Limited TCR repertoire of infiltrating T cells in the kidneys of Sjögren's syndrome patients with interstitial nephritis.

To analyze the mechanism of interstitial nephritis in patients with Sjörgren's syndrome (SS), we examined the TCR repertoire of infiltration T cells in kidney, labial salivary glands, and PBLs using a PCR. The repertoire of the TCR V beta gene on infiltrating T cells from the kidneys of SS patients was more restricted than those on infiltrating T cells in labial salivary glands and PBL. The TCR V beta 2 gene was expressed predominantly in six of seven (86%) SS patients. Junctional sequences of cDNAs encoding the V beta 2 gene on infiltrating T cells in the kidneys of five SS patients showed that some of the cells expanded clonally, indicating Ag-driven stimulation rather than superantigen-induced proliferation. The same V beta 2 clones in the kidney were not detected in labial salivary glands of the same SS patients; the conserved amino acid (arginine at position 96) in the CDR3 region of the V beta 2 gene was found at a frequency of 48.0% in the kidney, whereas it was detected in only 15.4% of the clones in lips. In conclusion, these findings suggest the possibility that T cells that infiltrate the kidneys of SS patients with interstitial nephritis might recognize different autoantigens than those that infiltrate labial salivary glands.