BROADLY REACTIVE ANTIBODIES AGAINST A GP120 V3 LOOP MULTI-EPITOPE POLYPEPTIDE NEUTRALIZE DIFFERENT ISOLATES OF HUMAN-IMMUNODEFICIENCY-VIRUSTYPE-1 (HIV-1)

A gene encoding for a novel multi-epitope polypeptide (TAB4) was synth esized and expressed in Escherichia coli. The protein Was composed of 15 amino acid fragments derived from the V3 loop of HIV-1 isolates MN, IIIB, RF, JY1, BRVA and LR150, joined by five-amino-acid linkers. Imm unogenicity of TAB4 in rabbits was studied, and the antibody response against individual peptides investigated, TAB4 was shown to be immunog enic in Complete Freund's Adjuvant in a dose-dependent manner, and was able to elicit a humoral response against all V3 epitopes included on the protein. Sera from some of the animals were able to neutralize th e replication of viral strain MN, and in one case IIIB, with moderate titers, Some ser-a also neutralized several Cuban clinical strains iso lated in peripheral blood mononuclear cells; after one round of amplif ication in MT4 cells. (C) 1997 Elsevier Science Ltd.