Fungal dissemination is limited by liver macrophage filtration of the blood

Nat Commun. 2019 Oct 8;10(1):4566. doi: 10.1038/s41467-019-12381-5.

Abstract

Fungal dissemination into the bloodstream is a critical step leading to invasive fungal infections. Here, using intravital imaging, we show that Kupffer cells (KCs) in the liver have a prominent function in the capture of circulating Cryptococcus neoformans and Candida albicans, thereby reducing fungal dissemination to target organs. Complement C3 but not C5, and complement receptor CRIg but not CR3, are involved in capture of C. neoformans. Internalization of C. neoformans by KCs is subsequently mediated by multiple receptors, including CR3, CRIg, and scavenger receptors, which work synergistically along with C5aR signaling. Following phagocytosis, the growth of C. neoformans is inhibited by KCs in an IFN-γ independent manner. Thus, the liver filters disseminating fungi from circulation via KCs, providing a mechanistic explanation for the enhanced risk of cryptococcosis among individuals with liver diseases, and suggesting a therapeutic strategy to prevent fungal dissemination through enhancing KC functions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Candida albicans / immunology
  • Candida albicans / isolation & purification
  • Candida albicans / pathogenicity
  • Complement C3 / genetics
  • Complement C3 / immunology
  • Complement C3 / metabolism
  • Cryptococcus neoformans / immunology
  • Cryptococcus neoformans / isolation & purification
  • Cryptococcus neoformans / pathogenicity
  • Disease Models, Animal
  • Female
  • Humans
  • Intravital Microscopy
  • Invasive Fungal Infections / blood
  • Invasive Fungal Infections / immunology*
  • Invasive Fungal Infections / microbiology
  • Kupffer Cells / immunology*
  • Kupffer Cells / metabolism
  • Kupffer Cells / microbiology
  • Liver / cytology
  • Liver / diagnostic imaging
  • Liver / immunology*
  • Male
  • Mice
  • Mice, Knockout
  • Microscopy, Confocal
  • Phagocytosis*
  • Receptors, Complement / genetics
  • Receptors, Complement / immunology
  • Receptors, Complement / metabolism

Substances

  • C3 protein, mouse
  • Complement C3
  • Receptors, Complement
  • VSIG4 protein, mouse