NK细胞在小鼠异基因骨髓移植中的作用

目的:研究自然杀伤(NK)细胞在异基因骨髓移植中对移植物抗宿主病(GVHD)、移植排斥、骨髓植入及造血重建的影响。方法:以近交系小鼠C57/6j(H-2^b)为供鼠、BALB/c(H-2^d)为受鼠,在移植物中增加供者的外周T细胞和/或NK细胞进行异基因骨髓移植,用流式细胞仪检测受鼠的CD₃₄^＋细胞计数和H-2K^b＋细胞表达水平,血细胞自动分析仪检测外周血白细胞计数,并结合临床表现和病理检查,比较不同移植组的存活率、GVHD、植入水平及造血重建等。结果:增加NK细胞组的小鼠存活率显著大于不增加NK细胞组,小鼠出现GVHD的数量少、程度轻,外周血白细胞及骨髓CD₃₄^＋细胞恢复快、H-2K^b＋细胞表达水平高。结论:NK细胞抑制小鼠异基因骨髓移植中的GVHD和移植排斥,促进骨髓植入及造血重建。     

Presence of natural killer-cell clones with variable proliferative capacity in chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus infection (CAEBV) is a syndrome that takes diverse clinical courses and is often associated with lymphoproliferative disorders of T/natural killer (NK)-cell lineage. We describe a patient with CAEBV associated with persistent pharyngeal ulcer, and with subsequent nasal T/NK-cell lymphoma in her neck lymph nodes and nasopharynx. Immunophenotyping of lymphoid cells showed that the lineage of Epstein-Barr virus (EBV)-positive cells in the patient was of NK-cell origin. By means of high-dose recombinant interleukin-2, we established an EBV-positive cell line of NK-cell lineage from her peripheral blood. Southern blot analysis for the number of terminal repeat sequences of EBV detected three NK-cell clones in the patient's lymph node. One of these clones was identical to the established cell line but was not observed in the pharyngeal ulcer, while the other two clones were present in the pharyngeal ulcer. These results suggest that the patient had expansion of the three NK-cell clones, one of which had proliferative capacity in vitro and was involved in the formation of the lymphoma. Moreover, the results suggest that the proliferative capacity of EBV-positive cells can be variable even in a single patient, and this variability may explain the clinical diversity in CAEBV.     

P-glycoprotein (MDR 1 gene product) in cells of the immune system: Its possible physiologic role and alteration in aging and human immunodeficiency virus-1 (HIV-1) infection

P-glycoprotein, a 170-kd glycoprotein encoded by theMDR 1 gene, is a member of a highly conserved superfamily of ATP-binding cassette (ABC) transport proteins. It shares extensive homology with numerous bacterial and eukaryotic ABC transport proteins. P-glycoprotein acts as an energy-dependent efflux pump that appears to transport structurally diverse agents ranging from ions to peptides. P-glycoprotein (P-gP) has been implicated as playing a role in multidrug (MDR) resistance in cancer, chloroquine-resistantPlasmodium falciparum infection, and possibly human immunodeficiency virus-1 (HIV-1) resistance to nucleoside compounds. A number of normal tissues in humans and rodents have been shown to express high levels of P-gp. The expression and function of P-gp in cells of the immune system have been explored in the past 2 years. This review presents a state of the art regarding the expression, regulation, and function of Pgp in cells of the immune system. In addition, its alteration in aging and HIV-1 infection is reviewed. A possible physiologic role of P-gp in cytokine secretion, antigen processing/presentation, and effector functions is also discussed.     

天然生物材料构建组织工程支架的研究进展

细胞培养支架材料是组织工程的重要研究内容之一.本文综述近年来几种典型天然生物材料构建组织工程支架的研究进展,并详细介绍了适用于天然生物材料制备组织工程支架的致孔方法.     

雷诺氏综合征患者的微循环特点和中西结合治疗

对40例雷诺氏综合征（RDS）患者应用益气通阳活血化瘀中药与西药倍他乐克联合治疗，同时观察RDS患者治疗前后的甲襞微循环（NFM）、血液流变性和彩色多普勒血流显像（CDFI）变化。结果显示RDS患者经治疗后NFM明显改善，细动脉增宽、血流加快（P＜0．05），全血粘度、血浆粘度、纤维蛋白原及体外血栓重量与长度明显减轻缩小（P＜0．01）；CDFI表现动脉痉挛消失，血流阻力下降以及血流量增加。提示：益气通阳活血化瘀中药和倍他乐克西药合用有明显的降粘、解聚、抗栓、改善微循环的作用，治疗RDS有较好的疗效。     

重视合理用药 提高药物疗效

目的:提高合理用药的意识,促进临床用药向安全、合理、高效、经济的目标发展。方法:结合临床实际,对用药的过程和结果进行分析讨论。结果:通过用药现状分析,证明不合理用药现象广泛存在。结论:合理用药应引起高度重视,以减少药物不良反应的发生,发挥药物的最佳疗效。     

