Progressive decrease in VH3 gene family expression in plasma cells of HIV-infected patients

We have analysed the expression of V_H gene families In totalperipheral plasma cells of µ and isotypes from a groupof HIV-infected patients. CD19^– and CD20^– cellswere separated from B lymphocytes, and anchored RT-PCR productswere hybridized with specific V_H gene family probes and witha consensus J_H region probe. The V_H/J_H hybridization Intensityratios were taken as a parameter to measure V_H expression. Invivo V_H3 gene family expression is reduced In plasma cells ofall HIV-infected patients compared with adult healthy donors.This decrease is maximal in patients with AIDS: >90%. Thisis true for both studied Isotypes. Conversely, the two othermain V_H gene families, V_H1 and V_H4, show no significant variationIn expression. We and others have previously shown that V_H3gene family expression is first expanded and then decreasedIn peripheral B lymphocytes of HIV-infected patients. The presentresults extend these observations and show that V_H3 gene familyexpression is also affected In plasma cells. The existence ofa B cell superantlgen In HIV Infection may explain these data.This pronounced reduction In Vh3 family expression may participateIn the Impaired humoral responses against bacterial agents foundIn HIV-infected patients.