Identification of a novel linear B-cell epitope within the collagenase equivalent domain of porcine epidemic diarrhea virus spike glycoprotein

Porcine epidemic diarrhea virus (PEDV) causes continuous, significant damage to the swine industry worldwide. By RT-PCR-based methods, this study demonstrated the ongoing presence of PEDV in pigs of all ages in Korea at the average detection rate of 9.92%. By the application of Bayesian phylogenetic analysis, it was found that the nucleocapsid (N) gene of PEDV could evolve at similar rates to the spike (S) gene at the order of 10−4 substitutions/site/year. Based on branching patterns of PEDV strains, three main N gene-base genogroups (N1, N2, and N3) and two sub-genogroups (N3a, N3b) were proposed in this study. By analyzing the antigenic index, possible antigenic differences also emerged in both the spike and nucleocapsid proteins between the three genogroups. The antigenic indexes of genogroup N3 strains were significantly lower compared with those of genogroups N1 and N2 strains in the B-cell epitope of the nucleocapsid protein. Similarly, significantly lower antigenic indexes in some parts of the B-cell epitope sequences of the spike protein (COE, S1D, and 2C10) were also identified. PEDV mutants derived from genetic mutations of the S and N genes may cause severe damage to swine farms by evading established host immunities.

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Identification of a novel B-cell epitope in the spike protein of porcine epidemic diarrhea virus

Virology Journal ◽

10.1186/s12985-020-01305-1 ◽

2020 ◽

Vol 17 (1) ◽

Cited By ~ 2

Author(s):

Ning Kong ◽

Qiong Meng ◽

Yajuan Jiao ◽

Yongguang Wu ◽

Yewen Zuo ◽

...

Keyword(s):

B Cell ◽

Porcine Epidemic Diarrhea Virus ◽

Cell Epitope ◽

Spike Protein ◽

Diarrhea Virus ◽

B Cell Epitope ◽

Porcine Epidemic Diarrhea

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Immunodominant and neutralizing linear B cell epitopes spanning the spike and membrane proteins of Porcine Epidemic Diarrhea Virus

10.1101/2021.10.05.463270 ◽

2021 ◽

Author(s):

Kanokporn Polyiam ◽

Marasri Ruengjitchatchawalya ◽

Phenjun Mekvichitsaeng ◽

Kampon Kaeoket ◽

Tawatchai Hoonsuwan ◽

...

Keyword(s):

B Cell ◽

Porcine Epidemic Diarrhea Virus ◽

M Protein ◽

B Cell Epitopes ◽

Diarrhea Virus ◽

M Proteins ◽

Porcine Epidemic Diarrhea ◽

Neutralizing Epitopes ◽

Immunodominant Epitopes ◽

Linear B

AbstractPorcine Epidemic Diarrhea Virus (PEDV) is the causative agent of PED, an enteric disease that causes high mortality rates in piglets. PEDV is an alphacoronavirus that has high genetic diversity. Insights into neutralizing B cell epitopes of all genetically diverse PEDV strains are of importance, particularly for designing a vaccine that can provide broad protection against PEDV. In this work, we aimed to explore the landscape of linear B cell epitopes on the spike (S) and membrane (M) proteins of global PEDV strains. All amino acid sequences of the PEDV S and M proteins were retrieved from the NCBI database and grouped. Immunoinformatics-based methods were next developed and used to identify putative linear B cell epitopes from 14 and 5 consensus sequences generated from distinct groups of the S and M proteins, respectively. ELISA testing predicted peptides with PEDV-positive sera revealed 9 novel immunodominant epitopes on the S protein. Importantly, 7 of these novel immunodominant epitopes and other subdominant epitopes were demonstrated to be neutralizing epitopes by neutralization-inhibition assay. Additionally, our study shows the first time that M protein is also the target of neutralizing antibodies as 7 neutralizing epitopes in the M protein were identified. Conservancy analysis revealed that epitopes in the S1 subunit are more variable than those in the S2 subunit and M protein. In this study, we offer the immunoinformatics approach for linear B cell epitope identification and a more complete profile of linear B cell epitopes across the PEDV S and M proteins, which may contribute to the development of a greater PEDV vaccine as well as peptide-based immunoassays.

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