Abstract
We partially characterized the interaction between 125I-labeled surface proteins of Staphylococcus aureus, obtained by thermal extraction, and purified plasma membranes from uninfected and influenza virus A/FM/1/47-infected Madin-Darby canine kidney cells. The radioactivity profile of surface-labeled proteins, derived from anion-exchange high-pressure liquid chromatography, showed a mixture of acidic polypeptides in a peak which contained approximately 5% of the total protein injected; adsorption with purified plasma membranes reduced radioactivity by 5 to 7% and altered elution profiles. Using a direct adhesin overlay procedure, we found that these surface-labeled proteins reacted with polypeptides located on the external surface of plasma membranes which were shared by both virus-infected and uninfected cells or were unique to virus-infected cells. Our data may help explain the enhanced adherence of S. aureus to influenza virus A-infected cells in vitro.