Molecular cloning of an immunoglobulin gene encoding the kappa chain of a monoclonal antibody specific for the pre-S2 antigen of hepatitis B virus

Abstract

We have cloned an immunoglobulin (Ig) gene which encodes the kappa (k) chain of a murine monoclonal antibody (mAb) (y2b, k) specific for the pre-S2 surface antigen of HBV from H8 hybridoma cell line. Southern analysis of H8 chromosomal DNA revealed that about 6-kb BamHI fragment carries a rearranged VK and Ck gene. The BamUI fragments were subcloned in切 pUC18 to constmct a partial genomic library, which was then screened with variable region of k chain-specific cDNA coding for the H8 mAb as a probe. Two positive clones (pMKG-S2) were isolated and characterized to be identical by the analysis of restriction maps. The nucleotide sequence analysis of the clone showed that the gene contains a functionally reananged VK gene and the transcriptional elements required for B cell-specific expression. The VK gene fused with human Ck gene and then expressed in murine myeloma cells directed the synthesis of the chain mRNA, suggesting