Tetraspanins and immunity

Studies of tetraspanins in cells of the immune system were the fi rst to reveal the interactions of tetraspanins with each other and with their associated molecular partners. The extensive knowledge of immune cell subsets, the functionally distinct molecules expressed by these cells, and the availability of specifi c antibody reagents has had a major impact on our understanding of how tetraspanins assemble in cell membranes, and how they affect the function of their partners. Here we briefl y introduce the various cell types that partake in innate and adaptive immune functions. We then highlight the role of tetraspanins in both arms of the immune system. Tetraspanins infl uence immune cell migration and antigen presentation. Moreover, they are present on both sides of immune synapses, namely, on antigen presenting cells and on T cells. Indeed, defi ciency of specifi c tetraspanins in both mice and humans results in immune impairments.