Antagonizing T cells

On page 579, Sumen et al. show that some mutant variants of antigens disable T cells by preventing the clustering of MHC molecules at the interface between T cells and antigen-presenting cells (APCs). The results also suggest that integrins are not the entire answer to getting T cells to stop at their targets.

Certain antigen variants, called antagonists, interfere with a T cell's ability to respond to otherwise stimulatory antigens. Although they are often effective only at high concentrations, antagonists may be used—either by pathogens or as therapies against autoimmune diseases—to thwart strong defense responses. But just how they get in the way is unclear. In the new work, the authors show ways in which antagonists hinder the formation of the immunological synapse—the junction between the T cell and the APC...