Naturally Occurring Human Antibodies to Streptococcal Enzymes*

Abstract

The present report is concerned with naturally occurring precipitating human antibodies to enzymes, in contrast to the other papers in this conference which have largely dealt with antibodies to enzymes developed by active immunization of animals. The human antibody-enzyme systems were encountered during an analysis of streptococcal infections by immunodiff usion technics.1-1lIt has long been known that streptococci can secrete an array of enzymes, e.g., hyaluronidase, desoxyribonuclease, proteinase, ribonuclease, lipoproteinase, and diphosphopyridine nu~leotidase.l~-~7 However, the discovery of these streptococcal enzymes and other antigens has been on a chance basis until recently. The development of immunodiffusion technics has opened the way for a rational analysis of the total number of antigens released by the organisms in vivo, as reflected by the number of antibody responses detected. With such an approach, the sera of patients with streptococcal disease have been found to contain numerous antibodies to extracellular streptococcal products, but to contain few if any to cellular components from the same strain.l~2JsJ9 Even patients without recent history of streptococcal disease were shown to contain variable, but usually small numbers of precipitating antibodies to the same extracellular antigens. Tests then made with pooled and concentrated normal human gamma globulinf solutions revealed that it was extraordinarily rich in such anti-streptococcal antibodies. An immunoelectrophoretic test of crude culture supernate concentrates of group A streptococcal growth against human gamma globulin revealed at least 20 extracellular products which must have been secreted in vivo.6 An example of these findings is shown in FIGURE 1, a1 and a2, in which two different culture concentrates from the C203S group A streptococcal strain and a group C streptococcal concentrate were separated electrophoretically, and then exposed to the antibodies in pooled human gamma globulin. In FIGURE l b is shown a diagrammatic representation of the results obtained with the crude streptococcal concentrate which was used as a reference standard system. The reproducibility of the general patterns observed was quite great, and high concentrations of the culture concentrates appeared essential.