A dominant human leucocyte antigen DR4-Dw15 restricted mycobacterial 65 kDa antigen-specific T-cell immunity in Chinese patients with rheumatoid arthritis.

The human leucocyte antigen DR4-associated immune responses to Mycobacterium tuberculosis 65 kDa heat shock protein were considered to be relevant to the pathogenesis of rheumatoid arthritis (RA). In the Chinese population, DR4-Dw15 was found to be the predominant DR4 subtype in RA. To further define the immune responses associated with DR4-Dw15 molecules, the proliferative responses of peripheral (PBMC) and synovial mononuclear cells (SFMC) to mycobacterial 65 kDa antigen were evaluated. The SFMC of all of our RA patients responded significantly to 65 kDa mycobacterial antigen. The responses of PBMC to this antigen in RA were much lower than those of SFMC. Our results further indicated that relatively low numbers of peripheral antigen-specific T-cells, but not incompetence of peripheral antigen presenting cells, might be related to the observed low responsiveness to 65 kDa antigen in PBMC of RA patients. Of utmost importance, DR4-Dw15 was proved to be one of the major restrictive molecules in mycobacterial 65 kDa antigen-specific immune responses in Chinese RA patients.