IN-VITRO ANTI-HIV-1 ANTIBODY-PRODUCTION IN SUBJECTS IN DIFFERENT STAGES OF HIV-1 INFECTION

We evaluated the in vitro antibody production from peripheral blood mo nonuclear cells (PBMC) against HIV-I proteins in infected adults. Fift y-four HIV-1 infected patients (four recent seroconverters, 15 asympto matics with a CD4 count higher than 500/mu l, 27 asymptomatics with a CD4 count between 200 and 500/mu l and eight symptomatic patients) wer e tested. PBMC were incubated in the presence or absence of 1% pokewee d mitogen (PWM) at 37 degrees C for 8 days. Western blot assay, p24 an tigen ELISA and anti-p24 antibody ELISA were performed on serum and cu lture supernatants. Spontaneous production of anti-env antibody in cul ture supernatants was evidenced in all subjects. All the positive supe rnatants for anti-core antibodies (18/54) were derived from asymptomat ic patients. PBMC from recent seroconverters and from symptomatic pati ents did not produce any anti-core antibody. Antibody production decre ased after stimulation with PWM. The concentration of p24 antigen did not significantly increase in p24 positive supernatants following acid ification (P = 0.1), suggesting that the inability to detect p24 antib ody was not due to the anti-p24 antibody complexed to p24 antigen in c ulture supernatants. In vitro production of anti-p24 antibodies was si gnificantly more frequent in asymptomatic subjects with high CD4(+) ce ll counts (P = 0.02) and was absent in recent seroconverters. This las t finding suggests that during the initial phases of the infection, an ti-p24 antibody production may be restricted to cells residing in lymp hoid organs. In addition, the lower percentage of anti-core antibody i n people with low CD4(+) cell counts is not merely a consequence of th e binding of the antibody to an increased amount of antigen, but proba bly reflects an impaired production or a sequestration of producing ce lls in lymphoid tissue during the late stages of the infection.