Protection from secondary human immunodeficiency virus type 1 infection in chimpanzees suggests the importance of antigenic boosting and a possible role for cytotoxic T cells.
Recent evidence suggests a much higher prevalence of human immunodeficiency virus type 1 (HIV-1) recombinants than previously anticipated. These recombinants arise from secondary HIV infections in individuals already infected with the virus. It remains unclear why some individuals acquire secondary HIV-1 infections and others do not. To address this question, a study was undertaken of a small cohort of chimpanzees with well-defined HIV-1 infection. After exposure to an infectious dose of heterologous primary isolate, 4 of 8 HIV-1 seropositive chimpanzees resisted secondary infection, whereas 2 naive controls became readily infected. Only animals who were immunologically boosted were protected. Protection from heterologous secondary exposure appeared to be related to the repertoire of the cytolytic CD8(+) T cell responses to HIV-1. Data suggested that immunologic boosting by HIV-1 antigens or exposure to subinfectious doses of virus may be important events in sustaining sufficient immunity to prevent secondary infections from occurring.
Balla-Jhagjhoorsingh
S S
SS
Department of Virology, Biomedical Primate Research Centre, Rijswijk, The Netherlands.
Mooij
P
P
ten Haaft
P J
PJ
Bogers
W M
WM
Teeuwsen
V J
VJ
Koopman
G
G
Heeney
J L
JL
D016915:AIDS Vaccines / Q000008:administration & dosage* / Q000276:immunology; D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000517:prevention & control*; D000818:Animals; D015658:HIV Infections / Q000276:immunology; D002679:Pan troglodytes; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016915:AIDS Vaccines