AUTHOR=McFarlane Emma , Mokgethi Thabang , Kaye Paul M. , Hurdayal Ramona , Brombacher Frank , Alexander James , Carter Katharine C. 

TITLE=IL-4 Mediated Resistance of BALB/c Mice to Visceral Leishmaniasis Is Independent of IL-4Rα Signaling via T Cells

JOURNAL=Frontiers in Immunology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01957

DOI=10.3389/fimmu.2019.01957

ISSN=1664-3224

ABSTRACT=<p>Previous studies infecting global IL-4Rα<sup>−/−</sup>, IL-4<sup>−/−</sup>, and IL-13<sup>−/−</sup>mice on a BALB/c background with the visceralizing parasite <italic>Leishmania donovani</italic> have shown that the T helper 2 cytokines, IL-4, and IL-13, play influential but not completely overlapping roles in controlling primary infection. Subsequently, using macrophage/neutrophil-specific IL-4Rα deficient BALB/c mice, we demonstrated that macrophage/neutrophil unresponsiveness to IL-4 and IL-13 did not have a detrimental effect during <italic>L. donovani</italic> infection. Here we expand on these findings and show that CD4<sup>+</sup> T cell-(Lck<sup>cre</sup>), as well as pan T cell-(iLck<sup>cre</sup>) specific IL-4Rα deficient mice, on a BALB/c background, unlike global IL-4Rα deficient mice, are also not adversely affected in terms of resistance to primary infection with <italic>L. donovani</italic>. Our analysis suggested only a transient and tissue specific impact on disease course due to lack of IL-4Rα on T cells, limited to a reduced hepatic parasite burden at day 30 post-infection. Consequently, the protective role(s) demonstrated for IL-4 and IL-13 during <italic>L. donovani</italic> infection are mediated by IL-4Rα-responsive cell(s) other than macrophages, neutrophils and T cells.</p>