HLA-DR ALLELES IN PATIENTS WITH SJÖGREN'S SYNDROME OVER-REPRESENTING Vβ2 AND Vβ13 GENES IN THE LABIAL SALIVARY GLANDS

Abstract

To identify genetic factors that play a role in the pathogenesis of patients with SS over-representing V beta 2 and V beta 13 genes in the lips, HLA-DR and -DQ alleles of 10 primary SS patients with predominant expression of V beta 2 and V beta 13 genes in the lips were analysed, using the polymerase chain reaction (PCR) and sequence specific oligonucleotide probes. The CDR3 amino acid sequences of cDNA clones encoding V beta 2 and V beta 13 genes were also determined by PCR. The results showed that the DRB4*0101 allele was significantly increased (80%) and that the frequency of DRB3 allele was decreased (0%) when compared to findings in healthy subjects (35.6 and 26%, respectively). Sequencing analyses demonstrated that 75% of V beta 2 cDNA clones and 87% of V beta 13 cDNA clones had a glutamine residue at position 106, in the CDR13 region. Moreover, the conserved sequences (Y*TLRNEQ) in the CDR3 of V beta 13-positive T cell were detected in two different clones (27%) from the two individual SS patients. These findings suggest that the decreased DRB3 and increased DRB4*0101 alleles may be associated with the antigens recognized by V beta 2- and V beta 13-positive T cells.