LIMITED TCR REPERTOIRE OF INFILTRATING T-CELLS IN THE KIDNEYS OF SJOGRENS-SYNDROME PATIENTS WITH INTERSTITIAL NEPHRITIS

To analyze the mechanism of interstitial nephritis in patients with Sj ogren's syndrome (SS), we examined the TCR repertoire of infiltrating T cells in kidney, labial salivary glands, and PBLs using a PCR. The r epertoire of the TCR V beta gene on infiltrating T cells from the kidn eys of SS patients was more restricted than those on infiltrating T ce lls in labial salivary glands and PBL. The TCR V beta 2 gene was expre ssed predominantly in six of seven (86%) SS patients. Junctional seque nces of cDNAs encoding the V beta 2 gene on infiltrating T cells in th e kidneys of five SS patients showed that some of the cells expanded c lonally, indicating Ag-driven stimulation rather than superantigen-ind uced proliferation. The same V beta 2 clones in the kidney were not de tected in labial salivary glands of the same SS patients; the conserve d amino acid (arginine at position 96) in the CDR3 region of the V bet a 2 gene was found at a frequency of 48.0% in the kidney, whereas it w as detected in only 15.4% of the clones in lips. In conclusion, these findings suggest the possibility that T cells that infiltrate the kidn eys of SS patients with interstitial nephritis might recognize differe nt autoantigens than those that infiltrate labial salivary glands.