Study on streptococcus group A antigens common with heart tissue elements.

Four different cross-reactive antigens were revealed in cultures of group A streptococci by immunoelectrophoresis using antistreptococcal sera unabsorbed, or absorbed with homogenates of rabbit heart tissue. Preliminary study of these sera by immunofluorescence showed that they react with different elements of the myocardium. The hypothesis is suggested that the biological (immunizing) action of microbial cross-reactive antigens depends on the presence or absence of immunological tolerance to these antigens in the individual immunized. The mechanism of autoantibody formation by immunization with such common antigens is discussed.