Expression of sequences homologous to htlv‐i tax gene in the labial salivary glands of japanese patients with sjögren's syndrome

Objective . To address the question of whether the human T cell leukemia virus type I (HTLV‐I) gene is associated with the etiology of Sjögren's syndrome (SS). Methods . RNA expression of HTLV‐I gag, pol, env , and tax genes in labial salivary glands (LSGs) from SS patients who were seronegative for antibodies to HTLV‐I was examined using reverse transcription and polymerase chain reaction techniques. Results . The HTLV‐I tax gene, but not the HTLV‐I gag, pol , or env genes, was detected in LSG samples from 4 of 14 patients (29%). The nucleotide sequences of the HTLV‐I pXIV region in these 4 patients' LSGs showed 100% homology to the HTLV‐I pXIV gene from the MT‐2 cell line. Conclusion . These findings suggest that products encoding sequences homologous to the HTLV‐I pXIV gene in SS patients' LSGs might be candidates for self‐antigen and/or lead to activation of autoreactive T lymphocytes through trans‐acting transcriptional activation.