Avian Inflammatory Macrophage Function: Shifts in Arachidonic Acid Metabolism, Respiratory Burst, and Cell-Surface Phenotype During the Response to Sephadex

Abstract

The avian inflammatory response to intraperitoneal (i.p.) Sephadex injection produces macrophages which display characteristics of an increasingly activated state over time. We examined elicited chicken peritoneal exudate cells (PECs) with respect to superoxide anion production, arachidonic acid metabolism and cell surface Ia and transferrin receptor (TfR) expression from 4 to 96 h after i.p. stimulation. Avian PECs showed the highest level of superoxide release when harvested just 4 h after injection, and did not produce PGE2 or 6-keto PGF1 alpha. Early (4-h) PECs produced elevated amounts of thromboxane as compared to later (42-h) macrophages. Expression of both Ia and TfR increased between 4 and 24 h after Sephadex stimulation; TfR remained elevated through 96 h, but Ia declined after 42 h. Some aspects of chicken macrophage regulation of superoxide anion, thromboxane release, and surface antigen expression are in contrast with those reported for mouse macrophages.