MOLECULAR CHARACTERIZATION OF THE HUMAN IMMUNOGLOBULIN-V-GAMMA-I GERMLINE GENE REPERTOIRE

To advance our understanding of the human immunoglobulin V-lambda germline gene contribution to normal as well as autoimmune responses, we have isolated and sequenced six germline genes of the V-lambda-I subgroup. These genes can be divided into three sub-subgroups on the basis of greater-than-or-equal-to 93% nucleotide sequence homology and greater-than-or-equal-to 88% deduced amino acid sequence similarity. Examination of all cDNA and protein sequences available for expressed V-lambda-I genes supports the assignment of these three sub-subgroups. Sequence comparisons also suggest that germline gene members of two of these sub-subgroups, I-a and I-b, are preferentially utilized in the expressed V-lambda-I repertoire. This finding may be at least partially attributable to regulatory sequence abnormalities apparent in two of the other V-lambda-I germline genes (Humlv101 and Humlv1041) which may interfere with their expression.