Anti-Mycoplasma pneumoniae secretory antibody in human breast milk.

The secretory antibody responses to M. pneumoniae polypeptides were assessed among human breast milk samples. M. pneumoniae polypeptides were resolved with conventional SDS-PAGE, and antibody responses were determined by immunoblotting. Antibodies that contained secretory component were found to recognize antigens of 200, 185, 170, 150, 135, 92, 85, 60, 43, 27, and 24 kDa (M(r)). Among the latter, antigens of 170, 150, 60, and 43 kDa were recognized from the majority. Although these antibody binding sites parallel those that are also generally recognized by human sera when equivalent antigen is used, the high frequency (80%) of 150 kDa antigen recognition is not common for serum responses. This antigen should be further explored for its potential in future assessments of component vaccines.