ABSTRACT
T cell responses directed toward TCR-derived peptides have been shown to be an important regulatory mechanism of protection against autoimmunity. Here, we show that a naturally induced TCR-directed immune response can delay the onset of collagen-induced arthritis (CIA), an animal model of autoimmune rheumatoid arthritis in humans. DBA/1 mice were pretreated with an immunodominant peptide, p245-270, from bovine type II collagen (bCII) and were subsequently immunized with whole bCII for the induction of arthritis. The results showed that preactivation of p245-270-reactive cells delayed the onset and reduced the severity of CIA, compared with animals in the control group. Interestingly, the serum antibody response to bCII and the bCII-specific cytokine were not affected under these conditions. This result indicates that the observed protection was neither directly due to a lower antibody response nor due to the immune deviation of the anti-bCII T cell response. Furthermore, immunization with p245-270, but not bCII, induced a strong response to the B5 peptide, an immunodominant region of the TCR V(beta)8.2 (amino acids 76-101) that binds very strongly to I-A(q). These data suggest that at a critical phase in the loss of self-tolerance, an effective anti-TCR response, induced naturally, can regulate the pathogenic autoimmune response and thus may provide protection against autoimmunity.