Cell decision underlying B-cell immune responses

项目摘要/摘要 体液免疫反应的一个特点是有两个阶段的抗体反应，第一个阶段是快速和 提供低亲和力抗体，第二次出现延迟一周但提供高亲和力 抗体。反应的两个阶段的适当平衡对于有效的免疫是至关重要的 回应。 两个阶段的体液免疫反应受代表B细胞群动态的B细胞支配 单个细胞是否进入生长期的决定和细胞周期的综合 导致分裂，是生存还是死亡，以及是否分化为分泌抗体的浆细胞 和/或记忆B细胞。在任何给定的时间点，B细胞的命运都是多种多样的，以前的研究 假设这是由于每一代个体细胞的随机命运决定。相反，我们的 最近建立的长期显微镜工作流程显示，细胞决定着高度确定的命运 决策，以及种群内细胞间的可变性很大程度上是由于创始人的异质性 细胞。这使得体液免疫更容易预测，只要我们有一个机械性的 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开发定量理解和多尺度模型 多二聚体核因子κB系统如何控制B细胞的决策，从而影响细胞的存活、增殖和 差异化。 拟议研究的首要假设是，NFκB家族成员的协调动力学 RelA和cRel控制B细胞增殖和分化的时相，从而控制亲和力、丰度 和抗体的多样性，因此体液免疫反应的有效性。 我们将用迭代的系统生物学方法解决这个假设，该方法分为以下三个部分 具体目标： 1.描述核因子κB系统动力学如何控制增殖的B细胞谱系 2.描述核因子κB系统动力学如何控制血浆B细胞分化 3.体内体液免疫的核因子κB系统调控：分阶段低亲和力抗体应答和高亲和力抗体应答 每个目标都涉及新的多尺度数学建模和定量实验，包括 史无前例的长期显微镜、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.