Potential role of host autophagy in Clonorchis sinensis infection

An in vivo mouse model of Clonorchis sinensis (C. sinensis) infection with or without the administration of autophagy inhibitor chloroquine (CQ) stimulation was established to assess the possible involvement of autophagic response during C. sinensis infection. Abnormal liver function was observed at 4, 6, and 8 weeks post-infection, as indicated by elevated levels of ALT/GPT, AST/GOT, TBIL, and α-SMA in the infected groups. These findings indicated that C. sinensis infection activated autophagy, as shown by a decreased LC3II/I ratio and accumulated P62 expression in infected mice. Interestingly, CQ administration exhibited dual and opposing effects during the infection. In the early stage of infection, the engagement of CQ appeared to mitigate symptoms by reducing inflammation and fibrotic responses. However, in the later stage of infection, CQ might contribute to parasite survival by evading autophagic targeting, thereby exacerbating hepatic impairment and worsening liver fibrosis. Autophagy in liver was suppressed throughout the infection. These observations attested that C. sinensis infection triggered autophagy, and highlighted a complex role for CQ, with both protective and detrimental effects, in the in vivo process of C. sinensis infection.