Stoeckle Christina, Gouttefangeas Cécile, Hammer Michael, Weber Ekkehard, Melms Arthur, Tolosa Eva
Department of General Neurology, Hertie Institute for Clinical Brain Research, Tuebingen, Germany.
Exp Hematol. 2009 Feb;37(2):266-75. doi: 10.1016/j.exphem.2008.10.011. Epub 2008 Dec 18.
Cathepsin W (CatW, lymphopain) is a putative cysteine protease with restricted expression to natural killer (NK) cells and CD8(+) T cells and so far unknown function and properties. Here, we characterize in detail, the regulation of human CatW during T-cell development in response to different stimuli and its functional involvement in cytotoxic lymphocyte effector function.
Western blots and real time polymerase chain reaction of sorted, unstimulated, and stimulated cell subsets (thymocytes, T cells, NK cells) and their culture supernatants were used to study regulation and expression of CatW. Primary CD8(+) T cells and short-term T-cell lines were transfected with small interfering RNA to study the involvement of CatW in effector function such as target cell killing and interferon-gamma production.
Levels of CatW expression correlate closely with cytotoxic capacity both during development and in response to factors influencing cytotoxicity. Furthermore, CatW is secreted during specific target cell killing. However, knockdown of CatW expression by small interfering RNA neither influences target cell killing nor interferon-gamma production.
Despite being expressed in the effector subset of CD8(+) and NK cells and of being released during target cell killing, our functional inhibition studies exclude an essential role of CatW in the process of cytotoxicity.
组织蛋白酶W（CatW，淋巴细胞蛋白酶）是一种推测的半胱氨酸蛋白酶，其表达局限于自然杀伤（NK）细胞和CD8(+) T细胞，目前其功能和特性尚不清楚。在此，我们详细阐述了人类CatW在T细胞发育过程中对不同刺激的反应调节及其在细胞毒性淋巴细胞效应功能中的作用。
采用蛋白质免疫印迹法和实时聚合酶链反应，对分选的、未刺激的和刺激后的细胞亚群（胸腺细胞、T细胞、NK细胞）及其培养上清液进行检测，以研究CatW的调节和表达。用小干扰RNA转染原代CD8(+) T细胞和短期T细胞系，以研究CatW在诸如杀伤靶细胞和产生γ干扰素等效应功能中的作用。
在发育过程中以及对影响细胞毒性的因子作出反应时，CatW的表达水平与细胞毒性能力密切相关。此外，在特异性杀伤靶细胞的过程中CatW会分泌出来。然而，用小干扰RNA敲低CatW的表达既不影响靶细胞杀伤，也不影响γ干扰素的产生。
尽管CatW在CD8(+)和NK细胞的效应亚群中表达，并在杀伤靶细胞的过程中释放，但我们的功能抑制研究排除了CatW在细胞毒性过程中的关键作用。
