According to classical dogma, the central nervous system (CNS) is defined as an immune privileged space. The basis of this theory was rooted in an incomplete understanding of the CNS microenvironment, however, recent advances such as the identification of resident dendritic cells (DC) in the brain and the presence of CNS lymphatics have deepened our understanding of the neuro-immune axis and revolutionized the field of neuroimmunology. It is now understood that many pathological conditions induce an immune response in the CNS, and that in many ways, the CNS is an immunologically distinct organ. Hyperactivity of neuro-immune axis can lead to primary neuroinflammatory diseases such as multiple sclerosis and antibody-mediated encephalitis, whereas immunosuppressive mechanisms promote the development and survival of primary brain tumors. On the therapeutic front, attempts are being made to target CNS pathologies using various forms of immunotherapy. One of the most actively investigated areas of CNS immunotherapy is for the treatment of glioblastoma (GBM), the most common primary brain tumor in adults. In this review, we provide an up to date overview of the neuro-immune axis in steady state and discuss the mechanisms underlying neuroinflammation in autoimmune neuroinflammatory disease as well as in the development and progression of brain tumors. In addition, we detail the current understanding of the interactions that characterize the primary brain tumor microenvironment and the implications of the neuro-immune axis on the development of successful therapeutic strategies for the treatment of CNS malignancies.

中文翻译：

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自身免疫性疾病和原发性脑肿瘤中的神经炎症：寻求正确的平衡。

根据经典教条，中枢神经系统（CNS）被定义为免疫特权空间。该理论的基础植根于对中枢神经系统微环境的不完全理解，然而，最近的进展，例如大脑中常驻树突细胞（DC）的识别和中枢神经系统淋巴管的存在，加深了我们对神经免疫轴的理解并彻底改变了神经免疫学领域。现在人们了解到，许多病理状况会诱发中枢神经系统的免疫反应，并且在许多方面，中枢神经系统是一个免疫学上独特的器官。神经免疫轴的过度活跃可导致原发性神经炎症性疾病，如多发性硬化症和抗体介导的脑炎，而免疫抑制机制则促进原发性脑肿瘤的发展和生存。在治疗方面，人们正在尝试使用各种形式的免疫疗法来针对中枢神经系统病理。中枢神经系统免疫疗法研究最活跃的领域之一是治疗胶质母细胞瘤（GBM），这是成人中最常见的原发性脑肿瘤。在这篇综述中，我们提供了稳态神经免疫轴的最新概述，并讨论了自身免疫性神经炎症疾病以及脑肿瘤发生和进展中神经炎症的机制。此外，我们详细介绍了目前对原发性脑肿瘤微环境相互作用的理解，以及神经免疫轴对中枢神经系统恶性肿瘤成功治疗策略开发的影响。