The study of inhibitory peptides on T cell activation in rheumatoid arthritis

Abstract

To study the inhibitory role of altered HA308 - 317 peptides in T cell responses in patients with rheumatoid arthritis (RA). Peripheral blood mononuclear cells (PBMC) were obtained from 27 HLA-DRB1 positive RA patients. T cell responses to altered HA308-317 peptides were examined by using (3)H incorporation assay. The level of IL-2 and IFNgamma in the supernatants was identified by an enzyme-linked immunosorbent assay. The CD69 expression on T cell surface was studied by using flow cytometry. Compared to wild type CII263 - 272 or HA308 - 317, altered HA308 - 317 peptides failed to stimulate T cell proliferation (P < 0.05) and production of IL-2 as well as IFNgamma and resulted in lower expression of CD69 in RA patients (P < 0.05). SI values for T cell coincubated with altered HA308 - 317 peptides and CII263 - 272 or wild type HA308 - 317 were significantly lower than coincubated with CII263 - 272 and wild type HA308 - 317 alone (P < 0.05). Substitution of TCR-binding residue of HA308 - 317 yielded weak or non-T-cell stimulating peptides, which might be potentially effective in blocking abnormal T cell responses in RA.