|Fangman, T - UNIV OF MISSOURI|
|Weidmeyer, C - UNIV OF MISSOURI|
|Hambach, A - UNIV OF MISSOURI|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: October 16, 2002
Publication Date: March 17, 2003
Citation: STRAUCH, T.A., CARROLL, J.A., FANGMAN, T.J., WEIDMEYER, C.E., HAMBACH, A.K. IMMUNE RESPONSE IN ESCHERICHIA COLI CHALLENGED PIGS EXHIBITING A FEBRILE RESPONSE IN ABSENCE OF ELEVATED TNF-ALPHA. JOURNAL OF ANIMAL SCIENCE SUPPLEMENT. 2003. v. 81(Suppl.2):Abstract p. 64. Technical Abstract: The objective of this study was to determine the immune response in pigs challenged with Escherichia coli. Twenty-two single-sourced, 24-d-old crossbred pigs (5.44 kg) were utilized. Pigs were individually housed, provided ad libitum feed and water, and assigned to blood collection (n=10) or rectal temperature measurement (n=12) groups. Blood collection pigs were non-surgically cannulated one day prior to blood collection. At 0 hr, all pigs received a 10 mL dose of 2.4 x 10**8 colony-forming units of E. coli K88 via a nasogastric tube. Blood collection and rectal temperature monitoring occurred hourly from -1 to 5 hr post-E. coli, every 30 minutes from 5 to 8 hrs, and at 24 hrs post-E. coli. Serum concentrations of cortisol (CS), interferon-gamma (IFN), tumor necrosis factor-alpha (TNF), interleukin-1beta (IL-1), interleukin-6 (IL-6), serum amyloid A (SAA), C-reactive protein (CRP), haptoglobin (HG), and lipopolysaccharide (LPS) were measured. After E. coli administration, CS, IFN, IL-1, IL-6, SAA, CRP, HG (P < 0.0001), and LPS (P < 0.002) increased. Peak concentrations of CS and IL-6 occurred at 4 hr post-E. coli, IFN and rectal temperature peaked at 5.5 hr post-E. coli, and IL-1 peaked at 6 hr post-E. coli. Serum concentrations of TNF were undetectable throughout the sampling period. The greatest circulating concentrations of LPS were detected at 7.5 hr post-E. coli, and the acute-phase proteins CRP, HG, and SAA were still increasing at 24 hr post-E. coli. While TNF was not associated with increased rectal temperature, positive correlations existed between rectal temperature and CS (r = 0.49; P < 0.0001), IFN (r = 0.29; P < 0.0009), IL-1 (r = 0.45; P < 0.0001), IL-6 (r = 0.31; P < 0.0003), and LPS (r = 0.29; P < 0.0009). These data indicate that circulating TNF does not play an integral role in initiating the febrile response in pigs challenged with E. coli; but that CS, IL-6, or IFN may act as endogenous pyrogens.