Table_2_Dendritic Cells Generated From Mops condylurus, a Likely Filovirus Reservoir Host, Are Susceptible to and Activated by Zaire Ebolavirus Infection.DOCX

Ebola virus infection of human dendritic cells (DCs) induces atypical adaptive immune responses and thereby exacerbates Ebola virus disease (EVD). Human DCs, infected with Ebola virus aberrantly express low levels of the DC activation markers CD80, CD86, and MHC class II. The T cell responses ensuing are commonly anergic rather than protective against EVD. We hypothesize that DCs derived from potential reservoir hosts such as bats, which do not develop disease signs in response to Ebola virus infection, would exhibit features associated with activation. In this study, we have examined Zaire ebolavirus (EBOV) infection of DCs derived from the Angolan free-tailed bat species, Mops condylurus. This species was previously identified as permissive to EBOV infection in vivo, in the absence of disease signs. M. condylurus has also been recently implicated as the reservoir host for Bombali ebolavirus, a virus species that is closely related to EBOV. Due to the absence of pre-existing M. condylurus species-specific reagents, we characterized its de novo assembled transcriptome and defined its phylogenetic similarity to other mammals, which enabled the identification of cross-reactive reagents for M. condylurus bone marrow-derived DC (bat-BMDC) differentiation and immune cell phenotyping. Our results reveal that bat-BMDCs are susceptible to EBOV infection as determined by detection of EBOV specific viral RNA (vRNA). vRNA increased significantly 72 h after EBOV-infection and was detected in both cells and in culture supernatants. Bat-BMDC infection was further confirmed by the observation of GFP expression in DC cultures infected with a recombinant GFP-EBOV. Bat-BMDCs upregulated CD80 and chemokine ligand 3 (CCL3) transcripts in response to EBOV infection, which positively correlated with the expression levels of EBOV vRNA. In contrast to the aberrant responses to EBOV infection that are typical for human-DC, our findings from bat-BMDCs provide evidence for an immunological basis of asymptomatic EBOV infection outcomes.

人类树突状细胞（DCs）感染埃博拉病毒（Ebola virus）可诱导非典型的适应性免疫反应，从而加剧埃博拉病毒病（EVD）。感染埃博拉病毒的人类DCs异常表达低水平的DC活化标志物CD80、CD86和MHC II类分子。由此引发的T细胞反应通常表现为无反应性，而非对EVD具有保护作用。我们假设，来自潜在宿主如蝙蝠的DCs，在埃博拉病毒感染后不出现疾病症状，将展现出与活化相关的特征。在本研究中，我们考察了安哥拉自由尾蝠（Mops condylurus）来源的DCs感染扎伊尔埃博拉病毒（Zaire ebolavirus，EBOV）的情况。该物种先前已被确认为在体内对EBOV感染具有易感性，但无疾病症状。M. condylurus最近也被认为是Bombali ebolavirus的宿主，该病毒与EBOV密切相关。由于缺乏预先存在的M. condylurus物种特异性试剂，我们对其从头转录组进行了表征，并定义了其与其他哺乳动物的系统发育相似性，从而识别了M. condylurus骨髓来源的DC（bat-BMDC）分化和免疫细胞表型鉴定的交叉反应试剂。我们的结果显示，bat-BMDCs对EBOV感染敏感，这通过检测EBOV特异性病毒RNA（vRNA）得到证实。vRNA在EBOV感染后72小时显著增加，并在细胞和培养上清液中检测到。通过观察感染重组GFP-EBOV的DC培养中的GFP表达，进一步证实了bat-BMDC的感染。在EBOV感染后，bat-BMDCs上调了CD80和趋化因子配体3（CCL3）的转录本，这与EBOV vRNA的表达水平呈正相关。与人类DC对EBOV感染的非典型反应相比，我们从bat-BMDCs中得到的研究结果表明，无症状EBOV感染的结果具有免疫学基础。