Recombinant mouse interferon-gamma is not chemotactic for macrophages or neutrophils

Recent evidence implicates interferon-gamma (IFN-gamma) in resistance to infection with the facultative intracellular bacterium, Listeria monocytogenes. Reports showing that inflammatory macrophages and neutrophils are highly bactericidal for listeria suggest that IFN-gamma might act by directly or indirectly causing recruitment of these cells. The purpose of the experiments described here was to test whether recombinant mouse IFN-gamma is chemotactic for macrophages or neutrophils in vivo or in vitro. In vivo experiments showed rIFN-gamma to have no ability to cause recruitment of inflammatory neutrophils or macrophages into the peritoneal cavities of mice. When tested in vitro, rIFN-gamma also did not induce migration of inflammatory neutrophils or macrophages through cellulose nitrate filters in a chemotaxis assay. The data indicate that rIFN-gamma has no direct or indirect chemotactic activity in vivo or in vitro for mouse macrophages or neutrophils.