DIFFERENT CLASSES OF PROTEOGLYCANS CONTRIBUTE TO THE ATTACHMENT OF BORRELIA-BURGDORFERI TO CULTURED ENDOTHELIAL AND BRAIN-CELLS

The Lyme disease spirochete, Borrelia burgdorferi, infects multiple ti ssues, such as the heart, joint, skin, and nervous system and has been shown to recognize heparan sulfate and dermatan sulfate proteoglycans . In this study, we examined the contribution of different classes of proteoglycans to the attachment of the infectious B. burgdorferi strai n N40 to several immortalized cell lines and primary cultured cells, i ncluding endothelial cells and brain cells. Bacterial attachment was i nhibited by exogenous proteoglycans or by treatment af host cells with inhibitors of proteoglycan synthesis or sulfation, indicating that pr oteoglycans play a critical role in bacterial binding to diverse cell types, Binding to primary bovine capillary endothelial cells or a huma n endothelial cell line was also inhibited fry digestion with heparina se or heparitinase but not with chondroitinase ABC. In contrast, bindi ng to glial cell-enriched brain cell cultures or to a neuronal cell li ne was inhibited by all three lyases. Binding of strain N40 to immobil ized heparin could be completely inhibited by dermatan sulfate, and co nversely, binding to dermatan sulfate could be completely blocked by h eparin. As measured by 50 % inhibitory dose, heparin was a better inhi bitor of binding than dermatan sulfate, regardless of whether the subs trate was heparin or dermatan sulfate. These results are consistent wi th the hypotheses that the species of proteoglycans recognized by B. b urgdorferi vary with cell type and that bacterial recognition of diffe rent proteoglycans is mediated by the same bacterial molecule(s).