Identification of transforming growth factor-beta and interleukin-6 in chicken ascites fluid.
Ascites fluids from chickens were analyzed for the occurrence of transforming growth factor-beta (TGF-beta) and interleukin-6 (Il-6) using the mink lung epithelial cell inhibition and B9 hybridoma proliferation assays, respectively. Both of these cytokines were significantly elevated in ascites fluids (TGF-beta, 0.129 +/- 0.017 ng/mg protein; Il-6, 0.054 +/- 0.011 ng/mg protein) relative to serum (TGF-beta, 0.005 +/- 0.003 ng/mg protein; Il-6, < 0.002 ng/mg protein) derived from the same individual birds. TGF-beta occurred in a latent form and required activation by heat or acid (heat, 100%; non-activated, 5.2 +/- 1.1%; acid-activated, 89.5 +/- 12.3%). Heat treatment destroyed Il-6 activity. Both TGF-beta and Il-6 activities could be neutralized by antibodies directed against the recombinant human counterpart of these cytokines. Increasing dilutions of ascites fluid caused proportionate decreases in cytokine activities. Il-6 activity was further characterized by gel filtration using high-pressure liquid chromatography, which yielded a peak of biological activity corresponding to an approximate molecular weight of 35,000. These data suggest that ascites fluid may be an interesting biological model and source for studying avian cytokines and their physiological relevance.
Rath
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USDA/Agricultural Research Service, University of Arkansas, Fayetteville 72701, USA.
Huff
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WE
Bayyari
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GR
Balog
J M
JM
D000818:Animals; D001201:Ascites / Q000276:immunology / Q000662:veterinary*; D001202:Ascitic Fluid / Q000378:metabolism; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D015850:Interleukin-6 / Q000302:isolation & purification*; D008297:Male; D009500:Neutralization Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000302:isolation & purification*
D015850:Interleukin-6; D016212:Transforming Growth Factor beta