The Th1/Th2 paradigm and experimental murine leishmaniasis.

In recent years, the Th1/Th2 concept has become of prime importance in the understanding of heterogeneous responses of the immune system and implications thereof for infectious and autoimmune diseases. Originally established on the basis of different cytokines produced by T cell clones, it is now known that the Th1/Th2 concept really defines totally different immune pathways that affect most if not all cells of the immune system. Murine experimental leishmaniasis was the first model to confirm the relevance of the Th1/Th2 concept in vivo. Herein, we summarize the current knowledge on the characteristics and generation of Th1 and Th2 cells, as well as on recent advances of the application of this concept to murine cutaneous leishmaniasis.