Lack of T Cell Dysfunction and Programmed Cell Death in Human Immunodeficiency Virus Type 1-Infected Chimpanzees Correlates with Absence of Monocytotropic Variants

1993 ◽  
Vol 168 (5) ◽  
pp. 1140-1147 ◽  
Author(s):  
H. Schuitemaker ◽  
L. Meyaard ◽  
N. A. Kootstra ◽  
R. Dubbes ◽  
S. A. Otto ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Death ◽  
T Cell ◽  
Programmed Cell Death ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cell Dysfunction ◽  
Immunodeficiency Virus ◽  
T Cell Dysfunction

Human Immunodeficiency Virus Type 1 Nef Protein Sensitizes CD4+ T Lymphoid Cells to Apoptosis via Functional Upregulation of the CD95/CD95 Ligand Pathway

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 1000-1010 ◽  
Author(s):  
Giorgio Zauli ◽  
Davide Gibellini ◽  
Paola Secchiero ◽  
Hélène Dutartre ◽  
Daniel Olive ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Death ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cd95 Ligand ◽  
Immunodeficiency Virus ◽  
Hiv 1

Many viruses have evolved genes encoding proteins that regulate cell death by apoptosis. The human immunodeficiency virus type 1 (HIV-1) Nef protein alters T-cell development and signaling and is required for optimal viral replication and pathogenicity in vivo. To analyze the interference of Nef with cell survival, we used both regulated and constitutively expressed nef alleles in stably transfected T-cell lines. Nef-expressing cells were sensitized to cell death by apoptosis, which was specifically exacerbated by an anti-CD95 IgM monoclonal antibody (MoAb). Flow cytometric analysis showed that the surface expression of both CD95 and CD95 ligand (CD95L) was upregulated by endogenous Nef expression. Nef-mediated apoptosis was almost completely suppressed by the addition in culture of an anti-CD95 Fab′ IgG MoAb, which specifically blocks CD95/CD95L interactions. Lastly, mutation of a proline motif in the core region of the nef gene, which disrupts its ability to interact with cellular kinases and reduces HIV-1 replication in vitro, completely abrogated the Nef-mediated induction of apoptosis as well as its ability to upregulate surface CD95 and CD95L. These findings may provide molecular insight into the role of endogenous Nef in the T-cell depletion observed in vivo, particularly HIV-specific cytotoxic CD8+ T cells.

Human Immunodeficiency Virus Type 1 Nef Protein Sensitizes CD4+ T Lymphoid Cells to Apoptosis via Functional Upregulation of the CD95/CD95 Ligand Pathway

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 1000-1010 ◽  
Author(s):  
Giorgio Zauli ◽  
Davide Gibellini ◽  
Paola Secchiero ◽  
Hélène Dutartre ◽  
Daniel Olive ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Death ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Cd95 Ligand ◽  
Immunodeficiency Virus ◽  
Hiv 1

Abstract Many viruses have evolved genes encoding proteins that regulate cell death by apoptosis. The human immunodeficiency virus type 1 (HIV-1) Nef protein alters T-cell development and signaling and is required for optimal viral replication and pathogenicity in vivo. To analyze the interference of Nef with cell survival, we used both regulated and constitutively expressed nef alleles in stably transfected T-cell lines. Nef-expressing cells were sensitized to cell death by apoptosis, which was specifically exacerbated by an anti-CD95 IgM monoclonal antibody (MoAb). Flow cytometric analysis showed that the surface expression of both CD95 and CD95 ligand (CD95L) was upregulated by endogenous Nef expression. Nef-mediated apoptosis was almost completely suppressed by the addition in culture of an anti-CD95 Fab′ IgG MoAb, which specifically blocks CD95/CD95L interactions. Lastly, mutation of a proline motif in the core region of the nef gene, which disrupts its ability to interact with cellular kinases and reduces HIV-1 replication in vitro, completely abrogated the Nef-mediated induction of apoptosis as well as its ability to upregulate surface CD95 and CD95L. These findings may provide molecular insight into the role of endogenous Nef in the T-cell depletion observed in vivo, particularly HIV-specific cytotoxic CD8+ T cells.

scholarly journals Mutually Exclusive T-Cell Receptor Induction and Differential Susceptibility to Human Immunodeficiency Virus Type 1 Mutational Escape Associated with a Two-Amino-Acid Difference between HLA Class I Subtypes

2006 ◽  
Vol 81 (4) ◽  
pp. 1619-1631 ◽  
Author(s):  
Xu G. Yu ◽  
Mathias Lichterfeld ◽  
Senica Chetty ◽  
Katie L. Williams ◽  
Stanley K. Mui ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Hla Class I ◽  
Viral Escape ◽  
Class I ◽  
Immunodeficiency Virus ◽  
Hiv 1

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.

scholarly journals Enhanced immunogenicity using an alphavirus replicon DNA vaccine against human immunodeficiency virus type 1

2005 ◽  
Vol 86 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Eva K. L. Nordström ◽  
Mattias N. E. Forsell ◽  
Christina Barnfield ◽  
Eivor Bonin ◽  
Tomas Hanke ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Dna Vaccine ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Semliki Forest Virus ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Hiv 1

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.

Sign in / Sign up

Export Citation Format

Share Document