Treg control of antimicrobial T cell responses.

Immunity to microbes depends on the function of numerous cell types and their products. These include T cells with regulatory function (Treg) against the components of the immune system. Recently, there has been much discussion regarding the circumstances in which protective or tissue-damaging T cell responses to microbes are affected by the activity of Treg. These relationships range from situations in which the Treg response seems to contribute to immune dysfunction to those that minimize tissue damage caused by immunoinflammatory T cell reactions. In several parasitic infections, Treg maintain equilibrium to ensure parasite persistence, minimal tissue damage and immunity to re-infection. Recently, several unresolved questions about the role of Treg in microbial infections have been raised and discussed. Learning how to successfully manipulate Treg responses could result in more effective vaccines and immunomodulators.