The 7th International Symposium on

Emerging and Re-emerging Pig Diseases

Proceedings

June 21-24, 2015

Kyoto Intemational Conference Center

Kyoto, Japan

ORGANIZERS

"'e - •..• r'e'TatlOoal Symposium on Emerging and Re-emerging Pig Diseases Organizing Cammittee

Science Cauncil af Japan

CO-ORGANIZERS

~ e ~a a ese ·e•. cf eterínary Science

GENETIC MARK.ERS ASSOCI TED WITH INFLUE, ZA VACCINATION EFFICACY IN SWINERicardc Zanella(1}, Danielle Ga a(2) ,Jane O. peixO}0(2), Rejane Schaefer(2) ,Janice RC. Zanetla'". NatalhaBiondoN, Marcos v.G. da Silva(4), Mauricio E. Cantão(2) & Mônica C. Ledur(2)I Universily of Passo Fundo, Passo Fundo, Brazil, 2 Embrapa Swme and Poultry National Research Center,

Brazil, J Santa Catarina State University, Brazil, 4 Embrapa Dairy Cattle National Research Center. Brazil.

, .';096

IntroductionInOuenza A virus (IAV) is one of lhe the mostimportant pathogen of the porcine respiratorydisease complex and genetically diverse IAVsubtypes (H1N1pdm, H1N2 and H3N2) arecirculating in pig farms in most of the Brazilianstates [1J. InfecHon of pigs with IAV causeconsiderable economic losses to the producersdue to the high morbidity among infected pigs and .it is also considered a global health concern [2].To reduce those tosses. several managementstrategies have been used. Currently, vaccinationis considered the most efficient method to controland to diminish the disease burden, reducing theclinical signs and the transmission of lhe disease[3]. However, the immune response to vaccinationcan be variable between individuais [4]. It hasbeen proposed that immune response tovaccination is a complex trait with variationresulting from environmental and genetic factors[5]. Therefore, lhe objective of this research wasto idenlify genetic mechanisms ínvolved in hostirnrnune response to IAV vaccination.

MateriaIs and methodsOne hundred and three piglets were vaccinatedwith an inactivated pandemic H1N1 IAV,A/swine/Brazil/1 07/2010 (KF683611-KF683618),with a titer of 10438 50% tis sue culture infectiousdose (TCID50) per mL. The vírus was inactivatedwith 2-bromoethylamine hydrobromíde and anadjuvant (Emulsigen D) was added to the vaccinepreparation. Piglets were vaccinated with 1.5mLvia intramuscular route at 34 days-old andboosted at 55 days-old. Blood samples werecolleded from piglets at 21, 34, 55 and 76 days-old and tested for the presence of antibodies forlhe nucleoprotein (NP) of IAVs using IDEXXInfluenza A- Ab test" (IDEXX Laboratories lnc).DNA was extracted from piglets' lungs and wasgenotyped usíng the IlIumina PorcineSNP60V2BeadChip which contains 61,565 SNPs evenlyspaceo across lhe swine qenorne. The aetiveimrnuruty was considered based on the presenceor absence of NP antibody related to lhevaccinalion (day 76). A standard chi-square testand the odds ratio was used to test associatron ofSNP and immune response using PLlNK [6J.Significance was considered if an unadjusted P-value was <5.0x105 [7].

ResultsAI day 34 none of lhe piglets had antibodies 10 IAV.indicating that any titer post-vaccination were dueto immunization. On day 76, seventy-five piglets(n=75) did not respond 10 vaccination and twenty-eight piglels (n=28) had antibodies to IAV

vaccination. When we tested the association ofSNPs with immune response, two markers onSSC 12, located ai 27,241,826bp and31,875,247bp of lhe r,ig genome, were moderatedassociated (P<5x10' ) with immune response IAVvaccination. The LD between these two markersrs81433411 and rs81341245 was D'= 0.861. Thefrequency of lhe "A" allele of rs81433411 was 0.58in control and 0.25 in case animais. For the SNPrs81341245, the frequency of the "G" atlele was0.31 in control and 0.62 in case animaIs. Testingthe combined effect of lhe associated rnarkers didnot improve lhe significance of the test.

DiscussionThe efficacy ot lhe in bouse vaccine was 28%.indicating a modera te levei of protection. Thismoderate protection was possibly caused by lhefinal amount of antigen delivered by lhe vaccine.The region on SSC 12 associated with immuneresponse to IAV vaceination harbor four annotatedgenes in lhe swine genome: T081, NME1, NME2and STAT2. Ali lhe genes located in lheassocrated region were previously described asinvolved with immunity, more specificalty withinfluenza vaccination in human, therefore they aregood positional and functional candidate genesthat could be used to explain the efficacy ofvaccination to IAV in swine[3,8,9,10] . Theidentification ot genetic markers and lheunderstanding of the genelic mechanismsinvolved in lhe immune response to vaceinationwould be useful to select pígs lha! better respondto IAV challenge It could contribule to reducelhe losses caused by IAV infection in swine.

AcknowledgementsZanetta, R is an early invesligator fellow (BJT)from CNPq ai Embrapa Swine and Poultry. Theaulhors sincerely appreeiate lhe technicalassistance of Marisete F Schiochet on ELlSAtests, Vanessa Haach 10 sampling cottection andDr. Jack Dekkers for lhe experimental designdiscussion.

References1. Schaefer et al.(2014). Arch Virol.2 Olsen et al.(2.002) Emerg Infec! Dis 8:814-819.3. Poland e al.(2014). C.O Imm. 29:62-68.4. Rajao et al.(2014). C.TMlmm. 385: 307-326.5. Newport et al.(2004). Genes Imm.5: 122-129.6 Purcell et ai (2007). Am J H. Gen. 81: 559-575.7. WTCCC (2007). Nature 447: 661-678.8.8. Salerno et al.(2014) Eur J 1m44: 646-649.9. Hasan et at. (2013) Inf 1m 81: 2499-2506.10. Nakaya et al. (2011) Nat 1m 12: 786-795.