Peripheral blood and jejunal intraepithelial immune cell phenotypes associated with body weight of newly weaned pigs (81.9)

Abstract

Abstract Early immune development has been purported to have ramifications on metabolic functions related to subsequent growth. To determine if specific immune cell populations were associated with pigs with heavy and light body weight (BW), piglets were weaned to an on-site conventional or a segregated weaning facility and immune cell phenotypes were characterized and correlated to piglet BW. Pig BW was measured and flow cytometry analyses were performed on PBMC and jejunal intraepithelial lymphocytes (IEL) on day 11, 18, and 25 after weaning. Ordination methods were performed to determine the relationship of specific immune cell phenotypes to piglet BW. Cell phenotypes consistent with γδ (CD4+γδ+CD8-, CD8+γδ+CD4-) and activated (CD25+) IEL were positively correlated to pig BW on day 11, whereas PBMC expressing MHC2 (MHC2+CD3-) resulted in a negative correlation. On day 18, CD25+CD8+CD4+ IEL were positively correlated and PBMC expressing CD8+CD4+ were negatively correlated to pig BW. CD25+ and CD4+CD8+ IEL populations were positively correlated to pig BW on day 25, whereas IEL γδ populations (γδ+CD8+CD4-, CD4+CD8+γδ+) and PBMC expressing MHC2 (MHC2+CD3-) were negatively correlated to BW. These data indicate that specific immune cell phenotypes correlate to pig BW after weaning. Specifically, IEL expressing CD25 are associated with pigs with heavier BW after weaning, whereas IEL expressing the γδ T cell receptor are associated with heavy BW pigs early after weaning but are correlated to low BW in older pigs.