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In Vitro Assay to Evaluate the Impact of Immunoregulatory Pathways on HIV-specific CD4 T Cell Effector Function
Published on: October 15, 2013
Increased CD95/Fas-induced apoptosis of HIV-specific CD8(+) T cells
Y M Mueller1, S C De Rosa, J A Hutton
1Department of Microbiology and Immunology, MCP Hahnemann University, Philadelphia, Pennsylvania 19129, USA.
Immunity
|January 5, 2002
Summary
HIV-specific CD8(+) T cells are more susceptible to apoptosis, hindering their ability to control HIV infection. This increased programmed cell death, mediated by CD95/Fas, impacts T cell survival and differentiation in HIV patients.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- The mechanisms by which HIV-specific CD8(+) T cells fail to control HIV infection remain unclear.
- Understanding T cell dysfunction is crucial for developing effective HIV therapies.
Purpose of the Study:
- To investigate the susceptibility of HIV-specific CD8(+) T cells to apoptosis.
- To determine the role of CD95/Fas signaling in HIV-specific CD8(+) T cell failure.
- To characterize the phenotype of HIV-specific CD8(+) T cells in the context of apoptosis.
Main Methods:
- Flow cytometry was used to analyze T cell phenotypes (CD45RA, CD62L) and apoptosis.
- Comparison of apoptosis sensitivity between HIV-specific and other virus-specific (CMV, EBV) CD8(+) T cells.
- Assessment of cytotoxicity and Interferon-gamma (IFNγ) production by HIV-specific CD8(+) T cells.
Main Results:
- HIV-specific CD8(+) T cells exhibit a 3-fold higher sensitivity to CD95/Fas-induced apoptosis compared to CMV-specific CD8(+) T cells.
- HIV-specific CD8(+) T cells display a CD45RA(-)CD62L(-) phenotype, lacking the T cell effector memory (T(EM)) phenotype, unlike CMV- and EBV-specific cells.
- Despite increased apoptosis, the cytotoxicity and IFNγ production of HIV-specific CD8(+) T cells were not impaired.
Conclusions:
- HIV-specific CD8(+) T cells are prone to CD95/Fas-induced apoptosis, potentially mediated by FasL-expressing HIV-infected cells.
- This apoptosis compromises the survival and differentiation of HIV-specific CD8(+) T cells, contributing to uncontrolled HIV infection.
- Targeting CD95/Fas pathways could be a therapeutic strategy to enhance HIV-specific T cell function.
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