CD47 Promotes Protective Innate and Adaptive Immunity in a Mouse Model of Disseminated Candidiasis

PLoS One. 2015 May 26;10(5):e0128220. doi: 10.1371/journal.pone.0128220. eCollection 2015.

Abstract

CD47 is a widely expressed receptor that regulates immunity by engaging its counter-receptor SIRPα on phagocytes and its secreted ligand thrombospondin-1. Mice lacking CD47 can exhibit enhanced or impaired host responses to bacterial pathogens, but its role in fungal immunity has not been examined. cd47-/- mice on a C57BL/6 background showed significantly increased morbidity and mortality following Candida albicans infection when compared with wild-type mice. Despite normal fungal colonization at earlier times, cd47-/- mice at four days post-infection had increased colonization of brain and kidneys accompanied by stronger inflammatory reactions. Neutrophil and macrophage numbers were significantly elevated in kidneys and neutrophils in the brains of infected cd47-/- mice. However, no defect in phagocytic activity towards C. albicans was observed in cd47-/- bone-marrow-derived macrophages, and neutrophil and macrophage killing of C. albicans was not impaired. CD47-deficiency did not alter the early humoral immune response to C. albicans. Th1, Th2, and Th17 population of CD4+ T cells were expanded in the spleen, and gene expression profiles of spleen and kidney showed stronger pro-inflammatory signaling in infected cd47-/- mice. The chemoattractant chemokines MIP-2α and MIP-2β were highly expressed in infected spleens of cd47-/- mice. G-CSF, GM-CSF, and the inflammasome component NLRP3 were more highly expressed in infected cd47-/- kidneys than in infected wild-type controls. Circulating pro- (TNF-α, IL-6) and anti-inflammatory cytokines (IL-10) were significantly elevated, but IL-17 was decreased. These data indicate that CD47 plays protective roles against disseminated candidiasis and alters pro-inflammatory and immunosuppressive pathways known to regulate innate and T cell immunity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • CD47 Antigen / genetics
  • CD47 Antigen / immunology*
  • Candida albicans / immunology*
  • Candidiasis / genetics
  • Candidiasis / immunology*
  • Cytokines / immunology
  • Disease Models, Animal
  • Immunity, Cellular*
  • Immunity, Innate*
  • Kidney / immunology
  • Macrophages / immunology
  • Mice
  • Mice, Knockout
  • Neutrophils / immunology
  • T-Lymphocytes, Helper-Inducer / immunology

Substances

  • CD47 Antigen
  • Cd47 protein, mouse
  • Cytokines