Fine specificity of the murine antibody response to HIV-1 gp160 determined by synthetic peptides which define selected epitopes.

In this report, we assess the humoral immune response in inbred strains of mice immunized with baculovirus-derived recombinant HIV-1 gp160 (rgp160). Six inbred strains of mice were each immunized with two different concns (5 and 50 micrograms) of rgp160, and the antibody response to rgp160 and synthetic peptides which define distinct gp160 epitopes was examined. Within a given inbred strain of mice, no significant difference in antibody titers to gp160 was observed in those groups receiving either 5 or 50 micrograms of rgp160 per injection. Following three immunizations with rgp160, differences in anti-gp160 titers were observed among the various inbred strains; however, these differences became less apparent after additional injections with rgp160. In addition, each mouse strain exhibited a unique reactivity pattern to seven gp160 epitopes defined by synthetic peptides. Multiple injections with rpg160 were required to induce responses to certain gp160 epitopes. The observed differences in the fine specificity of the humoral immune response to distinct gp160 epitopes among the six inbred strains suggest a genetic basis for regulating the antibody response to these epitopes. This apparent regulation can be overcome by multiple injections with rgp160.