Non-deletional CD8 T cell self-tolerance

摘要 自我耐受要求自我反应性T细胞要么物理上被消除，要么与自我隔离 抗原和/或对正常组织的反应丧失能力。已经有很多关于缺失的研究 CD8+T细胞对自身抗原的耐受性和“无知”，但关于无能是如何发生的，却知之甚少 调节这种反应的T细胞反应。对这个问题的研究尤其紧迫，因为最近的数据表明 无能是人类CD8+T细胞自我耐受的普遍机制--但我们缺乏适当的 用小鼠模型来研究这一关键机制。我们通过对小鼠CD8+T细胞的研究来解决这个问题 识别正常黑素细胞抗原的细胞，我们通过一种形式的细胞- 内在的无能。在目标1中，我们探索这种无能的基础，建立在初步研究的基础上 自身反应性CD8+T细胞在激活和使用RNA-SEQ后是否容易发生凋亡细胞死亡 和ATAC-SEQ方法，以确定无能和染色质可及性状态 功能性CD8+T细胞。在目标2中，我们测试无能的可逆性，评估持续自我 抗原暴露在维持这种状态中的作用，我们正式探索Treg作为一种细胞外源性的潜在作用。 诱导或维持CD8+T细胞无能的机制。最后，在目标3中，我们考察了缺乏 生理性暴露在正常皮肤感染和炎症中可能会损害当前小鼠的价值 诱导自身免疫性白癜风的模型(CD8+T细胞破坏后正常黑素细胞的破坏 细胞对黑素细胞抗原的自我耐受性)。我们的研究利用了急性皮肤炎症和感染的模型， 也包括自然感染正常小鼠微生物的近交系小鼠(“正常微生物 体验“老鼠，也被称为”脏“老鼠)--我们在明尼苏达大学开发的一个模型 加强小鼠研究，提高与人类的相关性。

Summary Self-tolerance requires that auto-reactive T cells either be physically eliminated, sequestered away from self- antigen and/or incapacitated in their response to normal tissues. There have been many studies on deletional tolerance and “ignorance” of self-antigens among CD8+ T cells, but much less is understood about how anergy regulates that response T cell response. Studies on this issue are especially urgent, since recent data suggest that anergy is the prevalent mechanism of CD8+ T cell self-tolerance in humans – but we lack appropriate mouse models to investigate this critical mechanism. We address this issue with studies on mouse CD8+ T cells that recognize the normal melanocyte antigens, which we demonstrate are tolerant through a form of cell- intrinsic anergy. In Aim 1, we explore the basis for this anergy, building on preliminary studies to investigate whether self-reactive CD8+ T cells are prone to apoptotic cell death following activation and using RNA-seq and ATAC-seq approaches to define the gene expression and chromatin accessibility status of anergic versus functional CD8+ T cells. In Aim 2, we test the reversibility of anergy, evaluating the role of continued self- antigen exposure in maintaining this state, and we formally explore the potential role of Treg, as a cell-extrinsic mechanism of inducing or perpetuating CD8+ T cell anergy. Finally, in Aim 3, we examine how the lack of physiological exposure to normal skin infections and inflammation may compromise the value of current mouse models for induction of autoimmune vitiligo (destruction of normal melanocytes following breakdown of CD8+ T cell self-tolerance to melanocyte antigens). Our studies utilize models of acute skin inflammation and infection, and also inbred mice that have been naturally infected with normal mouse microbes (“normal microbial experience” mice, also called “dirty” mice) – a model which we developed at the University of Minnesota to enhance mouse studies with improved relevance to humans.