Cell decision underlying B-cell immune responses

项目总结/摘要 体液免疫应答的标志是两个阶段的抗体应答，第一阶段是快速的， 提供低亲和力抗体，第二种延迟一周发生，但提供高亲和力抗体 抗体的反应的两个阶段的适当平衡对于有效的免疫至关重要 反应 两个阶段的体液免疫应答由B细胞群体动态控制，B细胞群体动态代表了免疫应答。 由单个细胞决定是否进入生长期和细胞周期的组合， 导致分裂，存活还是死亡，以及是否分化为分泌抗体的浆细胞 和/或存储器B细胞。在任何给定的时间点，B细胞的命运都有很大的变化， 假设这是由于每一代个体细胞的随机命运决定。而我们 最近建立的长期显微镜工作流程显示，细胞具有高度确定性的命运， 决定，并且群体内的细胞间变异性主要是由于创始人的异质性。 细胞这使得体液免疫实质上更可预测，只要我们有一个机制， 了解分子网络如何控制B细胞在增殖和分化中的决策。 拟议项目的总体目标是建立定量理解和多尺度模型， 多二聚体NFκB系统如何控制B细胞决策以影响细胞存活、增殖和 分化 这些研究的主要假设是NFκB家族成员的协调动力学 RelA和cRel控制B细胞增殖和分化的定相，从而控制B细胞的亲和力、丰度和分化。 以及抗体的多样性，从而提高体液免疫应答的效力。 我们将用一个迭代系统生物学方法来解决这个假设，该方法分为以下三个部分： 具体目标： 1.描述NFκB系统动力学如何控制增殖B细胞的谱系 2.阐明NFκB系统动力学如何控制血浆B细胞分化 3. NF-κB系统对体液免疫的调控：低亲和力和高亲和力抗体应答的阶段性变化 每个目标都涉及新颖的多尺度数学建模和定量实验，包括 前所未有的长期显微镜，新的荧光报告小鼠品系，和单细胞基因组 技术.

Project Summary/Abstract A hallmark of the humoral immune response is a two phased antibody response, the first being rapid and providing for low affinity antibodies, and the second occurring with a week delay but providing high affinity antibodies. An appropriate balance of both phases of the response is critical for an effective immune response. The two phased humoral immune response is governed by B-cell population dynamics that represent the composite of the decisions made by individual cells whether to enter a growth phase and the cell cycle that results in division, whether to survive or die, and whether to differentiate into antibody secreting plasma cells and/or memory B-cells. At any given timepoint there is a great variety of B-cell fates, and prior studies assumed that this is due to stochastic fate decisions by individual cells at each generation. Instead, our recently established long-term microscopy workflow revealed that cells make highly deterministic fate decisions, and that the cell-to-cell variability within the population is largely due to heterogeneity in the founder cells. This renders humoral immunity substantially more predictable, so long as we have a mechanistic understanding of how molecular networks control B-cell decision making in proliferation and differentiation. The overarching goal of the proposed project is to develop quantitative understanding and multi-scale model of how the multi-dimeric NFκB system controls B-cell decision making to effect cell survival, proliferation, and differentiation. The overarching hypothesis of the proposed studies is that the coordinated dynamics of NFκB family members RelA and cRel control the phasing of B-cell proliferation and differentiation and thus the affinity, abundance and diversity of antibodies and hence efficacy of the humoral immune response. We will address this hypothesis with an iterative systems biology approach structured into following three Specific Aims: 1. Delineate how NFκB system dynamics control the lineages of proliferating B-cells 2. Delineate how NFκB system dynamics control plasma B-cell differentiation 3. NFκB system control of humoral immunity in vivo: phasing low and high affinity antibody responses Each Aim involves novel multiscale mathematical modeling and quantitative experimentation, including unprecedented long term microscopy, novel fluorescent reporter mouse strains, and single cell genomic technologies.