The Contribution of B Lymphocyte to T1D Reversal by Imatinib

摘要 伊马替尼先前被用来预防和逆转NOD小鼠模型中的1型糖尿病(T1D) 加州大学旧金山分校的调查人员包括亚瑟·韦斯和杰弗里·布鲁斯通发现了这种疾病。与这些发现相关，并 由于酪氨酸激酶抑制剂伊马替尼对免疫细胞有很强的作用，目前正在进行临床试验。 对于新发病的T1D。伊马替尼治疗所需的细胞靶点尚未阐明，这可能 阻碍了这一原本很有希望的方法的成功临床翻译。在NOD小鼠中，自身反应B 淋巴细胞通过与胰岛反应性T细胞的相互作用成为疾病的关键驱动力。这 自身反应性T-B协作也仍然是我们对人类未来疾病的最佳预测指标，因为它导致 在T1D高危人群的血清中发现的自身抗体的产生。因为B 淋巴细胞在T1D进展中的这个关键节点起作用，我们假设它们可能是关键 伊马替尼保护作用的中介物。使用多种模型，其中我们在存在或存在的情况下建立T1D 缺乏B淋巴细胞，我们已经确定，在没有B淋巴细胞的情况下，伊马替尼永远不能逆转糖尿病 淋巴细胞。当B淋巴细胞存在时，伊马替尼的效果既快又持久；糖尿病 在几天内逆转，并在治疗停止后不会复发。当B淋巴细胞缺失时， 在任何时间范围内都不会对血糖产生影响。基于持久效应，我们假设伊马替尼 由控制免疫的B淋巴细胞诱导调节。在目标1中，我们通过以下方式探索这种免疫效应 用质量细胞术检测伊马替尼对哪些B淋巴细胞的调节作用 对新的B细胞亚群的影响，包括对自身抗原反应细胞的影响。我们进一步调查了 这些B淋巴细胞的免疫靶点及其作用机制。因为极快的效果是 仅发生在B淋巴细胞上，我们还假设伊马替尼对胰岛α细胞和β细胞有影响 通过其诱导的B淋巴细胞功能恢复功能。在目标2中，我们将探索这一创新 从B细胞依赖性研究免疫系统与胰岛细胞恢复之间的关系 对胰岛细胞质量、激素分泌和转录因子表达的治疗作用。总的来说，我们的 该方法将改变我们对B淋巴细胞在T1D靶向治疗中的作用的理解，通过定义它们的 诱导能力促进免疫耐受的恢复，同时增强胰岛细胞 功能恢复。

Summary Imatinib was previously established to prevent and reverse Type 1 diabetes (T1D) in the NOD mouse model of disease by investigators at UCSF including Arthur Weiss and Jeffrey Bluestone. Related to those findings and due to the potent action of imatinib, a tyrosine kinase inhibitor, on immune cells, it is presently in clinical trials for new onset T1D. The required cellular targets of imatinib therapy have not yet been elucidated, which may impede successful clinical translation of this otherwise promising approach. In the NOD mouse, autoreactive B lymphocytes are critical drivers of disease through their interactions with islet-reactive T cells. This autoreactive T-B collaboration also remains our best predictor of future disease in humans, as it results in the production of autoantibody that is found in the serum of individuals at high risk for T1D. Because B lymphocytes act at this critical node in T1D progression, we hypothesized that they could be the critical mediator of imatinib’s protective effect. Using multiple models in which we established T1D in the presence or absence of B lymphocytes, we have determined that diabetes is never reversed by imatinib in the absence of B lymphocytes. When B lymphocytes are present, the effect of imatinib is both rapid and durable; diabetes is reversed in a matter of days and does not recur after treatment is stopped. When B lymphocytes are absent, there is no effect on blood sugar in any time frame. Based on the durable effect, we hypothesize that imatinib has induced regulation by B lymphocytes that controls immunity. In Aim 1 we explore this immune effect by determining which B lymphocytes are modulated by imatinib using mass cytometry to identify the therapeutic effect on novel B cell subsets including the effect on autoantigen-reactive cells. We further investigate the immune targets of these B lymphocytes and the mechanism of effect. Because of the extremely rapid effect that only occurs with B lymphocytes, we also hypothesize that imatinib induces an effect on islet alpha and beta cell functional recovery through its induced B lymphocyte functions. In Aim 2, we will explore this innovative connection between the immune system and islet cell recovery by investigating the B cell dependent therapeutic effect on islet cell mass, hormone secretion, and transcription factor expression. Overall, our approach will shift our understanding of the role of B lymphocytes in targeted therapy for T1D by defining their inducible capacity to promote restoration of immune tolerance while simultaneously enhancing islet cell functional recovery.