Modulating ongoing Th2-cell responses in experimental leishmaniasis.

Dramatically polarized T helper (Th)-cell responses are seen in experimental murine infections with Leishmania major. Resistant mice develop a Th1-cell type response and heal the primary lesion, while susceptible mice develop non-protective Th2-cell responses, and the disease eventually proves fatal. Deservedly, much effort has gone into determining factors that influence the development of these T-cell subsets early in infection; however, little is known about how the polarity of established responses can be permanently modified. In this article, Gary Nabors reviews his findings on modifying ongoing Th2-cell responses in susceptible mice, and discusses therapies that have proven effective involving reducing the level of infection using a conventional antileishmanial drug, combined with agents that push the response towards the Th1 pole.