Crecelius D M, Deom C M, Schulze I T
Virology. 1984 Nov;139(1):164-77. doi: 10.1016/0042-6822(84)90337-4.
Chick embryo fibroblast (CEF)-grown stocks of the WSN strain of influenza A(HINI) contain two variants which were designated F and C for fuzzy and clear plaque morphology on Madin-Darby bovine kidney (MDBK) cells. During growth in MDBK cells plaque-isolated F virus was completely replaced by C virus (L. Noronha-Blob and I.T. Schulze (1976), Virology 69, 314-322). The parental (F) and the mutant (C) viruses contain hemagglutinins which differ in their ability to bind to host cells. In addition, the host cells from which the purified viruses are obtained affect their binding properties. Thus, as compared to MDBK-grown F virus (FBK), MDBK-grown C virus (CBK) produced high amounts of mRNA and high virus yields in MDBK cells. CBK had greater affinity for SA alpha 2,3Gal and SA alpha 2,6Gal linkages on derivatized human erythrocytes than did FBK, independent of whether neuraminidase was present on the virions. CBK was also resistant to components of calf serum which inhibited FBK hemagglutination at 37 degrees. As compared to FBK, CBK had increased ability to bind to both MDBK cells and CEF at 37 degrees in the presence or absence of an inhibitor of neuraminidase. In addition, when cells with virus bound at 0 degrees were transferred to 37 degrees, CBK remained cell associated whereas about 80% of FBK dissociated from both cells. Thus, mutation from F to C increased the ability of the virus to associate with MDBK cell receptors. Studies carried out with F and C viruses from both cells indicated that the expression of the mutation depended in part on the host cells in which the virus was grown and in part on the cells used to measure the binding properties. A model relating these observations to selection of HA variants in nature is presented.
在鸡胚成纤维细胞（CEF）中培养的甲型流感病毒（H1N1）WSN株含有两种变体，因其在马-达二氏牛肾（MDBK）细胞上形成模糊和清晰的蚀斑形态而分别命名为F和C。在MDBK细胞中生长时，蚀斑分离的F病毒完全被C病毒取代（L.诺罗尼亚-布洛布和I.T.舒尔茨（1976年），《病毒学》69卷，314 - 322页）。亲代（F）病毒和突变体（C）病毒所含的血凝素在与宿主细胞结合的能力上有所不同。此外，获得纯化病毒的宿主细胞会影响其结合特性。因此，与在MDBK细胞中培养的F病毒（FBK）相比，在MDBK细胞中培养的C病毒（CBK）在MDBK细胞中产生大量mRNA和高病毒产量。CBK对衍生化人红细胞上的唾液酸α2,3半乳糖和唾液酸α2,6半乳糖连接键的亲和力比FBK更高，这与病毒粒子上是否存在神经氨酸酶无关。CBK对小牛血清中的成分也具有抗性，这些成分在37℃时会抑制FBK的血凝反应。与FBK相比，在有或没有神经氨酸酶抑制剂的情况下，CBK在37℃时与MDBK细胞和CEF结合的能力均增强。此外，当在0℃结合病毒的细胞转移到37℃时，CBK仍与细胞结合，而约80%的FBK从两种细胞上解离。因此，从F到C的突变增加了病毒与MDBK细胞受体结合的能力。对来自两种细胞的F病毒和C病毒进行的研究表明，突变的表达部分取决于病毒生长所在的宿主细胞，部分取决于用于测量结合特性的细胞。本文提出了一个将这些观察结果与自然界中HA变体的选择相关联的模型。
