The roles of proteoglycans in the endothelial cell response to L. interrogans were tested based on previously published protocols [17] . Briefly, chondroitin sulfate B was shown to bind L. interrogans and to competitively inhibit L. interrogans to mammalian cells, so it was tested for the ability to inhibit the endothelial cell responses to the bacteria described below. In addition, inhibition of proteoglycan synthesis by b-xyloside, which also decreases L. interrogans attachment to mammalian cells, was tested for any effect. Controls included chondroitin sulfate A, to which L. interrogans does not bind, and the sugar analog a-galactoside, which does not affect proteoglycan synthesis.