The M1 and M2 proteins of influenza A virus are important determinants in filamentous particle formation
The M1 and M2 proteins of influenza A virus are important determinants in filamentous particle formation
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DOI：
10.1006/viro.1997.8916
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发表时间：
1998-01-05
期刊：
影响因子：
3.7
通讯作者：
Compans, RW
中科院分区：
文献类型：
--
作者：
Roberts, PC;Lamb, RA;Compans, RW
甲型流感病毒是高度多形性的，具有呈现球形或丝状形态的颗粒。这种多态性背后的机制及其在病毒发病机制中的重要性还不清楚。我们已经观察到，通过免疫荧光显微镜可以很容易地观察到丝状流感A/Udorn病毒颗粒的出芽。用抗M2 14 C2抗体处理细胞可抑制丝状体颗粒形成，但同种型相同的5C 4抗M2抗体或抗神经氨酸酶抗体不抑制丝状体颗粒形成。为了进一步探索丝状颗粒形成的病毒决定因素，我们研究了A/Udorn/72病毒的三种变体的形态和生长特征，这些变体先前已被选择为对14 C2抗M2单克隆抗体的生长抑制具有抗性。两种变异病毒5A和10A在M2蛋白质的胞质结构域中含有单个氨基酸取代，而1A变异体在病毒基质蛋白M1中含有单个氨基酸取代。发现变体5A和10A都保留了在亲本菌株A/Udorn/72中发现的丝状颗粒表型，并且两种变体产生的丝状病毒体对14 C2抗体的抑制具有抗性。然而，免疫荧光和电子显微镜显示，变体1A几乎完全由球形颗粒组成。与丝状病毒相比，1A变体显示出更高的病毒产量和更大的噬斑尺寸。此外，我们通过速度梯度离心分离高度富集球形或丝状颗粒的不同群体。这些颗粒的蛋白质组合物的分析表明，在丝状颗粒的NP：M1或NP：HA的比例显着低于球形颗粒，但细丝具有较高的NP/颗粒的水平。球形和丝状颗粒被发现具有相似的特异性感染性。这些结果表明，A/Udorn病毒的丝状形态取决于基质（M1）和/或M2蛋白。(C)北京：科学出版社.
Influenza A virus is highly pleomorphic with particles exhibiting either spherical or filamentous morphology. The mechanisms behind this pleomorphism and its importance in viral pathogenesis are not clearly understood. We have observed that budding of filamentous influenza A/Udorn virus particles can be readily visualized by immunofluorescence microscopy. Filamentous particle formation was inhibited by treatment of cells with the anti-M2 14C2 antibody, but was not inhibited with the isotype identical 5C4 anti-M2 antibody or by anti-neuraminidase antibody. To further explore the viral determinants of filamentous particle formation, we investigated the morphology and growth characteristics of three variants of A/Udorn/72 virus, which had previously been selected for their resistance to growth inhibition by the 14C2 anti-M2 monoclonal antibody. Two of the variant viruses, 5A and 10A, contain single amino acid substitutions in the cytoplasmic domain of the M2 protein, whereas the 1A variant contains a single amino acid substitution in the viral matrix protein, M1. Variants 5A and 10A both were found to retain the filamentous particle phenotype found in the parental strain A/Udorn/72, and the production of filamentous virions by both variants was resistant to inhibition by the 14C2 antibody. However, immunofluorescence and electron microscopy revealed that the variant 1A was composed almost exclusively of spherical particles. The 1A variant displayed higher viral yields and a larger plaque size than the filamentous viruses. In addition, we separated distinct populations highly enriched in spherical or filamentous particles by velocity gradient centrifugation. Analysis of the protein compositions of these particles revealed that the NP:M1 or NP:HA ratios in filamentous particles were significantly lower than in spherical particles, but the filaments have higher levels of NP per particle. The spherical and filamentous particles were found to have similar specific infectivity. These results indicate that the filamentous morphology of the A/Udorn virus depends upon the matrix (M1) and/or M2 proteins. (C) 1998 Academic Press.