Leishmania (L.) major is a protozoan parasite that infects mammalian hosts and causes a spectrum of disease manifestations that is strongly associated with the genetic background of the host. Interleukin (IL)-6 is an acute phase proinflammatory cytokine, known in vitro to be involved in the inhibition of the generation of regulatory T cells. IL-6-deficient mice were infected with L. major, and T cell and monocyte subsets were analyzed with flow cytometry. Our data show that at the site of infection in the footpad and in the draining popliteal lymph node, numbers of regulatory T cells remain unchanged between WT and IL- 6-deficient mice. However, the spleens of IL-6-/- mice contained fewer regulatory T cells after infection with L. major. The development of cutaneous lesions is similar between WT and IL-6-deficient mice, while parasite burden in IL-6-/- mice is reduced compared to WT. The development of IFN-c or IL-10 producing T cells is similar in IL-6-/- mice. Despite a comparable adaptive T cell response, IL-6-deficient mice develop an earlier peak of some inflammatory cytokines than WT mice. This data indicate that the role of IL-6 in the differentiation of regulatory T cells is complex in vivo, and the effect of an absence of this cytokine can be counter-intuitive.
History
Publication title
Experimental Parasitology
Volume
129
Pagination
270-276
ISSN
0014-4894
Department/School
Menzies Institute for Medical Research
Publisher
Academic Press Inc Elsevier Science
Place of publication
525 B St, Ste 1900, San Diego, USA, Ca, 92101-4495