Expression of Interferon Gamma by a Recombinant Rabies Virus Strongly Attenuates the Pathogenicity of the Virus via Induction of Type I Interferon
Expression of Interferon Gamma by a Recombinant Rabies Virus Strongly Attenuates the Pathogenicity of the Virus via Induction of Type I Interferon
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DOI：
10.1128/jvi.01572-14
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发表时间：
2015-01-01
影响因子：
5.4
通讯作者：
Hooper, D. Craig
中科院分区：
文献类型：
--
作者：
Barkhouse, Darryll A.;Garcia, Samantha A.;Hooper, D. Craig
先前的动物模型实验表明，干扰素γ (ifn - γ)表达与减毒狂犬病毒（RABV）感染后的存活和神经系统后遗症的减少之间存在相关性。因此，我们假设狂犬病毒本身快速产生小鼠ifn - γ会诱导比小鼠自然产生的更强的抗病毒反应。为了验证这一假设，我们利用逆向工程技术将小鼠ifn - γ基因克隆到狂犬病病毒致病性主干SPBN中，产生重组狂犬病病毒SPBN γ。监测鼻内感染SPBN γ或SPBN（-）对照病毒的小鼠的发病率和死亡率，以确定ifn - γ表达引起的衰减程度。将干扰素- γ掺入狂犬病毒基因组后，病毒的毒性大大降低。SPBN具有50%致死剂量（LD50），比SPBN（-）大100倍以上。体外和体内小鼠实验表明，SPBN γ感染可增强I型干扰素的产生。此外，缺乏通过I型干扰素受体（IFNAR(-/-)）发出信号的能力的敲除小鼠不能控制SPBN γ感染并迅速死亡。这些数据表明，ifn - γ的产生在狂犬病中具有抗病毒作用，主要是由于I型干扰素的诱导。狂犬病的存活取决于病毒复制和传播的早期控制。一旦病毒到达中枢神经系统（CNS），这就变得非常成问题。中枢神经系统对RABV免疫的研究表明，复制控制始于T细胞进入中枢神经系统，并在病毒中和抗体出现之前产生ifn - γ。此外，抗体缺陷小鼠能够控制但不能从中枢神经系统清除减毒的RABV。我们在这里发现ifn - γ触发I型干扰素的早期产生，具有预期的抗病毒作用。我们还发现，在感染组织中直接表达ifn - γ的致死性狂犬病毒可以减少狂犬病毒的复制和传播，限制其在正常和免疫功能低下小鼠中的致病性。因此，将ifn - γ载体递送到大脑可能有可能治疗那些本来会死于狂犬病病毒感染的个体。
Previous animal model experiments have shown a correlation between interferon gamma (IFN-gamma) expression and both survival from infection with attenuated rabies virus (RABV) and reduction of neurological sequelae. Therefore, we hypothesized that rapid production of murine IFN-gamma by the rabies virus itself would induce a more robust antiviral response than would occur naturally in mice. To test this hypothesis, we used reverse engineering to clone the mouse IFN-gamma gene into a pathogenic rabies virus backbone, SPBN, to produce the recombinant rabies virus designated SPBN gamma. Morbidity and mortality were monitored in mice infected intranasally with SPBN gamma or SPBN(-) control virus to determine the degree of attenuation caused by the expression of IFN-gamma. Incorporation of IFN-gamma into the rabies virus genome highly attenuated the virus. SPBN has a 50% lethal dose (LD50) more than 100-fold greater than SPBN(-). In vitro and in vivo mouse experiments show that SPBN gamma infection enhances the production of type I interferons. Furthermore, knockout mice lacking the ability to signal through the type I interferon receptor (IFNAR(-/-)) cannot control the SPBN gamma infection and rapidly die. These data suggest that IFN-gamma production has antiviral effects in rabies, largely due to the induction of type I interferons.IMPORTANCE Survival from rabies is dependent upon the early control of virus replication and spread. Once the virus reaches the central nervous system (CNS), this becomes highly problematic. Studies of CNS immunity to RABV have shown that control of replication begins at the onset of T cell entry and IFN-gamma production in the CNS prior to the appearance of virus-neutralizing antibodies. Moreover, antibody-deficient mice are able to control but not clear attenuated RABV from the CNS. We find here that IFN-gamma triggers the early production of type I interferons with the expected antiviral effects. We also show that engineering a lethal rabies virus to express IFN-gamma directly in the infected tissue reduces rabies virus replication and spread, limiting its pathogenicity in normal and immunocompromised mice. Therefore, vector delivery of IFN-gamma to the brain may have the potential to treat individuals who would otherwise succumb to infection with rabies virus.