Quantitative binding of Fc-receptors, and antibody-dependent cell-mediated cytotoxicity of blood lymphocytes in healthy and chronic lymphocytic leukemic cattle.

The binding capacity of Fc-receptors for IgG of blood lymphocytes was studied in healthy cattle and cattle with chronic lymphocytic leukemia before and after incubation at 37 degrees C in basal Eagle's medium without serum. It was found that lymphocytes of leukemic cattle possess twice the amount of Fc-receptors found in normal lymphocytes. The changes in the binding capacity of Fc-receptors for IgG of normal and leukemic lymphocytes correlated with those of antibody-dependent cell-mediated cytotoxicity (ADCC) of the corresponding lymphocytes. The lower ADCC of leukemic lymphocytes in comparison with normal ones was accompanied by a lower association constant of the leukemic lymphocyte Fc-receptors towards IgG.