Immune response to oligopeptide permease A (OppA) protein in pigs naturally and experimentally infected with Haemophilus parasuis. (August 2016)

• Record Type: Journal Article
• Authors: Macedo, Nubia; Oliveira, Simone; Torremorell, Montserrat; Rovira, Albert
• Is Part Of: Research in veterinary science. Volume 107(2016)
• Page Start: 62
• Page End: 67
• Publication Date: 2016-08
• Subjects: OppA oligopeptide permease A -- rOppA recombinant OppA -- SPF specific pathogen free -- PRRSV porcine reproductive and respiratory syndrome virus -- IAV influenza A virus -- ABC ATP-biding cassette -- PCR Polymerase Chain Reaction -- ERIC Enterobacterial Repetitive Intergenic Consensus -- SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis -- PVDF polyvinyl difluoride -- NFDM non-fat dried milk -- PBS phosphate buffer saline -- TPBS phosphate buffer saline and tween 20 -- DPI days post-infection; Haemophilus parasuis -- OppA -- Immunity -- Pigs; Veterinary medicine -- Periodicals; Veterinary Medicine -- Periodicals; Médecine vétérinaire -- Périodiques; Médecine vétérinaire -- Recherche -- Périodiques; Diergeneeskunde; 636.089
• DOI: 10.1016/j.rvsc.2016.05.006
• Languages: English
• ISSNs: 0034-5288

Abstract

Abstract: Haemophilus parasuis is an important swine pathogen that causes Glasser's disease, characterized by pneumonia, polyserositis and meningitis. Protection against H. parasuis infection is associated with the presence of homologous antibodies in serum. However, a H. parasuis antigen that can elicit a protective immune response against all H. parasuis strains has yet to be found. A novel immunogenic and species-specific H. parasuis protein was identified by screening H. parasuis whole cell proteins using swine convalescent sera. One protein of 52 kDa was clearly immunodominant and conserved among different H. parasuis strains. This protein was further identified as an oligopeptide permease A (OppA). Because OppA elicited a specific antibody response in pigs that recovered from H. parasuis infection, we investigated its potential role in diagnostics and protective immunity. An ELISA test using recombinant OppA (rOppA) as its coating antigen was further developed and tested. H. parasuis specific antibodies to rOppA were detected in serum from convalescent pigs but not in serum from specific pathogen free (SPF) or conventional pigs. Pigs immunized with rOppA protein had robust serological responses. However, the antibodies were not protective against challenge infection. We conclude that OppA is a universal species-specific H. parasuis immunogen, and a good marker for previous systemic infection with H. parasuis . Highlights: Haemophilus parasuis oligopeptide permease A (OppA) was identified by Western blot using swine convalescent sera. Recombinant OppA (rOppA)-based ELISA is useful to track systemic infection against H. parasuis . Immunization with H. parasuis rOppA protein had robust serological responses. Antibodies to rOppA do not protect pigs against H. parasuis challenge.