人肿瘤细胞TH2类细胞因子的逆转与NK抗性变化的研究

目的研究促使人肿瘤细胞中ＴＨ２类细胞因子表达向ＴＨ０型的逆转及逆转后的肿瘤细胞对ＮＫ抗性的变化。方法首先用ＭＴＴ方法对悬浮培养的肿瘤细胞株ＤＢ大淋巴细胞瘤、Ｋａｒｐａｓ淋巴瘤、Ｍｉｃｈａｅｌ淋巴瘤、Ｒａｊｉ、ＨＬ６０和Ｋ５６２进行了ＮＫ杀伤敏感性的筛选。选择ＮＫ不敏感的Ｋａｒｐａｓ淋巴瘤和ＨＬ６０，用ｒｈＩＦＮγ、ｒｈＩＬ－１２和抗ＩＬ－１０ＭｃＡｂ经不同组合对其进行由ＴＨ２类细胞因子表达向ＴＨ１类细胞因子表达的促逆转研究，并观察促逆转后的肿瘤细胞对ＮＫ抗性的变化。结果ＲＴ－ＰＣＲ结果表明，经上述不同细胞因子组合诱导后，Ｋａｒｐａｓ淋巴瘤细胞均从表达ＴＨ２类细胞因子为主向ＴＨ０型逆转，并且各组逆转后的肿瘤细胞对ＮＫ的抗性均有不同程度的减弱。结论ＴＨ１类细胞因子（如ＩＦＮγ）、ＴＨ２类细胞因子拮抗剂（如ＩＬ－１０单抗）和ＩＬ－１２不同程度地促进肿瘤细胞表达的细胞因子由ＴＨ２型向ＴＨ０／ＴＨ１型逆转。促逆转后可以改善肿瘤细胞对机体杀伤作用的敏感性，提高抗肿瘤免疫能力     

Mild Brachmann–de Lange syndrome: Changes of phenotype with age

We present a girl with mild manifestations of the Brachmann-de Lange syndrome (BDLS) with gradual change of the phenotype. Her findings support the hypothosis of variability of the phenotypic spectrum of the disorder.     

Functional characterization of human natural killer cells responding to Mycobacterium bovis bacille Calmette-Guérin

The kinetics of activation and induction of several effector functions of human natural killer (NK) cells in response to Mycobacterium bovis bacille Calmette-Guérin (BCG) were investigated. Owing to the central role of monocytes/macrophages (MM) in the initiation and maintenance of the immune response to pathogens, two different experimental culture conditions were analysed. In the first, monocyte-depleted nylon wool non-adherent (NW) cells from healthy donors were stimulated with autologous MM preinfected with BCG (intracellular BCG). In the second, the NW cells were directly incubated with BCG, which was therefore extracellular. In the presence of MM, CD4+ T lymphocytes were the cell subset mainly expressing the activation marker, CD25, and proliferating with a peak after 7 days of culture. In contrast, in response to extracellular BCG, the peak of the proliferative response was observed after 6 days of stimulation, and CD56+ CD3- cells (NK cells) were the cell subset preferentially involved. Such proliferation of NK cells did not require a prior sensitization to mycobacterial antigens, and appeared to be dependent upon contact between cell populations and bacteria. Following stimulation with extracellular BCG, the majority of interferon-gamma (IFN-gamma)-producing cells were NK cells, with a peak IFN-gamma production at 24-30 hr. Interleukin (IL)-2 and IL-4 were not detectable in NK cells or in CD3+ T lymphocytes at any time tested. IL-12 was not detectable in the culture supernatant of NW cells stimulated with extracellular BCG. Compared to the non-stimulated NW cells, the NW cells incubated for 16-20 hr with BCG induced the highest levels of expression of apoptotic/death marker on the NK-sensitive K562 cell line. BCG also induced expression of the activation marker, CD25, and proliferation, IFN-gamma production and cytotoxic activity, on negatively selected CD56+ CD3- cells. Altogether, the results of this study demonstrate that extracellular mycobacteria activate several NK-cell functions and suggest a possible alternative mechanism of NK-cell activation as the first line of defence against mycobacterial infections.     

Natural killer cells and malaria

Summary:  Malaria, caused by the infection with parasites of the germs Plasmodium , is one of the three most important infectious diseases worldwide, along with tuberculosis and infection with human immunodeficiency virus. Natural killer (NK) cells are lymphocytes classically involved in the early defense against viral infections and intracytoplasmic bacterial infections and are also implicated during the course of tumor development and allogeneic transplantation. These cells display important cytotoxic activity and produce high levels of proinflammatory cytokines. In both mouse and human models of malaria, NK cells appear to be a major source of interferon-γ during the early phase of infection. In humans, indirect signaling through monocytes/macrophages required to optimally stimulate NK cell activity. However, the in vivo functions of NK cells during malaria are still enigmatic, and many issues remain to be dissected, such as the molecular basis of the direct recognition of iRBCs by NK cells.