Egyed László, Zöldi Viktor, Szeredi Levente
Institute for Veterinary Medical Research, Agricultural Research Center of the Hungarian Academy of Sciences, Budapest, Hungary.
Intervirology. 2015;58(6):369-72. doi: 10.1159/000443833. Epub 2016 Mar 3.
In this study, we investigated the dose dependence of tick-borne encephalitis virus (TBEV) infection in one of the reservoirs, i.e. Apodemus agrarius, a small rodent species.
The animals were challenged with TBEV per os and intramuscularly with infectious doses ranging from 1 to 1,500 plaque-forming units (pfu). Clinical signs were recorded and clinical and pathological features were evaluated by histological, immunohistochemical, and serological methods.
High perorally administered infectious doses resulted in virus replication in the brain, which is the first sign of subclinical viral encephalitis in the Apodemus genus. The animals seroconverted at infectious doses greater than 100 pfu, and all animals remained asymptomatic.
Our work shows the first evidence that subclinical TBEV encephalitis may occur in Apodemus species, depending on the virus load of the inoculum. The antiviral response of the local innate immune system may influence the resistance of Apodemus individuals to lower infectious doses. Per oral/nasal infection seems to be more dangerous for the host than other routes of infection.
在本研究中，我们调查了蜱传脑炎病毒（TBEV）在其中一种宿主——即小林姬鼠（一种小型啮齿动物）中的感染剂量依赖性。
用剂量范围为1至1500个蚀斑形成单位（pfu）的TBEV经口和肌肉注射对动物进行攻毒。记录临床症状，并通过组织学、免疫组织化学和血清学方法评估临床和病理特征。
经口给予的高感染剂量导致病毒在脑中复制，这是姬鼠属动物亚临床病毒性脑炎的首个迹象。感染剂量大于100 pfu时动物血清阳转，且所有动物均无症状。
我们的研究首次证明，取决于接种物的病毒载量，亚临床TBEV脑炎可能在姬鼠属物种中发生。局部先天免疫系统的抗病毒反应可能影响小林姬鼠个体对较低感染剂量的抵抗力。经口/鼻感染似乎比其他感染途径对宿主更危险。
