Activation specificity of commonly employed mitogens for canine B- and T-lymphocytes

Six day in vitro cultures of canine mononuclear leukocytes with or without prior carbonyl iron depletion were established with 5 commonly employed mitogens. Cultures were assessed for B-cell differentiation by induction of cytoplasmic and supernatant released IgG, M and A and T-cell differentiation by expression of Thy-1 antigen on the cell surface of lymphoblasts. The mitogen concanavalin A was shown to be a restricted T-cell mitogen, whereas pokeweed mitogen and protein A from Staphylococcus aureus stimulated maximal B-cell differentiation. These data establish the mitogenic specificity for canine lymphocytes in unfractionated peripheral blood leukocyte cultures and will permit an in vitro evaluation of various substances upon T- and B-lymphocyte functions.