The Role Of Srec-I In Innate Immunity To Aspergillus Fumigatus Keratitis

PURPOSE. To determine the role of scavenger receptor expressed by endothelial cell-1 (SREC-I) in vitro and in a mouse model of Aspergillus fumigatus keratitis.METHODS. SREC-I mRNA and protein expression were tested in both normal and A fumigatus stimulated human corneal epithelial cells (HCECs). Immunofluorescence was used to detect SREC-I expression in human corneas with or without A fumigatus infection. HCECs were incubated with SREC-I small interfering RNA, then the mRNA levels of LOX-1, IL-1 beta, and TNF-alpha were detected after A fumigatus stimulation. A mouse fungal keratitis (FK) model was established and SREC-I mRNA and protein expression were detected by RT-PCR, Western blot and immunofluorescence. The severity of FK was evaluated by clinical score. CLCX1, LOX-1, IL-1 beta, and TNF-alpha mRNA expression levels were tested before and after anti-SREC-I treatment.RESULTS. SREC-I expressed in normal and A fumigatus treated HCECs and human corneal epithelium. In vitro experiment showed that SREC-I mRNA and protein levels were significantly increased after A fumigatus stimulation. SREC-I small interfering RNA treatment inhibited the expressions of LOX-1, IL-1 beta, and TNF-a in HCECs. The expressions of CLCX1, LOX-1, IL-1 beta, and TNF-alpha were elevated in mice with A fumigatus keratitis, which could be decreased by SREC-I-neutralizing antibody treatment.CONCLUSIONS. SREC-I is a key mediator in inflammatory response induced by A fumigatus keratitis. SREC-I blockade could be a potential therapeutic approach for FK.