体外扩增造血细胞重建小鼠造血功能的实验研究

目的 探讨体外扩增造血祖儿定向诱导功能血红细胞生成的条件及扩增细胞重建长期造血能力的维持。方法 应用免疫磁珠法（ＭＡＣＳ）分离纯化脐带血ＣＤ３４＾＋造血干或祖细胞,在体外液体培养体系中经不同细胞因子的组合进行扩增和定向诱导,并将扩增细胞移植经亚致死剂量照射的ＳＣＩＤ小鼠。结果 ＦＬ、干细胞因子血小板生成素（ＴＰＯ）等细胞因子的不同组合可分别扩增细胞总数、粒系及巨核系造血祖细胞、ＣＤ３４＾＋ＣＤ３８     

Defective interfering influenza virus confers only short-lived protection against influenza virus disease: Evidence for a role for adaptive immunity in DI virus-mediated protection in vivo

We have shown earlier that a single dose of cloned defective interfering (DI) influenza A virus strongly protects mice from disease following a lethal challenge with different subtypes of influenza A virus. These animals suffered no clinical disease but experienced a subclinical infection which rendered them immune to reinfection with the same challenge virus. However, little is known about how DI virus achieves such protection. Here we investigated the role of adaptive immunity in DI virus-mediated protection using severe-combined immunodeficient (SCID) mice, which lack competence in both B- and T-cell compartments but retain NK cell activity. SCID mice which were treated with DI virus and infected with influenza virus initially remained completely well, while infected litter mates that received UV-inactivated DI virus became seriously ill and died. However, after 10 days of good health, the DI virus-protected SCID mice developed a clinical disease that was similar, but not completely identical, to the acute influenza disease. Disease was delayed longer by a higher dose of DI virus. We excluded the possibilities that the DI virus load in the lungs had declined, that the DI RNA sequence had changed so that it no longer interfered with the infectious genome, or that infectious virus had become resistant to the DI virus. These data show that while DI virus provides full protection from the acute disease in the absence of adaptive immunity, that same immunity is essential for clearing the infection. This indicates that the conventional view that DI virus-induced protection is mediated solely by competition for replication with the challenge virus is incorrect for influenza virus.     

重度联合免疫缺陷小鼠的繁育及其应用初报

应用带过滤罩的透明鼠在层流柜内繁育Ｔ和Ｂ淋巴细胞缺失的重度联合免疫缺陷（ｓｃｉｄ）小鼠获得成功，１９９３年５月至１９９４年４月，共繁育ｓｃｉｄ小鼠２２１只，寿命均超过１２个月。平均每窝产仔数为５．５只，显著低于对照组ＢＡＬＢ／ｃ小鼠，不育率为１４．９％，离乳率为８８．２％，与ＢＡＬＢ／ｃ小鼠相比均无明显差异。ｓｃｉｄ小鼠４～１０周龄的体重与同龄ＢＡＬＢ／ｃ小鼠相比无明显差异，微生物学检测均符合ＳＰ     

人源性抗EB病毒IgG/VCA抗体在SCID小鼠中的诱导

将人外周血淋巴细胞（ＰＢＬ）和腹腔淋巴结淋巴细胞（ＰＬＮＬ）移植入严重联合免疫缺陷疾病（ＳＣＩＤ）小鼠腹腔，２个月后，小鼠血清内产生人源性ＩｇＧ和抗ＥＢ病毒壳抗原ＩｇＧ抗体（ＩｇＧ／ＶＣＡ）。比较结果显示，用Ｂ９５－８细胞作为ＶＣＡ来源所诱导的实验组１０只小鼠，ＩｇＧ／ＶＣＡ阳性率为７０％（７／１０），对照组为１７％（２／１２）。ＩｇＧ／ＶＣＡ的几何平均滴度（ＧＭＴ）和血清ＩｇＧ浓度，在１４只ＳＣＩＤ－ＰＬＮＬ小鼠中为１∶１０８和（９６．２±５６．４）μｇ／Ｌ；在８只ＳＣＩＤ－ＰＢＬ小鼠为１∶７．８和（１３．８４±６．０）μｇ／Ｌ。该结果提示，ＳＣＩＤ－ＰＬＮＬ小鼠较ＳＣＩＤ－ＰＢＬ小鼠更适合用于人源性特异ＩｇＧ的诱导。     

Transplantation of marrow cells from children with standard risk-acute lymphoblastic leukemia at the end of therapy into NOD/SCID mice for detecting residual leukemic cells with in vivo growth potential

In the present work, we developed a strategy for detecting residual leukemia in the marrow of children with standard risk-acute lymphoblastic leukemia (sr-ALL) at the end of therapy, based on the capacity of human leukemic cells for growing in the NOD/SCID mice marrow microenvironment. Mononuclear (MN) marrow cells from 62 patients were injected into sublethally irradiated NOD/SCID mice and the engraftment kinetics and composition of the human grafts were determined periodically. The presence of human leukemic cells with immunophenotypes and clonal DNA markers similar to those of the original leukemic clone was studied.     

