Chicken macrophage activation by interferon: do birds lack the molecular homologue of mammalian interferon-gamma?
In mammalian species, interferon-gamma (IFN-gamma) is a lymphokine with a wide range of biological effects, of which the antiviral and macrophage-activating capacities are those best characterized. In birds, no equivalent with a similar range of actions has as yet been isolated. Chicken splenocytes were stimulated by mitogens in conditions that were similar to those used for the induction of mammalian IFN-gamma. Culture fluids were assayed for antiviral and macrophage-activating capacities. As much as 1000 units/ml of an interferon-like antiviral activity was found in the culture fluid of Staphylococcus aureus lysate-induced spleen cells. Seroneutralization assays with a polyclonal antiserum against purified interferon and physicochemical studies revealed that the antiviral activity is identical to or closely related to type I interferon (interferon-alpha/beta). The presence of macrophage activating factors (MAF) in the splenocyte medium was demonstrated by measuring increased production of H2O2 by chicken peritoneal macrophage cultures and a chicken macrophage cell line (HD11). The heat stability of this MAF activity was similar to that of the antiviral factor, and was completely neutralized by the anti-IFN-alpha/beta antiserum. These results show that when the classical procedure used for the production of mammalian IFN-gamma is applied to chicken splenocytes, it does not yield an equivalent for IFN-gamma/MAF. This suggests that the classification of interferons into types (alpha, beta and gamma), while generally applicable in mammals, may not be applicable in birds.
Dijkmans
R
R
Rega Institute for Medical Research, University of Leuven Medical School, Belgium.
Creemers
J
J
Billiau
A
A
D000818:Animals; D002478:Cells, Cultured; D002645:Chickens / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D006861:Hydrogen Peroxide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007370:Interferon Type I / Q000096:biosynthesis / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D016215:Macrophage-Activating Factors / Q000096:biosynthesis / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D008934:Mitogens; D012672:Semliki forest virus / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013696:Temperature
D007370:Interferon Type I; D016215:Macrophage-Activating Factors; D008934:Mitogens; D007371:Interferon-gamma; D006861:Hydrogen Peroxide