Institute of Neuropathology, University Medical Center, Göttingen, Germany.
Department of Neurology, University Medical Center, Göttingen, Germany.
Acta Neuropathol. 2020 Oct;140(4):535-548. doi: 10.1007/s00401-020-02204-z. Epub 2020 Aug 6.
Anti-CD20-mediated B-cell depletion effectively reduces acute multiple sclerosis (MS) flares. Recent data shows that antibody-mediated extinction of B cells as a lasting immune suppression, harbors the risk of developing humoral deficiencies over time. Accordingly, more selective, durable and reversible B-cell-directed MS therapies are needed. We here tested inhibition of Bruton's tyrosine kinase (BTK), an enzyme centrally involved in B-cell receptor signaling, as the most promising approach in this direction. Using mouse models of MS, we determined that evobrutinib, the first BTK inhibiting molecule being developed, dose-dependently inhibited antigen-triggered activation and maturation of B cells as well as their release of pro-inflammatory cytokines. Most importantly, evobrutinib treatment functionally impaired the capacity of B cells to act as antigen-presenting cells for the development of encephalitogenic T cells, resulting in a significantly reduced disease severity in mice. In contrast to anti-CD20, BTK inhibition silenced this key property of B cells in MS without impairing their frequency or functional integrity. In conjunction with a recent phase II trial reporting that evobrutinib is safe and effective in MS, our mechanistic data highlight therapeutic BTK inhibition as a landmark towards selectively interfering with MS-driving B-cell properties.
抗 CD20 介导的 B 细胞耗竭可有效减少急性多发性硬化症(MS)的发作。最近的数据表明,抗体介导的 B 细胞耗竭作为一种持久的免疫抑制,随着时间的推移存在产生体液缺陷的风险。因此,需要更具选择性、更持久和更可逆的 B 细胞定向 MS 治疗方法。我们在此测试了布鲁顿酪氨酸激酶(BTK)的抑制,作为该方向最有希望的方法,BTK 是一种在 B 细胞受体信号传导中起核心作用的酶。使用 MS 的小鼠模型,我们确定正在开发的第一个 BTK 抑制分子依鲁替尼可剂量依赖性地抑制抗原触发的 B 细胞激活和成熟以及它们释放促炎细胞因子。最重要的是,依鲁替尼治疗可使 B 细胞作为抗原呈递细胞为致脑炎 T 细胞的发育的功能受损,导致小鼠疾病严重程度显著降低。与抗 CD20 不同,BTK 抑制在 MS 中沉默了 B 细胞的这一关键特性,而不损害其频率或功能完整性。结合最近一项报道依鲁替尼在 MS 中安全有效的 II 期试验,我们的机制数据强调了治疗性 BTK 抑制是选择性干扰 MS 驱动的 B 细胞特性的一个里程碑。