Medical Entomology & Zoology, ICMR-National Institute of Virology, Pune, India.
Dengue & Chikungunya, ICMR-National Institute of Virology, Pune, India.
Indian J Med Res. 2019 Jun;149(6):771-777. doi: 10.4103/ijmr.IJMR_453_17.
BACKGROUND & OBJECTIVES: Chikungunya virus (CHIKV), a mosquito-borne arthritogenic virus causes infections ranging from febrile illness to debilitating polyarthralgia in humans. Re-emergence of the virus has affected millions of people in Africa and Asia since 2004. During the outbreak, a new lineage of the virus has evolved as an adaptation for enhanced replication and transmission by Aedes albopictus mosquito. A study was designed to compare the susceptibility of four vertebrate cell lines, namely Vero E6 (African green monkey kidney), BHK-21 (Baby hamster kidney), RD (human rhabdomyosarcoma), A-549 (human alveolar basal epithelial cell) and C6/36 (Ae. albopictus) to Asian genotype and two lineages of East, Central and South African (E1:A226 and E1:A226V) of CHIKV.
One-step growth kinetics of different CHIKV strains was carried out in the above five cell lines to determine the growth kinetics and virus yield. Virus titre was determined by 50 per cent tissue culture infectious dose assay and titres were calculated by the Reed and Muench formula. Growth and virus yield of the three strains in Ae. aegypti mosquitoes was studied by intrathoracic inoculation and virus titration in Vero E6 cell line.
Virus titration showed Vero E6, C6/36 and BHK-21 cell lines are high virus yielding with all the three lineages while RD and A-549 yielded low virus titres. C6/36 cell line was the most sensitive and yielded the maximum titre. Ae. aegypti mosquitoes, when inoculated with high titre virus, yielded an almost equal growth with the three strains while rapid growth of E1:A226V and Asian strain was observed with 1 log virus.
INTERPRETATION & CONCLUSIONS: C6/36 cell line was found to be the most sensitive and high yielding for CHIKV irrespective of lineages while Vero E6 and BHK-21 cell lines yielded high titres and may find application for vaccine/diagnostic development. Infection of Ae. aegypti mosquitoes with the three CHIKV strains gave almost identical pattern of growth.
基孔肯雅病毒（CHIKV）是一种虫媒传播的关节炎病毒，可引起人类从发热性疾病到衰弱性多关节炎的感染。自 2004 年以来，该病毒在非洲和亚洲再次出现，影响了数百万人。在疫情爆发期间，病毒出现了一种新的谱系，这是一种适应通过白纹伊蚊增强复制和传播的进化。本研究旨在比较四种脊椎动物细胞系，即非洲绿猴肾（Vero E6）、仓鼠肾（BHK-21）、人横纹肌肉瘤（RD）、人肺泡基底上皮细胞（A-549）和白纹伊蚊（Ae. albopictus）C6/36 对亚洲基因型和东、中、南非两个谱系（E1：A226 和 E1：A226V）的易感性。
在上述五种细胞系中进行不同 CHIKV 株的一步生长动力学研究，以确定生长动力学和病毒产量。通过 50%组织培养感染剂量测定法测定病毒滴度，并通过 Reed 和 Muench 公式计算滴度。通过胸腔内接种和在 Vero E6 细胞系中进行病毒滴定研究三种毒株在埃及伊蚊中的生长和病毒产量。
病毒滴定显示，Vero E6、C6/36 和 BHK-21 细胞系对所有三个谱系都是高病毒产量，而 RD 和 A-549 产生低病毒滴度。C6/36 细胞系最敏感，产生的病毒滴度最大。当用高滴度病毒接种埃及伊蚊时，三种毒株的生长几乎相同，而 E1：A226V 和亚洲株的快速生长观察到 1 个对数病毒。
无论谱系如何，C6/36 细胞系被发现对 CHIKV 最敏感且产量最高，而 Vero E6 和 BHK-21 细胞系产生高滴度，可能有助于疫苗/诊断的开发。三种 CHIKV 株感染埃及伊蚊的生长模式几乎相同。
