Chikungunya virus (CHIKV), a mosquito-borne alphavirus, has become an important re-emerging pathogen with its rapid spread to many non-endemic areas. The lack of effective vaccines and antiviral agents is largely attributed to the elusive infection and dissemination dynamics in vivo. In this study, we designed and developed a novel, replication-competent, CHIKV reporter virus (CHIKV-iRFP) encoding a near infrared fluorescent protein (iRFP). In vitro and in vivo characterization demonstrated that CHIKV-iRFP retained similar replication and virulence phenotypes to its parental virus. Neonatal BABL/c mice and IFNAR-/- A129 mice were highly susceptible to CHIKV-iRFP infection. Following intracranial (i.c.) inoculation, CHIKV-iRFP efficiently replicated and disseminated into whole body, resulting in rapid death in an age-dependent manner. Remarkably, upon footpad injection, CHIKV-iRFP readily disseminated from footpad to head and whole skeleton, with a specific tropism for bone marrow. Taken together, this novel reporter virus provides a powerful tool to track real time CHIKV replication and to test the in vivo efficacy of vaccines and antiviral therapeutics.

中文翻译：

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在体外和体内可视化的基孔肯雅病毒感染。

基孔肯雅病毒（CHIKV）是一种由蚊子传播的甲病毒，已迅速传播到许多非流行地区，已成为一种重要的新兴病原体。缺乏有效疫苗和抗病毒剂的主要原因是体内难以捉摸的感染和传播动态。在这项研究中，我们设计和开发了一种新型的，具有复制能力的CHIKV报告病毒（CHIKV-iRFP），该病毒编码近红外荧光蛋白（iRFP）。体外和体内鉴定表明，CHIKV-iRFP保留了与其亲本病毒相似的复制和毒力表型。新生儿BABL / c小鼠和IFNAR-/-A129小鼠对CHIKV-iRFP感染高度敏感。颅内（ic）接种后，CHIKV-iRFP有效复制并传播到全身，导致年龄依赖性死亡。值得注意的是 注射脚垫后，CHIKV-iRFP可以很容易地从脚垫传播到头部和整个骨骼，对骨髓具有特定的向性。两者合计，这种新型的报告病毒提供了一个强大的工具，可以跟踪实时CHIKV复制并测试疫苗和抗病毒疗法的体内功效。