Characterization of epitopes recognized by anti-Streptococcus mutans P1 monoclonal antibodies.

Sequences contributing to epitopes recognized by a panel of monoclonal antibodies (mAbs) against the Streptococcus mutans surface protein P1 were delineated by Western blot and enzyme-linked immunosorbent assay using a battery of deletion constructs and recombinant polypeptides. mAbs that recognize complex discontinuous epitopes reconstituted by combining the alanine-rich and proline-rich repeat domains and varying degrees of flanking sequence were identified as well as mAbs that bound epitopes contained within contiguous segments of P1. Cross-reactivity with SspA and SspB from Streptococcus gordonii is also reported. This information enables insight into the structure and function of a streptococcal adhesin and its correlates of protection and furthers our understanding of the immunomodulatory and bacterial-adherence inhibition activities of anti-P1 mAbs.