Transcriptome of activated human and mouse MAIT cells

We sought to describe in detail the consequences of MAIT cell activation using a transcriptomic approach to define the basic transcriptome of a MAIT cell in both humans and mice and to determine how this is modulated by activation. Fresh human peripheral blood cells were obtained from three donors. These were cultured for 6 hours with (‘stimulated’) or without (‘unstimulated’) 10 nM 5-OP-RU, magnetically enriched on MR1-tetramer+ cells, and flow-sorted for RNA sequencing of live CD3+TCR Valpha7.2+ MR1-5-OP-RU tetramer+ MAIT cells, and of unstimulated naïve live CD8+CD45RA+ T cells as a comparator cell type. For the murine samples we included within the same sequencing experiment live pulmonary CD3+45.2+19-MR1-5-OP-RU tetramer+ MAIT cells which were magnetically enriched and flow-sorted from the lungs of mice 7 days after infection with 1x104 CFU L. longbeachae (‘acute’), or at least 12 weeks post infection (‘resolution’) or 7 days after a second intranasal infection with 2x104 CFU L. longbeachae in mice that had recovered from infection 12 weeks previously (‘reinfection’). Live CD3+CD45.2+CD19-CD8+CD44-CD62L+ naïve T cells from uninfected mice were used as a comparator cell type. Illumina sequencing of human and murine MR1-5-OP-RU tetramer+ MAIT cells in comparison with naïve CD8 T cells. 3 biological replicates of each of the following conditions: Human peripheral blood MAIT cell unstimulated. Human peripheral blood MAIT cells stimulated for 6 h with 5-OP-RU. Human peripheral blood CD8+45RA+ T cells. Murine pulmonary MAIT cells 7 days after legionella infection, 12 weeks after legionella infection, 7 days after reinfection with legionella, Murine naive pulmonary CD8+CD45+44-62L+ T cells. Full details of the study can be downloaded at https://www.biorxiv.org/content/early/2018/12/09/490649?rss=1

本研究旨在通过转录组学方法详细解析黏膜相关恒定T细胞（MAIT cell）活化后的效应特征，明确人类与小鼠体内MAIT细胞的基础转录组，并探究活化状态对该转录组的调控机制。
本研究从3名供者体内获取新鲜人外周血细胞，将其分为两组：分别以10 nM 5-OP-RU刺激培养6小时（刺激组）或不做刺激（未刺激组）；随后通过磁珠富集法分选MR1-四聚体（MR1-tetramer）阳性细胞，再经流式细胞术分选出活的CD3+TCR Vα7.2+MR1-5-OP-RU四聚体阳性MAIT细胞，同时分选未刺激的初始型T细胞（naïve T cells）作为对照细胞群。
对于小鼠样本，本研究在同一测序实验中纳入了如下肺源性MAIT细胞：从感染1×10^4 CFU长滩军团菌（L. longbeachae）7天后的小鼠肺部（急性感染组）、感染后至少12周的小鼠肺部（感染消退组），以及经12周感染恢复后再次经鼻内感染2×10^4 CFU长滩军团菌7天后的小鼠肺部（再次感染组），磁珠富集并流式分选出活的CD3+CD45.2+CD19-MR1-5-OP-RU四聚体阳性MAIT细胞；同时以未感染小鼠体内的活的CD3+CD45.2+CD19-CD8+CD44-CD62L+初始型T细胞作为对照细胞群。
本研究采用Illumina测序技术，对人类与小鼠的MR1-5-OP-RU四聚体阳性MAIT细胞进行转录组测序，并以初始型T细胞作为对照。各实验条件均设置3次生物学重复，具体包括：未刺激的人外周血MAIT细胞、经5-OP-RU刺激培养6小时的人外周血MAIT细胞、人外周血CD8+CD45RA+ T细胞、军团菌感染7天后的小鼠肺源性MAIT细胞、军团菌感染12周后的小鼠肺源性MAIT细胞、军团菌再次感染7天后的小鼠肺源性MAIT细胞，以及未感染小鼠的肺源性初始型CD8+CD45+44-CD62L+ T细胞。
本研究的完整细节可从以下链接下载：https://www.biorxiv.org/content/early/2018/12/09/490649?rss=1