LAMININ-BINDING EPITOPE ON GP43 FROM PARACOCCIDIOIDES-BRASILIENSIS ISRECOGNIZED BY A MONOCLONAL-ANTIBODY RAISED AGAINST STAPHYLOCOCCUS-AUREUS LAMININ RECEPTOR

Adhesion is regarded as an important step in the pathogenesis of sever al microorganisms. Thus, the ability to recognize extracellular matrix proteins, such as laminin or fibronectin, has been correlated with in vasiveness. Studying the already characterized laminin-binding protein of Paracoccidioides brasiliensis, the 43 kDa glycoprotein (gp43), we evaluated whether MAb 1.H12, raised against the laminin-binding protei n from Staphylococcus aureus, cross-reacts with that fungal protein. B y immunoblot analysis we show that MAb 1.H12 recognizes gp43. This int eraction is able to inhibit the laminin-mediated adhesion to epithelia l cells as well as the P. brasiliensis infection in vitro. Moreover, t hrough immunoenzymatic assays, we show that MAb 1.H12 recognizes gp43 in solid phase and that this interaction is partially inhibited by the addition of anti-gp43 MAbs. These results show that MAb 1.H12 recogni zes the gp43, suggesting the presence of an epitope similar to those f ound in the other laminin-binding proteins from phylogenetically very distant cells. These findings reinforce the possibility of evolutionar y conservation of such epitopes.