Epidermal growth factor receptor is a co-factor for transmissible gastroenteritis virus entry

Area of Science:

• Veterinary Virology
• Molecular Biology
• Cellular Microbiology

Background:

• Transmissible gastroenteritis virus (TGEV) causes significant disease in piglets.
• The porcine intestinal epithelium is the primary target for TGEV infection.
• The precise mechanisms of TGEV entry into host epithelial cells are not fully understood.

Purpose of the Study:

• To elucidate the role of epidermal growth factor receptor (EGFR) in TGEV invasion.
• To investigate the synergistic interaction between APN and EGFR in TGEV infection.
• To identify the endocytic pathways utilized by TGEV for host cell entry.

Main Methods:

• Co-immunoprecipitation assays to detect protein interactions.
• Confocal microscopy to visualize receptor clustering and internalization.
• Western blotting to analyze signaling pathway activation (PI3K/AKT, MEK/ERK1/2).
• Inhibition studies using specific pathway modulators and endocytosis inhibitors.

Main Results:

• The extracellular receptor binding domain 1 of EGFR interacts with the TGEV spike protein.
• APN and EGFR colocalize and cluster upon TGEV infection, promoting viral entry.
• TGEV infection activates PI3K/AKT and MEK/ERK1/2 signaling pathways, dependent on APN and EGFR.
• TGEV entry into IPEC-J2 cells occurs through both clathrin- and caveolin-mediated endocytosis.
• EGFR internalization is mediated by a clathrin-dependent pathway following TGEV binding.

Conclusions:

• EGFR acts as a co-receptor, synergizing with APN to facilitate TGEV invasion of porcine intestinal epithelial cells.
• EGFR plays a crucial role in the early stages of TGEV infection by promoting viral entry.
• Understanding these interactions provides potential targets for therapeutic interventions against TGEV.