A Highly Conserved Epitope (RNNQIPQDF) of Porcine teschovirus Induced a Group-Specific Antiserum: A Bioinformatics-Predicted Model with Pan-PTV Potential

Abstract

Porcine teschovirus (PTV) is an OIE-listed pathogen with 13 known PTV serotypes. Heterologous PTV serotypes frequently co-circulate and co-infect with another swine pathogen, causing various symptoms in all age groups, thus highlighting the need for a pan-PTV diagnostic tool. Here, a recombinant protein composed of a highly conserved “RNNQIPQDF” epitope on the GH loop of VP1, predicted in silico, and a tandem repeat of this epitope carrying the pan DR (PADRE) and Toxin B epitopes was constructed to serve as a PTV detection tool. This recombinant GST-PADRE-(RNNQIPQDF)n-Toxin B protein was used as an immunogen, which effectively raised non-neutralizing or undetectable neutralizing antibodies against PTV in mice. The raised antiserum was reactive against all the PTV serotypes (PTV–1–7) tested, but not against members of the closely related genera Sapelovirus and Cardiovirus, and the unrelated virus controls. This potential pan-PTV diagnostic reagent may be used to differentiate naturally infected animals from vaccinated animals that have antibodies against a subunit vaccine that does not contain this epitope or to screen for PTV before further subtyping. To our knowledge, this is the first report that utilized in silico PTV epitope prediction to find a reagent broadly reactive to various PTV serotypes.

Identification of a novel porcine Teschovirus 2 strain as causative agent of encephalomyelitis in suckling piglets with high mortality in China

“…Previous studies showed that antigenic drift, one of the major reasons for immune evasion, were mainly recognized in VP1 and VP2 [ 1 , 8 ]. Comparing to the other PTV-2 strains from China, 24 unique amino acid (aa) mutations were discovered in the VP1 region, and 12 unique aa mutations were discovered in the VP2 of isolate HeNZ1 (labeled with orange frame in Fig.…”

“…Therefore, phylogenetic analysis of VP1 has been used as a reliable approach for characterizing the PTV genotypes [1]. Also, neutralizing epitopes mainly locate within VP1 and VP2 [1,[7][8][9].…”

A computational approach to rapidly design peptides that detect SARS-CoV-2 surface protein S

“…Computational approaches have thus emerged as powerful options for effective and rapid development of infectious disease diagnostics. They can predict antigenic epitopes of target viral proteins ( 15 ) and prioritize diagnostic protein candidates. Computational-based approaches can alternately target viral proteins of interest using short peptide sequences, with high precision, even when the target protein is mixed with dense populations of irrelevant proteins, as described in this study.…”