Surface-Displayed Porcine IFN-λ3 in Lactobacillus plantarum Inhibits Porcine Enteric Coronavirus Infection of Porcine Intestinal Epithelial Cells

Interferons (IFNs) play a crucial role in the innate immune response to viral infection. Interferon- (IFN-), also referred to as type III IFN, belongs to the family of cytokines that shares similarity with the IFN-/ family and was recently discovered, in 2003 [1, 2]. IFN-3 comprises two family members in swine (IFN-1 and IFN-3) IFN-3 is rapidly produced after infection and leads to stimulation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway, inducing the expression of IFN-stimulated genes (ISGs) to modulate antiviral activity. Recently, IFN-3 was found to have a dominant impact in mucosae, including the epithelial surfaces of the gastrointestinal and respiratory systems The IFN-3 receptor consists of two chains (the IFN-R1 signaling chain-a single heterodimeric receptor and the IL-10Rb auxiliary chain). However, IFN-R1 is predominantly expressed on epithelial cells. Thus, IFN-3 is expected to be an antiviral agent for mucosae.