Lymphocyte Dynamics

淋巴细胞动力学

基本信息

批准号：
8946366
负责人：
William Paul
金额：
$ 99.94万
依托单位：
NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/8946366
关键词：
Adjuvant Age Antigens Blastomyces CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CD8B1 gene Cell Count Cells Cessation of life Complex Computational Biology Emigrant Frequencies Genes Goals HIV HIV Infections Heating Homeostasis IL2RA gene Immune response Immunization Individual Infection Interferon Type I Interleukin-1 Interleukin-10 Interleukin-12 Interleukin-17 Knock-out Lead Life Ligands Listeria monocytogenes Liver Lung Lymphocyte Lymphocyte Count Lymphocytic choriomeningitis virus Measurement Measures Mediating Memory Molecular Mus NR4A1 gene Natural Killer Cells Neonatal Pattern Peptide/MHC Complex Peptides Peripheral Phenotype Physiological Population Process Production Proliferating Proteins RNA Recording of previous events Regimen Regulation Relative (related person)Role SIV Self Stimulation Series Specificity T cell response T-Cell Depletion T-Cell Proliferation T-Lymphocyte TLR3 gene Time Tissues Transgenic Organisms Vaccines Vaccinia Vaccinium antigen challenge base cytokine granzyme B in vivo insight interdisciplinary approach killings lymphocyte proliferation memory CD4 T lymphocyte migration pathogen receptor response tool development

