Effect of monoclonal antibodies to the attachment-tip on experimental Mycoplasma pneumoniae infection of hamsters. A preliminary report.

Mycoplasma pneumoniae, an important human pathogen, is an extra-cellular parasite, colonizing mucosal surfaces. Attachment to epithelial cells of the host is therefore an important mechanism of pathogenicity, and inhibition of adhesion might protect the host. M. pneumoniae predominantly adheres with a special organelle, the attachment-tip, to host cells. In vitro studies confirmed the observation that monoclonal antibodies (MOAB) to the tip inhibited adherence to erythrocytes. In animal experiments, high numbers of virulent M. pneumoniae exposed for 4 h at 37 C to MOAB and kept in suspension with MOAB 1:100 were inoculated intranasally into hamsters. A significant reduction in the lung lesion score, but not in the numbers of organisms in lung tissue or wash fluid of the upper respiratory tract, was seen in hamsters 14 days after inoculation of MOAB-treated organisms, as compared with controls. These observations, although preliminary, may have implications for the understanding of pathogenesis and for vaccine development.