TERTIARY LYMPHOID ORGANS IN TYPE I DIABETES MELLITUS

这项工作的长期目标是了解I型糖尿病的发病机制，重点是阐明炎症和决定因素传播的机制。有待检验的假设是，作为许多自身免疫性疾病特征的局部三级淋巴器官对IDDM至关重要。 在胰岛素启动子控制下的胰高血糖素（LT α; TNF β）转基因小鼠（RIPLT小鼠）在胰腺和肾脏中表达转基因，并在这些部位发生炎症。 胰岛炎和肾炎具有淋巴结（LN）特征，包括T、B细胞区室化，抗原呈递细胞（FDC和DC），具有高内皮微静脉（HEV）形态和抗原（MAdCAM-1和PNAd）特征的血管，免疫后分泌特异性IgG的浆细胞。 这个过程，称为淋巴新器官形成，需要TNFR 1，并可能是一个模型的LT的作用，在发展中，因为小鼠缺乏LT/TNF家族的成员有深刻的缺陷，在淋巴器官。 LT β R促进PNAd表达并影响三级淋巴器官中幼稚细胞的比例。趋化因子（RANTES、MCP-1和IP-10）在RIPLT胰岛中被诱导。 当RIPLT小鼠与RIPB 7小鼠杂交时，发生糖尿病。 具体目标是：1.通过将RIPLT小鼠与RIPLT胰岛中诱导的趋化因子（MCP-1）或鉴定为参与淋巴器官发育和单核细胞运输（BRL-1）的趋化因子缺陷的小鼠杂交并通过原位杂交来鉴定趋化因子在胰岛三级淋巴器官中的作用; 2.用β细胞特异性LT四环素（Dox）诱导系统表征三级淋巴器官的动力学; 3.确定胰岛浸润物是否是能够呈递内源性（Y-Ae）和外源性抗原的功能性淋巴器官; 4.确定胰岛浸润物是否为能够对抗原应答的功能性淋巴器官; 5.发现决定簇扩散是否发生在LT诱导的糖尿病中，以及这一过程是否需要三级淋巴器官的维持。 这些研究将提供深入了解抗原是如何和在哪里提出的炎症自身免疫集中在确定细胞，分子和解剖学的要求，这一过程。 它们还提供了对发育中淋巴器官的细胞因子诱导机制的深入了解。 了解胰岛三级淋巴器官的建立和功能将有助于确定决定簇扩散和IDDM组织损伤的治疗靶点。

The long term objective of this work is to understand the pathogenesis of Type I diabetes mellitus with an emphasis on elucidating mechanisms of inflammation and determinant spreading. The hypothesis to be tested is that tertiary lymphoid organs at the local site, which are characteristic of many autoimmune diseases, are crucial for IDDM. Mice transgenic for lymphotoxin (LTalpha; TNFbeta) under the control of the insulin promoter (RIPLT mice) express the transgene in the pancreas and kidney and develop inflammation at those sites. The insulitis and nephritis have lymph node (LN) characteristics, including T, B cell compartmentalization, antigen presenting cells (FDC and DC), vessels with the morphologic and antigenic (MAdCAM-1 and PNAd) characteristics of high endothelial venules (HEV), and plasma cells secreting specific IgG after immunization. This process, termed lymphoid neo-organogenesis, requires TNFR1 and may be a model for LT's role in development since mice deficient in members of the LT/TNF family have profound defects in lymphoid organs. LTbetaR contributes to PNAd expression and influences the ratio of naive cells in the tertiary lymphoid organ. Chemokines (RANTES, MCP-1, and IP-10) are induced in RIPLT islets. When RIPLT mice are crossed to RIPB7 mice, diabetes occurs. The specific aims are to: 1. Identify the role of chemokines in islet tertiary lymphoid organs by crossing RIPLT mice with mice deficient in chemokines induced in RIPLT islets (MCP-1) or identified to be involved in lymphoid organ development and mononuclear trafficking (BRL-1) and by in situ hybridization; 2. Characterize the kinetics of tertiary lymphoid organs with a beta cell specific LT tetracycline (Dox) inducible system; 3. Determine whether the islet infiltrate is a functional lymphoid organ capable of presenting endogenous (Y-Ae) and exogenous antigen; 4. Determine whether the islet infiltrate is a functional lymphoid organ capable of responding to antigen; 5. Discover whether determinant spreading occurs in LT-induced diabetes and if maintenance of a tertiary lymphoid organ is required for this process. These studies which will provide insight into how and where antigens are presented in inflammatory autoimmunity concentrate on identifying cellular, molecular, and anatomic requirements for this process. They also provide insight into the mechanism of cytokine induction of lymphoid organs in development. Understanding how islet tertiary lymphoid organs are established and function will allow identification of therapeutic targets for determinant spreading and tissue damage in IDDM.