PMID- 25472653 OWN - NLM STAT- MEDLINE DCOM- 20151120 LR - 20181113 IS - 1746-6148 (Electronic) IS - 1746-6148 (Linking) VI - 10 DP - 2014 Dec 4 TI - Variation in time and magnitude of immune response and viremia in experimental challenges with Porcine circovirus 2b. PG - 286 LID - 10.1186/s12917-014-0286-4 [doi] LID - 286 AB - BACKGROUND: Porcine circovirus 2 is the primary agent responsible for inducing a group of associated diseases known as Porcine Circovirus Associated Diseases (PCVAD), which can have detrimental effects on production efficiency as well as causing significant mortality. The objective of this study was to evaluate variation in viral replication, immune response and growth across pigs (n = 974) from different crossbred lines. The approach used in this study was experimental infection with a PCV2b strain of pigs at an average of 43 days of age. RESULTS: The sequence of the PCV2b isolate used in the challenge was similar with a cluster of PCV2b isolates known to induce PCVAD and increased mortality rates. The swine leukocyte antigen class II (SLAII) profile of the population was diverse, with nine DQB1 haplotypes being present. Individual viremia and antibody profiles during challenge demonstrate variation in magnitude and time of viral surge and immune response. The correlations between PCV2 specific antibodies and average daily gain (ADG) were relatively low and varied between - 0.14 to 0.08 for IgM and -0.02 and 0.11 for IgG. In contrast, PCV2 viremia was an important driver of ADG decline following infection; a moderate negative correlation was observed between viral load and overall ADG (r = - 0.35, P < 0.001). The pigs with the lowest 10% level of viral load maintained a steady increase in weekly ADG (P < 0.0001) compared to the pigs that had the 10% greatest viral load (P < 0.55). In addition, the highly viremic group expressed higher IgM and IgG starting with d 14 and d 21 respectively, and higher tumor necrosis factor - alpha (TNF-alpha) at d 21 (P < 0.005), compared to low viremic group. CONCLUSIONS: Molecular sources of the observed differences in viremia and immune response could provide a better understanding of the host factors that influence the development of PCVAD and lead to improved knowledge of swine immunity. FAU - Engle, Taylor B AU - Engle TB AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. tbengle@huskers.unl.edu. FAU - Jobman, Erin E AU - Jobman EE AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. e_jobman09@hotmail.com. FAU - Moural, Timothy W AU - Moural TW AD - School of Veterinary Medicine and Biological Sciences, University of Nebraska, Lincoln, USA. mouraltm@gmail.com. AD - Bluegrass Community & Technical College, Lexington, USA. mouraltm@gmail.com. FAU - McKnite, Autumn M AU - McKnite AM AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. amcknite@gmail.com. FAU - Bundy, Justin W AU - Bundy JW AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. justin@billbarr.com. FAU - Barnes, Sarah Y AU - Barnes SY AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. sarah.barnsie@gmail.com. FAU - Davis, Emily H AU - Davis EH AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. emilyhdavis@me.com. FAU - Galeota, Judith A AU - Galeota JA AD - School of Veterinary Medicine and Biological Sciences, University of Nebraska, Lincoln, USA. judith.galeota@unl.edu. FAU - Burkey, Thomas E AU - Burkey TE AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. tburkey2@unl.edu. FAU - Plastow, Graham S AU - Plastow GS AD - Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada. plastow@ualberta.ca. FAU - Kachman, Stephen D AU - Kachman SD AD - Department of Statistics, University of Nebraska, Lincoln, USA. steve.kachman@unl.edu. FAU - Ciobanu, Daniel C AU - Ciobanu DC AD - Animal Science Department, University of Nebraska, Lincoln, NE, 68583-0908, USA. dciobanu2@unl.edu. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20141204 PL - England TA - BMC Vet Res JT - BMC veterinary research JID - 101249759 SB - IM MH - Animals MH - Circoviridae Infections/immunology/*veterinary/virology MH - Circovirus/*immunology/pathogenicity MH - Disease Susceptibility/immunology/veterinary/virology MH - Immunity/immunology MH - Swine/growth & development/virology MH - Swine Diseases/immunology/*virology MH - Time Factors MH - Viral Load/veterinary MH - Viremia/immunology/*veterinary/virology MH - Virus Replication PMC - PMC4264338 EDAT- 2014/12/05 06:00 MHDA- 2015/12/15 06:00 PMCR- 2014/12/04 CRDT- 2014/12/05 06:00 PHST- 2014/08/06 00:00 [received] PHST- 2014/11/19 00:00 [accepted] PHST- 2014/12/05 06:00 [entrez] PHST- 2014/12/05 06:00 [pubmed] PHST- 2015/12/15 06:00 [medline] PHST- 2014/12/04 00:00 [pmc-release] AID - s12917-014-0286-4 [pii] AID - 286 [pii] AID - 10.1186/s12917-014-0286-4 [doi] PST - epublish SO - BMC Vet Res. 2014 Dec 4;10:286. doi: 10.1186/s12917-014-0286-4.