Role of HLA class II genes in demyelination

描述（由申请人提供）：多发性硬化（MS）的易感性与某些HLA II类基因有关，尽管对其确切功能的分析仍然很复杂。我们最近在缺乏所有内源性II类基因的新的完全II类敲除MHCII-/-小鼠（由Benoist和马西斯产生）的背景下产生了人源化II类转基因小鼠（AEo）。与我们的“Abo”转基因小鼠相反，在这个新的转基因系“AEo”中，T细胞在其细胞表面上表达II类，并且也可以呈递抗原。PLP 91 -110肽在HLA-DR 3.AEo小鼠中诱导严重的EAE，其特征在于与DR 3. Abo小鼠相比，疾病发作早且发病率增加。患有EAE的进一步小鼠在CMS中显示出严重的炎症和脱髓鞘。因此，我们的新转基因系以T细胞上MHC II类表达的形式以及严重的CNS脱髓鞘来模拟人MS。我们假设在自身免疫性疾病如MS中，表达II类的自身反应性CD 4 + T细胞可以在CNS内呈递额外的髓鞘抗原，从而传播最终导致CNS损伤的炎症反应。使用这种疾病模型，我们将首先探索人类II类在疾病过程中的作用，特别强调神经功能缺损和CNS组织病理学。在CNS病理学中，我们将评估脊髓中脱髓鞘、髓鞘再生和轴突缺失的程度以及脑中炎症、神经元坏死和白色物质脱髓鞘的程度。接下来，我们将分析II类在脑和脊髓的不同区域以及CNS浸润细胞中的表达及其在调节疾病发病机制中的作用。我们还将分析CD 4 T细胞和CDS T细胞在EAE的发病机制和调节中的作用，因为已经表明它们在MS/EAE中可以发挥致病和保护作用。接下来，我们也将分析辅助分子、共刺激分子和细胞因子在调节疾病中的作用和贡献。最后利用双转基因小鼠研究DR和DQ基因互补对易感HLA II类转基因小鼠疾病发生和发展的影响。在这个建议中概述的综合研究应产生一个深入了解HLA II类基因在人类多发性硬化症的易感性，发病，进展，严重程度，调制和干预的作用。最后，这种新的人源化II类EAE模型可能为MS的发病机制提供新的见解。

DESCRIPTION (provided by applicant): Susceptibility to multiple sclerosis (MS) has been linked to certain HLA class II genes, although analysis of their exact function remains complicated. We have recently generated humanized class II transgenic mice (AEo) in the context of the new complete class II knockout MHCII-/- mice (produced by Benoist and Mathis) lacking all endogenous class II genes. In contrast to our "Abo" transgenic mice, in this new transgenic line "AEo", T cells express class II on their cell surface and can also present antigen. PLP91-110 peptide induced a severe EAE in HLA-DR3.AEo mice characterized by early disease onset and increased disease incidence as compared to DR3.Abo mice. Further mice with EAE showed severe inflammation and demyelination in CMS. Thus our new transgenic line simulates human MS both in form of expression of MHC class II on T cells as well as severe CNS demyelination. We hypothesize that in autoimmune diseases such as MS, auto- reactive CD4+ T cells expressing class II can present additional myelin antigen inside CNS thus propagate the inflammatory response which ultimately leads to CNS injury. Using this disease model, we will first explore role of human class II in the disease process with particular emphasis on neurological deficits and CNS histopathology. In CNS pathology, we will assess extent of demyelination, remyelination and axonal loss in spinal cord as well as the extent of inflammation, neuronal necrosis and white matter demyelination in brain. Next, we will analyze the expression of class II in different regions of brain and spinal cord as well as on CNS infiltrating cells and its role in modulating disease pathogenesis. We will also analyze role of CD4 T cells and CDS T cells both in pathogenesis as well as regulation of EAE as it has been suggested that they can play both pathogenic and protective role in MS/EAE. Next we will also analyze role and contribution of accessory molecules, costimulatory molecules, and cytokines in modulating the disease. Finally using double transgenic mice, we will study that how gene complementation between DR and DQ gene affect the disease initiation and progression in a susceptible HLA class II transgenic mice. The comprehensive studies outlined in this proposal should yield an insight into the role of HLA class II genes in predisposition, onset, progression, severity, modulation, and intervention of human multiple sclerosis. Finally, this new humanized class II model of EAE may provide new insight into the pathogenesis of MS.