Adaptation to cell culture induces functional differences in measles virus proteins
Adaptation to cell culture induces functional differences in measles virus proteins
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DOI：
10.1186/1743-422x-5-129
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发表时间：
2008-10-27
期刊：
影响因子：
4.8
通讯作者：
Rota, Paul A.
中科院分区：
文献类型：
--
作者：
Bankamp, Bettina;Fontana, Judith M.;Rota, Paul A.
背景：活的减毒麻疹病毒 (MeV) 疫苗株是通过适应细胞培养而产生的。疫苗株减毒的遗传基础尚不清楚。我们之前报道过，致病性野生型 MeV 对 Vero 细胞或原代鸡胚成纤维细胞 (CEF) 的适应导致恒河猴致病性丧失。 CEF 适应病毒 (D-CEF) 在 C 和基质 (M) 蛋白中包含单个氨基酸变化，在磷蛋白 (P) 和 V 蛋白的共享氨基末端结构域中包含两个取代。 Vero 适应病毒 (D-VI) 的血凝素 (H) 蛋白的细胞质尾部发生突变。结果：使用体外测定来测试野生型和突变蛋白的功能。 D-CEF C 蛋白的取代降低了其抑制小基因组复制的能力，而野生型和突变型 M 蛋白则以相同程度抑制复制。 D-VI H 蛋白胞质尾部的取代导致定量融合测定中融合减少。 M蛋白与野生型融合蛋白和H蛋白的共表达降低了融合活性，但D-CEF的M蛋白的突变并不影响这种功能。 D-CEF 的 P 和 V 蛋白的突变均降低了这些蛋白抑制 I 型和 II 型干扰素信号传导的能力。结论：野生型 MeV 适应细胞培养物，选择基因改变，导致病毒蛋白出现可测量的功能差异。
Background: Live, attenuated measles virus (MeV) vaccine strains were generated by adaptation to cell culture. The genetic basis for the attenuation of the vaccine strains is unknown. We previously reported that adaptation of a pathogenic, wild-type MeV to Vero cells or primary chicken embryo fibroblasts (CEFs) resulted in a loss of pathogenicity in rhesus macaques. The CEF-adapted virus (D-CEF) contained single amino acid changes in the C and matrix (M) proteins and two substitutions in the shared amino terminal domain of the phosphoprotein (P) and V protein. The Vero-adapted virus (D-VI) had a mutation in the cytoplasmic tail of the hemagglutinin (H) protein. Results: In vitro assays were used to test the functions of the wild-type and mutant proteins. The substitution in the C protein of D-CEF decreased its ability to inhibit mini-genome replication, while the wild-type and mutant M proteins inhibited replication to the same extent. The substitution in the cytoplasmic tail of the D-VI H protein resulted in reduced fusion in a quantitative fusion assay. Co-expression of M proteins with wild-type fusion and H proteins decreased fusion activity, but the mutation in the M protein of D-CEF did not affect this function. Both mutations in the P and V proteins of D-CEF reduced the ability of these proteins to inhibit type I and II interferon signaling. Conclusion: Adaptation of a wild-type MeV to cell culture selected for genetic changes that caused measurable functional differences in viral proteins.