Abstract

Cetacean immunology is a rapidly progressing field. As part of our current efforts to develop assays and reagents to study the immune system of marine mammals, the present study reports on the characterization of a monoclonal antibody to CD11/CD18. The specificity of this antibody was demonstrated by immunoprecipitation of the antigen it recognizes, flow cytometry, and the functions it performs. Although labeling only a proportion of peripheral blood neutrophils, our monoclonal antibody was shown to inhibit almost completely phagocytosis (upon stimulation with latex microspheres) and respiratory burst (upon stimulation with PMA), the two most important functions of neutrophils. This antibody, as a potential marker of neutrophil activation, could become a very useful tool in monitoring the early stimulation of the immune system at the onset of disease processes.