No differences in cellular immune responses between asymptomatic HIV type 1- and type 2-infected Gambian patients.
Fewer people infected with human immunodeficiency virus (HIV) type 2 progress to acquired immunodeficiency syndrome, compared with those infected with HIV-1. To understand the immune mechanisms leading to slow progression in HIV-2 infection, cell-mediated immune responses were compared between the 2 infections in asymptomatic subjects with a CD4 cell count > or =20%. Interferon- gamma release from T lymphocytes and the cytotoxicity of CD8+ T lymphocytes were measured by ELISPOT and 51Cr release assays. The level of responses and the proportion of responders were similar in the 2 infections, despite a 20-fold difference in their geometric mean plasma virus loads. The proliferation of CD4+ T helper cells, which was evaluated by thymidine incorporation, was not different between the 2 infections. Contrary to widely held views, our results suggest that nonprogression in HIV-2 infection may not be due to more vigorous immune responses.
Jaye
Assan
A
Medical Research Council Laboratories, Banjul, The Gambia. ajaye@mrc.gm.
Sarge-Njie
Ramu
R
Schim van der Loeff
Maarten
M
Todd
Jim
J
Alabi
Abraham
A
Sabally
Shehu
S
Corrah
Tumani
T
Whittle
Hilton
H
D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005260:Female; D005714:Gambia; D015658:HIV Infections / Q000097:blood / Q000276:immunology* / Q000821:virology; D015497:HIV-1 / Q000276:immunology*; D015498:HIV-2 / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000032:analysis; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology; D019562:Viral Load
D007371:Interferon-gamma