Single B cell sorting-based amplification and functional identification of HIV-1 monoclonal antibody genes

Abstract

Objective To amplify and identify monoclonal antibody genes from HIV-1-infected patients. Methods Single cell sorting was used to isolate antigen-specific single B cells. Sequence Identity Matrix and the international ImMunoGeneTics information system were used to analyze antibody variable region genes. Binding abilities were detected by enzyme linked immunosorbent assay. Neutralizing activities were tested by TZM-bl/pseudovirus assay. Results The heavy and light chain genes of four, seven, and eleven antibodies were amplified and sequenced from three HIV-1-infected patients, respectively. They were derived from various germline genes with flexible CDR3 lengths and somatic mutations. A1 and B3 antibodies bound to HIV-1 clade B, CRF01_AE, and CRF07_BC antigens. The half maximal inhibitory concentration values of A1 and B3 against MW965 virus were 0.04 μg/ml and 37.34 μg/ml. Conclusion In this study, we acquired a lot of monoclonal antibody genes and two HIV-1 monoclonal binding and neutralizing antibodies, which would provide basic data for further research on monoclonal antibody identification. Key words: Single B cell sorting; Antibody gene; Sequence analysis; Binding ability; Neutralizing activity