ALTERNATIVE COMPLEMENT PATHWAY ACTIVATION BY CD4-CELLS OF HIV-INFECTED INDIVIDUALS - A POSSIBLE ROLE IN AIDS PATHOGENESIS( T)

The mechanisms by which CD4(+) T cells are eliminated during HIV infec tion are poorly understood. We have previously shown that HIV infected cell lines activate and fix C3 via the alternative complement pathway (ACP). In the present study we examined the ability of blood lymphocy tes from 40 HIV+ individuals to fix C3. A large fraction of the CD4(+) T cells reacted with anti-gp120 antibodies. These cells also carried C3 fragments in vivo and could further fix C3 if exposed to human seru m in vitro. C3 activation occurred via the ACP. In some cases exposure of the lymphocytes to human serum under conditions allowing ACP activ ation resulted in partial elimination of CD4(+) T cells. The results s uggest that complement activation and fixation by CD4(+) T cells opson ized with HIV particles or gp120 may contribute to their selective des truction.