Effector responses induced by polarized CD4+ T helper 2 (Th2) cells drive nonhealing responses in BALB/c mice infected with Leishmania major. Th2 cytokines IL-4 and IL-13 are known susceptibility factors for L. major infection in BALB/c mice and induce their biological functions through a common receptor, the IL-4 receptor alpha chain (IL-4Ralpha). IL-4Ralpha-deficient BALB/c mice, however, remain susceptible to L. major infection, indicating that IL-4/IL-13 may induce protective responses. Therefore, the roles of polarized Th2 CD4+ T cells and IL-4/IL-13 responsiveness of non-CD4+ T cells in inducing non-healer or healer responses have yet to be elucidated. CD4+ T cell-specific IL-4Ralpha (Lck(cre)IL-4Ralpha(-/lox)) deficient BALB/c mice were generated and characterized to elucidate the importance of IL-4Ralpha signaling during cutaneous leishmaniasis in the absence of IL-4-responsive CD4+ T cells. Efficient deletion was confirmed by loss of IL-4Ralpha expression on CD4+ T cells and impaired IL-4-induced CD4+ T cell proliferation and Th2 differentiation. CD8+, gammadelta+, and NK-T cells expressed residual IL-4Ralpha, and representative non-T cell populations maintained IL-4/IL-13 responsiveness. In contrast to IL-4Ralpha(-/lox) BALB/c mice, which developed ulcerating lesions following infection with L. major, Lck(cre)IL-4Ralpha(-/lox) mice were resistant and showed protection to rechallenge, similar to healer C57BL/6 mice. Resistance to L. major in Lck(cre)IL-4Ralpha(-/lox) mice correlated with reduced numbers of IL-10-secreting cells and early IL-12p35 mRNA induction, leading to increased delayed type hypersensitivity responses, interferon-gamma production, and elevated ratios of inducible nitric oxide synthase mRNA/parasite, similar to C57BL/6 mice. These data demonstrate that abrogation of IL-4 signaling in CD4+ T cells is required to transform non-healer BALB/c mice to a healer phenotype. Furthermore, a beneficial role for IL-4Ralpha signaling in L. major infection is revealed in which IL-4/IL-13-responsive non-CD4+ T cells induce protective responses.
Pubmed ID: 17500591 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
A healthcare company that provides biomedical solutions and diagnostic and preclinical systems to life science professionals.
View all literature mentionsAmerican chemical, life science and biotechnology company owned by Merck KGaA. Merger of Sigma Chemical Company and Aldrich Chemical Company. Provides organic and inorganic chemicals, building blocks, reagents, advanced materials and stable isotopes for chemical synthesis, medicinal chemistry and materials science, antibiotics, buffers, carbohydrates, enzymes, forensic tools, hematology and histology, nucleotides, proteins, peptides, amino acids and their derivatives.
View all literature mentionslaboratory mouse with name BALB/cAnNCrl from MGI.
View all literature mentions