Expression of plasminogen activator Pla of Yersinia pestis enhances bacterial attachment to the mammalian extracellular matrix

The effect of the plasminogen activator Pla of Yersinia pestis on the adhes iveness of bacteria to the mammalian extracellular matrix was determined. Y . pestis KIM D27 harbors the 9.5-kb plasmid pPCP1, encoding Pla and pestici n; the strain efficiently adhered to the reconstituted basement membrane pr eparation Matrigel, to the extracellular matrix prepared from human lung NC I-H292 epithelial cells, as well as to immobilized laminin. The isogenic st rain Y. pestis KIM D34 lacking pPCP1 exhibited lower adhesiveness to both m atrix preparations and to laminin. Both strains showed weak adherence to ty pe I, IV, and V collagens as well as to human plasma and cellular fibronect in. The Pla-expressing recombinant Escherichia coli LE392(pC4006) exhibited specific adhesiveness to both extracellular matrix preparations as well as to laminin. The Pla-expressing strains showed a low-affinity adherence to another basement membrane component, heparan sulfate proteoglycan, but not to chondroitin sulfate proteoglycan. The degradation of radiolabeled lamini n, heparan sulfate proteoglycan, or human lung extracellular matrix by the Pla-expressing recombinant E. coli required the presence of plasminogen, an d degradation was inhibited by the plasmin inhibitors aprotinin and alpha 2 -antiplasmin. Our results indicate a function of Pla in enhancing bacterial adhesion to extracellular matrices. Y. pestis also exhibits a low level of Pla-independent adhesiveness to extracellular matrices.