Characterization of F21.A, a monoclonal antibody that recognize a leucocyte surface antigen for killer whale homologue to beta-2 integrin.
The specificity of F21.A, a monoclonal antibody raised against bottlenose dolphin leucocytes, was characterized in killer whale on the basis of immunoprecipitation of a protein of 94 kDa, as well as flow cytometric analysis. While minimally expressed on resting cells, F21.A labeled a homologue to beta-2 integrin in 89-97% of PMA-activated neutrophils, 53-66% of activated monocytes, and activated B cells but not T cells. Activation of neutrophils reached its maximum 10 min after PMA stimulation. F21.A did not label intracellular stores as did both cross-reacting anti-canine CD11b and CD18, suggesting that an activation-induced conformational change would expose a neoepitope recognized by F21.A. F21.A labeling was largely inhibited by pre-incubation with plasma, suggesting a binding site closely related to that for fibrinogen. In vitro phagocytosis and respiratory burst were almost fully inhibited upon pre-incubation with F21.A, demonstrating its functional importance. This antibody is foreseen as a possible valuable diagnostic and research tool in cetacean immunology.
De Guise
S
S
Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616, USA. sdeguise@canr.uconn.edu
Erickson
K
K
Blanchard
M
M
DiMolfetto
L
L
Lepper
H D
HD
Stott
J L
JL
Ferrick
D A
DA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D000918:Antibody Specificity; D018821:CD18 Antigens / Q000276:immunology*; D004289:Dolphins / Q000276:immunology*; D005434:Flow Cytometry; D007962:Leukocytes / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010587:Phagocytosis / Q000276:immunology; D011233:Precipitin Tests; D016897:Respiratory Burst / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000276:immunology
D000911:Antibodies, Monoclonal; D018821:CD18 Antigens; D013755:Tetradecanoylphorbol Acetate