiency virus type 1 (HIV-1) vectors with genetically modified dendritic cells was developed in order to induce T-cell immunity. We introduced the vector into dendritic cells as a plasmid DNA using polyethylenimine as the gene delivery system, thereby circumventing the problem of obtaining viral vector expression in the absence of integration. Genetically modified dendritic cells (GMDC) presented viral epitopes efficiently, secreted interleukin 12, and primed both CD4+ and CD8+ HIV-specific T cells capable of producing gamma interferon and exerting potent HIV-1-specific cytotoxicity in vitro. In nonhuman primates, subcutaneously injected GMDC migrated into the draining lymph node at an unprecedentedly high rate and expressed the plasmid DNA. The animals presented a vigorous HIV-specific effector cytotoxic-T-lymphocyte (CTL) response as early as 3 weeks after a single immunization, which later developed into a memory CTL response. Interestingly, antibodies did not accompany these CTL responses, indicating that GMDC can induce a pure Th1 type of immune response. Successful induction of a broad and long-lasting HIV-specific cellular immunity is expected to control virus replication in infected individuals.


2005 ◽  
Vol 79 (5) ◽  
pp. 3195-3199 ◽  
Author(s):  
Jean-Daniel Lelièvre ◽  
Frédéric Petit ◽  
Damien Arnoult ◽  
Jean-Claude Ameisen ◽  
Jérôme Estaquier

ABSTRACT Fas-mediated T-cell death is known to occur during human immunodeficiency virus (HIV) infection. In this study, we found that HIV type 1 LAI (HIV-1LAI) primes CD8+ T cells from healthy donors for apoptosis, which occurs after Fas ligation. This effect is counteracted by a broad caspase inhibitor (zVAD-fmk). Fas-mediated cell death does not depend on CD8+ T-cell infection, because it occurred in the presence of reverse transcriptase inhibitors. However, purified CD8+ T cells are sensitive to Fas only in the presence of soluble CD4. Finally, we found that interleukin 7 (IL-7) increases Fas-mediated CD4+ and CD8+ T-cell death induced by HIV-1LAI. Since high levels of IL-7 are a marker of poor prognosis during HIV infection, our data suggest that enhancement of Fas-mediated T-cell death by HIV-1LAI and IL-7 is one of the mechanisms involved in progression to AIDS.


2007 ◽  
Vol 81 (11) ◽  
pp. 5547-5560 ◽  
Author(s):  
Clare Jolly ◽  
Ivonne Mitar ◽  
Quentin J. Sattentau

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T cells leads to the production of new virions that assemble at the plasma membrane. Gag and Env accumulate in the context of lipid rafts at the inner and outer leaflets of the plasma membrane, respectively, forming polarized domains from which HIV-1 buds. HIV-1 budding can result in either release of cell-free virions or direct cell-cell spread via a virological synapse (VS). The recruitment of Gag and Env to these plasma membrane caps in T cells is poorly understood but may require elements of the T-cell secretory apparatus coordinated by the cytoskeleton. Using fixed-cell immunofluorescence labeling and confocal microscopy, we observed a high percentage of HIV-1-infected T cells with polarized Env and Gag in capped, lipid raft-like assembly domains. Treatment of infected T cells with inhibitors of actin or tubulin remodeling disrupted Gag and Env compartmentalization within the polarized raft-like domains. Depolymerization of the actin cytoskeleton reduced Gag release and viral infectivity, and actin and tubulin inhibitors reduced Env incorporation into virions. Live- and fixed-cell confocal imaging and assay of de novo DNA synthesis by real-time PCR allowed quantification of HIV-1 cell-cell transfer. Inhibition of actin and tubulin remodeling in infected cells interfered with cell-cell spread across a VS and reduced new viral DNA synthesis. Based on these data, we propose that HIV-1 requires both actin and tubulin components of the T-cell cytoskeleton to direct its assembly and budding and to elaborate a functional VS.


2006 ◽  
Vol 87 (5) ◽  
pp. 1285-1294 ◽  
Author(s):  
Guerau Fernàndez ◽  
Anuska Llano ◽  
Miriam Esgleas ◽  
Bonaventura Clotet ◽  
José A. Esté ◽  
...  

Human immunodeficiency virus type 1 (HIV-1) infection is established by virus variants that use the CCR5 co-receptor for entry (CCR5-tropic or R5 variants), whereas viruses that use CXCR4 as co-receptor (CXCR4-tropic or X4 variants) emerge during disease progression in approximately 50 % of infected subjects. X4 variants may have a higher fitness ex vivo and their detection is usually accompanied by faster T-cell depletion and the onset of AIDS in HIV-1-positive individuals. Here, the relationship between the sequence variation of the HIV-1 env V3–V5 region and positive selective pressure on R5 and X4 variants from infected subjects with CD4 T cell counts below 200 cells μl−1 was studied. A correlation was found between genetic distance and CD4+ cell count at late stages of the disease. R5 variants that co-existed with X4 variants were significantly less heterogeneous than R5 variants from subjects without X4 variants (P<0·0001). Similarly, X4 variants had a significantly higher diversity than R5 variants (P<0·0001), although residues under positive selection had a similar distribution pattern in both variants. Therefore, both X4 and R5 variants were subjected to high selective pressures from the host. Furthermore, the interaction between X4 and R5 variants within the same subject resulted in a purifying selection on R5 variants, which only survived as a homogeneous virus population. These results indicate that R5 variants from X4 phenotype samples were highly homogeneous and under weakly positive selective pressures. In contrast, R5 variants from R5 phenotype samples were highly heterogeneous and subject to positive selective pressures.


1990 ◽  
Vol 172 (4) ◽  
pp. 1151-1158 ◽  
Author(s):  
B Ardman ◽  
M A Sikorski ◽  
M Settles ◽  
D E Staunton

Sera from human immunodeficiency virus type 1 (HIV-1)-infected and -noninfected individuals were screened for antibodies that could bind to native T cell differentiation antigens. Antibodies that could immunoprecipitate CD43 (sialophorin, leukosialin) from a T cell lymphoma line were detected in sera from 27% of patients, and antibodies that could bind specifically to transfected cells expressing CD43 were detected in 47% of patients. The anti-CD43 antibodies were related to HIV-1 infection in that no patients with other chronic viral infections or systemic lupus erythematosus contained such antibodies in their sera. The anti-CD43 autoantibodies bound to a partially sialylated form of CD43 expressed by normal human thymocytes, but not by normal, circulating T lymphocytes. However, the determinant(s) recognized by the anti-CD43 autoantibodies was present on a large proportion of circulating T lymphocytes, but masked from antibody recognition by sialic acid residues. These results demonstrate that HIV-1 infection is specifically associated with the production of autoantibodies that bind to a native T cell surface antigen.


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