Dendritic cells do not transduce inflammatory stimuli via the capsaicin receptor TRPV1.
Inflammatory stimuli provide critical activation signals for dendritic cells (DC). Signaling through the capsaicin receptor TRPV1 is reported to initiate DC maturation and migration. We attempted to characterize TRPV1 channels in DC. Capsaicin or extracellular protons failed to elicit a change in intracellular [Ca(2+)] or membrane current in DC. In contrast, capsaicin evoked a sustained increase in [Ca(2+)] and large inwards currents in sensory neurons and TRPV1-expressing HEK293 cells. TRPV1 expression was confirmed by RT-PCR in sensory neurons, but was undetectable in DC. Interestingly, and in contrast to capsaicin, the inflammatory neuropeptide substance P evoked Ca(2+) transients in DC. Thus, our data do not support the hypothesis that DC express TRPV1 channels. Rather, signaling through TRPV1 in sensory nerves may modulate DC via neurogenic actions.
O'Connell
Peta J
PJ
Robarts Research Institute, 100 Perth Drive, P.O. Box 5015, London, Ont., Canada N6A 5K8. peta@robarts.ca
Pingle
Sandeep C
SC
Ahern
Gerard P
GP
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000378:metabolism; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018408:Patch-Clamp Techniques; D051381:Rats; D015398:Signal Transduction / Q000502:physiology*; D013373:Substance P / Q000378:metabolism; D050916:TRPV Cation Channels
D007473:Ion Channels; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D013373:Substance P; D002211:Capsaicin; D002118:Calcium