Division of Biomedical Science, Research School of Biology, The Australian National University, Canberra, Australia.
Department of Medical Technology, Faculty of Applied Health Sciences, Thammasat University, Bangkok, Thailand.
BMC Immunol. 2018 Jun 26;19(1):21. doi: 10.1186/s12865-018-0255-y.
Splenic stroma overlaid with hematopoietic progenitors supports in vitro hematopoiesis with production of dendritic-like cells. Co-cultures of murine lineage-depleted bone marrow over the 5G3 stromal line produce two populations of cells, characterised as CD11bCD11cMHC-II dendritic-like 'L-DC', and CD11bCD11cMHC-II cells, resembling conventional dendritic cells (cDC). To date, the functional capacity of these two subsets has not been clearly distinguished.
Here we show both the L-DC and cDC-like subsets can be activated and induce proliferation of OT-I CD8 T cells, being strong inducers of IL-2 and IFN-γ production. Both subsets lack ability to induce proliferation of OT-II CD4 T cells. The cDC-like population is shown here to resemble regulatory DC in that they induce FoxP3 expression and IL-10 production in OT-II CD4 T cells, in line with their function as regulatory DC. L-DC did not activate or induce the proliferation of CD4 T cells and did not induce FoxP3 expression in CD4 T cells. L-DC can be distinguished from cDC-like cells through their superior endocytic capacity and expression of 4-1BBL, F4/80 and Sirp-α. A comparison of gene expression by the two subsets was consistent with L-DC having an activated or immunostimulatory DC phenotype, while cDC-like cells reflect myeloid dendritic cells with inflammatory and suppressive properties, also consistent with functional characteristics as regulatory DC. When a Transwell membrane was used to prevent hematopoietic cell contact with stroma, only cDC-like cells and not L-DC were produced, and cell production was dependent on M-CSF production by stroma.
Co-cultures of hematopoietic progenitors over splenic stroma produce two distinct subsets of dendritic-like cells. These are here distinguished phenotypically and through gene expression differences. While both resemble DC, there are functionally distinct. L-DC activate CD8 but not CD4 T cells, while the cDC-like population induce regulatory T cells, so reflecting regulatory DC. The latter can be enriched through Transwell co-cultures with cell production dependent on M-CSF.
覆盖造血祖细胞的脾脏基质支持体外造血，并产生树突状样细胞。在 5G3 基质系上共培养鼠系细胞耗竭的骨髓产生两种细胞群，特征为 CD11bCD11cMHC-II 树突状样“L-DC”和 CD11bCD11cMHC-II 细胞，类似于常规树突状细胞（cDC）。迄今为止，这两个亚群的功能能力尚未明确区分。
在这里，我们表明 L-DC 和 cDC 样亚群都可以被激活，并诱导 OT-I CD8 T 细胞增殖，是 IL-2 和 IFN-γ产生的强诱导剂。这两个亚群都缺乏诱导 OT-II CD4 T 细胞增殖的能力。这里显示 cDC 样群体类似于调节性 DC，因为它们在 OT-II CD4 T 细胞中诱导 FoxP3 表达和 IL-10 产生，符合其作为调节性 DC 的功能。L-DC 不能激活或诱导 CD4 T 细胞增殖，也不能诱导 CD4 T 细胞中 FoxP3 的表达。L-DC 可以通过其优越的内吞能力和 4-1BBL、F4/80 和 Sirp-α 的表达与 cDC 样细胞区分开来。两个亚群的基因表达比较表明，L-DC 具有激活或免疫刺激 DC 表型，而 cDC 样细胞反映具有炎症和抑制特性的髓样树突状细胞，这也与作为调节性 DC 的功能特征一致。当使用 Transwell 膜防止造血细胞与基质接触时，只有 cDC 样细胞而不是 L-DC 产生，并且细胞产生依赖于基质产生的 M-CSF。
在脾脏基质上共培养造血祖细胞可产生两种不同的树突状样细胞亚群。这些通过表型和基因表达差异来区分。虽然两者都类似于 DC，但功能上有区别。L-DC 激活 CD8，但不激活 CD4 T 细胞，而 cDC 样群体诱导调节性 T 细胞，因此反映了调节性 DC。后者可以通过 Transwell 共培养来富集，细胞产生依赖于 M-CSF。