项目摘要

Lymphocyte numbers are regulated both by responses to conventional exogenous antigens and endogenous microflora, by stimulation by self-peptide/MHC complexes and by the action of a series of cytokines. This multifaceted regulation permits individuals to maintain a broad repertoire of lymphocytes of distinctive specificities, allowing responses against a vast array of foreign substances and, at the same time, providing a pattern of memory based on the immunization history of the individual. The study of the process of lymphocyte dynamics that underlies this regulation requires a multidisciplinary approach, aimed both at the molecular underpinnings of the processes through which lymphocytes survive and proliferate and a systemics/ computational biology approach to appreciate the overall mechanisms governing total numbers of lymphocytes of distinct phenotype and distinct specificity. Emphasis has been placed on four aspects of this problem: the priming, expansion and differentiated phenotype of naive CD4 T cells in response to antigen challenge, the dynamics of lymphocyte memory and of memory phenotype cells, the mechanisms underlying CD4 T cell depletion in HIV infection, and the process of homeostatic proliferation and death. In an effort to develop strategies to enhance response of nave and memory cells to their cognate antigens, it was observed that the most potent stimulant of such expansion was the cytokine IL-1. When expansion of CD4 TCR transgenic T cells in a syngeneic host in response to antigen was measured, it was found that administering IL-1 over a 3 to 5 day period caused a ten-fold or greater enhancement in the degree of expansion when compared to that seen using conventional adjuvants such as LPS. This was equally true for naive and memory cells and was not mediated by other cytokines. The effect could only be partially explained by enhanced proliferation so that greater survival was also implicated. The use of recipients that were IL-1 receptor knockouts and IL-1 receptor-sufficient donors of TCR transgenic T cells showed that IL-1 could act directly on the responding CD4 or CD8 T cells to mediate expansion. The IL-1 receptor antagonist diminished the adjuvant effect of LPS indicating that a substantial portion of the effect of this conventional adjuvant was due to endogenous production of IL-1. Initial analysis of genes activated and suppressed in cells responding to antigen in the presence of LPS suggest avenues for further analysis that may lead to a mechanistic understanding of the IL-1 effect. The very robust effect of IL-1 suggests it may have a role in certain immunization strategies. IL-1 acts directly on CD4 T cells to enhance their differentiation into IL-17 producing cells. However, although IL-1 acts directly on CD8 cells to mediate their expansion, differentiation of CD8 into efficient cytotoxic cells requires the action of IL-1 on non T cells. IL-1 strikingly enhances the frequency of effector/memory CD8 T cells that migrate into peripheral tissues such as lung and liver. Such migration requires expression of IL-1R1 on a cell other than the responding T cells. Strikingly, the effects of IL-1 during priming are retained at the time of secondary challenge even though IL-1 is not administered again. Thus, the secondary response in mice primed in the presence of IL-1 includes increased in numbers of antigen-specific effector CD8 T cells, a greater presence in the tissues, and the expression of large amounts of granzyme B. Administration of IL-1 with weak vaccines, such as heat killed Listeria monocytogenes, the gD2 protein of H. simplex, heat killed Blastomyces or peptides associated with vaccinia, result strikingly enhances their protective capacity. Memory CD4 T cell proliferation was shown to be quite slow. Specific T cells from mice infected with LCMV divide at a rate of <2% per day. By contrast CD44bright CD25- CD4 T cells divide much more rapidly, at 8 to 10% per day. This rapid steady state proliferation of "memory phenotype" CD4 T cells is similar in conventional and germfree mice. Analysis of the repertoire of memory phenotype undergoing proliferation revealed no difference in receptor complexity from that of non-dividing memory phenotype cells. This implies that division is largely stochastic and probably dominantly driven by cytokines or other endogenous ligands rather than by peptide/ MHC complexes, whether of exogenous or endogenous origin. Memory phenotype and authentic memory cells differ from one another not only in their proliferative rates but, based on an RNA-SEQ analysis, also on the expression of NUR77, the latter being highly expressed on authentic memory cells even 30 days after priming, when they are already quiescent. Interestingly, in neonatal mice, the memory phenotype pool is efficiently colonized and preliminary results suggests that after 2 weeks of age, thymic emigrants enter the pool very inefficiently. We suspect then that the memory phenotype pool represents a set of self-specific cells generated early in the life of the individual and capable of producing Th1, Th2 or Th17 type cytokines early in infections as a results of stimulation of these cells through key cytokines, self-peptide mHC complexes or a combination of the two. In a sense, these cells are adaptive Th cells with a potent innate functionallity Efforts to understand the role of distinct priming regimens to induce particular phenotypic CD4 T cells responses to lung immunization reveal a profound effect of different "adjuvants". Priming in the presence of LPS leads to a TH17 response whereas priming in the presence of polyI:C to an exclusive IFNgamma response. Based on studies with KO mice, the results have been interpreted as indicated that LPS, through its activation of Myd88, results in robust IL-10 production, blocking IL-12 production and Th1 priming. In parallel, though its activation of TRIF/TRAM, LPS activates IL-1 production, markedly enhancing Th17 priming. By contrast, polyI:C, acting through TLR3 and TRIF activates type I interferon and IL-12, enhancing IFNgamma priming and blocking Th17 induction. These results give important insight into the precise regulation of CD4 T cells responses to distinct pathogens in the lung.

