T cell receptor V beta repertoire in HIV-infection individuals: lack of evidence for selective V beta deletion.
The gradual decline of CD4+ T lymphocytes in HIV-infected individuals culminates in the lethal immunosuppression of AIDS. The mechanism of CD4+ T cell loss is currently unknown, but has recently been suggested to occur as a result of an HIV-encoded superantigen which facilitates a selective deletion of T cells expressing specific V beta genes. To verify and extend such observations, peripheral blood leucocytes (PBL) from 15 HIV+ individuals, 10 of which had very low CD4 T cell counts (< 200/mm3), were analysed for T cell receptor (TCR) V beta gene expression. In contrast to a recent study, the results presented here fail to provide evidence that selective loss of V beta-bearing T cells occurs in HIV+ individuals. Furthermore, when PBL from HIV+ individuals were stimulated with Staphylococcal enterotoxin B (SEB), T cells expressing V beta subfamilies known to engage this superantigen were expanded, indicating that such cells were not deleted and were responsive to stimulation by a bacterial superantigen. Collectively, these data suggest that CD4 loss in HIV patients does not occur in a V beta-selective, superantigen-mediated fashion.
Boyer
V
V
Immune Response Corporation, Carlsbad, CA 92008.
Smith
L R
LR
Ferre
F
F
Pezzoli
P
P
Trauger
R J
RJ
Jensen
F C
FC
Carlo
D J
DJ
D001483:Base Sequence; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D004768:Enterotoxins / Q000276:immunology; D017353:Gene Deletion; D015870:Gene Expression; D006678:HIV / Q000276:immunology; D015488:HIV Antigens / Q000276:immunology; D015658:HIV Infections / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007958:Leukocyte Count; D008213:Lymphocyte Activation / Q000276:immunology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics* / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D004768:Enterotoxins; D015488:HIV Antigens; D016693:Receptors, Antigen, T-Cell, alpha-beta; C031818:enterotoxin B, staphylococcal