FIG. 3.

Anti-gp120_CD4BD MAb 654-D, either by itself or complexed with gp120, does not inhibit CD4 T-cell recognition of gp120-derived peptides. Proliferative responses of the gp120-specific CD4 T-cell line DMg26 to its peptide epitope p740.19 (gp120 residues 221 to 240) was measured in the presence of MAb 654-D/gp120 complexes or MAb 654-D. To form the complexes, recombinant gp120_IIIB (3 μg/ml) was mixed with 654-D (10 μg/ml). The complexes or MAb 654-D alone (10 μg/ml) were then added to APCs along with p740.19 (0.1 to 10 μg/ml). Heterologous HLA-DR1⁺ PBMCs were used as APCs in this experiment. The T-cell response to APCs with no peptide was 2,674 cpm.