title: IL-27 regulates IL-10 and IL-17 from CD4+ cells in nonhealing Leishmania major infection.
abstract: Control of infection caused by Leishmania major requires the development of IFN-gamma+CD4+ lymphocytes for the induction of microbicidal activity in host macrophages. We recently reported on the inability of conventionally resistant C57BL/6 mice to successfully resolve infection by an isolate of L. major, despite a strong IFN-gamma response by the host. Susceptibility was caused by Ag-specific IL-10 from CD4+ cells that were also producing IFN-gamma. In the present studies, we have explored the role for IL-27 in the regulation of IL-10 from Th1 cells in leishmaniasis. Cytokine analysis of CD4+ cells in the lesions and draining lymph nodes of infected IL-27R-deficient (WSX-1(-/-)) mice revealed diminished IL-10 from IFN-gamma+ CD4+ cells, which was accompanied by a reduction in total IFN-gamma+CD4+ cells and an increase in IL-4. Despite the inhibition of IL-10 from CD4+ cells, no significant change in parasite numbers was observed, due both to the shift in the Th1/Th2 balance and to residual levels of IL-10. Strikingly, infected WSX-1(-/-) mice developed more severe lesions that were associated with the appearance of IL-17+ CD4+ cells, demonstrating a function for IL-27 in blocking the development of inappropriate Th17 cells during L. major infection. The results demonstrate the pleiotropic effects that IL-27 has on L. major-driven Th1, Th2, and Th17 development, and reinforce its function as a key regulatory cytokine that controls the balance between immunity and pathology.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Anderson
authors.forename: Jason S
authors.initials: JS
authors.lastname: Stumhofer
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Hunter
authors.forename: David
authors.initials: D
authors.lastname: Sacks
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D051858:Forkhead Transcription Factors / Q000378:metabolism; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis / Q000378:metabolism*; D020381:Interleukin-17 / Q000096:biosynthesis / Q000378:metabolism; D007378:Interleukins / Q000502:physiology*; D018320:Leishmania major / Q000276:immunology*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018121:Receptors, Cytokine / Q000172:deficiency / Q000235:genetics; D018123:Receptors, Interleukin; D018417:Th1 Cells / Q000276:immunology* / Q000378:metabolism
chemical_list: D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C486767:Il27 protein, mouse; C484747:Il27ra protein, mouse; D020381:Interleukin-17; D007378:Interleukins; D018121:Receptors, Cytokine; D018123:Receptors, Interleukin; D016753:Interleukin-10; D007371:Interferon-gamma