Dynamics of cytokine production during coccidial infections in chickens: colony-stimulating factors and interferon

Abstract

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.

Immunological basis of differences in disease resistance in the chicken

“…There is a correlation between resistance to these diseases and early and higher IFN-γ production. A high level of IFN-γ production has also been shown in chicken strains that are resistant to coccidiosis [20,90,139]. These observations suggest that chicken lines with an enhanced IFN-γ response are more resistant to some viral and parasitic infections.…”

Avian Leukocytic Cytokines

“…Some cytokine activities can also be observed in the blood from chicks challenged with pathogens or immunogens. For example, coccidiosis increases plasma concentrations of TNF-a activity, CSF activity, and interferon (Byrnes et al, 1993b), and Salmonella typhimuriutn lipopolysaccharide increases the plasma concentrations of IL-1 activity in chicks . Presumably, some cytokines are released at the site of challenge in sufficient quantities to make their way into the general circulation, where they may act on distant tissues to coordinate recruitment of new leukocytes and the acute phase response.…”

Interferon-γ is expressed in both gut and spleen duringEimeria tenellainfection

“…Several reports have described IFN-g -like activity in the CM of cells from Eimeria-infected birds (Prowse & Pallister, 1989;Byrnes et al, 1993;Martin et al, 1994;Breed et al, 1997), both following primary infection and in some cases after repeated challenge. However, some of these studies have detected IFN-g expression from splenocytes from both infected and naṏ ve birds (Martin et al, 1994;Breed et al, 1997), suggesting that splenocytes might not be a useful source of lymphocytes for studying cytokine responses to eimerian infections.…”

“…IFN-like activities from antigen-or mitogen-stimulated immune T cells can inhibit the invasion or development of Eimeria tenella in cultured cells (Kogut & Lange, 1988, 1989aProwse et al, 1992). Also, IFN-like activity was shown to be produced by spleen cells from birds previously infected with E. tenella (Prowse & Pallister, 1989) and Eimeria maxima (Byrnes et al, 1993). Recently, Breed et al (1997) showed that peripheral blood lymphocytes (PBL) from E. tenella-infected chickens specifically produce IFNg after in vitro stimulation.…”