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 peripher al 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 f amily probes and with a consensus J(H) region probe. The V-H/J(H) hybr idization intensity ratios were taken as a parameter to measure V-H ex pression. In vivo V(H)3 gene family expression is reduced in plasma ce lls of all HIV-infected patients compared with adult healthy donors, T his decrease is maximal in patients with AIDS: >90%. This is true for both studied isotypes. Conversely, the two other main V-H gene familie s, V(H)1 and V(H)4, show no significant variation in expression. We an d others have previously shown that V(H)3 gene family expression is fi rst expanded and then decreased in peripheral B lymphocytes of HIV-inf ected patients, The present results extend these observations and show that V(H)3 gene family expression is also affected in plasma cells. T he existence of a B cell superantigen in HIV infection may explain the se data, This pronounced reduction in V(H)3 family expression may part icipate in the impaired humoral responses against bacterial agents fou nd in HIV-infected patients.