CROSS-NEUTRALIZING ACTIVITY AGAINST DIVERGENT HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 ISOLATES INDUCED BY THE GP41 SEQUENCE ELDKWAS

Previously we identified the highly conserved amino acids Glu-Leu-Asp- Lys-Trp-Ala (ELDKWA) on the ectodomain of gp41 as the epitope of a neu tralizing monoclonal antibody (2F5) directed against human immunodefic iency virus type 1. In the present study, the sequence defining the ep itope was introduced into the loop of antigenic site B of the influenz a virus hemagglutinin. The resulting chimeric virus was able to elicit ELDKWA-specific immunoglobulins G and A in antisera of mice. Moreover , the distantly related human immunodeficiency virus type 1 isolates M N, RF, and IIIB were neutralized by these antisera. These data suggest that this conserved B-cell epitope is a promising candidate for inclu sion in a vaccine against AIDS. The results also show that influenza v irus can be used to effectively present the antigenic structure of thi s B-cell epitope.