Very early plasma cell differentiation

摘要 活化的B细胞启动抗体合成的生化途径 和分泌，同时进行细胞分裂是未知的。电流 模型预测，早期的浆细胞产生细胞器结构， 通过激活未折叠蛋白反应（UPR）来应答， 增加抗体的合成，并通过有丝分裂依赖的过程。这个项目 中心是另一种模型，其中活化的B细胞为浆细胞功能做准备 通过在增加抗体合成之前制定普遍定期审议， 分裂。因此，我们认为B细胞中UPR的诱导与它的作用一样积极。 是反应性的。我们将测试这个新模型，同时也剖析过去的观察， 边缘区B细胞比大多数B细胞更快地产生浆细胞。我们提出 三个具体目标：1）定义协调早期PC的生化途径 2）确定组成型mTORC 1信号在MZ B细胞中的作用 3）解偶联有丝分裂和早期PC分化。

Abstract The biochemical pathways through which activated B cells initiate antibody synthesis and secretion while simultaneously undergoing cell division are unknown. Current models predict that early plasma cells generate the organelle structures needed for robust antibody secretion by activating the unfolded protein response (UPR) in response to increased antibody synthesis and through a mitosis-dependent process. This project centers on an alternative model where activated B cells prepare for plasma cell function by enacting the UPR well before increased antibody synthesis and independently of mitosis. Hence we propose that induction of the UPR in B cells is as much proactive as it is reactive. We will test this new model while also dissecting the past observations that marginal zone B cells generate plasma cells much faster than most B cells. We propose three specific aims: 1) Define biochemical pathways coordinating very early PC differentiation, 2) Define the role of constitutive mTORC1 signaling in MZ B cell differentiation, and 3) Uncouple mitosis and early PC differentiation.