Synthetic Analysis on the mechanisms of survival and differentiation of hematopoietic cells

1.尽管致白血病酪氨酸激酶激活了常见的下游分子，但这些LTK引起的白血病的表型是不同的。在本研究中，我们利用高嗜酸性粒细胞综合征/慢性嗜酸性粒细胞白血病的致病基因F1P1L1-PDGFRα(F-PRα)来分析其机制。将F-PRβ(T-PRβ)导入c-Kit^&gt；High&gt；Sca-1^+系细胞(KSL)后，可促进Gr-1^&lt；+&gt；IL-5Rα^&gt；+&gt；嗜酸性粒细胞前体(EOPs)的发育。此外，F-PRα还促进了普通髓系祖细胞(CMPS)的嗜酸性粒细胞发育。此外，当F-PRα在巨核/红系祖细胞(MEP)和普通淋巴祖细胞(CLP)中表达时，它们会从MEP和CLP异常地发展成EOP。对于这一机制，逆转录聚合酶链式反应分析表明，F-PRα上调了C/EBpα和GATA-2的表达，而降低了PU。1个表达式。此外，在荧光素酶分析中，F-PRα及其下游RAS增强GATA-2活性，而抑制PU1活性。我们先前克隆了一个新的抗细胞凋亡基因Anamorsin(AM)。在这项研究中，我们产生了AM的转基因(TG)小鼠虽然AM-TG小鼠没有自发形成任何肿瘤，但由于B细胞的生长，观察到明显的脾肿大。另外，免疫组织化学染色发现AM的表达是弥漫性大B细胞淋巴瘤这一特殊亚型的不良预后因素。以人骨髓间充质干细胞(HMSC)为基质，建立了从脐带血中分离纯化的CD34+细胞制备B淋巴细胞的长期培养体系。利用此共培养体系，可从2000个CD34~+细胞中培养出1~5×10~(-5)×10~(-5)~(-1)CD10~+细胞。在该系统中，4周后开始出现表面IgM+的未成熟B细胞。此外，我们发现激活素A选择性地抑制B淋巴细胞的产生。

1. Although leukemogenic tyrosine kinases activate common downstream molecules, the phenotypes of leukemia caused by these LTKs are distinct. In this study, we analyzed its mechanism using F1P1L1-PDGFRα(F-PRα), a causative gene of hypereosinophilic syndrome/chronic eosinophilic leukemia. When introduced into c-Kit^<high>Sca-1^+ Lineage cells (KSLs), F- PRa but not TEL-PDGFRβ (T-PRβ) enhanced the development of Gr-1^<+>IL-5Rα^<+> eosinophil progenitors(EoPs). Also, F- PRα promoted eosinophil development from common myeloid progenitors (CMPs). Furthermore, when expressed in megakaryocyte/erythrocyte progenitors (MEPs) and common lymphoid progenitors (CLPs), F-PRα aberrantly developed EoPs from MEPs and CLPs. Regarding this mechanism, RT-PCR analysis revealed that F-PRα augmented the expression of C/EBPα and GATA-2, while it reduced PU. 1 expression. Furthermore, F-PRα and its downstream Ras enhanced GATA- 2 activity, while they inhibited PU.1 activity in luciferase assays.2. We previously cloned a novel anti-apoptotic gene, Anamorsin(AM). In this study, we generated transgenic(Tg) mice for AM. Although AM Tg mice did not develop any tumors spontaneously, marked splenomegaly due to the outgrowth of B cells was observed. In addition, we found that the expression of AM was a poor prognostic factor for the special subtype of diffuse large B-cell lymphoma using immunohistochemical staining.3. We developed a long-term culture system to produce B lymphocytes from human CD34_+ cells purified from umbilical cord blood using human mesenchymal stem cells (hMSC) as stroma. Using this cocultures, we could develop 1-5 x 10^<5> CD10_+ cells from 2000 CD34_+ cells. In this system, surface IgM_+ immature B cells began to appear after 4 weeks. In addition, we found that Activin A selectively suppressed B lymphocyte production.