淋巴细胞数通过对常规外源抗原和内源性菌群的反应，通过自肽/MHC复合物刺激以及一系列细胞因子的作用来调节淋巴细胞。这种多方面的调节允许个人维持广泛的特异性淋巴细胞，允许针对各种异物的反应，同时，基于个体的免疫历史提供了记忆模式。该调节基础的淋巴细胞动力学过程的研究需要多学科的方法，这既针对淋巴细胞生存和增殖的过程的分子基础，又是一种系统/计算生物学方法，以欣赏整体机制的总体机制，构成了不同的淋巴结型和不同型的型物型。重点已放在此问题的四个方面：启动，扩张和分化的CD4 T细胞的启动，淋巴细胞记忆和记忆表型细胞的动力学，HIV感染中CD4 T细胞耗竭的机制以及稳态增殖和死亡的过程。为了制定增强中殿和记忆细胞对同源抗原的反应的策略，观察到这种扩张中最有效的刺激物是细胞因子IL-1。当测量合成宿主中CD4 TCR转基因T细胞的膨胀时，与使用常规辅助剂（如LPS（如LP）相比，在3至5天内给予IL-1在膨胀程度上施用IL-1。对于天真和记忆细胞而言，这同样是正确的，并且不是由其他细胞因子介导的。这种效果只能通过增强的增殖来部分解释，因此也涉及更大的生存。使用IL-1受体敲除和TCR转基因T细胞的IL-1受体充满供体的受体的使用表明，IL-1可以直接作用于反应的CD4或CD8 T细胞上以介导膨胀。 IL-1受体拮抗剂减少了LP的辅助作用，表明该常规辅助剂的很大一部分是由于内源性产生IL-1所致。在LPS存在下对抗原反应的细胞中激活和抑制的基因的初步分析提出了进一步分析的途径，这可能会导致对IL-1效应的机械理解。 IL-1的非常强大的作用表明它可能在某些免疫策略中起作用。 IL-1直接作用于CD4 T细胞，以增强其分化为IL-17产生的细胞。但是，尽管IL-1直接作用于CD8细胞以介导其膨胀，但将CD8分化为有效的细胞毒性细胞需要IL-1对非T细胞的作用。 IL-1明显地增强了效应子/记忆CD8 T细胞的频率，这些细胞迁移到肺和肝脏等周围组织。这种迁移需要在反应T细胞以外的细胞上表达IL-1R1。令人惊讶的是，即使不再施用IL-1，IL-1在次要挑战时仍保留IL-1的效果。因此，在IL-1存在下引发的小鼠中的次级反应包括抗原特异性效应的CD8 T细胞的数量增加，在组织中较大的存在以及大量粒酶B的表达。用弱疫苗（例如热量杀死李斯特氏菌基因生成液），单纯烟的GD2蛋白，热量杀死的胚乳或与疫苗相关的肽的疫苗给予IL-1，从而显着增强了其保护能力。记忆CD4 T细胞增殖表明非常慢。来自感染LCMV的小鼠的特异性T细胞以<2％的速率分裂。相比之下，CD44Bright CD25- CD4 T细胞以每天8至10％的速度更快地分裂。在常规小鼠和无毛虫小鼠中，“记忆表型” CD4 T细胞的这种快速稳态增殖相似。对发生增殖的记忆表型曲目的分析表明，受体复杂性与非分散记忆表型细胞的复杂性没有差异。这意味着分裂在很大程度上是随机的，并且可能主要由细胞因子或其他内源配体驱动，而不是由肽/ MHC复合物（无论是外源性还是内源性起源）驱动。记忆表型和真实的记忆细胞不仅在其增殖速率上相互不同，而且基于RNA-seq分析，也基于NUR77的表达，即使在启动后30天，后者也已经在正宗的记忆细胞上高度表达。有趣的是，在新生儿小鼠中，记忆表型池有效地定殖，初步结果表明，两周龄后，胸腺移民非常效率低下。然后，我们怀疑记忆表型池代表了个体生命早期产生的一组自我特异性细胞，并能够在感染早期产生Th1，Th2或Th17型细胞因子，这是通过关键细胞因子，自肽MHC MHC复合物或两者组合刺激这些细胞的结果。从某种意义上说，这些细胞是具有有效的先天功能性的自适应TH细胞了解不同的启动方案诱导特定表型CD4 T细胞对肺部免疫的作用的努力揭示了不同的“佐剂”的深刻作用。在存在LPS的情况下进行启动会导致Th17响应，而在Polyi：C存在下启动对独家IFNGAMMA响应。基于对KO小鼠的研究，结果已解释为表明，LPS通过其激活MyD88的激活导致IL-10产生的稳健IL-10产生，从而阻止了IL-12的产生和Th1启动。同时，尽管它激活了TRIF/TRAM，但LPS激活IL-1的产生，显着增强了Th17启动。相比之下，通过TLR3和TRIF作用Polyi：C激活I型干扰素和IL-12，从而增强IFNGAMMA启动并阻止Th17诱导。这些结果使人们对CD4 T细胞对肺中不同病原体的反应的精确调节具有重要的见解。