AKNA, germinal center reaction and immunity.

体液免疫反应是由次级淋巴中富含T细胞的区域的B细胞激活引起的 导致生发中心(GC)前体募集到次级毛囊的器官，在那里它们分化 转化为存储单元。B细胞的激活需要同源受体/配体的相互作用，其中，B-cetl-1的连接 CD40通过T细胞CD40配体(CD154)为细胞的增殖、存活和B细胞的诱导提供必要的刺激。 细胞记忆。本研究对生发中心B-AKNA表达的AT-Hook蛋白AKNA进行了研究。 淋巴细胞与富含A/T的CD40和CD154启动子调控元件结合并调节其转录。在……里面 与这一概念一致，小鼠AKNA(MoAKNA)也是一种由B和T淋巴细胞表达的核蛋白， 展示AT-钩状DNA结合基序，上调CD154并诱导CD40表达。总的来说，这些 研究结果表明，AKNA在调节GCs内的Ag依赖反应中发挥作用。具体目标是： 1.体外研究AKNA在基因转录中的作用。利用小鼠模型，我们将确定moAKNA 在CD40、CD154等基因靶点表达中的作用。我们将研究moAKNA介导的机制 基因调控，并评估其DNA结合要求和特异性。2.检查moAKNA是否 由树突状细胞(DC)表达，以及它是否在DC成熟和功能中起作用，moAKNA表达将 体内依赖Fit3配体(FItL)的DC动员和不同阶段特异性DC的分选后进行分析 子集。我们还将检查AKNA的表达是否随着抗原提呈细胞的获得而达到峰值 (APC)表型和CD40、CD154.3的表达。在体内评估AKNA功能的意义。 将产生AKNA缺陷小鼠，以阐明其在免疫反应中的功能。我们将研究一下 免疫后二次免疫反应的发展，检查共刺激分子的表达， 生发中心的形成和抗体的产生。淋巴样结构、细胞的组织学分析 增殖、表型、CD40和CD154的表达以及血清Ig的测定将评估是否存在 缺乏功能成熟的B淋巴细胞库。树突状细胞的成熟及其刺激抗原和T细胞的能力 我们将研究CD40/CD154依赖的方式。胸腺内T细胞的分化、选择及其能力 家中的次级卵泡和提供同源帮助的人将接受测试。AKNA缺陷细胞的免疫功能将 在体内和体外检测它们对抗原刺激的反应、增殖、产生抗体和/或 细胞因子，对生存/死亡信号作出反应，并发展免疫记忆。

Humoral immune responses are initiated by the activation of B cells in the T cell-rich areas of secondary lymphoid organs that lead to the recruitment of germinal center (GC) precursors into secondary follicles, where they differentiate into memory cells. B cell activation requires cognate receptor/ligand interactions, among which, the ligation of B cetl- CD40 by the T celI-CD40 ligand (CD154) provides the essential stimuli for cell proliferation, survival, and induction of B cell memory. The present study focuses on the AT-hook protein AKNA that is expressed by germinal center B- lymphocytes, binds to A/T-rich regulatory elements of CD40 and CD154 promoters and regulates their transcription. In keeping with this notion, mouse AKNA (moAKNA) is also a nuclear protein that is expressed by B and T lymphocytes, exhibits the AT-hook DNA-binding motifs, upregulates CD154 and induces the expression of CD40. Collectively these findings suggest that AKNA plays a role in the regulation of Ag-dependent responses within GCs. The specific aims are: 1. To assess in vitro the role of AKNA in gene transcription. Using the murine model, we shall determine moAKNA's role in the expression of CD40, CD154 and other gene targets. We shall study the mechanisms of moAKNA-mediated gene regulation and assess its DNA-binding requirements and specificity. 2. To examine whether moAKNA is expressed by dendritic cells (DC) and whether it plays any role in DC maturation and function, moAKNA expression will be analyzed following in vivo Fit3 ligand(FItL)-dependent DC mobilization, and sorting of distinct stage-specific DC subsets. We shall also examine whether AKNA expression peaks with the acquisition of the antigen presenting cell (APC) phenotype and the expression of CD40 and CD154.3. To assess in vivo the significance of AKNA's function. AKNA-deficient mice will be generated to elucidate its function in the immune response. We shall examine the development of secondary immune responses after immunization, examine the expression of costimulatory molecules, formation of germinal centers and antibody production. The histological analysis of lymphoid architecture, cell proliferation, phenotype, CD40 and CD154 expression, and determination of serum Ig will assess the presence or absence of functional mature B lymphocyte repertoires. DC maturation and their ability to stimulate T cells in an Ag and CD40/CD154-dependent manner will be examined. Intrathymic T cell differentiation, selection, and their capacity to home to the secondary follicles and provide cognate help will be tested. Immune functions of AKNA-deficient cells will be examined in vivo and in vitro for their capacity to respond to Ag stimuli, proliferate, produce antibodies and/or cytokines, respond to survival/death signaling, and develop immunological memory.