胸腺上皮细胞的起源与分化

胸腺提供复杂的微环境来调节T细胞的存活、分化、选择和迁移,是T细胞发育、分化和成熟的场所也是自身免疫耐受的中心。胸腺上皮细胞包括胸腺皮质上皮细胞和髓质上皮细胞,其来源于内胚层,并由胸腺上皮祖细胞分化而来。胸腺上皮细胞的分化空间结构的建立有赖于转录因子和信号通路分子在胸腺上皮细胞不同时段复杂的分子调控。胸腺上皮细胞成熟过程也是胸腺上皮细胞一系列特异性表面标记分子的变化过程,对胸腺上皮细胞特异标记分子的研究是分析胸腺上皮细胞复杂分化过程的重要工具。本文重点探讨胸腺上皮细胞起源发展模型及分化过程中分子调控作用,以期更好的理解胸腺上皮细胞如何成为能够支持T细胞分化的特异哺育者。     

FOXN1 recombinant protein enhances T‐cell regeneration after hematopoietic stem cell transplantation in mice

A prolonged period of T‐cell recovery is the major challenge in hematopoietic stem cell transplantation (HSCT). Thymic epithelial cells (TECs) are the major component of the thymic microenvironment for T‐cell generation. However, TECs undergo degeneration over time. FOXN1 plays a critical role in TEC development and is required to maintain adult TECs for thymopoiesis. To investigate the potential application of FOXN1, we have cloned and expressed recombinant FOXN1 protein (rFOXN1) that was fused with cell‐penetrating peptides. We show here that the rFOXN1 protein can translocate from the cell surface into the cytoplasm and nucleus. Administration of rFOXN1 into both congenic and allogeneic HSCT recipient mice increased the number of TECs, resulting in enhanced thymopoiesis that led to an increased number of functional T cells in the periphery. The increased number of TECs is due to the enhanced survival and proliferation of TECs. Our results suggest that rFOXN1 has the potential to be used in enhancing T‐cell regeneration in patients following HSCT.     

Absolute dependence of T cell receptorhi cell generation and relative dependence of T cell receptorint cell generation on the thymus

Recent evidence indicates that conventional T cells are generated by the mainstream of T cell differentiation in the thymus and acquire a high density of T cell receptor expression (i.e. TCR^hi). In contrast, primordial T cells (or NK1.1⁺ T cells) are generated by the extrathymic pathways or an alternative intrathymic pathway and express an intermediate density of TCR (i.e. TCR^int). To obtain further evidence, it was examined how thymus grafting influenced the distribution of T cell populations in athymic nude mice. When BALB/c nu/nu mice were engrafted with thymocyte-depleted BALB/c+/+ fetal thymi, two changes emerged after grafting: nude mice generated TCR^hi cells de novo in the periphery as well as in the grafted thymi, and the absolute number of interleukin-2 receptor β chain⁺ TCR^int cells increased prominently in number in the periphery. Among thymic hormones tested, the administration of thymosin α induced a slight expansion of CD3^int cells in nude mice. To examine a possible interaction of TCR^int cells with TCR^hi cells in the periphery, B6 nu/nu mice (Ly5.2⁺) were injected with TCR^hi cells purified from the spleen of B6 Ly5.1 congenic mice. In this case, TCR^int (Ly5.2⁺) cells expanded well in all tested organs of nude mice. These results suggest that the generation of TCR^hi cells is absolutely dependent on the thymus and that TCR^int cells expand under the influence of the thymus (humoral) and due to interaction with thymus-derived conventional T cells.     

FoxM1靶向调控bcl-2促进急性髓系白血病发生

目的:探讨叉头框蛋白M1(Fox M1)及其调控的原癌基因B细胞白血病/淋巴瘤-2(bcl-2)在急性髓系白血病(AML)发生中的作用。方法:RT-q PCR和免疫荧光方法检测17例AML初诊患者、17例治疗后达完全缓解(CR)患者、17例难治复发(RR)患者和15例正常骨髓标本中Fox M1的m RNA和蛋白表达;转染Fox M1 si RNA和对照si RNA至白血病HL60细胞和K562细胞,观察Fox M1对细胞生长和克隆形成的影响,流式细胞术检测Fox M1对凋亡的影响,RT-q PCR和Western blot法检测Fox M1对Bcl-2表达的影响,双萤光素酶活性实验检测Fox M1是否可以靶向作用于bcl-2启动子区域进而影响Bcl-2的表达。结果:AML初诊患者骨髓标本的Fox M1表达较正常对照显著升高,CR患者的Fox M1表达较初诊组降低,RR组的Fox M1表达较初诊组进一步升高。转染Fox M1 si RNA沉默HL60细胞和K562细胞的Fox M1表达后,细胞生长速率显著下降,细胞克隆形成能力显著降低,细胞凋亡率显著升高,bcl-2表达降低,Fox M1可靶向调控bcl-2。结论:初步证实Fox M1可通过靶向调控bcl-2促进AML发生发展,干扰Fox M1表达可抑制细胞增殖并促进细胞凋亡,提示Fox M1是治疗AML的潜在靶标。     

