Definition of follicular stromal cell subset interactions with B cells

滤泡基质细胞亚群与 B 细胞相互作用的定义

• 批准号: 8492703
• 负责人: ANN M HABERMAN
• 金额: $ 8.31万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8492703
• 关键词: Activated Lymphocyte; Adjuvant; Antigens; Architecture; Area; Asses; B-Lymphocytes; Behavior; Blood; Bone Marrow; Cell Communication; Cells; Cellular Morphology; Chimera organism; Collection; Complex; Dendrites; Endothelial Cells; Environment; Event; Fingerprint; Follicular Dendritic Cells; Histology; Immune response; Immunization; In Situ; Laser Scanning Microscopy; Lymph; Lymph Node Subcapsular Sinus; Lymphocyte; Lymphocyte antigen; Lymphoid Tissue; Mediating; Morphology; Movement; Mus; Neighborhoods; Pericytes; Positioning Attribute; Relative (related person); Research Infrastructure; Reticular Cell; Role; Signal Transduction; Stromal Cells; Structure; Synapses; T-Lymphocyte; Testing; Time; Tissues; Vaccines; ameboid movement; base; cell motility; cell type; chemokine; chemokine receptor; intravital imaging; intravital microscopy; notch protein; pathogen; public health relevance; receptor expression; reconstruction; research study; response; two-photon

DESCRIPTION (provided by applicant): The initiation of immune responses within lymphoid tissue involves a carefully orchestrated movement of activated lymphocytes within an elaborate network of stationary stromal cells. Lymphoid tissue architecture is comprised of distinguishable microanatomic "neighborhoods" that are based on a complex arrangement of stromal cells. Due to the secretion of distinctive combinations of chemokines by stromal cell subsets, the chemokine fingerprint within B cell follicles is distinguishable from its neighboring T cell zone. Through shifts in chemokine receptor expression after activation, antigen engaged B and T cells reposition themselves to congregate within new niches, promoting their cognate encounters and enabling key steps in the differentiation of critical effectors. Although on a macro scale, the uniform distribution of na¿ve B cells throughout the follicle might suggest a similar uniformity in the stationary structural underpinnings, there are instead many stromal cell subsets positioned within follicles. In addition to the well characterized follicular dendritic cell (FDC), B cell folicles also harbor lymph and blood endothelial cells, the later covered by pericytes. Fibroblastic reticular cells rim the inside edge of the border of the follicle closest to the T cell zone, wheres the subcapsular sinus lining is a collection of yet more cell types including a marginal reticular cell with descending dendrites. Despite the critical role of stromal cells in defining the landmark for lymphocyte orientation during initial activation events, many fundamental aspects of B cell interactions with follicular stroma are unknown. Here we propose to examine the interactions between B cells and the stromal cell subsets that make up the follicular infrastructure. Aim 1: Define the stromal cell framework of B cell follicles. Using intravital microscopy of fluorescent bone marrow chimeras, the relative positioning of blood and lymph vessels vis-¿-vis FDCs and other intra-follicular stromal cells will be defined. We will assess the consistency of their juxtapositions, spacing and associated cell types before and after immunization. Aim 2: Define the propensity of na¿ve and activated B cells to interact with stromal cell subsets via intravital microscopy. The morphodynamics and mode of propulsion between B cells in contact with stroma will be compared to those within regions that lack stroma, and the impact of blood or lymph-borne antigen/adjuvants on this behavior determined. Motility parameters of na¿ve and activated B cells within stromal gaps will be quantified to test the hypothesis that such movement is transient and a directed shift from one stromal contact to another. Aim 3: Examine B cells in situ for intracellular indicators of potential signaling events during contacts with strmal cell subsets. B cells with synaptic morphology adjacent to stromal cells will be examined by histology for intracellular indicators of Notch, BMP and BCR mediated signaling coincident with stromal cell subset contacts. To test the hypothesis that such contacts support BCR derived tonic signaling, we will perform intravital imaging of B cells transfected with a NFAT-eGFP retroviral construct within LNs of fluorescent BM chimeras.

描述（由适用提供）：淋巴组织中免疫复杂的倡议涉及精心策划的固定基质细胞网络中活化淋巴细胞的策划运动。淋巴组织结构由基于基于基质细胞的复杂排列的独特微解剖学“邻域”组成。由于基质细胞亚集对趋化因子的独特组合分泌，因此B细胞福利中的趋化因子指纹与其相邻的T细胞区域可区分。通过激活后趋化因子受体表达的转移，抗原参与B和T细胞重新定位，以聚集在新的壁ches中，促进其同源相遇，并在分化关键效应的区分中实现关键步骤。尽管在宏观尺度上，整个叶片中Na�VEB细胞的均匀分布可能表明类似的均匀性 固定的结构基础，相反，有许多位于卵泡中的基质细胞子集。除了表征良好的卵泡树突状细胞（FDC）外，B细胞叶还含有淋巴和血液内皮细胞，后来被周细胞覆盖。成纤维细胞的网状细胞边缘边缘最接近T细胞区域的Follic边界的内部边缘，在该区域中，下囊窦内衬是较多的细胞类型的集合，包括基质细胞在定义LANDMARK在最初激活事件过程中淋巴细胞方向的地标在定义LANDMARK方面的关键作用，许多基本细胞相互作用是Foll follic follic的。在这里，我们建议检查构成卵泡基础设施的B细胞与基质细胞子集之间的相互作用。 AIM 1：定义B细胞的基质细胞框架。使用荧光骨髓嵌合体的浸润式显微镜，将定义血液和淋巴管的相对定位，而VIS FDC和其他热膜内基质细胞的相对定位。我们将评估免疫之前和之后的并置，间距和相关细胞类型的一致性。 AIM 2：定义NA¿VE和活化的B细胞通过插入显微镜与基质细胞亚群相互作用的希望。将与基质的B细胞接触的B细胞之间的形态动力学和推进模式将与缺乏基质的区域中的形态学和推进模式进行比较，以及血液或淋巴传播的抗原/辅助因素对确定这种行为的影响。 NA¿VE的运动参数和基质间隙中激活的B细胞的运动参数将被量化，以检验以下假设：这种运动是短暂的，并且是从一个基质接触到另一种运动的定向转移。 AIM 3：原位检查B细胞是否在与基质细胞亚群接触期间的潜在信号传导事件的细胞内指标。与基质细胞相邻的合成形态学的B细胞将通过组织学检查Notch，BMP和BCR介导的信号传导与基质细胞子集接触一致。为了测试这种接触支持BCR衍生的补品信号传导的假设，我们将对用NFAT-EGFP逆转录病毒构建体翻译的B细胞进行浸入式成像。