Shared actions of endotoxin and taxol on TNF receptors and TNF release
Receptors, Cell Surface
Tumor Necrosis Factor-alpha
Bacterial lipopolysaccharide (LPS) exerts profound effects on mammalian hosts in part by inducing macrophages to release tumor necrosis factor-alpha (TNF-alpha); the mechanisms involved are unresolved. The microtubule stabilizer taxol shared two actions of LPS on macrophages: it rapidly decreased TNF-alpha receptors and triggered TNF-alpha release. Both actions of taxol were absent in LPS-hyporesponsive C3H/HeJ mice. In recombinant inbred mice, the genes controlling responses to LPS and to taxol were closely linked. Dexamethasone blocked release of TNF-alpha by both stimuli but did not block the decrease in TNF-alpha receptors. Thus, a protein associated with microtubules may be a cellular target of LPS.