perhexiline-maleate and margatoxin

Peptidoglycans (PGN) from bacterial cell walls may modify the course of an infection with bacterial pathogens. The present study explored the effect of PGN on cytosolic Ca2+ activity, cytokine production and phagocytosis of mouse dendritic cells (DCs), essential cells in the initiation and direction of antigen-specific T cell responses. Exposure of DCs to PGN was followed by a rapid increase in cytosolic Ca2+ activity ([Ca2+]i), which was due to Ca2+ release from intracellular stores and influx of extracellular Ca2+ across the cell membrane. In DCs isolated from Toll-like receptor 2 (TLR2) deficient mice the effect of PGN on [Ca2+]i was dramatically impaired. The PGN-induced increase of [Ca2+]i was dependent on voltage-gated K+ (Kv) channel activity. PGN-induced increase of [Ca2+]i was significantly blunted by margatoxin (MgTx) and perhexiline maleate (PM), inhibitors of Kv1.3 and Kv1.5, respectively. PGN further stimulated the release of tumour necrosis factor alpha (TNFalpha), interleukin-12 (IL-12) and interleukin-10 (IL-10), an effect significantly blunted by PM and the specific blocker of store-operated Ca2+ channels SKF-96365. Moreover, phagocytic capacity was dramatically increased in PGN-stimulated DCs in the presence of either Kv channel inhibitors or SKF-96365. The observations disclose Ca2+ and Kv channel-dependent cytokine production and phagocytosis in PGN-stimulated DCs.

Topics: Animals; Calcium; Calcium Channel Blockers; Cells, Cultured; Cytokines; Dendritic Cells; Dose-Response Relationship, Drug; Drug Combinations; Electrophysiology; Female; Femur; Fluorescent Dyes; Fura-2; Imidazoles; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Neurotoxins; Patch-Clamp Techniques; Peptidoglycan; Perhexiline; Phagocytosis; Potassium Channels, Voltage-Gated; Scorpion Venoms; Staphylococcus aureus; Tibia; Toll-Like Receptor 2