Galectin-3 induces death of Candida species expressing specific beta-1,2-linked mannans.
Lectins play a critical role in host protection against infection. The galectin family of lectins recognizes saccharide ligands on a variety of microbial pathogens, including viruses, bacteria, and parasites. Galectin-3, a galectin expressed by macrophages, dendritic cells, and epithelial cells, binds bacterial and parasitic pathogens including Leishmania major, Trypanosoma cruzi, and Neisseria gonorrhoeae. However, there have been no reports of galectins having direct effects on microbial viability. We found that galectin-3 bound only to Candida albicans species that bear beta-1,2-linked oligomannans on the cell surface, but did not bind Saccharomyces cerevisiae that lacks beta-1,2-linked oligomannans. Surprisingly, binding directly induced death of Candida species containing specific beta-1,2-linked oligomannosides. Thus, galectin-3 can act as a pattern recognition receptor that recognizes a unique pathogen-specific oligosaccharide sequence. This is the first description of antimicrobial activity for a member of the galectin family of mammalian lectins; unlike other lectins of the innate immune system that promote opsonization and phagocytosis, galectin-3 has direct fungicidal activity against opportunistic fungal pathogens.
Kohatsu
Luciana
L
Department of Pathology and Laboratory Medicine, Jonsson Comprehensive Cancer Center, School of Medicine, University of California-Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA.
Hsu
Daniel K
DK
Jegalian
Armin G
AG
Liu
Fu-Tong
FT
Baum
Linda G
LG
D002175:Candida / Q000276:immunology* / Q000378:metabolism; D002177:Candidiasis / Q000378:metabolism; D016923:Cell Death / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000276:immunology / Q000378:metabolism*; D037502:Galectin 3 / Q000276:immunology / Q000378:metabolism*; D006099:Granuloma / Q000378:metabolism / Q000382:microbiology; D006801:Humans; D008351:Mannans / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding
D005656:Fungal Proteins; D037502:Galectin 3; D008351:Mannans