Integrin α5β1, as a Receptor of Fibronectin, Binds the FbaA Protein of Group A <i>Streptococcus</i> To Initiate Autophagy during Infection
Jiachao Wang, Meiqi Meng, Miao Li, Xiaofei Guan, Jianguo Liu, Xue Gao, Qingqing Sun, Jinquan Li, Cuiqing Ma, Lin Wei
Abstract
Autophagy is generally considered a strategy used by the innate immune system to eliminate invasive pathogens through capturing and transferring them to lysosomes. Currently, researchers pay more attention to how virulence factors secreted by GAS regulate the autophagic process. Here, we provide the first evidence that the structural protein FbaA of M1 GAS strain SF370 is a potent inducer of autophagy in epithelial cells. Furthermore, we demonstrate that integrin α5β1 in epithelial cells in vitro and in vivo acts as a receptor to initiate the signaling for inducing autophagy by binding to FbaA of M1 GAS strain SF370 via Fn. Our study reveals the underlying mechanisms by which pathogens induce Fn-integrin α5β1 to trigger autophagy in a conserved pattern in epithelial cells.