Interpretation of properdin levels determined by phage neutralization technique

THE FORMATION AND PROPERTIES OF POLIOVIRUS-NEUTRALIZING ANTIBODY. IV. NORMAL ANTIBODY AND EARLY IMMUNE ANTIBODY OF RABBIT ORIGIN: A COMPARISON OF BIOLOGICAL AND PHYSICOCHEMICAL PROPERTIES

Rabbit sera were found to possess neutralizing activity (normal antibody) to polioviruses and Coxsackie B viruses. This normal antibody showed high specificity in cross-neutralization and absorption tests. It was associated with heat-stable, mercaptan-sensitive, 19S γ₁-β-macroglobulins, which formed weak complexes with the viral antigen. In rare instances, sera with normal macroglobulin antibody, also contained very low activity which was due to 7S γ₂-globulins. The neutralization of poliovirus by normal 19S γ₁-β-antibody appeared to follow first order kinetics, and the thermodynamic parameters of this reaction were the same as those of serological reactions employing immune antibody. The electrophoretic mobility, sedimentation properties, sensitivity to mercaptan, thermostability, and avidity of normal and early (up to day 3) immune antibodies to poliovirus were similar, but differed in several respects from those of late immune antibodies. Thus, the available evidence suggested, that earlier reported differences between normal and immune antibodies reflected differences between antibodies of diverse physicochemical properties rather than between normal and immune antibodies per se. It is proposed that the normal macroglobulin antibody is associated with an immunological response to repeated stimulation with minute amounts of antigen.

Enhancement of resistance to infectious diseases by oral administration of brewer's yeast

The effect of oral administration of brewer's yeast on resistance to infectious diseases was studied in laboratory animals. It was shown that there was a significantly increased enhancement of resistance to seasonal respiratory and enteric infections in rhesus monkeys. Similarly, enhanced resistance to experimental chronic infections was observed in mice after yeast administration. A 2-week lag occurred between the initiation of yeast treatment and the expression of enhanced resistance. Study of the mechanism of the yeast-induced enhancement of resistance to infection leads to the conclusion that it is based on in vivo stimulation of phagocytosis, as measured by the "phagocytic index." No effect of brewer's yeast on circulating antibody levels was detected.