Article

CD39 is the dominant Langerhans cell-associated ecto-NTPDase: modulatory roles in inflammation and immune responsiveness.

Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Nature Medicine (Impact Factor: 28.05). 05/2002; 8(4):358-65. DOI: 10.1038/nm0402-358
Source: PubMed

ABSTRACT CD39, the endothelial ecto-nucleoside triphosphate diphosphohydrolase (NTPDase), regulates vascular inflammation and thrombosis by hydrolyzing ATP and ADP. Although ecto-NTPDase activities have been used as a marker of epidermal dendritic cells (DCs) known as Langerhans cells, the identity and function of these activities remain unknown. Here we report that Langerhans cells in CD39-/- mice express no detectable ecto-NTPDase activity. Irritant chemicals triggered rapid ATP and ADP release from keratinocytes and caused exacerbated skin inflammation in CD39-/- mice. Paradoxically, T cell-mediated allergic contact hypersensitivity was severely attenuated in CD39-/- mice. As to mechanisms, T cells increased pericellular ATP concentrations upon activation, and CD39-/- DCs showed ATP unresponsiveness (secondary to P2-receptor desensitization) and impaired antigen-presenting capacity. Our results show opposing outcomes of CD39 deficiency in irritant versus allergic contact dermatitis, reflecting its diverse roles in regulating extracellular nucleotide-mediated signaling in inflammatory responses to environmental insults and DC-T cell communication in antigen presentation.

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