Location: Animal Parasitic Diseases LaboratoryTitle: Phage displayed peptide recognizing porcine aminopeptidase N is a potent small molecule inhibitor of PEDV entry Author
Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/16/2014
Publication Date: 3/25/2014
Citation: Meng, F., Suo, S., Zarlenga, D.S., Cong, Y., Ma, X., Zhao, Q., Ren, X. 2014. Phage displayed peptide recognizing porcine aminopeptidase N is a potent small molecule inhibitor of PEDV entry. Virology. 456-457:20-27. Interpretive Summary: Porcine epidemic diarrhea virus (PEDV) causes porcine epidemic diarrhea (PED) which in turn can result in very high mortality in newborn piglets. The disease was first reported in England in 1971 and has since been reported worldwide. Although conventional inactivated and attenuated vaccines are used in some areas, such vaccines have drawbacks such as recovery of virulence, spread of viruses, high cost, and poor protection efficacy. Therefore, development of novel and effective methods are necessary for the control of PED. In this study, phage libraries capable of expressing random peptides on their surface were bound to a key virus surface protein in order to find phages producing peptides capable of binding to the virus and inhibiting infection. Three peptides/phage were identified, the most important of which (peptide H) was shown to be highy effective in reducing infection of swine cells by PEDV. The studies which followed corroborated our hypothesis that peptide H functions in part by interacting with ability of PEDV to bind to the cell surface. Future studies will focus on identifying the specific site of interaction of peptide H and whether or not such a peptide can be used in vivo to eliminate or reduce PEDV infections. Eventually, these data may facilitate the development of effective viral gene vaccines and broad use by the veterinary community.
Technical Abstract: Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. These same peptides had no inhibitory effects on infection of Vero cells by porcine epidemic diarrhea virus (PEDV). However, when PEDV, TGEV and porcine pseudorabies virus were incubated with peptide H (HVTTTFAPPPPR), only infection of Vero cells by PEDV was inhibited. Immunofluoresence assays indicated that inhibition of PEDV infection by peptide H was independent of pAPN. Western blots demonstrated that peptide H interacted with PEDV spike protein and that pre-treatment of PEDV with peptide H led to a higher inhibition than synchronous incubation with cells. These results indicate direct interaction with the virus is necessary to inhibit infectivity. Temperature shift assays demonstrated that peptide H inhibited preattachment of the virus to the cells.