Expression of adhesion and Fcγ-receptors on canine blood eosinophils and neutrophils studied by anti-human monoclonal antibodies

Commercially available anti-human monoclonal antibodies were tested as markers of adhesion receptors and Fcγ-receptors on canine neutrophils and eosinophils. Purified populations of eosinophils and neutrophils were incubated with selected monoclonal antibodies and binding was measured by flow cytometry. Most of the anti-human monoclonal antibodies used in this study crossreacted with canine granulocytes and many showed expression similar to that of human granulocytes. The results suggest that the adhesion and Fcγ-receptors are well conserved among species. Canine eosinophils and neutrophils were simultaneously purified by a two-layer Percoll density gradient centrifugation. The purity of the neutrophil fraction was ≥97% after lysis of the erythrocytes. In the eosinophil fraction, 27–92% were eosinophils (mean 60%). After purification, the neutrophils and eosinophils were incubated with selected monoclonal antibodies and analysed by flow cytometry. Human anti-CD11b and CD18 antibodies bound intensely to both canine eosinophils and neutrophils. Canine neutrophils did label with anti-CD29, but eosinophils did not. Anti-CD49d bound weakly to both eosinophils and neutrophils. Both anti-CD16 and anti-CD32 antibodies labelled neutrophils, but not eosinophils. There was no binding of anti-CD9 to canine neutrophils and the binding of anti-CD9 to canine eosinophils varied between dogs.