Cutting edge: Inflammatory signaling by Borrelia burgdorferi lipoproteins is mediated by toll-like receptor 2

The agent of Lyme disease, Borrelia burgdorferi, produces membrane lipoprot eins possessing potent inflammatory properties linked to disease pathology. The recent association of toll-like receptors (TLR) 2 and 4 with LPS respo nses prompted the examination of TLR involvement in lipoprotein signaling, The ability of human cell lines to respond to lipoproteins was correlated w ith the expression of TLR2, Transfection of TLR2 into cell lines conferred responsiveness to lipoproteins, lipopeptides, and sonicated B. burgdorferi, as measured by nuclear translocation of NP-KB and cytokine production, The physiological importance of this interaction was demonstrated by the 10-fo ld greater sensitivity of TLR2-transfected cells to lipoproteins than LPS, Futhermore, TLR2-dependant signaling by lipoproteins was facilitated by CD1 4, These data indicate that TLR2, facilitates the inflammatory events assoc iated with Lyme arthritis, In addition, the widespread expression of lipopr oteins by other bacterial species suggests that this interaction may have b road implications in microbial inflammation and pathogenesis.