Progressive decrease in V(H)3 gene family expression in plasma cells of HIV-infected patients

We have analysed the expression of V-H gene families in total peripheral plasma cells of mu and gamma isotypes from a group of HIV-infected patients. CD19(-) and CD20(-) cells were separated from B lymphocytes, and anchored RT-PCR products were hybridized with specific V-H gene family probes and with a consensus J(H) region probe. The V-H/J(H) hybridization intensity ratios were taken as a parameter to measure V-H expression. In vivo V(H)3 gene family expression is reduced in plasma cells of all HIV-infected patients compared with adult healthy donors, This decrease is maximal in patients with AIDS: >90%. This is true for both studied isotypes. Conversely, the two other main V-H gene families, V(H)1 and V(H)4, show no significant variation in expression. We and others have previously shown that V(H)3 gene family expression is first expanded and then decreased in peripheral B lymphocytes of HIV-infected patients, The present results extend these observations and show that V(H)3 gene family expression is also affected in plasma cells. The existence of a B cell superantigen in HIV infection may explain these data, This pronounced reduction in V(H)3 family expression may participate in the impaired humoral responses against bacterial agents found in HIV-infected patients.