Common antigens of stable L-forms of group A streptococcus and human myocardial muscle fibers

Abstract

Common antigenic features of stable streptococcal L-forms and of the cytoplasmic membrane of muscle fibers of the human myocardium were demonstrated by an immunofluorescence method. The common antigen is a component of the surface membrane of the muscle cell, adjacent to the sarcolemmal sheath, and of the membranes of the transverse tubules of the macroplasmic reticulum, which pass through the sarcomeres of the muscle fiber in the zone of the L-disks. The reaction was completely prevented by exhaustion of the antiserum against antigen of L-forms by means of a human myocardial tissue homogenate or a suspension of cultures of L-forms grown on a meat or casein medium. Exhaustion with a tissue homogenate of other organs (liver) or with concentrated nutrient medium had virtually no effect on the intensity of the reaction. In the authors' view, the presence of common antigens in cultures of stable L-forms of group A streptococcus and the myocardium may be one cause of the long persistence of L-forms in the human and animal body.