RRC ID 71845
Author Arunachalam D, Namperumalsamy VP, Prajna L, Kuppamuthu D.
Title Human Corneal Epithelial Cells Internalize Aspergillus flavus Spores by Actin-Mediated Endocytosis.
Journal Infect Immun
Abstract Human corneal epithelial (HCE) cells play a significant role in the innate immune response by secreting cytokines and antimicrobial peptides when they encounter fungal pathogens. But the detailed mechanism of attachment and engulfment of the fungal conidia by HCE cells is not well understood. Here, we show the phagocytosis of Aspergillus flavus conidia by RCB2280 cells and primary HCE cultures using confocal microscopy and proteomic analysis of conidium-containing phagosomes. Phalloidin staining showed actin polymerization, leading to an actin ring around engulfed conidia. Cytochalasin D inhibited the actin-mediated endocytosis of the conidia. Immunolabeling of the early endosomal markers CD71 and early endosomal antigen (EEA1) and the late endosomal markers lysosome-associated membrane protein 1 (LAMP1), Rab7, and cathepsin G showed that endosomal proteins were recruited to the site of conidia and showed maturation of the conidium-containing phagosomes. Lysotracker red DND 99 labeling showed the acidification of the phagosomes containing conidia. Phagosome-specific proteome analysis confirmed the recruitment of various phagosomal and endosomal proteins to the conidium-containing phagosomes. These results show that the ocular surface epithelium contributes actively to antifungal defense by the phagocytosis of invading fungal conidia.
Volume 89(6)
Published 2021-5-17
DOI 10.1128/IAI.00794-20
PII IAI.00794-20
PMID 33753415
PMC PMC8316143
MeSH Aspergillus flavus / immunology* Cornea / cytology* Disease Susceptibility Endocytosis* Endosomes / metabolism Epithelial Cells / immunology Epithelial Cells / metabolism Epithelial Cells / microbiology* Humans Keratitis / immunology Keratitis / metabolism Keratitis / microbiology Phagosomes / metabolism Proteome Proteomics / methods Spores, Fungal / immunology*
IF 3.201
Human and Animal Cells HCE-T(RCB2280)