MATERNAL MONOCLONAL-ANTIBODY TO THE V3 LOOP ALTERS SPECIFICITY OF THERESPONSE TO A HUMAN-IMMUNODEFICIENCY-VIRUS VACCINE

The effect of maternally transferred monoclonal antibody (MAb) on the offspring antibody response to rgp120(SF2) was examined in a murine mo del. Two MAbs were studied: MAb 83.1, which recognizes a determinant i n the V3 loop of gp120 from human immunodeficiency virus-1 (HIV-1) SF2 , and MAb 26.2D3, which recognizes a conserved N-terminal region of gp 120 from HIV-1(SF2). Offspring were immunized at 18-21 days of age wit h 100 mu g of rgp120(SF2) in complete Freund's adjuvant. Offspring imm unized in the presence of preexisting MAb 83.1 but not MAb 26.2D3 demo nstrated inhibition of the IgG anti-V3 response. The total IgG anti-rg p120(SF2) response was not affected by preexisting MAb. Since newborns at risk for HIV may be immunized in the presence of maternal or admin istered anti-HN antibody, alternative strategies may be required to ci rcumvent inhibition of the infant's epitope-specific response to HIV i mmunization by preexisting antibody.