Direct Evidence for Involvement of NF-κB in Transcriptional Activation of Tumor Necrosis Factor by a Spirochetal Lipoprotein

Variable major lipoprotein (Vmp) is a major tumor necrosis factor (TNF)-inducing component of Borrelia recurrentis, the agent of louse-borne relapsing fever. B. recurrentis Vmp rapidly stimulates nuclear translocation of NF-κB and proinflammatory cytokine gene expression in the human monocyte-like cell line MonoMac 6. By overexpressing disabled mutant IκBα in MonoMac 6 cells cotransfected with a reporter gene, we provide evidence that NF-κB is essential for the transcriptional activation of TNF in this system.