131I-BDI-1在荷人膀胱癌裸鼠体内的生物分布研究及辐射剂量评估

目的 探讨131I-BDI-1在荷人膀胱癌裸鼠模型中的体内生物分布和对肿瘤的靶向定位性能以及其生物安全性,并由此估算131I-BDI-1在人体内主要脏器的内照射吸收剂量和人体有效剂量.方法 通过氯胺-T法用131I溶液直接标记抗人膀胱癌单克隆抗体BDI-1,制备131I-BDI-1,荷人膀胱癌EJ细胞裸鼠尾静脉注射222kBq 131I-BDI-1后,于不同时刻处死动物,取感兴趣器官和组织,称重并测量放射性计数,计算131I-BDI-1在荷瘤裸鼠中的标准摄取值和靶/非靶组织比值.利用标准的MIRD数据表计算人体的％ID/g,通过MIRDOSE3.1软件估算131 I-BDI-1对人体各个器官的辐射吸收剂量及有效剂量.结果 生物分布数据示131I-BDI-1血液清除缓慢,肿瘤部位放射性明显持续滞留,除血液外,具有较高的靶/非靶组织比值.131I-BDI-1人体内照射的有效剂量为1.46×10-2 mGy/MBq.结论 131I-BDI-1对肿瘤有良好的靶向性,有望成为一种新型的针对人膀胱癌肿瘤的诊治药物,其辐射吸收剂量较低,作为肿瘤治疗药物是安全的.     

FAP在胃癌间质中的表达及其与微血管密度的关系

Objective To investigate the expression of fibroblast activation protein (FAP) in human gastric carcinoma (GC) and the relationship between FAP expression and microvessel density ( MVD). Methods Human GC specimens from one hundred sixty-two patients were available for study. Nude mice model was subcutaneously transplanted with human gastric carcinoma SGC-7901 cells. The expression of FAP and CD34 in gastric carcinoma tissue was detected by immunohistochemistry. Results FAP expresses in stromal fibroblasts in 90.74% (147 cases) patients with GC, while carcinoma cells and normal gastric tissues are negatively for FAP. In gastric carcinoma, FAP expression and MVD associate with tumor invasion(χ2=51. 882,P <0.01; χ2 = 46.383,P<0.01), differentiation(χ2=40. 193,P<0. 01;χ2 =21. 617,P <0.01) and lymph node metastasis(χ2=24. 232,P <0.01 ;χ2 =13. 393,P<0.01). In fifteen cases of tumor tissue from nude mice transplanted subcutaneously with human gastric carcinoma SGC-7901 cells, all tumors show different degrees of FAP expression. MVD significantly correlates with FAP intensity in both human gastric carcinoma(χ2=97. 710,P < 0. 01) and mouse tumor tissue(χ2= 11. 100,P <0. 01). MVD increases in samples with increased FAP expression. Conclusion In GC, FAP expression correlates with the invasion and metastasis. FAP may promote tumor growth, invasion and metastasis by facilitating tumor angiogenesis.     

FAP在胃癌间质中的表达及其与微血管密度的关系

Objective To investigate the expression of fibroblast activation protein (FAP) in human gastric carcinoma (GC) and the relationship between FAP expression and microvessel density ( MVD). Methods Human GC specimens from one hundred sixty-two patients were available for study. Nude mice model was subcutaneously transplanted with human gastric carcinoma SGC-7901 cells. The expression of FAP and CD34 in gastric carcinoma tissue was detected by immunohistochemistry. Results FAP expresses in stromal fibroblasts in 90.74% (147 cases) patients with GC, while carcinoma cells and normal gastric tissues are negatively for FAP. In gastric carcinoma, FAP expression and MVD associate with tumor invasion(χ2=51. 882,P <0.01; χ2 = 46.383,P<0.01), differentiation(χ2=40. 193,P<0. 01;χ2 =21. 617,P <0.01) and lymph node metastasis(χ2=24. 232,P <0.01 ;χ2 =13. 393,P<0.01). In fifteen cases of tumor tissue from nude mice transplanted subcutaneously with human gastric carcinoma SGC-7901 cells, all tumors show different degrees of FAP expression. MVD significantly correlates with FAP intensity in both human gastric carcinoma(χ2=97. 710,P < 0. 01) and mouse tumor tissue(χ2= 11. 100,P <0. 01). MVD increases in samples with increased FAP expression. Conclusion In GC, FAP expression correlates with the invasion and metastasis. FAP may promote tumor growth, invasion and metastasis by facilitating tumor angiogenesis.     

