Girolomoni G, Santantonio M L, Bergstresser P R, Cruz P D, Giannetti A
Department of Dermatology, University of Modena, Italy.
J Invest Dermatol. 1992 Nov;99(5):18S-19S. doi: 10.1111/1523-1747.ep12668253.
Epidermal Langerhans cells (LC) possess a plasma membrane Mg(++)- or Ca(++)-dependent ecto-ATPase (mATPase), the function of which is not known. On the other hand, extracellular ATP (ATPo) has been shown to cause a rapid increase in cell-membrane permeability for selected cells, thus inducing the entry of exogenous substances, leading eventually to cell death. ATPo has also been shown to be a mediator of T cell-mediated cytotoxicity. We have observed human LC to be resistant to the permeabilizing effects of ATPo when compared to cultured human keratinocytes and J774 macrophages. In addition, our preliminary evidence in vitro suggests that mATPase on LC may provide protection against the lytic effects of ATPo. Finally, we propose that this latter mechanism may also operate in vivo.
表皮朗格汉斯细胞（LC）具有一种质膜镁离子（Mg²⁺）或钙离子（Ca²⁺）依赖性外切ATP酶（mATPase），其功能尚不清楚。另一方面，细胞外ATP（ATPo）已被证明可使某些细胞的细胞膜通透性迅速增加，从而诱导外源性物质进入，最终导致细胞死亡。ATPo还被证明是T细胞介导的细胞毒性的介质。与培养的人角质形成细胞和J774巨噬细胞相比，我们观察到人类LC对ATPo的通透作用具有抗性。此外，我们的体外初步证据表明，LC上的mATPase可能提供针对ATPo裂解作用的保护。最后，我们提出后一种机制在体内也可能起作用。
