Regulating Pathogen-induced Protective and Pathogenic CD8 T cells in the CNS

神经系统疾病是导致死亡和残疾的主要原因，尽管病因多种多样，但 免疫功能障碍的共同主题。免疫系统和神经系统都能很好地适应 感知并协调对外部刺激的反应。大脑中有数十亿个神经元，但我们知道 几乎没有关于脑神经元如何与中枢神经系统中的免疫系统交互作用的内容。的最新进展 神经免疫学包括脑膜淋巴管的发现，免疫细胞在中枢神经系统内稳态中的作用 以及在中枢神经系统感染后持续存在于大脑中的组织驻留记忆T细胞(Trm)的特征。我们 最近(Urban等人，自然免疫学，2020)提供的证据表明，Trm也是在 外周免疫和感染后的大脑，表明大脑特有的过程可能 在外周免疫后，培养Trm在该器官中的持久性。然而，目前还不清楚是否有特定的神经元 大脑中的通路有助于Trm的产生或在该器官中的持久性，以及神经元信号转导 影响中枢神经系统Trm的保护。 人类中的几种中枢神经系统疾病都有免疫学病因，T细胞被认为与 病毒性脑炎(VE)、脑型疟疾(CM)的发病机制因此，第二个未知的是大脑的作用 T细胞介导的中枢神经系统疾病中的神经元信号通路。 我们将使用化学遗传学来解决这些问题。具体地说，有高度保守的神经元 在脑干内，如中缝背核(DR)，它广泛投射到整个CNS并在 对免疫相关信号的反应，如压力、疼痛和瘙痒。表达SERT-的转基因B6小鼠 CRE以DR神经元为靶点。表达FLOX/Stop Designer的腺相关病毒的立体定向注射 由特制药物(DREADD)特异性激活的受体只在cre-1中表达DREADD。 表达神经元。通过mCherry表达检测到转导的cre表达的神经元，并可以 根据它们的性质(由精确的DREADD指定的激活或抑制信号)，由 注射一种设计好的配体。我们已经获得了这些小鼠和病毒系统，并提供了我们能力的证据 进行复杂的立体定向手术，并将DREADD结构传递给目标神经元。 我们将利用化学遗传学技术和我们的能力来评估中枢神经系统免疫和免疫介导性 发病机制以检验脑神经元信号通路参与脑出血的中心假说 中枢神经系统Trm的产生、维持和功能与T细胞介导的中枢神经系统疾病的转归 具体目标1.确定DR神经元信号是否调节神经元的产生、维持或保护 脑Trm的功能 特定目的2.确定DR神经元信号是否调节CD8 T细胞介导的淋巴细胞 脉络膜脑膜炎病毒(LCMV)可引起VE或实验性脑型疟疾(ECM)。

Neurological diseases are a leading cause of death and disability, and despite diverse etiologies, share a common theme of immunological dysfunction. The immune and nervous systems are finely tuned to both sense and orchestrate responses to external stimuli. There are billions of neurons in the brain, yet we know next to nothing about how brain neurons interface with the immune system in the CNS. Recent advances in neuroimmunology include the discovery of meningeal lymphatic, roles for immune cells in CNS homeostasis and characterization of tissue resident memory T cells (Trm) that persist in the brain after CNS infection. We recently (Urban et al, Nature Immunology, 2020) provided evidence that Trm were also generated uniquely in the brain after peripheral immunizations and infections, suggesting that processes unique to the brain may foster Trm persistence in this organ after peripheral immunization. However, it is unknown if specific neuronal pathways in the brain contribute to Trm generation or persistence in this organ and whether neuronal signaling influences protection by CNS Trm. Several CNS diseases in humans have immunological etiologies, with T cells thought contribute to the pathogenesis of viral encephalitis (VE), cerebral malaria (CM) Thus, a second unknown is the role of brain neuronal signaling pathways in T cell-mediated diseases of the CNS. We will attack these problems using chemogenetics. Specifically, there are highly conserved neurons within the brainstem, such as the dorsal raphe (DR), which project broadly throughout the CNS and activate in response to immunity-relevant signals such as stress, pain, and itch. Transgenic B6 mice expressing SERT- cre target DR neurons. Stereotaxic injection of adeno-associated viruses expressing flox/stop designer receptors exclusively activated by designer drugs (DREADD), results in expression of the DREADD only in cre- expressing neurons. Transduced cre-expressing neurons are detected by mCherry expression and can be manipulated, depending on their nature (activating or inhibitory signals specified by the precise DREADD), by injection of a designer ligand. We have obtained these mice and virus systems and provided proof of our ability to perform the sophisticated stereotaxic surgeries and deliver the DREADD constructs to the targeted neurons. We will use the chemogenetic technology and our capacity to evaluate CNS immunity and immune-mediated pathogenesis to test the central hypothesis that brain neuronal signaling pathways contribute to the generation, maintenance and function of CNS Trm and the outcome of T cell-mediated CNS diseases. Specific Aim 1. Determine if DR neuronal signaling regulates the generation, maintenance or protective function of brain Trm. Specific Aim 2. Determine if DR neuronal signaling regulates CD8 T cell-mediated lymphocytic choriomeningitis virus (LCMV) induced VE or experimental cerebral malaria (ECM).