Zhang Junjie, Li Gang, Liu Xiaoling, Wang Zengfu, Liu Wenjun, Ye Xin
Graduate University of Chinese Academy of Sciences, Beijing 100101, PR China.
Center for Molecular Immunology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
J Gen Virol. 2009 Nov;90(Pt 11):2751-2758. doi: 10.1099/vir.0.014316-0. Epub 2009 Aug 5.
The matrix (M1) protein of influenza A virus is a conserved multifunctional protein that plays essential roles in regulating the viral life cycle. This study demonstrated that M1 is able to interact with complement C1qA and plays an important inhibitory function in the classical complement pathway. The N-terminal domain of M1 protein was required for its binding to the globular region of C1qA. As a consequence, M1 blocked the interaction between C1qA and heat-aggregated IgG in vitro and inhibited haemolysis. It was shown that M1 protein prevented the complement-mediated neutralization of influenza virus in vitro. In addition, studies on mice indicated that the administration of M1 could promote a higher virus propagation rate in lung and shortened survival of mice infected with the virus. Taken together, these results suggest strongly that the M1 protein plays a critical role in protecting influenza virus from the host innate immune system.
甲型流感病毒的基质（M1）蛋白是一种保守的多功能蛋白，在调节病毒生命周期中发挥着重要作用。本研究表明，M1能够与补体C1qA相互作用，并在经典补体途径中发挥重要的抑制功能。M1蛋白的N端结构域是其与C1qA球状区域结合所必需的。因此，M1在体外阻断了C1qA与热聚集IgG之间的相互作用，并抑制了溶血。结果表明，M1蛋白在体外可防止补体介导的流感病毒中和。此外，对小鼠的研究表明，给予M1可促进病毒在肺中的更高传播率，并缩短感染病毒小鼠的存活时间。综上所述，这些结果强烈表明，M1蛋白在保护流感病毒免受宿主先天免疫系统攻击方面起着关键作用。
