T cells expressing γδ chain receptors in rheumatoid arthritis

Abstract

Whereas the majority of T cells use α and β chains to form their T-cell receptor, a small minority of T cells, which do not express the CD4 or CD8 surface markers, use other chains termed γ and δ to form their receptor. Flow cytometry was performed on cells isolated from the blood and synovial joints of patients with rheumatoid arthritis. Monoclonals which recognise the γ and δ chains were used to compare the proportion of TCR γδ cells in these sites. Approximately half the patients had more TCR γδ in the joints than in their blood and one newly diagnosed patient had high numbers of TCR γδ cells in both blood and joints. In this preliminary study it is not possible to evaluate the role of these cells in the disease process, but it is of interest that in some RA patients there is an overabundance of both T cells that arise early in ontogeny (TCR γδ cells) and B cells that arise early in ontogeny, the CD5 B cell.