Sedelies Karin A, Sayers Thomas J, Edwards Kirsten M, Chen Weisan, Pellicci Daniel G, Godfrey Dale I, Trapani Joseph A
Cancer Immunology Laboratory, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, East Melbourne, 8006, Australia.
J Biol Chem. 2004 Jun 18;279(25):26581-7. doi: 10.1074/jbc.M312481200. Epub 2004 Apr 6.
We analyzed the expression of granzyme H in human blood leukocytes, using a novel monoclonal antibody raised against recombinant granzyme H. 33-kDa granzyme H was easily detected in unfractionated peripheral blood mononuclear cells, due to its high constitutive expression in CD3(-)CD56(+) natural killer (NK) cells, whereas granzyme B was less abundant. The NK lymphoma cell lines, YT and Lopez, also expressed high granzyme H levels. Unstimulated CD4(+) and particularly CD8(+) T cells expressed far lower levels of granzyme H than NK cells, and various agents that classically induce T cell activation, proliferation, and enhanced granzyme B expression failed to induce granzyme H expression in T cells. Also, granzyme H was not detected in NK T cells, monocytes, or neutrophils. There was a good correlation between mRNA and protein expression in cells that synthesize both granzymes B and H, suggesting that gzmH gene transcription is regulated similarly to gzmB. Overall, our data indicate that although the gzmB and gzmH genes are tightly linked, expression of the proteins is quite discordant in T and NK cells. The finding that granzyme H is frequently more abundant than granzyme B in NK cells is consistent with a role for granzyme H in complementing the pro-apoptotic function of granzyme B in human NK cells.
我们使用针对重组颗粒酶H产生的新型单克隆抗体，分析了颗粒酶H在人血白细胞中的表达。由于其在CD3(-)CD56(+)自然杀伤（NK）细胞中的高组成性表达，在未分离的外周血单核细胞中很容易检测到33 kDa的颗粒酶H，而颗粒酶B的含量较少。NK淋巴瘤细胞系YT和Lopez也表达高水平的颗粒酶H。未刺激的CD4(+)尤其是CD8(+) T细胞表达的颗粒酶H水平远低于NK细胞，并且经典诱导T细胞活化、增殖和增强颗粒酶B表达的各种试剂未能诱导T细胞中颗粒酶H的表达。此外，在NK T细胞、单核细胞或中性粒细胞中未检测到颗粒酶H。在同时合成颗粒酶B和H的细胞中，mRNA和蛋白质表达之间存在良好的相关性，表明gzmH基因转录的调控与gzmB相似。总体而言，我们的数据表明，尽管gzmB和gzmH基因紧密相连，但蛋白质在T细胞和NK细胞中的表达差异很大。颗粒酶H在NK细胞中通常比颗粒酶B更丰富这一发现，与颗粒酶H在补充人NK细胞中颗粒酶B的促凋亡功能方面的作用一致。
