Cryptococcus neoformans-derived microvesicles enhance the pathogenesis of fungal brain infection

• Published in: PloS one 2012-11, Vol.7 (11), p.e48570-e48570
• Main Authors: Huang, Sheng-He, Wu, Chun-Hua, Chang, Yun C, Kwon-Chung, Kyung J, Brown, Robert J, Jong, Ambrose
• Format: Article
• Language: English
• Subjects: 14-3-3 protein; 14-3-3 Proteins - metabolism; Animals; Astrocytes; Biology; Biomarkers - metabolism; Blood-brain barrier; Blood-Brain Barrier - microbiology; Blood-Brain Barrier - pathology; Brain; Brain - blood supply; Brain - microbiology; Brain - pathology; Brain research; Cell Fusion; Central nervous system; Central Nervous System Fungal Infections - microbiology; Central Nervous System Fungal Infections - pathology; Cerebrospinal fluid; Cryptococcosis - microbiology; Cryptococcosis - pathology; Cryptococcus neoformans; Cryptococcus neoformans - cytology; Cryptococcus neoformans - physiology; Cytoplasmic Vesicles - metabolism; Endothelial cells; Endothelial Cells - metabolism; Endothelial Cells - microbiology; Endothelial Cells - pathology; Female; Fluorescence; Fungal diseases; Fungal infections; Fungal Proteins - metabolism; Fungi; Fusion protein; Glial fibrillary acidic protein; Green Fluorescent Proteins - metabolism; Health aspects; Hematology; Hospitals; Humans; Immunofluorescence; Infection; Infections; Infectious diseases; Intermediate filament proteins; Laboratories; Lesions; Lipid rafts; Lipids; Medicine; Membrane Microdomains - metabolism; Meningoencephalitis; Mice; Mice, Inbred C57BL; Microvasculature; Mycoses; Neuroimaging; Oncology; Pathogenesis; Pathogens; Pediatrics; Proteins; Rafts; Recombinant Fusion Proteins - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0048570

Cryptococcal meningoencephalitis is the most common fungal disease in the central nervous system. The mechanisms by which Cryptococcus neoformans invades the brain are largely unknown. In this study, we found that C. neoformans-derived microvesicles (CnMVs) can enhance the traversal of the blood-brain barrier (BBB) by C. neoformans invitro. The immunofluorescence imaging demonstrates that CnMVs can fuse with human brain microvascular endothelial cells (HBMECs), the constituents of the BBB. This activity is presumably due to the ability of the CnMVs to activate HBMEC membrane rafts and induce cell fusogenic activity. CnMVs also enhanced C. neoformans infection of the brain, found in both infected brains and cerebrospinal fluid. In infected mouse brains, CnMVs are distributed inside and around C. neoformans-induced cystic lesions. GFAP (glial fibrillary acidic protein)-positive astrocytes were found surrounding the cystic lesions, overlapping with the 14-3-3-GFP (14-3-3-green fluorescence protein fusion) signals. Substantial changes could be observed in areas that have a high density of CnMV staining. This is the first demonstration that C. neoformans-derived microvesicles can facilitate cryptococcal traversal across the BBB and accumulate at lesion sites of C. neoformans-infected brains. Results of this study suggested that CnMVs play an important role in the pathogenesis of cryptococcal meningoencephalitis.