Complement Components on the Surface of Normal Human Lymphocytes

The presence of complement components Clq, C4, C3 and C3 activator is demonstrated on human lymphocytes from peripheral blood of healthy subjects. The methods employed are double layer immunofluorescence technique and cytophoto-metry. Furthermore, simultaneous detection of immunoglobulin and complement components has been possible. An amount of 10–25 % of the isolated lymphocytes showed presence of complement components, distributed in a manner comparable to immunoglobulins on the surface of the lymphocytes. The simultaneous double marking technique revealed an invariable co-occurrence of immunoglobulins and complement components on the lymphocytes. This study may indicate that the cytotoxicity of the B lymphocytes resembles the cytotoxical actions of the humoral immune system.