calpain and Coronavirus-Infections

The thick mucus layer covering of the intestinal epithelium has received increasing attention, owing to its protective role in intestinal infection. However, the exact mechanisms by which the mucus increases intestinal resistance against viral infection remain largely unclear. Here, we identify prominent antiviral activity of the small intestinal mucus and extracted total mucus proteins, as evidenced by their inhibitory effects against porcine epidemic diarrhea virus (PEDV) infection. Of all the extracted mucus proteins, mucin 2 and fraction III (~70 kDa) exhibited potent antiviral activity. We further evaluated the antiviral effects of three candidate factors in fraction III and found that calpain-1 contributed substantially to its antiviral activity.

Topics: Amino Acids; Animals; Antiviral Agents; Calcium; Calpain; Coronavirus Infections; Enteritis; Mucin-2; Mucus; Porcine epidemic diarrhea virus; Spike Glycoprotein, Coronavirus; Swine; Swine Diseases; Viral Proteins