Immunoinformatics approach for predicting epitopes in HN and F proteins of Porcine rubulavirus.

Luis I Siañez-Estrada,Gerardo Santos-López,José F Rivera-Benítez,Julio Reyes-Leyva,Nora H Rosas-Murrieta,Irma Herrera-Camacho

doi:10.1371/journal.pone.0239785

Abstract

Porcine rubulavirus (PRV), which belongs to the family Paramyxoviridae, causes blue eye disease in pigs, characterized by encephalitis and reproductive failure in newborn and adult pigs, respectively. There is no effective treatment against PRV and no information on the effectiveness of the available vaccines. Continuous outbreaks have occurred in Mexico since the early 1980s, which have caused serious economic losses to pig producers. Vaccination can be used to control this disease. Searching for effective antigen candidates against PRV, we first sequenced the PAC1 F protein, then we used various immunoinformatics tools to predict antigenic determinants of B-cells and T-cells against the two glycoproteins of the virus (HN and F proteins). Finally, we used AutoDock Vina to determine the binding energies. We obtained the F gene sequence of a PRV strain collected in the early 1990s in Mexico and compared its amino acid profile with previous and more recent strains, obtaining an identity similarity of 97.78 to 99.26%. For the F proteins, seven linear B-cell epitopes, six conformational B-cell epitopes and twenty-nine T-cell MHC class I epitopes were predicted. For the HN proteins, sixteen linear B-cell epitopes, seven conformational B-cell epitopes and thirty-four T-cell MHC class I epitopes were predicted. The ATRSETDYY and AAYTTTTCF epitopes of the HN protein might be important for neutralizing the viral infection. We determined the in silico binding energy between the predicted epitopes on the F and HN proteins and swine MHC-I molecules. The binding energy of these epitopes ranged from -5.8 to -7.8 kcal/mol. The present study aimed to assess the use of HN and F proteins as antigens, either as recombinant proteins or as a series of peptides that could activate different responses of the immune system. This may help identify relevant immunogens, saving time and costs in the development of new vaccines or diagnostic tools.

Highlights

Porcine rubulavirus (PRV), known as La Piedad Michoacan virus (LPMV), is a member of the Paramyxoviridae family
In 1997, PRV was isolated from different outbreaks; these isolates were named Produccion Animal Cerdos (PAC)
There is no specific treatment against PRV but there are two PRV vaccines commercially available, both of which are based on inactivated viruses; there are no studies showing their level of protection against PRV

Summary

Introduction

Porcine rubulavirus (PRV), known as La Piedad Michoacan virus (LPMV), is a member of the Paramyxoviridae family. PRV causes the blue eye disease (BED) in pigs. BED is characterized by uni- or bilateral corneal opacity, respiratory distress and progressive neurological signs, with high rates of mortality in piglets and reproductive failure in adults [1,2,3]. PRV was first isolated in La Piedad, Michoacan, Mexico, in 1980. There have been several outbreak reports (1984–2015). In 2015, an outbreak of BED was observed in Central Mexico; it was characterized by an increase in the number of adult pigs with neurological signs. The seroprevalence of PRV ranged from 9 to 23.7%, and there were PRV reports in 16 states of Mexico. There is no specific treatment against PRV but there are two PRV vaccines commercially available, both of which are based on inactivated viruses; there are no studies showing their level of protection against PRV

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