P^53基因在U937细胞生长和分化过程中的调节作用

The expression of p53 gene has been found to be regulated during the induction of differentiation of U937 leukemic cells into mature macrophages by recombinant human granulocyte- macrophage colony stimulating factors (rhGM-CSF) We showed here that the increased expression of p53 seemed to be necessary for the differentiation of U937 cells induced by rh-GM-CSF. The inhibition of p53 expression by a p53 antisense oligodeoxynucleotide lead to the significant decrease of formation of mature macrophages from U 937 cells in the presence of rhGM-CSF. By contrast, the p53 sense oligodeoxynucleotide had no any effect. Furthermore, we have analysed the growth of U937 cells in the presence or absence of rhGM-CSF. The results showed that rhGM-CSF dramatically inhibited the growth of U 937 cells in the cultures. At the same time, the antisense inhibition experiment demonstrated that the inhibition of p53 expression partially diminished the growth-inhibitory effect of rhGM-CSF on U 937 cells. These results suggested that the p53 was required for the initiation of rhGM-CSF-induced differentiation of U 937 cells on one hand, and the inhibition of cell growth on the other hand. Thus we deduce that the increased expression of p53 induced by rhGM-CSF may be a coupling event of switch of U 937 cells from growth into differentiation.     

TNF—α在PMA和IFN—γ诱导U937细胞生长和分化过程中的作用

本文报道了佛波酯（ＰＭＡ）和γ－干扰素（ＩＦＮ－γ）对Ｕ９３７细胞生长和分化的调控作用及其机制。ＰＭＡ和ＩＦＮ－γ能以剂量依赖的方式诱导Ｕ９３７细胞向成熟单核／巨噬细胞样细胞分化,同时抑制其细胞的生长。实验发现ＰＭＡ和ＩＦＮ－γ可诱导Ｕ９３７细胞表达ＴＮＦ－α特异性ｍＲＮＡ和蛋白质。Ｕ９３７细胞培养中加入特异性抗ＴＮＦ－α抗体可以抑制ＰＭＡ和ＩＦＮ－γ诱导Ｕ９３７细胞的分化和生长。这说明内源性的Ｔ     

表皮生长因子对雄性生殖功能发生作用

表皮生长因子(EGF)在小鼠的颌下腺中含量丰富,也存在于血液循环中。雄激素、孕激素和肾上腺素能类制剂能增加颌下腺中 EGF 的产生。颌下腺来源的 EGF 可在雌鼠的乳腺发育和肿瘤发生方面起作用,雄性小鼠的颔下腺中 EGF 的量至少是雌鼠中的10倍。在雄性小鼠颌下腺中 EGF 的产量一直增加到7周     

人白细胞介素-2功能性受体在小鼠细胞可重建

白细胞介素-2(IL-2)与其受体相互作用,可促进已活化的T 细胞生长,但只当IL-2与高亲和性受体结合才能释放与生长相关的传导信号。作者从正常人用合成的寡聚核苷酸探针筛选出编码IL-2受体特异的基因克隆。筛选出的数个阳性克隆中,P~(IL-2R)-6克隆经分析发现能编码成人T 细胞白血病细胞表达的IL-2受体的全部序列。作者为了使IL-2受体cDNA 在哺乳细胞中稳定表达,构建了一个P~(SVIL-2R)-3质粒,并     

IL-2对淋巴细胞膜中特异性鸟苷酸结合蛋白有刺激作用

IL-2是多肽生长因子,可刺激 T 淋巴细胞的增殖分化。活化的 T 细胞、克隆化的 IL-2依赖细胞系以及几种其它类型的细胞都表达有 IL-2受体。已证实 IL-2受体没有内部信号传导功能;也证实 IL-2与高亲和力受体相互作用,可激活钙离子或磷脂-依赖的蛋白激酶 C(PKC)。鸟苷酸结合蛋白(G 蛋白)可调节一系列的     

体外诱导绵羊红细胞特异性抗体形成及单纯疱疹病毒感染对它的影响

本文建立了一种较稳定、理想的人淋巴细胞体外诱导绵羊红细胞(SRBC)特异性抗体生成的系统。用SRBC体外刺激人扁桃体淋巴细胞,用溶血空斑法计数针对SRBC特异性抗体形成细胞。发现极低量抗原可诱导其抗体形成,抗体形成量随抗原量呈规律性变化;在抗原刺激后的第4天特异性抗体开始出现,第6天达高峰,并稳定维持至第8天;在辅助刺激剂美洲商陆(PWM)存在下,抗体形成量显著高于无PWM的情况;除去人扁桃体细胞中粘附细胞(主要是巨噬细胞)才能诱导最适抗体形成。将具感染性的HSV-1与SRBC一起加入淋巴细胞培养中,可显著抑制SRBC诱导的特异性抗体形成,这一抑制效应与病毒的感染量有关。此系统中同时加入α-干扰素则可部分解除病毒的抑制效应,并且解除效果与α-干扰素的剂量有关。     

白细胞介素—2加强小鼠T淋巴细胞产生白细胞介素—3

In addition to the regulation of T cell growth, IL-2 exerts effects on the induction of certain lymphokines. We show here that IL-2 synergizes with 5 micrograms/ml of ConA to promote the production of IL-3 in mouse splenic T cell cultures. IL-3 was measured as CFU-GEMM-inducing activity on mouse bone marrow progenitor cells in the supernatant of the stimulated mouse splenic T cells (TCM). The resting T cells produced no CFU-GEMM-inducing activity, but could be induced to produce low level of CFU-GEMM-inducing activity in the presence of ConA. In vitro exposure to IL-2 markedly increased CFU-GEMM-inducing activity production (nearly up to 8-fold) by the ConA-activated T cells. Optimal stimulation was observed when 80 u/ml IL-2 was used for 48 h incubation. Anti-mouse IL-3 monoclonal antibody inhibited the CFU-GEMM inducing activity of TCM. Moreover, the TCM stimulated the proliferation of IL-3 dependent cell line FDC-P1. We also show that IL-2 and ConA-treated T cells expressed high level of IL-3 mRNA through dot blot analysis. These results confirmed the nature of CFU-GEMM-inducing activity of TCM as IL-3. The capacity of IL-2 to promote the production of IL-3 may represent an important mechanism by which it mediate the communication between the immune and hematopoietic systems.