Role of macrophages in fungal keratitis

Abstract

Fungal keratitis is a serious blinding eye disease. The development of fungal infections depends primarily on the interaction of fungal virulence with host immune defense factors. The cornea is considered an immune-privileged organ, and resident macrophages are the main immune cells that respond to the heterogeneity exhibited by the microenvironment with their polarization. In the early stage of infection, macrophages polarize towards M1, which promotes inflammation and facilitates fungal clearance but produces a cellular storm that exacerbates immune damage; in the late stage of infection, macrophages polarize towards M2, which suppresses the inflammatory response and facilitates tissue repair, but may be immunosuppressed or even immune escape to the detriment of pathogen clearance. The balance between pro-inflammatory and anti-inflammatory responses is key to maintaining the functional integrity of the cornea. Current antifungal drug therapy is limited, so it is particularly important to find a therapeutic target for the inflammatory response triggered by the immune response in addition to antifungal therapy. In this review, the functional and phenotypic characterization of macrophage subsets associated with fungal keratitis was reviewed, more in-depth research is needed to explore the specific mechanisms by which macrophage polarization and their impact on fungal keratitis. Targeted regulation of macrophage differentiation based on their phenotype and function could be an effective approach to treat and manage fungal keratitis in the future.

Keywords

• macrophages
• polarization
• m1/m2
• fungal keratitis
• immune
• neutrophils