Inhibition of Mycoplasma pneumoniae hemadsorption and adherence to respiratory epithelium by antibodies to a membrane protein

Antiserum and purified immunoglobulin directed against Mycoplasma pneumoniae membrane protein P1 were examined for their influence on mycoplasma viability, metabolism, and cytadsorption. Anti-P1 immunoglobulin inhibited adherence of M. pneumoniae to hamster tracheal rings in vitro by up to 80% and inhibited hemadsorption by greater than 90%. Cytadsorption was also inhibited by anti-P1 Fab fragments. Anti-P1 antibodies had no effect on M. pneumoniae viability or metabolism. The data indicate that anti-P1 antibody obstructs the interaction of M. pneumoniae adhesin P1 with its host receptors.