Transcriptional profile of brain TRM in Toxoplasma gondii infection

During chronic infection memory T cells acquire a unique phenotype and become dependent on different survival signals than those needed for memory T cells generated during an acute infection. The distinction between the role of effector and memory T cells in an environment of persistent antigen remains unclear. Here, in the context of chronic Toxoplasma gondii infection we demonstrate that a population of CD8 T cells exhibiting a tissue resident memory (TRM) phenotype persists in the brain. We show that this population is distributed throughout the brain in both parenchymal and extraparenchymal spaces. Furthermore, this population is transcriptionally distinct and exhibits a transcriptional signature consistent with the TRM observed in acute viral infections. Differential gene expression analysis with the following specified comparisons: 1) brain CD103+ CD8 T cells to brain CD103- CD8 T cells 2) brain CD103+ CD8 T cells to spleen CD103+ CD8 T cells 3) brain CD103+ CD8 T cells to spleen CD103- CD8 T cells

慢性感染过程中，记忆T细胞会获得独特的表型，且其存活所依赖的信号与急性感染诱导产生的记忆T细胞所需的存活信号截然不同。在持续抗原暴露的环境中，效应T细胞与记忆T细胞的功能分工仍未明确。本研究以慢性刚地弓形虫（Toxoplasma gondii）感染为研究模型，证实大脑中存在一群呈现组织驻留记忆（tissue resident memory, TRM）表型的CD8 T细胞群体且可长期存活。该细胞群体广泛分布于大脑的实质与实质外间隙；此外，该群体具有独特的转录特征，其转录谱与急性病毒感染中报道的组织驻留记忆T细胞的转录特征高度一致。本研究通过以下三组指定对照开展差异基因表达分析：1) 大脑CD103+ CD8 T细胞与大脑CD103- CD8 T细胞；2) 大脑CD103+ CD8 T细胞与脾脏CD103+ CD8 T细胞；3) 大脑CD103+ CD8 T细胞与脾脏CD103- CD8 T细胞