Galectin-3 impacts Cryptococcus neoformans infection through direct antifungal effects

Nat Commun. 2017 Dec 6;8(1):1968. doi: 10.1038/s41467-017-02126-7.

Abstract

Cryptococcus neoformans is an encapsulated fungal pathogen that causes cryptococcosis, which is a major opportunistic infection in immunosuppressed individuals. Mammalian β-galactoside-binding protein Galectin-3 (Gal-3) modulates the host innate and adaptive immunity, and plays significant roles during microbial infections including some fungal diseases. Here we show that this protein plays a role also in C. neoformans infection. We find augmented Gal-3 serum levels in human and experimental infections, as well as in spleen, lung, and brain tissues of infected mice. Gal-3-deficient mice are more susceptible to cryptococcosis than WT animals, as demonstrated by the higher fungal burden and lower animal survival. In vitro experiments show that Gal-3 inhibits fungal growth and exerts a direct lytic effect on C. neoformans extracellular vesicles (EVs). Our results indicate a direct role for Gal-3 in antifungal immunity whereby this molecule affects the outcome of C. neoformans infection by inhibiting fungal growth and reducing EV stability, which in turn could benefit the host.

Publication types

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

MeSH terms

  • Adaptive Immunity
  • Animals
  • Antifungal Agents / immunology*
  • Antifungal Agents / pharmacology*
  • Bacterial Capsules / drug effects
  • Blood Proteins
  • Brain / immunology
  • Cryptococcosis / drug therapy*
  • Cryptococcosis / immunology*
  • Cryptococcosis / microbiology
  • Cryptococcus neoformans / drug effects*
  • Cryptococcus neoformans / growth & development
  • Cryptococcus neoformans / immunology
  • Cytokines / metabolism
  • Disease Models, Animal
  • Galectin 3 / blood
  • Galectin 3 / genetics
  • Galectin 3 / immunology*
  • Galectin 3 / pharmacology*
  • Galectins
  • Gene Expression
  • Humans
  • Lung / immunology
  • Macrophages / drug effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Spleen / immunology

Substances

  • Antifungal Agents
  • Blood Proteins
  • Cytokines
  • Galectin 3
  • Galectins
  • LGALS3 protein, human