THE STRUCTURE OF THE VARIABLE REGIONS OF MOUSE MONOCLONAL-ANTIBODIES TO HEPATITIS-B VIRUS CORE ANTIGEN

From a panel of monoclonal antibodies (MoAbs) directed against E. coli -derived native and denatured hepatitis B virus (HBV) core antigen we have selected a set of specific MoAbs which recognize different linear antigenic determinants: MoAb C1-5-cl epitope; MoAb 14K8-less immunoge nic N-terminal region; and MoAbs 13C9, 10F10 and 14E11, 14G3-the immun odominant region between amino acids 134 and 140. We have applied the polymerase chain reaction technique to clone Ig V(H) and V(L) region g enes, and appropriate full-length cDNA clones were obtained and charac terized by nucleotide sequence analysis. Among the six heavy chain var iable region sequences examined, three V(H) families were represented. Two of them belong to the 7183 (MoAb C1-5) and 3609 (14B8) families r espectively and four, having only two amino acid changes in the CDR2 r egion, to the J558 family. These four probably are derived from a sing le expanded B-cell clone. The light chain sequences indicate that thei r V(L) are encoded by V(kappa)21, V(kappa)19 and V(kappa)3 germline ge nes. Unlike V(H) genes, light chain genes are closely related to known representatives of mouse kappa light chain families and are employed also by MoAbs raised against other antigens.