EFFECT OF PASTEURELLA-HAEMOLYTICA OUTER-MEMBRANE PROTEINS ON BOVINE NEUTROPHILS

The major outer membrane proteins (OMPs) isolated from Pasteurella hae molytica induce alterations of the biological activity of bovine polym orphonuclear leukocytes (PMNs). A dose-dependent reduction of the capa city of adherence to nylon wool in vitro was observed. OMPs also acted as chemotaxins at concentrations between 5 and 20 mu g/ml. Concentrat ions lower than 5 mu g/ml did not give considerable results. Preincuba tion with 5 mu g/ml of OMPs led to modifications in the values of the phagocytic index and of intracellular killing, which were found to be diminished with respect to controls. (C) 1998 Federation of European M icrobiological Societies. Published by Elsevier Science B.V.