Induction of IgA and IgG antibodies in vaginal fluid, serum and saliva following immunization of genital and gut associated lymphoid tissue.

Vaginal immunization with the Simian immunodeficiency virus (SIV) was investigated in macaques in order to study genital mucosal antibodies. A combined route of genital- and gut-associated lymphoid tissues was used to stimulate IgA and IgG antibodies in vaginal fluid, serum and saliva. Macaques were immunized with a recombinant, particulate SIV antigen (SIV gag P27), covalently linked to the mucosal adjuvant cholera toxin B subunit (CTB). The animals were immunized sequentially as follows: vaginal (x2) followed by oral (x3), or the reverse sequence of immunization. The results show that both vaginal followed by oral immunization or the reverse sequence induces specific p27 IgA and IgG antibodies in the vaginal fluid and serum. IgA antibodies were also detected in saliva. Vaginal IgA antibodies have the secretory component and J chain suggesting that they are of secretory origin.