Sheep dendritic cells CD26+ and CD26- versus total dendritic cells. Ovis aries

Transcriptomic profiling of ovine skin lymph dendritic cell subsets CD26+ and CD26- compared to total enriched lymph dendritic cells. CD26+ and CD26- dendritic cells (DC) from sheep skin lymph were sorted by flow cytometry and were analysed for their transcriptomic profile. We demonstrate that the minor sheep CD26+ skin lymph DC subset shares significant transcriptomic similarities with mouse CD8a+ and human BDCA3+ DC. This allowed the identification of a common set of phenotypic characteristics for CD8a-like DC in the 3 mammalian species, i.e. SIRPlo, CADM1hi, CLEC9Ahi, DEC205hi, XCR1hi. Compared to CD26- DC, the sheep CD26+ DC show (1) potent stimulation of allogeneic naive CD8+ T cells with high selective induction of the Ifn-gamma and Il22 genes; (2) dominant efficacy in activating specific CD8+ T cells against exogenous soluble antigen; (3) selective expression of functional pathways associated to high capacity for antigen cross-presentation. Overall design: Reference design (total enriched lymph dendritic cells) - Biological replicates: 2 sheep #10081 and #30066

本研究针对绵羊皮肤淋巴源CD26阳性（CD26+）与CD26阴性（CD26-）树突状细胞（dendritic cell, DC）亚群，与总富集淋巴树突状细胞开展转录组对比分析。研究人员通过流式细胞术分选出绵羊皮肤淋巴源CD26+与CD26-树突状细胞，并对其转录组特征进行分析。本研究证实，占比稀少的绵羊CD26+皮肤淋巴树突状细胞亚群，与小鼠CD8a阳性（CD8a+）及人BDCA3阳性（BDCA3+）树突状细胞存在显著的转录组相似性。基于该发现，研究人员得以确定三类哺乳动物中CD8a样树突状细胞共有的一套表型特征，即SIRP低表达（SIRPlo）、CADM1高表达（CADM1hi）、CLEC9A高表达（CLEC9Ahi）、DEC205高表达（DEC205hi）与XCR1高表达（XCR1hi）。与CD26-树突状细胞相比，绵羊CD26+树突状细胞具备如下特性：(1) 可有效刺激同种异体初始CD8阳性（CD8+）T细胞，并选择性诱导Ifn-gamma与Il22基因的高表达；(2) 在激活针对外源性可溶性抗原的特异性CD8+ T细胞方面效果突出；(3) 选择性表达与抗原交叉呈递高能力相关的功能通路。实验整体设计：采用参照设计（以总富集淋巴树突状细胞为参照样本）——生物学重复：2只绵羊，编号分别为#10081与#30066。