Unravelling the genetic components involved in the immune response of pigs vaccinated against influenza virus

Abstract

A genome-wide association study for immune response to influenza vaccination in a crossbred swine population was conducted. Swine influenza is caused by influenza A virus (FLUAV) which is considered one of the most prevalent respiratory pathogens in swine worldwide. The main strategy used to control influenza in swine herds is through vaccination. However, the currently circulating FLUAV subtypes in swine are genetically and antigenically diverse and their interaction with the host genetics poses a challenge for the production of efficacious and cross-protective vaccines. In this study, 103 pigs vaccinated with an inactivated H1N1 pandemic virus were genotyped with the Illumina PorcineSNP60V2 BeadChip for the identification of genetic markers associated with immune response efficacy to influenza A virus vaccination. Immune response was measured based on the presence or absence of HA (hemagglutinin) and NP (nucleoprotein) antibodies induced by vaccination and detected in swine sera by the hemagglutination inhibition (HI) and ELISA assays, respectively. The ELISA test was also used as a measurement of antibody levels produced following the FLUAV vaccination. Associations were tested with x(2) test for a case and control data and using maximum likelihood method for the quantitative data, where a moderate association was considered if p<5×10(-5). When testing the association using the HI results, three markers with unknown location and three located on chromosomes SSCX, SSC14 and SSC18 were identified as associated with the immune response. Using the response to vaccination measured by ELISA as a qualitative and quantitative phenotype, four genomic regions were associated with immune response: one on SSC12 and three on chromosomes SSC1, SSC7, and SSC15, respectively. Those regions harbor important functional candidate genes possibly involved with the degree of immune response to vaccination. These results show an important role of host genetics in the immune response to influenza vaccination. Genetic selection for pigs with better response to FLUAV vaccination might be an alternative to reduce the impact of influenza virus infection in the swine industry. However, these results should to be validated in additional populations before its use.

Genome‐wide association study of periweaning failure‐to‐thrive syndrome (PFTS) in pigs

“…Genetics involved in the susceptibility (Settles and others 2009) and tolerance to diseases (Zanella and others 2011) have been widely investigated as an additional tool to select animals that will better cope with specific challenges (Boddicker and others 2014, Zanella and others 2015). In this context, the use of high density SNP panels has allowed the identification of genetic markers associated with phenotypes of interest (Settles and others 2009, Wilson and others 2012).…”

Genomic Tools and Animal Health

“…Here, we present results of an association study of genetic markers with the immune response to influenza vaccination in a swine herd [ 7 ]. Animals were vaccinated with an inactivated H1N1pdm virus and tested for the association of genetic markers with immune response efficacy to influenza vaccination (IAV).…”

“…Using the response to vaccination as a qualitative phenotype, a region on SSC12 was identified to be associated with the immune response. When we tested the efficacy of the response to the vaccination as a quantitative phenotype, four additional associated chromosomes were identified: SSC0 , SSC1 , SSC7 and SSC15 [ 7 ]. These results suggest the complexity of the immune traits when used to test their interaction with host genetics.…”

“…Vaccination and good management practices have been widely used to control and to avoid pathogens spreading in populations, providing variable levels of protection. However, the mechanism involving immune protection is not fully understood; therefore, not all the animals respond to the treatment, leading to the discovery of new approaches to address those failures [ 7 , 8 ]. It is common to observe in a vaccinated population some differences in the immune response between animals [ 7 ].…”

“…However, the mechanism involving immune protection is not fully understood; therefore, not all the animals respond to the treatment, leading to the discovery of new approaches to address those failures [ 7 , 8 ]. It is common to observe in a vaccinated population some differences in the immune response between animals [ 7 ]. Also, differences in the severity of infection of animals exposed to similar doses of pathogens were found, suggesting a possible role of genetics involved with tolerance and resistance to infection [ 9 ].…”