Primary human splenic macrophages, but not T or B cells, are the principal target cells for dengue virus infection in vitro
Primary human splenic macrophages, but not T or B cells, are the principal target cells for dengue virus infection in vitro
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DOI：
10.1128/jvi.01568-07
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发表时间：
2007-12-01
影响因子：
5.4
通讯作者：
Jin, Xia
中科院分区：
文献类型：
--
作者：
Blackley, Shanley;Kou, Zhihua;Jin, Xia
了解登革出血热（DHF）和登革休克综合征（DSS）的发病机制需要精确鉴定登革病毒（DV）允许的靶细胞。在以前的研究中，使用未分级的人外周血单核细胞，我们发现，单核细胞，而不是B或T细胞，是主要的DV-容许细胞在缺乏DV-免疫汇集的人血清（PHS）和抗体依赖性增强的主要介质在PHS的存在。为了进一步鉴定其他组织和器官中的DV允许靶细胞，我们分离人脾单核细胞（MNCs），在存在或不存在PHS的情况下用DV 2型（菌株16681）接种它们，并直接使用流式细胞术和逆转录-PCR（RT-PCR）测定或间接通过空斑测定来评估它们的感染。我们发现，在没有PHS的情况下，与流式细胞术检测的染色对照相比，一小部分脾巨噬细胞似乎对DV抗原呈阳性（0.77%+/-1.00% vs 0.18%+/-0.12%; P = 0.07），并且在暴露于DV的MNC中，通过RT-PCR检测可检测到病毒RNA。此外，DV暴露的MNC培养物的上清液含有感染性病毒粒子，这些病毒粒子可通过空斑试验轻易检测到。在存在高度稀释的PHS的情况下，脾巨噬细胞的感染程度显著增强（5.41%+/-3.53% vs 0.77%+/-1.00%; P = 0.001）。相比之下，原代T和B细胞在PHS存在或不存在的情况下均未被感染。这些结果首次提供了证据，证明人原代脾巨噬细胞，而不是B或T细胞，是脾脏中主要的DV-容许细胞，并且它们在导致某些DV-感染个体中DHF/DSS的免疫增强的初始步骤中可能是独特重要的。
Understanding the pathogenesis of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) requires the precise identification of dengue virus (DV)-permissive target cells. In a previous study using unfractionated human peripheral blood mononuclear cells, we found that monocytes, but not B or T cells, were the principal DV-permissive cells in the absence of DV-immune pooled human sera (PHS) and the major mediators of antibody-dependent enhancement in the presence of PHS. To further identify DV-permissive target cells in other tissues and organs, we isolated human splenic mononuclear cells (MNCs), inoculated them with DV type 2 (strain 16681) in the presence or absence of PHS, and assessed their infection either directly using flow cytometry and reverse transcription-PCR (RT-PCR) assays or indirectly by plaque assay. We found that in the absence of PHS, a small proportion of splenic macrophages appeared to be positive for DV antigens in comparison to staining controls by the flow cytometric assay (0.77% +/- 1.00% versus 0.18% +/- 0.12%; P = 0.07) and that viral RNA was detectable by the RT-PCR assay in MNCs exposed to DV. Additionally, supernatants from cultures of DV-exposed MNCs contained infectious virions that were readily detectable by plaque assay. The magnitude of infection was significantly enhanced in splenic macrophages in the presence of highly diluted PHS (5.41% +/- 3.53% versus 0.77% +/- 1.00%; P = 0.001). In contrast, primary T and B cells were not infected in either the presence or absence of PHS. These results provide evidence, for the first time, that human primary splenic macrophages, rather than B or T cells, are the principal DV-permissive cells in the spleen and that they may be uniquely important in the initial steps of immune enhancement that leads to DHF/DSS in some DV-infected individuals.