Construction of human combinatorial antibody library and screening of monoclonal antibody Fabs to human immunodeficiency virus type I

The heavy chain Fd genes and κ chain genes of immunoglobulin were amplified by RT-PCR from PBL of three volunteer donors with HIV-positive. Phage antibody library was constructed with the Fd genes and κ chain genes using pComb3 as vector. Three-round selection against coated gp120 showed specific enrichment of phage antibodies. After the third round selection, 40 out of 50 clones exhibited gp120 binding capacity. The specificity of the clones was verified by ELISA and competition inhibition ELISA. The VH was derived from subgroups VHII and VHIII, VL belonged to subgroups VKI and VK HI with DNA sequencing. These results suggest that the antibodies obtained are specific to gp120.