复发性流产患者NK细胞毒性和子宫动脉血流灌注对妊娠结局的影响

目的:探讨复发性流产(RPL)患者NK细胞毒性和子宫动脉血流灌注对妊娠结局的影响。方法:回顾分析162例RPL患者的临床资料,根据妊娠结局分为流产组(n=30)和分娩组(n=132),比较两组的NK细胞毒性和子宫动脉血流阻力指数(U-RI)变化。结果:流产组的孕前NK细胞毒性高于分娩组,差异有统计学意义(P=0.02),两组的孕前U-RI比较差异无统计学意义(P=0.12);早孕期流产组各孕周的NK细胞毒性均高于分娩组,但差异无统计学意义(P0.05)。U-RI在早孕期较孕前明显降低(P0.001),且分娩组U-RI随孕周增加逐渐降低;与分娩组相比,孕7、8、9周时流产组的URI明显升高,差异有统计学意义(P=0.008,P=0.001,P=0.043)。结论:孕前NK细胞毒性增高,孕7~9周子宫动脉血流灌注量下降的患者再次自然流产风险增高,两者为独立危险因素。     

无医疗干预初产妇自然分娩的妊娠结局分析

目的:探讨无医疗干预初产妇自然分娩的妊娠结局。方法:将2013年1月至2014年12月在山东大学齐鲁医院住院分娩的3000例初产妇根据有无产程干预分为观察组和对照组,观察组1500例孕妇自然分娩,第一产程自由活动、饮食、休息,第二产程自主用力、自由体位分娩、无会阴保护、自然娩肩,第三产程延迟断脐、胎盘自然娩出;对照组1500例孕妇给予不同程度的医疗干预。比较两组孕妇的最终分娩方式及母儿结局。结果:观察组的自然分娩率、会阴完整率、新生儿评分高于对照组,而会阴切开率、会阴二度裂伤率、剖宫产率、产后出血量、羊水污染率明显低于对照组,差异有统计学意义(P0.05)。两组孕妇的孕周、总产程、新生儿出生体重、新生儿入住NICU率、羊水量、脐带绕颈等方面比较,差异无统计学意义(P0.05)。结论:对于低危初产妇,减少医疗干预,促进自然分娩,可获得较好的母儿结局。     

The influence of natural antibody specificity on antigen immunogenicity

The natural antibody repertoire in humans, apes and Old World primates is distinct from the repertoire of all other placental mammals, and encodes antibodies specific for the carbohydrate epitope Galalpha1-3Galbeta1-4GlcNAc-R (alphaGal). Here, we examined whether conjugating antigens to the alphaGal epitope can augment their immunogenicity in alpha(1,3)galactosyltransferase knockout mice (GT0 mice) which, like humans, produce alphaGal-specific antibodies. Immunization of GT0 mice with BSA conjugated to alphaGal (alphaGal-BSA) led to significant production of anti-BSA IgG antibodies without the need for adjuvant. This response was dependent on the presence of alphaGal-reactive antibodies. Immunization of wild-type mice with alphaGal-BSA failed to induce an anti-BSA response. The presence of alphaGal-reactive antibodies also led to an increase in the T cell response to BSA following immunization with alphaGal-BSA when compared with mice that received BSA alone, resulting in an increased frequency of IFN-gamma- and IL-4-producing BSA-specific T cells. In addition, the ability to produce alphaGal-reactive antibodies enhanced the cytotoxic T lymphocyte anti-viral antigen response following vaccination with murine leukemia virus transformed cell lines that express alphaGal on their cell surface. Natural antibodies that bind alphaGal therefore play a key role in increasing the efficiency of priming to antigens decorated with alphaGal epitopes.     

Differential expression of human granzymes A, B, and K in natural killer cells and during CD8+ T cell differentiation in peripheral blood

NK cells and cytotoxic T lymphocytes can induce apoptosis in virus-infected and transformed target cells via the granule exocytosis pathway. The key components of the cytolytic granules are perforin and several serine esterases, termed granzymes. While the cellular distribution of human granzymes A (GrA) and B (GrB) has been well characterized much less is known about the expression pattern of human granzyme K (GrK). In this study GrA, GrB, and GrK expression was analyzed in human peripheral blood lymphocytes using flow cytometry. There was a distinct population of GrK expressing CD8+ T cells with a CD27+/CD28+/CCR5high/CCR7-/perforin-/low/IFN-gamma+ memory-like phenotype, while all CD56bright NK cells were also positive for GrK. In addition, GrK was also expressed in subpopulations of CD56+ T cells, CD4+ T cells, and TCRgammadelta+ T cells. In contrast, GrB was primarily expressed in CD56dim NK cells and differentiated memory CD8+ T cells with the CD27-/low/CD28-/low/CCR5-/low/CCR7-/CD11b+/perforinhigh phenotype. Only few CD8+ T cells expressed both GrB and GrK. GrA was found to be co-expressed in all GrB- and GrK-expressing T cells. Our findings suggest that granzyme expression during the differentiation process of memory CD8+ T cells might be as follows: GrA+/GrB-/GrK+ --> GrA+/GrB+/GrK+ --> GrA+/GrB+/GrK-.     

