Molecular cloning of a human immunoglobulin lambda chain variable sequence

We have cloned a human V lambda cDNA sequence from an Ig lambda-producing human Burkitt lymphoma cell line (BL2) by taking advantage of a cloned constant region gene as a primer for cDNA synthesis instead of an oligo(dT) primer. The amino acid sequence deduced from the nucleotide sequence of V lambda clones is highly related to that of the NEW V lambda protein of subgroup I. Southern blot hybridization of human DNAs with the V lambda I probe showed at least 12 hybridizing V lambda fragments. These fragments are amplified in K562 cells which derive from a case of chronic myelogenous leukemia and contain an amplified c-abl oncogene and amplified C lambda sequences.