Jones Grant S, Smith Victoria C, D'Orazio Sarah E F
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536.
Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY 40536
J Immunol. 2017 Dec 1;199(11):3789-3797. doi: 10.4049/jimmunol.1700970. Epub 2017 Oct 20.
Recent fate-mapping studies and gene-expression profiles suggest that commonly used protocols to generate bone marrow-derived cultured dendritic cells yield a heterogeneous mixture, including some CD11c cells that may not have a bona fide counterpart in vivo. In this study, we provide further evidence of the discordance between ex vivo-isolated and in vitro-cultured CD11c cells by analyzing an additional phenotype, the ability to support cytosolic growth of the facultative intracellular bacterial pathogen Two days after foodborne infection of mice with GFP-expressing , a small percentage of CD103 and CD103 conventional dendritic cells (cDC) in the intestinal lamina propria and mesenteric lymph nodes were GFP However, in vitro infection of the same subsets of cells harvested from naive mice resulted in inefficient invasion by the bacteria (<0.1% of the inoculum). The few intracellular bacteria detected survived for only a few hours. In contrast, cultured CD103CD11c cells induced by GM-CSF readily supported exponential growth of Flt3 ligand-induced cultures yielded CD103CD11c cells that more closely resembled cDC, with only a modest level of replication. For both culture protocols, the longer the cells were maintained in vitro, the more readily they supported intracellular growth. The results of this study suggest that cDC are not a niche for intracellular growth of during intestinal infection of mice.
最近的命运图谱研究和基因表达谱表明，常用的生成骨髓来源的培养树突状细胞的方案会产生异质混合物，包括一些在体内可能没有真正对应物的CD11c细胞。在本研究中，我们通过分析另一种表型，即支持兼性细胞内细菌病原体胞质生长的能力，进一步证明了体外分离的和体外培养的CD11c细胞之间的不一致性。在用表达绿色荧光蛋白（GFP）的鼠伤寒沙门氏菌经食物感染小鼠两天后，肠道固有层和肠系膜淋巴结中的一小部分CD103⁺和CD103⁻常规树突状细胞（cDC）呈GFP⁺。然而，对从未感染小鼠中收获的相同细胞亚群进行体外感染时，细菌的侵袭效率很低（<接种物的0.1%）。检测到的少数细胞内细菌仅存活了几个小时。相比之下，GM-CSF诱导的培养CD103⁻CD11c细胞很容易支持鼠伤寒沙门氏菌的指数生长。Flt3配体诱导的培养产生的CD103⁻CD11c细胞与cDC更相似，鼠伤寒沙门氏菌的复制水平适中。对于这两种培养方案，细胞在体外维持的时间越长，它们就越容易支持细胞内生长。本研究结果表明，在小鼠肠道感染期间，cDC不是鼠伤寒沙门氏菌细胞内生长的微环境。
