Cryptococcus gattii evades CD11b-mediated fungal recognition by coating itself with capsular polysaccharides
- PMID: 33728652
- DOI: 10.1002/eji.202049042
Cryptococcus gattii evades CD11b-mediated fungal recognition by coating itself with capsular polysaccharides
Abstract
Cryptococcus gattii is a capsular pathogenic fungus causing life-threatening cryptococcosis. Although the capsular polysaccharides (CPs) of C. gattii are considered as virulence factors, the physiological significance of CP biosynthesis and of CPs themselves is not fully understood, with many conflicting data reported. First, we demonstrated that CAP gene deletant of C. gattii completely lacked capsule layer and its virulence, and that the strain was susceptible to host-related factors including oxidizing, hypoxic, and hypotrophic conditions in vitro. Extracellular CPs recovered from culture supernatant bound specifically to C. gattii acapsular strains, not to other fungi and immune cells, and rendered them the immune escape effects. In fact, dendritic cells (DCs) did not efficiently uptake the CP-treated acapsular strains, which possessed no visible capsule layer, and a decreased amount of phosphorylated proteins and cytokine levels after the stimulation. DCs recognized C. gattii acapuslar cells via an immune receptor CD11b- and Syk-related pathway; however, CD11b did not bind to CP-treated acapsular cells. These results suggested that CPs support immune evasion by coating antigens on C. gattii and blocking the interaction between CD11b and C. gattii cells. Here, we describe the importance of CPs in pathogenicity and immune evasion mechanisms of C. gattii.
Keywords: Cryptococcus gattii; capsular polysaccharides; dendritic cells; fungal recognition; integrins.
© 2021 Wiley-VCH GmbH.
Comment in
-
Cryptococcus gattii polysaccharide capsule: An insight on fungal-host interactions and vaccine studies.Freitas GJC, Santos DA. Freitas GJC, et al. Eur J Immunol. 2021 Sep;51(9):2206-2209. doi: 10.1002/eji.202149349. Epub 2021 Aug 15. Eur J Immunol. 2021. PMID: 34396521
References
-
- Kwon-Chung, K. J., Fraser, J. A., Doering, T. L., Wang, Z., Janbon, G., Idnurm, A. and Bahn, Y. S., Cryptococcus neoformans and Cryptococcus gattii, the etiologic agents of cryptococcosis. Cold Spring Harb. Perspect. Med. 2014. 4: a019760.
-
- O'Meara, T. R. and Alspaugh, J. A., The Cryptococcus neoformans capsule: a sword and a shield. Clin. Microbiol. Rev. 2012. 25: 387-408.
-
- Hagen, F., Khayhan, K., Theelen, B., Kolecka, A., Polacheck, I., Sionov, E., Falk, R. et al., Recognition of seven species in the Cryptococcus gattii/Cryptococcus neoformans species complex. Fungal Genet. Biol. 2015. 78: 16-48.
-
- Kwon-Chung, K. J., Bennett, J. E., Wickes, B. L., Meyer, W., Cuomo, C. A., Wollenburg, K. R., Bicanic, T. A. et al., The case for adopting the "species complex" nomenclature for the etiologic agents of cryptococcosis. mSphere 2017. 11: e00357.
-
- Galanis, E., MacDougall, L., Kidd, S. and Morshed, M., British Columbia Cryptococcus gattii Working Group, Epidemiology of Cryptococcus gattii, British Columbia, Canada, 1999-2007. Emerg. Infect. Dis. 2010. 16: 251-257.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Other Literature Sources
Research Materials
Miscellaneous