裸鼠与正常鼠杂交子一代的免疫功能研究

将BALB/cAnN-nu裸鼠与BALB/cAnN正常鼠杂交的子一代(F_1)与其亲代进行免疫功能比较,单向与双向混合淋巴细胞反应(MLR)。结果表明,F_1与亲代裸鼠在遗传关系上更接近。淋巴细胞转化试验表明F_1由裸鼠遗传获得对ConA诱导T细胞亚群转化活性低、B细胞功能活性高、以及对异种C57BL/6J小鼠MLR反应性低等性状。F_1具有部分细胞免疫功能较亲代裸鼠高而低于亲代BALB/c小鼠的特性,可考虑供细胞免疫功能低下的试验小鼠模型之用。     

Human mammary cancers in nu/nu-Mice. A model for testing in research and clinic

Summary 37 (85%) of 44 human breast cancers are successfully transplanted on thymus-aplastic nu/nu-mice without adjunctive immunotherapy. 16 weeks after transplantation 4 rapidly growing tumours are showing human, female karyotypes. Subsequent investigations proved a good correlation between original tumour and transplant: histology, 3H-thymidine marking index and receptors of androgen and estrogen.We are indebted to Mrs. Geisler, Dr. biol., Institut für Humangenetik der Universität Frankfurt am Main, for the preparation of chromosomes     

三阴型乳腺癌FOXA1和BRCA1的表达及其对预后的意义

目的: 研究三阴型和非三阴型乳腺癌中叉头框蛋白A1(FOXA1)、BRCA1蛋白、P53和血管内皮生长因子(VEGF)的表达情况和预后意义。方法: 收集暨南大学附属第一医院乳腺癌的标本113例,根据免疫组化检测雌激素受体、孕激素受体和HER-2的表达情况分为三阴型(A组)、luminal型(B组)及HER-2过表达型(C组)乳腺癌。应用免疫组化EnVision两步法检测3组样本FOXA1、BRCA1、P53和VEGF的表达情况。结果: FOXA1总的阳性表达率为63.7%(72/113),A组阳性表达率为45.2%(19/42),B组为88.0%(44/50),C组为42.9%(9/21),FOXA1在3组中的表达存在显著差异(P<0.01);BRCA1总的阳性表达率为47.8%(54/113),A组阳性表达率为66.7%(28/42),B组为44.0%(22/50),C组为19.0%(4/21),BRCA1在3组中的表达存在显著差异(P<0.01);FOXA1阳性表达率在Ⅰ~Ⅱ期临床分期和组织学1~2级中高于阴性表达组(P<0.05),FOXA1阳性表达率与P53、VEGF表达和复发率呈负相关(P<0.05);BRCA1阳性表达率在Ⅲ期临床分期和组织学3级中高于阴性表达组(P<0.05),BRCA1阳性表达率与P53、 VEGF表达和复发率呈正相关(P<0.05)。结论: FOXA1和BRCA1在乳腺癌中表达存在差异。BRCA1可作为三阴型乳腺癌预后不良的指标。     

Image analysis and autoradiographic study of organogenesis in the amphibian thymus

The development and the regression of the cell populations in the thymus of the newt Pleurodeles waltlii Michah., from hatching (14 days) until the adult aged 600 days, were studied by means of histological and autoradiographic methods, and by using the Samba 200 cell images analyser. Cell counts show a quasi-exponential growth up to metamorphosis; then, after a short plateau, they begin to decrease slowly. The labelled-mitoses curves demonstrate the progressive lengthening of the generation time. Growth fraction, labelling index, and mitotic index increase up to stage 50, then decrease progressively. Careful microscopic observation allows to distinguish several cell populations; they can be taken into account by the cell images analyser, which is able to discriminate for each of them the cycling cells (growth fraction) and non-cycling (Go) cells. This leads us to propose a comprehensive view of the developmental history of the thymus, from stage 42 to adult, including the migration of the Go stem cells into the thymic bud, the start of their proliferation and differentiation into lymphoblasts according to a precise schedule, and including also the proportion of functional T-lymphocytes leaving the thymus during each period. Two hypotheses concerning the relationships between lymphoid cell population proliferation and differentiation are discussed; one of them fits perfectly all the experimental data, and gives us a complete view of the development and of the regression of this complex organ.     

小鼠胸腺基质细胞系(MTEC1)在裸鼠体内生物学特性研究

通过流式细胞仪（ＦＡＣＳ）、组织学染色和免疫组化的方法研究了脾内注射的小鼠胸腺上皮细胞系ＭＴＥＣ１和初代培养的小鼠胸腺基质细胞在裸鼠脾脏内存活状态及功能特性。结果发现ＭＴＥＣ１细胞不仅能够在脾脏内存活，而且在ＭＴＥＣ１细胞周围有大量不成熟的淋巴细胞。初代培养的小鼠胸腺基质细胞则不能在脾脏内存活。     

Basal cell carcinoma xenografts in nude mice: studies on epithelial differentiation and stromal relationships

Thirty-three basal cell carcinomas (BCC) were transplanted into athymic mice, and foci of tumour were identified in 17 grafts recovered after intervals of 2-5 months. Fifteen of these xenografts contained apparently normal differentiated epithelia, considered to derive from elements within the original tumours. The level of differentiation was very close in original and corresponding xenograft BCC. Morphologically recognizable 'specialized' stroma was present in some but not all xenografted BCC, and was also present in some grafts containing only differentiated elements. A monoclonal antibody specific to human type IV collagen showed intact epithelial and also vascular basement membranes within the graft. Surprisingly, mouse cells were found to line these vessels, and the stroma around normal and neoplastic epithelial islands was a mixture of mouse and human cells, with no consistent composition. These observations question the proposed dependence of BCC on its 'specialized' stroma.