CD8+ T cell responses to human immunodeficiency viruses type 2 (HIV-2) and type 1 (HIV-1) gag proteins are distinguishable by magnitude and breadth but not cellular phenotype.

Journal article

The mechanisms underlying the relatively slow progression of human immunodeficiency virus type 2 (HIV-2) compared with HIV-1 infection are undefined and could be a result of more effective immune responses. We used HIV-2 and HIV-1 IFN-gamma enzyme-linked immunospot assays to evaluate CD8(+) T cell responses in antiretroviral-naive HIV-2- ('HIV-2(+)') and HIV-1-infected ('HIV-1(+)') individuals. Gag-specific responses were detected in the majority of HIV-2(+) and HIV-1(+) subjects. Overlapping gag peptide analysis indicated a significantly greater magnitude and breadth of responses in the HIV-1(+) cohort, and this difference was attributable to low responses in HIV-2(+) subjects with undetectable viral load (medians 2107 and 512 spot-forming units per 10(6) PBMC, respectively, p=0.007). We investigated the phenotype of viral epitope-specific CD8(+) T cells identified with HLA-B53- and HLA-B58-peptide tetramers (8 HIV-2(+), 11 HIV-1(+) subjects). HIV-2-specific CD8(+) T cells were predominantly CD27(+) CD45RA(-), and only a minority expressed perforin. The limited breadth and low frequency of CD8(+) T cell responses to HIV-2 gag in aviremic HIV-2(+) subjects suggests that these responses reflect antigen load in plasma, as is the case in HIV-1 infection. Immune control of HIV-2 does not appear to be related to the frequency of perforin-expressing virus-specific CD8(+) T cells.

Authors: Gillespie, G; Pinheiro, S; Sayeid-Al-Jamee, M; Alabi, A; Kaye, S

• Publication status: Published
• Journal: European journal of immunology
• Volume: 35
• Issue: 5
• Pages: 1445-1453
• Publication date: 2005-05-01
• DOI: 10.1002/eji.200526007
• EISSN: 1521-4141
• ISSN: 0014-2980
• Language: English
• Keywords: HIV Antigens; Pore Forming Cytotoxic Proteins; Viral Load; Amino Acid Sequence; Perforin; HIV Infections; HIV-2; Molecular Sequence Data; Epitopes, T-Lymphocyte; Enzyme-Linked Immunosorbent Assay; Humans; CD8-Positive T-Lymphocytes; Membrane Glycoproteins; HIV-1; Gene Products, gag; Interferon-gamma; Phenotype