AUTHOR=Rodríguez Ernesto , Carasi Paula , Frigerio Sofía , da Costa Valeria , van Vliet Sandra , Noya Verónica , Brossard Natalie , van Kooyk Yvette , García-Vallejo Juan J. , Freire Teresa 

TITLE=Fasciola hepatica Immune Regulates CD11c+ Cells by Interacting with the Macrophage Gal/GalNAc Lectin

JOURNAL=Frontiers in Immunology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2017.00264

DOI=10.3389/fimmu.2017.00264

ISSN=1664-3224

ABSTRACT=<p>Fasciolosis, caused by <italic>Fasciola hepatica</italic> and <italic>Fasciola gigantica</italic>, is a trematode zoonosis of interest in public health and livestock production. Like other helminths, <italic>F. hepatica</italic> modulates the host immune response by inducing potent polarized Th2 and regulatory T cell immune responses and by downregulating the production of Th1 cytokines. In this work, we show that <italic>F. hepatica</italic> glycans increase Th2 immune responses by immunomodulating TLR-induced maturation and function of dendritic cells (DCs). This process was mediated by the macrophage Gal/GalNAc lectin (MGL) expressed on DCs, which recognizes the Tn antigen (GalNAc-Ser/Thr) on parasite components. More interestingly, we identified MGL-expressing CD11c<sup>+</sup> cells in infected animals and showed that these cells are recruited both to the peritoneum and the liver upon <italic>F. hepatica</italic> infection. These cells express the regulatory cytokines IL-10, TNFα and TGFβ and a variety of regulatory markers. Furthermore, MGL<sup>+</sup> CD11c<sup>+</sup> cells expand parasite-specific Th2/regulatory cells and suppress Th1 polarization. The results presented here suggest a potential role of MGL in the immunomodulation of DCs induced by <italic>F. hepatica</italic> and contribute to a better understanding of the molecular and immunoregulatory mechanisms induced by this parasite.</p>