*2.3.2 Autophagy*

Autophagy is a lysosome-mediated degradation process, which regulates intracellular homeostasis of eukaryotes by mediating the degradation of proteins and organelles [47]. It can be activated in response to starvation, stress, hypoxia, tumor, and infection [48]. Autophagy is proved to be involved in immune responses, a previous study found that autophagy maintains the cellular and immune homeostasis during the *Candida albicans* infection [49]. Autophagy can regulate IL-1β release in human primary macrophage to resist the fungal infection [50].

A study by Li C et al. reported that the progression of FK caused by *A. fumigatus* result in increased expression of autophagy and the severity of *A. fumigatus* keratitis, aggravated with inhibition of autophagy. The induction of autophagy reduced the severity of keratitis via regulating the recruitment of PMNs, balancing the pro-inflammatory and anti-inflammatiory cytokines release, and possibly affecting the differentiation of neutrophils. Autophagy may become a novel target for the treatment of FK in future. Further studies may add our understanding regarding the protective role of autophagy in FK [51].
