Fusarium solani Activates Dectin-1 in Experimentally Induced Keratomycosis.

Abstract

In this study, the response of Dectin-1 on macrophages to Fusarium solani (F. solani) and the expression patterns of Dectin-1 in experimentally F. solani-induced keratomycosis were investigated. Peritoneal macrophages isolated after intraperitoneal injection of sodium thioglycollate were co-cultured with laminarin and spores of F. solani for 12 h. The expression levels of Dectin-1 and CARD9 were detected by immunofluorescence and real-time quantitative polymerase chain reaction. A mouse model of fungal keratitis was established by substromal inoculation with spores of F. solani. Corneal lesions and inflammatory responses were observed by slit-lamp and histopathology at 1, 2, 3, 5, and 7 day(s) after infection. Dectin-1 expression was significantly upregulated on macrophages stimulated by spores of F. solani. Dectin-1 was not detected in normal corneas of C57BL/6 mice, but detected in infected corneas from the first day after inoculation, with high mRNA levels observed on days 2 and 3. CARD9, a key transducer of Dectin-1 signaling, was also upregulated in infected corneas. In conclusion, Dectin-1 is an important recognition receptor in F. solani-induced keratitis, but the molecular mechanisms warrant further investigation.