SELECTIVE VARIATIONS IN-VIVO OF V(H)3 AND V(H)1 GENE FAMILY EXPRESSION IN PERIPHERAL B-CELL IGM, IGD AND IGG DURING HIV-INFECTION

We have analyzed the expression of V-H gene families in IgM, IgD and IgG of peripheral blood B cells from a group of HIV-infected patients. CD19(+)CD20(+) cells were purified and anchored reverse transcriptase-polymerase chain reaction products were hybridized with V-H gene family probes. IgM, IgD and IgG that expressed a V(H)3 gene family segment, were decreased in patients with low CD4 counts and to a greater extend in patients with AIDS symptoms (up to 85 % for IgG) compared to adult healthy donors. This was correlated with elevated levels of IgM and IgG encoded by a V(H)1 gene family segment (around 60 % for IgG). These results confirm and extend previous work that has detected the V(H)3 gene family under-representation in HIV infection. Here, we show that. in vivo, this phenomenon actually affects the different B cell populations of the peripheral blood: IgM(+) or IgG(+) B cells and also IgM(+)IgD(+) naive B cells. In the course of HIV infection, this results in their gradual depletion. Data presented here strengthen the hypothesis that a B cell superantigen exists in HIV infection. These pronounced variations of the normally most-expressed V, gene family may be related to B cell abnormalities detected in HIV-infected patients.