[Pathomechanism of HTLV-I associated arthropathy and the role of tax gene].

HTLV-I is known to be a causative agent for adult T cell leukemia. Recent studies revealed this virus is also related to several autoimmune disorders, such as arthropathy, myelopathy and Sjögren's syndrome. We studied etiology of HTLV-I associated arthropathy (HAAP), and found that tax is a causative gene for synovial proliferation and induction of immunogenicity. HTLV-I transgenic mice supported the etiopathological role of tax gene. Our results suggested that HAAP is considered to be a prototype of rheumatoid arthritis, and tax is a best tool for recognizing pathomechanism of rheumatoid arthritis.