PHORBOL ESTER RESPONSIVE B LYMPHOCYTES

这项拟议研究的目标是了解Ly-1系B细胞是如何 刺激增殖并阐明细胞内机制 负责S在这些单元格中的阶段进入。(1)在第一个具体项目中 目的我们将扩展我们以前的工作，表明Ly-1+B细胞是 独一无二地被刺激以启动佛波酯的DNA合成，而不需要 共有丝分裂原，通过更充分地探索佛波酯的性质 有反应的B细胞。将检查反应性B细胞的表型 预激活的问题将通过评估 B细胞激活的标志。(2)在第二个具体问题中 目的我们将探索细胞内的机制，它负责 佛波酯诱导Ly-1+B细胞进入S时相。初步结果 建议蛋白激酶C发挥核心作用。我们将评估PKC活性 和同工酶，特别注意佛波酯之间的差异 反应性(Ly-1+)和无反应性(常规)B细胞。到时候我们会的 开始将PKC活动与“下游”事件联系起来，通过确定 C-myc、c-fos和c-jun 3个早期反应基因的刺激表达-- 并通过鉴定可能调节基因的Fos相关蛋白 表达及我们发现Ly-1+B细胞不能通过 通过确定SLG中介的信号被颠覆的级别来签名。 我们将通过测量IP3的产量来评估第二代信使 和DAG以及PKC的易位，我们将检查更远端的 早期反应基因表达的事件。LY-1+B细胞产生 自身抗体与自身免疫的发病机制有关 疾病；Ly-1+B细胞容易发生肿瘤性转化和 代表了许多B细胞肿瘤的起源细胞。澄清： 控制Ly-1+B细胞增殖的机制可能有助于理解 淋巴细胞自身免疫性疾病和恶性疾病的起源及建议 影响其结果的手段。

The goal of the proposed studies is to learn how Ly-1 lineage B cells are stimulated to proliferate and to elucidate the intracellular mechanisms responsible for S phase entry in these cells. (1) In the first specific aim we will extend our previous work showing that Ly-1+ B cells are uniquely stimulated to initiate DNA synthesis by phorbol ester, without a co-mitogen, by more fully exploring the nature of the phorbol ester responsive B cell. The phenotype of responsive B cells will be examined and the issue of pre-activation will be addressed through evaluation of markers that are signs of B cell activation. (2) In the second specific aim we will explore the intracellular mechanisms that are responsible for phorbol ester induced S phase entry in Ly-1+ B cells. Preliminary results suggest a central role for protein kinase C. We will evaluate PKC activity and isozymes with particular attention to difference between phorbol ester responsive (Ly-1+) and nonresponsive (conventional) B cells. We will then begin to link PKC activity with "downstream" events by determining the stimulated expression of 3 early response gene--c-myc, c-fos, and c-jun-- and by characterizing Fos associated proteins that may regulate gene expression and our finding that Ly-1+ B cells fail to be stimulated through sIg by identifying the level at which sLg mediated signaling is subverted. We will evaluate second messenger generation by measuring production of IP3 and DAG and translocation of PKC, and we will examine the more distal events of early response gene expression. Ly-1+ B cells produce autoantibodies and are implicated in the pathogenesis of autoimmune diseases; ly-1+ B cells readily undergo neoplastic transformation and represent the cell of origin for many B cell tumors. Elucidation of the mechanisms that govern Ly-1+ B cells proliferation may aid in understanding the origin of autoimmune and malignant diseases of lymphocytes and suggest means of influencing their outcomes.