T-CELL RECEPTOR USAGE IN RHEUMATOID-ARTHRITIS

The structure of alpha beta T cell receptors (TCR) is restricted in a number of rodent and human antigen responses. In several rodent EAE mo dels of multiple sclerosis a limited range of T cell receptors are exp ressed by T cells which respond to the inciting antigen and are capabl e of transferring the disease to naive animals. These observations hav e raised the question of whether in rheumatoid arthritis (RA), a parti cular T cell receptor structural signature can be identified among T c ells derived from the synovium compared to autologous peripheral blood . The parameters which are usually measured are TCR variable region us age, oligoclonality and/or limited junctional region usage. A large nu mber of studies have been carried out and results are variable with so me authors claiming evidence for the effect of uncharacterised superan tigens expanding or deleting T cells with particular V beta regions wh ile others have suggested that observations of restricted V region usa ge and limited junctional regions imply that clones of cells have been expanded by antigen. So far none of these studies have led to the ide ntification of an antigen or superantigen which plays a role in RA pat hogenesis.