Characterization of the human Ig VλII gene family and analysis of VλII and Cλ polymorphism in systemic lupus erythematosus

We report the cDNA sequence of an expressed human VλII gene and present an RFLP analysis of the Ig gene family defined by this clone. This VλII gene was expressed in a monoclonal B cell line generated from a patient with SLE by transformation with EBV. The encoded λL chain displays the 8.12 Id, an Id common to anti-DNA antibodies from patients with SLE. Using a coding region probe we estimate from Southern blot analysis that the germ-line VλII gene family contains at least 15 members. Many of the VλII restriction fragments are polymorphic both in SLE patients and in nonautoimmune individuals. EcoRI, HindIII, and TaqI RFLP analyses of the VλII gene family and EcoRI analysis of the Cλ gene family reveal no polymorphisms specific to SLE. Observed VλII and Cλ allele frequencies are the same among SLE patients and nonautoimmune individuals, and show no evidence of linkage disequilibrium between the two loci.