ANTIBODIES TO RECOMBINANT GP160 IN MUCOSAL SECRETIONS AND SERA OF PERSONS INFECTED WITH HIV-1 AND SERONEGATIVE VACCINE RECIPIENTS

An enzyme immunoassay (EIA) was developed to detect secretory IgA (sIg A) antibodies to HIV-1 envelope glycoprotein, using a mouse monoclonal antibody and a highly purified, baculovirus-expressed recombinant gp1 60 (rgp160) as antigen. Detection of sIgA was enhanced by prior immuno precipitation of IgG. IgG and sIgA rgp160 antibodies were measured in parotid saliva and nasal wash samples of 18 HIV-1-seropositive volunte ers and 14 HIV-1-seronegative adult volunteers immunized 3 times with HIV-1 IIIB rgp160 vaccine at 1 of 4 dosage levels: 40 mug (N = 3), 80 mug (N = 3), 160 mug (N = 4), and 640 mug (N = 4). We detected rgp160- specific IgG antibody in the nasal wash samples of all HIV-1-seroposit ive volunteers and 4/8 vaccinees (50%) immunized with the two highest doses of rgp160 vaccine. All infected volunteers tested had rgp160-spe cific sIgA in their nasal wash samples. None of the vaccinees and very few of infected volunteer specimens had detectable antibody in the pa rotid saliva samples (5/8 had IgG and 1/8 had sIgA). We also detected IgG antibody to rgp160 in the sera of all infected volunteers and 13/1 4 vaccineees (93%). With this EIA, sIgA antibody can be measured in mu cosal secretions of recipients of appropriate candidate HIV-1 vaccines .