Figure 3.

The effects of swine coronaviruses on host cells. Swine coronaviruses replicate in the cytoplasm of host cells and form double-membrane vesicles (DMVs), leading to endoplasmic reticulum (ER) stress, apoptosis, and alterations in cell morphology (Table 2). Swine coronaviruses may either induce or inhibit autophagy. These changes further evolve into degeneration, loss of host cells, necrosis, and inflammation. Furthermore, chronic alteration in cell morphology induces epithelial-mesenchymal transition (EMT). Some of these molecular and subcellular changes can be appreciated in vivo by pathological examination of tissues from infected swine, while others are found only in in vitro settings and remain to be found in clinical specimens (Table 1).