Evaluation of the use of prenatal immune stimulation on the ability to alter postnatal immune function in weaned pigs

Authors: Sanchez, Nicole; MITCHELL, TY - Texas Tech University; Broadway, Paul; BOWEN, BROOKE - Texas Tech University; DAVIS, EMILY - Texas Tech University; DOBBINS, THOMAS - Texas Tech University; BARKER, SAMANTHA - Texas Tech University; LEGAKO, JERRAD - Texas Tech University; PETRY, AMY - Texas Tech University; Carroll, Jeffery - Jeff Carroll

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/12/2022
Publication Date: 10/18/2022
Citation: Sanchez, N.C., Mitchell, T., Broadway, P.R., Bowen, B.M., Davis, E.M., Dobbins, T., Barker, S.N., Legako, J.F., Petry, A.L., Carroll, J.A. 2022. Evaluation of the use of prenatal immune stimulation on the ability to alter postnatal immune function in weaned pigs. USDA-ARS & TTU Research Spotlight.

Interpretive Summary:

Technical Abstract: One of the biggest areas where improvements can be made in swine production is in the area of swine health. This study was designed to determine whether exposure to a low dose of endotoxin (lipopolysaccharide; LPS) in gestation can enhance immunity to a subsequent challenge in piglets after weaning. Pregnant crossbred sows were assigned to a prenatal immune stimulation (LPS; n = 7; administered 2.5 µg/kg BW LPS i.m. at ~76 d of gestation) or saline treatment group (CON; n = 7). From the 2 prenatal treatment groups, barrows (n = 17 LPS, 17 CON) were identified at weaning (21 d of age) to subsequently receive an LPS challenge. On d -7, pigs were transported to the USDA-ARS Livestock Issues Research Unit in Lubbock, TX where they were housed in individual pens in an environmentally controlled room with ad libitum access to water and a starter ration. On d -1, pigs were fitted with indwelling jugular catheters and subcutaneous temperature loggers. On d 0, pigs were challenged i.v. with LPS (10 µg/kg BW) and blood samples were collected at -2, 0, 1, 2, 4, 6, 8, 12 and 24 h relative to LPS challenge. Following collection of the 24 h sample, pigs were humanely euthanized for collection of samples from the small intestine, liver and muscle. There was a treatment × time interaction for subcutaneous temperature (P < 0.01), where temperature increased more quickly at 1 and 2 h post-challenge in LPS compared to CON pigs. There was a tendency (P = 0.08) for less change in white blood cells, relative to baseline values, in LPS compared to CON pigs. There was a treatment × time interaction (P = 0.01) for lymphocyte concentrations where concentrations were reduced in LPS compared to CON pigs at 8 h post-challenge. There was also a treatment × time interaction (P = 0.01) for the change in eosinophil concentrations, were there was less change in eosinophil concentrations from 1 to 12 h in LPS compared to CON pigs. There was a tendency (P = 0.08) for a treatment × time interaction for interleukin-6 (IL-6) concentrations, where concentrations were reduced in LPS compared to CON pigs at 2 h (P = 0.01) and tended to be reduced at 1 and 4 h post-challenge (P = 0.11). There was a tendency (P = 0.06) for a treatment × time interaction for IL-8 concentrations, where concentrations were reduced in LPS compared to CON pigs at 1 and 4 h (P = 0.01) and tended to be reduced at 2 h post-challenge (P = 0.06). Granulocyte macrophage colony stimulating factor and tumor necrosis factor-a tended (P = 0.08) to be reduced in LPS compared to CON pigs. While data analysis continues on this project, this preliminary data suggests that pigs exposed to endotoxin in utero responded to postnatal endotoxin quicker and with a blunted immune cell and cytokine response compared to control pigs.