Interleukin-7 enhances memory CD8(+) T-cell recall responses in health but its activity is impaired in human immunodeficiency virus infection.

Abstract

Memory CD8(+) T cells regain function during a recall response, but the requirement of signals in addition to antigen during a secondary immune response is unknown. In this study, the ability of interleukin-7 (IL-7) to enhance memory CD8(+ ) CD45RA(- ) CD127(+) T-cell responses in health and in human immunodeficiency virus (HIV) infection was investigated. CD8(+) T-cell-depleted peripheral blood mononuclear cells (PBMCs) from HIV(-) and untreated HIV(+) donors were pulsed with a cytomegalovirus/Epstein-Barr virus/influenza (CEF) peptide pool, and co-cultured with autologous memory CD8(+) T cells in the presence of IL-7. Cell survival and the function of memory CD8(+) T-cell subsets were then evaluated. Memory CD8(+) T-cell proliferation and interferon-γ (IFN-γ) production was enhanced by the presence of antigen, and the addition of IL-7 further enhanced antigen-induced proliferation. In HIV(+) individuals, the presence of antigen enhanced IFN-γ production to a small degree but did not enhance proliferation. Lastly, IL-7 did not enhance antigen-mediated proliferation of memory CD8(+) T cells from HIV(+) individuals. IL-7 therefore appears to have a role in secondary immune responses and its activity is impaired in memory CD8(+) T cells from HIV(+) individuals. These results further our understanding of the signals involved in secondary immune responses, and provide new insight into the loss of CD8(+) T-cell function in HIV infection.

• Authors: Alison M O'Connor, Angela M Crawley, Jonathan B Angel
• Journal: Immunology (Immunology) Vol. 131 Issue 4 Pg. 525-36 (Dec 2010) ISSN: 1365-2567 [Electronic] England
• PMID: 20673240 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2010 The Authors. Immunology © 2010 Blackwell Publishing Ltd.

Chemical References

• Antigens, Viral
• IL7 protein, human
• Interleukin-7
• Peptides
• Viral Proteins
• Interferon-gamma

Topics

• Antigens, Viral (immunology, pharmacology)
• CD8-Positive T-Lymphocytes (immunology)
• Cell Proliferation
• Cell Survival (drug effects, immunology)
• Coculture Techniques
• HIV (immunology)
• HIV Infections (immunology, pathology)
• Humans
• Immunologic Memory (drug effects, immunology)
• Interferon-gamma (immunology)
• Interleukin-7 (immunology)
• Peptides (immunology, pharmacology)
• Viral Proteins (immunology, pharmacology)