Expression and sequences of T cell receptor β-chain variable genes in the enlarged lymph nodes of C57BL/6-lpr/lpr mice

An autosomal recessive gene, lpr, is responsible for lymphoproliferation and autoimmunity of lpr-mice, in which background genes are also known to influence the development of autoimmune disease. To define the differences in abnormally proliferating T cells between C57BL/6-lpr/lpr and MRL/Mp-lpr/lpr mice, and to try and understand the influence of background in the differing expression of autoimmune disease in both strains, we analysed the sequences of T cell antigen receptor V(β) genes expressed in the cells from the enlarged lymph nodes of C57BL/6-lpr/lpr mice. Eleven β cDNAs out of the 38 Cβ-specific cDNAs contained sequences with open reading frames from the beginning of the variable region to the expected termination codons at the end of the constant regions. Notably, 36% of the functional β-chain mRNAs expressed V(β8.3) genes, whereas V(β8.1) and V(β8.2) genes were not found. These results are consistent with a relatively lower frequency of the V(β8.1) or V(β8.2) expressing cells in the hypertrophic lymph nodes of C57BL/6-lpr/lpr mice, detected by KJ16-133 monoclonal antibody. Interestingly, other V(β) genes expressed in these mice were completely distinct from those in MRL/Mp-lpr/lpr mice as described by Singer et al. (1986). The different distribution of V(β) genes expressed in C57BL/6-lpr/lpr from that in MRL/Mp-lpr/lpr mice might be related to the differences in the genetic background and the expression of lpr-gene associated autoimmunity.