Identification of X-linked severe combined immunodeficiency by mutation analysis of blood and hair roots

Severe combined immunodeficiency is a heterogenous syndrome of varied genetic origins of which the X-linked type is the commonest (XSCID). The most sensitive method for diagnosis of XSCID in the absence of X-linked inheritance pattern is by mutation analysis. In this report we have performed mutation analysis in 13 unrelated boys transplanted (BMT) for SCID without a known cause to determine the frequency of XSCID. Five boys had an affected male relative. We also assessed the utility of hair roots for children without pre-transplant blood stored for mutation analysis since donor genotype was expressed in peripheral blood post BMT. Screening was performed by analysis of single-strand conformational polymorphism (SSCP) followed by sequencing of candidate exons. Mutations were found in 11 cases, of which six were sporadic, and maternal mosaicism was found in one family. Three mothers of the six sporadic cases were identified as carriers. The majority (6/8) of boys with SCID had gammac deficiency despite the absence of X-linked inheritance pattern. The significant frequency of de novo mutations and the occurrence of maternal germline mosaicism highlights the importance of mutation analysis. The strategy of using DNA from hair roots was particularly valuable where no pre-transplant blood was stored. Characterization of the mutations will also enable research into the correction of these genetic defects.     

Cell autonomous expression of IgD is not essential for the maturation of conventional B cells.

To analyse the function of IgD in vivo, we generated a 'loss of function' mouse model utilizing gene targeting technology. By homologous recombination in a (C57BL/6 x CBA)F1 mouse embryonic stem cell (ES) line one allele of the delta heavy chain gene was rendered non-functional. In chimeric mice obtained after injection of the targeted ES cells into blastocysts derived from severe combined immunodeficient mice we analysed ES cell derived B lymphocytes expressing the targeted or the wild-type allele by using allotype specific reagents. We show that B cells expressing the targeted allele appear in the periphery as IgM+ D- cells at normal frequency. They express the CD23 marker and respond to a T cell dependent antigen. Thus, cell autonomous expression of IgD is neither essential for B cell maturation into an antigen responsive state nor for antigen dependent triggering of the cells into an immune response.     

Effects of 2-methoxyestradiol on endometrial carcinoma xenografts

Purpose We have previously demonstrated that 2-methoxyestradiol (2-ME) inhibits the growth of human endometrial cancer HEC-1-A and RL-95-2 cells in vitro. In this study, we examined the effects of 2-ME on human endometrial carcinoma in severe combined immune deficient (SCID) mice. The potential side effects of 2-ME on SCID mice were also investigated. Methods Severe combined immune deficient mice were injected with HEC-1-A cells (1 × 10⁶/mouse) and a 18 day administration of 2-ME was followed after 1 week cell implantation. Tumor volume, weight, body weight and blood chemistry were determined. Tumor tissues were examined with an antibody against the proliferative cell nuclear antigen (PCNA) and Ki-67. Liver, spleen, kidney, heart, lung and uterus were screened by pathological examinations. Results 2-ME (100 mg/kg p.o.) did not inhibit the growth of human endometrial carcinoma as compared to control. Necrotic areas were similar in both 2-ME-treated and -untreated tumor tissues. The expressions of PCNA and Ki-67 were similar in 2-ME-treated and untreated tumor sections. The wet weight of uterus was increased to more than threefold. The epithelial cells and glands in endometrium were increased. No significant difference was detected in blood AST, ALT and BUN. Conclusions 2-ME has no antitumor effects on human endometrial carcinoma in our animal model. Its proliferative effects on endometrium and uterus might limit its use in gynecological cancers. Founding sources: Swedish Medical Research Council, Selanders fund and Family Planning’s fund.     

Enhanced self-renewal capability in hepatic stem/progenitor cells drives cancer initiation

BACKGROUND & AIMS: Transformed hematopoietic stem/progenitor cells with an enhanced or acquired self-renewal capability function as leukemic stem cells. In a variety of solid cancers, stem/progenitor cells could be also targets of carcinogenesis. However, it remains unclear whether disruption of stem cell function directly contributes to cancer initiation. We sought to elucidate the mechanisms of self-renewal in hepatic stem/progenitor cells and the relation between stem cell function and hepatocarcinogenesis. METHODS: Functional analyses of polycomb-group protein Bmi1 and Wnt/beta-catenin, the molecules that are responsible for the self-renewal capability of many types of stem cells, were conducted in c-Kit(-)CD29(+)CD49f(+/low)CD45(-)Ter-119(-) hepatic stem/progenitor cells using retrovirus- or lentivirus-mediated gene transfer. The tumorigenicity of these cells transduced with the indicated retroviruses was also assessed by transplantation into nonobese diabetic/severe combined immunodeficient mice. RESULTS: Forced expression of Bmi1 and constitutively active beta-catenin mutant similarly promoted the self-renewal of hepatic stem/progenitor cells. The transplantation of Bmi1- or beta-catenin-transduced cells clonally expanded from single hepatic stem/progenitor cells produced tumors, which exhibited the histologic features of combined hepatocellular and cholangiocarcinoma. CONCLUSIONS: These observations imply that the dysregulated self-renewal of hepatic stem/progenitor cells serves as an early event in hepatocarcinogenesis, and they highlight the important roles of Bmi1 and the Wnt/beta-catenin pathway in regulating the self-renewal of normal or cancer stem cells in liver.