Antiviral cytokines induce hepatic expression of the granzyme B inhibitors, proteinase inhibitor 9 and serine proteinase inhibitor 6
Antiviral cytokines induce hepatic expression of the granzyme B inhibitors, proteinase inhibitor 9 and serine proteinase inhibitor 6
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DOI：
10.4049/jimmunol.172.10.6453
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发表时间：
2004-05-15
影响因子：
4.4
通讯作者：
Thiele, DL
中科院分区：
文献类型：
--
作者：
Barrie, MB;Stout, HW;Thiele, DL
颗粒酶B抑制剂、人蛋白酶抑制剂9（PI-9）或鼠直向同源物丝氨酸蛋白酶抑制剂6（SPI-6）的表达通过穿孔素和颗粒酶依赖性效应器机制赋予对CTL或NK杀伤的抗性。鉴于先前的研究表明，病毒感染的肝细胞选择性地抵抗这种CTL效应机制，本研究调查了PI-9和SPI-6在肝细胞和肝癌细胞中的表达，以响应腺病毒感染和抗病毒免疫应答过程中产生的细胞因子。在未感染的鼠或人肝细胞中，通过免疫印迹法均未检测到PI-9和SPI-6的表达。类似地，发现人Huh-7肝癌细胞仅表达非常低水平的PI-9，相对于在穿孔素和颗粒酶抗性CTL或淋巴因子激活的杀伤细胞中检测到的水平。在体内腺病毒感染或体外培养IFN-α或IFN-γ后，在鼠肝细胞中诱导SPI-6表达。类似地，在用IFN-α培养后，在人肝细胞和Huh-7细胞中观察到PI-9 mRNA和蛋白表达的诱导。IFN-γ和TNF-α还诱导Huh-7细胞中PI-9 mRNA表达水平升高4至10倍，而编码相关丝氨酸蛋白酶抑制剂蛋白酶抑制剂8的mRNA水平不受Huh-7细胞与IFN-α、IFN-γ或TNF-α培养物的影响。这些发现表明，促进抗病毒细胞病变反应的细胞因子也调节细胞保护分子PI-9和SPI-6在肝细胞中的表达，这是CTL和NK效应机制的潜在靶点。
Expression of the granzyme B inhibitors, human proteinase inhibitor 9 (PI-9), or the murine orthologue, serine proteinase inhibitor 6 (SPI-6), confers resistance to CTL or NK killing by perforin- and granzyme-dependent effector mechanisms. In light of prior studies indicating that virally infected hepatocytes are selectively resistant to this CTL effector mechanism, the present studies investigated PI-9 and SPI-6 expression in hepatocytes and hepatoma cells in response to adenoviral infection and to cytokines produced during antiviral immune responses. Neither PI-9 nor SPI-6 expression was detected by immunoblotting in uninfected murine or human hepatocytes. Similarly, human Huh-7 hepatoma cells were found to express only very low levels of PI-9 relative to levels detected in perforin- and granzyme-resistant CTL or lymphokine-activated killer cells. Following in vivo adenoviral infection or in vitro culture with IFN-alphabeta or IFN-gamma, SPI-6 expression was induced in murine hepatocytes. Similarly, after culture with IFN-alpha, induction of PI-9 mRNA and protein expression was observed in human hepatocytes and Huh-7 cells. IFN-gamma and TNF-alpha also induced 4- to 10-fold higher levels of PI-9 mRNA expression in Huh-7 cells, whereas levels of mRNA encoding a related serine proteinase inhibitor, proteinase inhibitor 8, were unaffected by culture of Huh-7 cells with IFN-alpha, IFN-gamma, or TNF-alpha. These findings indicate that cytokines that promote antiviral cytopathic responses also regulate expression of the cytoprotective molecules, PI-9 and SPI-6, in hepatocytes, that are potential targets of CTL and NK effector mechanisms.