T cell receptor beta-chain usage in experimental autoimmune uveoretinitis

Genomic rearrangements to the T-cell receptor (TCR) V beta 8 gene locus were examined in T cells derived from the lymph nodes of Lewis rats immunized with either S-Antigen or peptides derived from interphotoreceptor retinoid binding protein (IRBP). The cells used in these studies are from T-cell lines that have been selected by several cycles of antigen/IL-2 stimulations, or clones isolated from these lines. No apparent rearrangement of the V beta 8 gene was observed by Southern analysis, suggesting that if indeed there are T cells using V beta 8 gene elements they represent small proportions of the cells in these T-cell lines that induce EAU (uveitogenic T cells) and that the lines may consist of large numbers of clones. On the other hand, we have demonstrated V beta 8 gene expression in uveitogenic T-cell populations by Northern analysis and by polymerase chain reaction (PCR). Although V beta 8 gene transcripts were detectable in pathogenic, but not in non-pathogenic, T-cell lines using a V beta 8 cDNA probe, RNA from pathogenic T cell lines did not hybridize to another probe specific for rat V beta 8.2. Taken together, these results suggest that, unlike the T-cell lines that mediate experimental allergic encephalomyelitis (EAE), some T-cell lines that induce EAU do not predominantly express V beta 8.2 gene but other member(s) of the V beta 8 family.