Dynamics of cytokine production during coccidial infections in chickens: colony-stimulating factors and interferon.
We assayed two classes of immunoregulatory cytokines, colony-stimulating factors (CSF) and interferon (IFN), during and immediately after a primary coccidial infection in chickens. Coccidial infection induces significant alterations in serum colony-stimulating activity (CSA) and these alterations immediately precede the characteristic biphasic leukocytosis. CSA rose sharply during the first 24 h post-inoculation (PI), but returned to control levels by 48 h PI. At this time, we detected an increase in peripheral blood leukocytes which peaked at 96 h PI. A second phase of CSA increase began 96 h PI and peaked at 120-144 h PI which again preceded the second phase of leukocytosis. We also examined the production of IFN during the first 20 days PI. Splenic T cells from Eimeria maxima-infected chickens produced significantly less IFN on day 5 PI compared to T cells from the coccidia-free controls. By days 10 and 15 PI, there was no significant difference in IFN production between the T cells of infected and non-infected chickens. However, by day 20 PI, IFN production by the T cells of the infected birds produced significantly more IFN than the control T cells. The results of our studies indicated the differential production of two different cytokines by chickens during and following a primary coccidial infection. Based on these experiments, CSF may be some of the first cytokines produced during an E. maxima-infection, while IFN may be one of the later cytokines produced.
Byrnes
S
S
Department of Biological Sciences, University of Arkansas, Fayetteville.
Emerson
K
K
Kogut
M
M
D000818:Animals; D002645:Chickens / Q000276:immunology*; D003048:Coccidiosis / Q000097:blood / Q000276:immunology / Q000662:veterinary*; D003114:Colony-Forming Units Assay / Q000662:veterinary; D003115:Colony-Stimulating Factors / Q000096:biosynthesis*; D004539:Eimeria / Q000276:immunology; D007372:Interferons / Q000096:biosynthesis*; D007958:Leukocyte Count; D008297:Male; D011201:Poultry Diseases / Q000097:blood / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
D003115:Colony-Stimulating Factors; D007372:Interferons