COMMON T-CELL RECEPTOR CLONOTYPE IN LACRIMAL GLANDS AND LABIAL SALIVARY-GLANDS FROM PATIENTS WITH SJOGRENS-SYNDROME

Sjogren's syndrome (SS) is an autoimmune disease characterized by lymp hocytic infiltration into lacrimal and salivary glands leading to symp tomatic dry eyes and mouth. Immunohistological studies have clarified that the majority of infiltrating lymphocytes around the lacrimal glan ds and labial salivary glands are CD4 positive alpha beta T cells, To analyze the pathogenesis of T cells infiltrating into lacrimal and lab ial salivary glands, we examined T cell clonotype of these cells in bo th glands from four SS patients using PCR-single-strand conformation p olymorphism (SSCP) and a sequencing method, SSCP analysis showed that some infiltrating T cells in both glands expand clonally, suggesting t hat the cells proliferate by antigen-driven stimulation. Intriguingly, six to sixteen identical T cell receptor (TCR) V beta genes were comm only found in lacrimal glands and labial salivary glands from individu al patients. This indicates that some T cells infiltrating into both g lands recognize the shared epitopes on autoantigens. Moreover, highly conserved amino acid sequence motifs were found in the TCR CDR3 region bearing the same TCR V beta family gene from four SS patients, suppor ting the notion that the shared epitopes on antigens are limited, In c onclusion, these findings suggest that some autoreactive T cells infil trating into the lips and eyes recognize restricted epitopes of a comm on autoantigen in patients with SS.