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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #319505
Title: Putative phage-display epitopes of the porcine epidemic diarrhea virus S1 protein and their anti-viral activity

Author
item CAO, LIYAN - Northeast Agricultural University
item GE, XUYING - Northeast Agricultural University
item GAO, YU - Inner Mongolian Agriculture University
item Zarlenga, Dante
item LI, XUNLIANG - Northeast Agricultural University
item YIN, XIANGPING - Northeast Agricultural University
item QIN, ZHAOHENG - Gansu Institute
item LIU, JISHENG - Gansu Institute
item REN, XIAOFENG - Northeast Agricultural University
item LI, GUANGXIN - Northeast Agricultural University

Submitted to: Virus Genes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2015
Publication Date: 8/21/2015
Citation: Cao, L., Ge, X., Gao, Y., Zarlenga, D.S., Li, X., Yin, X., Qin, Z., Liu, J., Ren, X., Li, G. 2015. Putative phage-display epitopes of the porcine epidemic diarrhea virus S1 protein and their anti-viral activity. Virus Genes. 51(2):217-224.

Interpretive Summary: Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea in newborn piglets which in turn can result in very high mortality rates. 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 to control PED. In this study, in order to identify small peptides that may be involved in antiviral activity, a monoclonal antibody (MAb-5E12) against the immunodominant region of the PEDV Spike protein (S1) and with antiviral activity was used as the target to pan or screen a phage display expressing random peptides on their surfaces. This allowed the identification of regions on the native protein that bind the antibody. Three peptides/phage designated L, W and H, were identified that recognize MAb-5E12 and exhibited partial antiviral activity by stopping adsorption of the virus onto the cell surface. Eventually, these data may facilitate the development of effective viral gene vaccines and have broad use by the veterinary community.

Technical Abstract: Porcine epidemic diarrhea virus (PEDV) is a pathogen of swine that causes severe diarrhea and dehydration resulting in substantial morbidity and mortality in newborn piglets. Phage display is a technique with wide application, in particular, the identification of key antigen epitopes for the development of therapeutic and diagnostic reagents and vaccines. To identify antigen epitopes with specificity for PEDV, a monoclonal antibody (MAb-5E12) against the immunodominant region of the PEDV Spike protein (S1) was used as the target for biopanning a 12-mer phage display, random peptide library. After multiple rounds of biopanning and stringent washing, three phage-displayed peptides, designated L, W and H, were identified that recognize MAb-5E12. Sequence analysis showed that the one or more of the peptides exhibited partial sequence similarity to the native S1 sequence ‘MQYVYTPTYYML’ at position 201-212. In combination with software analysis for the prediction of B cell epitopes, aa 201-212 exhibited characteristics of a linear epitope on the PEDV S1 protein. In contrast to peptide H, a consensus motif ‘PxxY’ was identified on both peptides L and W, and on the S1 protein. The MAb-5E12-recognizing peptides L and W significantly inhibited the adsorption of PEDV on the cell surface as monitored through plaque-reduction assays. Furthermore, data from real-time PCR and indirect immunofluorescence assays were consistent with the ability of peptides L and W to block viral protein expression and thereby function as antiviral agents for PEDV.