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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.
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Objective] To amplify and sequence the light chain of anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum. [Methods] By comparing the conserved regions at each end of the nucleotide sequences of murine germ line genes enco ding FR1 and FR4 regions of immunoglobulin light chain variable regions, we designed a set of primers for amplification of V L gene. The hybridoma cells secreting anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum were cultured and their genome DNAs were extracted and used as templates for PCR. The PCR product was then cloned into pUC19 vector. The recombinants were sequenced by Sanger′s method. The V L gene was compared with GenBank and published mouse V L genes. [Results] The full length of V L gene was 318 bp. The V L gene was a member of mouse Ig ? light chain subgroup IV and generated from rearrangement of germ line V and J? 4 genes. The V L gene sequence has been registered by GenBank(accession No. AF206720). [Conclusion] The obtained V L gene was a potentially functional gene of anti idiotypic monoclonal antibody NP30 of Schistosoma japonicum .
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For construction of anti-CD3 human/murine chimeric antibody genes, a selective first-strand cDNA synthesis from mRNA or RNA of murine McAb HIT3a was performed using murine Ig constant region primers, and then cDNA of heavy and light chain variable domains of murine immunoglobulin were amplified by PCR using a set of degenerated oligonucleotide primers. Using these cDNA fragments as probes, the L and H chain V region exons encoding the murine McAb anti-CD3 were isolated from the gene library of HIT3a DNA and inserted into mammalian expression vectors containing the human ? and yl constant region exons for construction of human/murine chimeric antibody genes.