Two TCRs Are Better Than One

T cells normally bear only one type of T cell receptor (TCR) for antigen on the cell surface but a few can bear two. Having more than one is thought to be detrimental, because the second may cause autoimmune diseases. In the February issue of Nature Immunology, scientists show that these so-called dual TCR cells actually play a beneficial role in the immune system by increasing the ability of T cells to recognize invading microbes.

Charles Janeway and colleagues from Yale University School of Medicine have found that each TCR on dual TCR cells plays a different role. In their mouse model, one of the TCRs allows the T cell to develop and enter the blood stream, whereas the other, nonselected, TCR recognizes foreign matter that the first TCR is not capable of seeing. Thus, dual TCR cells can benefit the immune response by increasing the likelihood that T cells will recognize and eliminate foreign matter from the body. This would explain why dual TCR cells are retained at low frequencies in healthy individuals-the benefit of having such cells around apparently outweighs the potential risk of inducing autoimmune disease.

Author Contact:

Xin He
Yale University
New Haven
CT, USA
Tel: +1 203 436 0031
E-mail: xin.he@yale.edu

Additional Contact:

Alexander Rudensky
University of Washington
Seattle
WA, USA
Tel: +1 206 685 7644
E-mail: aruden@u.washington.edu

(C) Nature Immunology press release.

Message posted by: Trevor M. D'Souza