NEUTRALIZATION OF HIV-1 BY SECRETORY IGA INDUCED BY ORAL IMMUNIZATIONWITH A NEW MACROMOLECULAR MULTICOMPONENT PEPTIDE VACCINE CANDIDATE

Control of pandemic infection of human immunodeficiency virus type 1 ( HIV-1) requires some means of developing mucosal immunity against HIV- 1 because sexual transmission of the virus occurs mainly through the m ucosal tissues. However, there is no evidence as yet that the secretor y immunoglobulin A (IgA) antibody induced by immunization with antigen s in experimental animals can neutralize HIV-1. We demonstrate here th at oral immunization with a new macromolecular peptide antigen and cho lera toxin (CT) induces a high titre (1:2(11)) of gut-associated and s ecretory IgA antibody to HIV-1. Using three different neutralizing ass ays, we clearly demonstrate that this secretory IgA antibody is able t o neutralize HIV-1(III), HIV-1(F2) and HIV-1(MN). Our new approach may prove to be important in the development of a mucosal vaccine that wi ll provide protection of mucosal surfaces against HIV-1.