Immunologic Research

, Volume 27, Issue 2, pp 489–498

Development and regulation of cell-mediated immunity in experimental Leishmaniasis


DOI: 10.1385/IR:27:2-3:489

Cite this article as:
Scott, P. Immunol Res (2003) 27: 489. doi:10.1385/IR:27:2-3:489


The development of a Th1 response is critical for controlling many intracellular pathogens. Our laboratory has focused on the role IL-12 plays in initiating such a Th1 response following infection with the obligate intracellular protozoan, Leishmania. Infection of several mouse strains with L. major is associated with IL-12 production and the development of a Th1 response and resistance, although, interestingly, some species of Leishmania (L. mexicana and L. amazonenesis) fail to initiate a Th1 response in the same mouse strains. Consistent with these observations was our finding that IL-12 is an effective adjuvant for the induction of a Th1 response in leishmaniasis (1). Surprisingly, however, in spite of the fact that following resolution of a primary leishmanial infection there is substantial and long-lived resistance to reinfection, an effective prophylactic or therapeutic vaccine for human leishmaniasis does not exist. Our ability to induce a Th1 response in a primate Leishmania vaccine model, but not protection, suggests that long-term resistance to Leishmania requires more than simply initiating a Th1 response (2). Therefore, we recently expanded our studies to investigate how infection-induced resistance to Leishmania operates. We made the unexpected finding that IL-12 is required for L. major-infected mice to remain immune (3). We are now studying how IL-12 participates in maintaining cell-mediated immunity, and more broadly, how immunologic memory works in L. major-healed mice, as well as defining parasite factors that may block the development of cell-mediated immunity.

Key Words

Th cell subsets Cell-mediated immunity IL-12 Leishmania Memory 

Copyright information

© Humana Press Inc. 2003

Authors and Affiliations

  1. 1.Department of Pathobiology School of Veterinary MedicineUniversity of PennsylvaniaPhiladelphia

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