10th International Virology Summit
Nanjing Agricultural University, China
Title: A novel pathway of virus dissemination within the host: spread of porcine epidemic diarrhea virus (PEDV) from the nasal cavity to the intestinal mucosa in swine
Biography: Yuchen Li
Porcine epidemic diarrhea (PED) has made catastrophic impacts on the global pig industry since 2011. The causative agent, porcine epidemic diarrhea virus (PEDV), was a typical intestinal coronavirus and transmitted by the generally acknowledged fecal-oral route. However, high infectivity of airborne PEDV and quickly spread between pig farm (even over the far distance) indicated that airborne transmission may make contributions to the rapid spread of PEDV. This study demonstrated that PEDV could cause typical diarrhea in piglets through nasal spraying and the exact mechanisms involved has been well studied in vitro and in piglets. At first, PEDV was detected by immunohistochemistry test in nasal epithelium at early stages of the infection. Then, the results were further verified by establishing air liquid interface culture of pig’s nasal epithelial cells (NECs) in vitro. Moreover, PEDV captured by dendritic cells (DCs) in nasal passage were observed in nasal passage and DC/NECs co-culture system, demonstrating that PEDV could recruit DCs to the nasal epithelial cells (ECs) and form transepithelial dendrites (TEDs) to capture luminal viruses. Subsequently, PEDV carried DCs could form firm adhesion with T cells and transmit the virus to CD3+T cells via virological synapse. Additionally, the virus loaded CD3+T lymphocyte could enter the blood circulation through the lymphocyte recirculation and reach the intestinal mucosa. Finally, virus caused infection in intestinal epithelium (Vero cells, Susceptible cells for PEDV) by CD3+ T cells medicated transfer infection. Our finding is the first to demonstrate a novel pathway of PEDV dissemination within host and illustrated the mechanism of it transport from entry site to pathogenic site, which sheds light on prevention measures and pathogenic mechanism for viruses with the same characteristics.