Studies on the bactericidal action of normal serum and the properdin system. II. With special reference to immuno-electrophoretic analysis

Abstract

The purpose of the present investigation was to clarify the nature of normal antibody responsible for the bactericidal activity of normal serum mainly against Gram-negative bacilli, as comparing with properdin, a new bactericidal entity in serum, reported by Pillemer et al.Properdin-zymosan or normal antibody-organism complexes were respectively prepared by the absorption of normal serum with zymosan, Sh. dysenteriae 1 and Sal. typhosa 0-901 W at the defined temperatures. These complexes were placed in the reservoirs of agar gel in a barbital buffer, pH 8.2, ionic strength 0.05, and then the immunoelectrophoresis was performed. The obtained results were as follows.1. Both of the normal antibody and properdin of human serum were demonstrated as a single precipitin arcs at β1-globulin position; those of rabbit serum at α2, p1-globulin position. It was, furthermore, shown that normal antibody is substantially different from properdin.2. By means of the mutual absorption of rabbit serum with Sal. typhosa and Sh. dysenteriae, the precipitin arcs of the normal antibodies against these bacteria were individually observed at the same position of α2, β1-globulin. Accordingly, it may be taken to indicate that normal antibodies against enteric bacteria posses a marked specifity, in contrast with properdin which is non specific.3. The precipitin arcs of the immune antibodies against zymosan and Sh. dysenteriae, on the other hand, were clearly observed at the γ-globulin position. The above-mentioned findings suggest that normal antibody and properdin, in substance, differ from so-called immune antibody.