天然林保护对莱姆病自然疫源地特征的影响

为了探讨西部大开发中天然林保护工程的实施对莱姆病自然疫源地特征的影响,选择了天然林保护区和苗圃林保护区两个样区,从媒介、宿主以及人群感染等自然疫源地特征方面分析了自然环境变化对莱姆病传播的影响。结果表明,天然林保护区内,莱姆病的媒介、宿主在种群数量、种群多样性指数方面均高于苗圃林区;媒介和宿主潜能以及自然疫源地活力也显著高于苗圃林。可见,天然林保护工程的实施对于莱姆病的媒介、宿主在一定程度上起保护作用,其潜能、自然疫源地活力等增加,人群感染的危险性明显增高,提示了对进入天然林保护区的人员加强防护与监测的必要性。     

小鼠子宫uNK细胞的分离及其特性研究

目的：建立小鼠子宫淋巴细胞分离方法，并初步观察小鼠子宫uNK细胞的特性。方法：分别用机械法和酶消化法制备单细胞悬液分离小鼠子宫淋巴细胞，用二色或三色荧光标记技术检测子宫uNK细胞的比例及相关特征。结果：机械法分离淋巴细胞技术相对稳定、纯度较高；酶消化法未降低DX5 细胞所占的比例，但酶的消化过程容易使淋巴细胞活化水平升高，表现为活化分子CD69的表达上调。子宫中存在大量的uNK细胞(NK1．1 CD3-或DX5 CD3-细胞)，小鼠怀孕早期和中期，uNK细胞占子宫淋巴细胞的比例随着怀孕天数的增长而增长，到怀孕的第10天达到高峰(uNK细胞比例达到48.74％)，之后比例开始迅速下降。结论：成功建立了小鼠子宫uNK细胞分离方法，子宫uNK细胞作为重要的天然免疫淋巴细胞，可能参与妊娠子宫对半同种异体胚胎的保护性免疫反应。     

妊娠17～37周胎儿可溶性白介素2受体和NK细胞含量的变化

目的：探讨妊娠17～37周正常和宫内感染时胎儿外周血可溶性白介素2受体（Soluble interleuldn-2 receptor，sIL-2R）和自然杀伤细胞（Natural killer，NK）含量的变化。方法：超声引导下行脐带穿刺术，收集129例胎儿外周血，包括97例正常对照组胎儿血，32例宫内感染组（单纯疱疹病毒感染、弓形虫感染、风疹病毒感染）胎儿血，采用双色免疫荧光标记流式细胞仪技术测定胎JLPF周血NK细胞百分率，双抗体夹心酶联免疫吸附试验测定胎JLPF周血中sIL-2R的含量，分析生理状态下胎儿外周血NK细胞、sIL-2R的状况和宫内感染时NK细胞和sIL-2R含量的变化。结果：妊娠17—37周胎儿外周血NK细胞、sIL-2R含量不随孕周改变，r（NK）=-0．03，P〉0．05；r（sIL-2R）=0．167，P〉0．05，宫内感染时NK细胞含量减少，sIL-2R含量增多，与正常对照组相比差异有显著意义；t（NK）=4．29，P〈0．01；t（sIL-2R）=-5．833，P〈0．01。结论：妊娠17—37周胎儿外周血有一定量的NK细胞和sIL-2R存在，但机体免疫功能仍不完善，宫内感染时机体容易出现免疫抑制状态。     

Influence of glycosylphosphatidylinositol-linked H-2Dd molecules on target cell protection and natural killer cell specificity in transgenic mice

The expression of certain major histocompatibility complex (MHC) class I ligands on target cells is one important determinate of their susceptibility to lysis by natural killer (NK) cells. NK cells express receptor molecules that bind to MHC class I. Upon binding to their MHC class I ligand, the NK cell is presumed to receive a signal through its receptor that inhibits lysis. It is unclear what role the MHC class I molecules of the effector and target cells play in signaling to the NK cell. We have investigated the role of the cytoplasmic and transmembrane domains of MHC class I molecules by producing a glycosylphosphatidylinositol (GPI)-linked H-2D^d molecule. The GPI-linked H-2D^d molecule is recognized by H-2D^d-specific antibodies and cytotoxic T lymphocytes. Expression of the GPI-linked H-2D^d molecule on H-2^b tumor cells resulted in protection of the tumor cells after transplantation into D8 mice (H-2^b, H-2D^d) from rejection by NK cells. In addition, NK cells from mice expressing the GPI-linked H-2D^d molecule as a transgene were able to kill nontransgenic H-2^b lymphoblast target cells. The GPI-linked MHC class I molecule was able to alter NK cell specificity at the target and effector cell levels. Thus, the expression of the cytoplasmic and transmembrane domains of MHC class I molecules are not necessary for protection and alteration of NK cell specificity.     

Tyrosine kinase-dependent activation of human NK cell functions upon triggering through CD44 receptor

We recently showed evidence of CD44-mediated enhancement of natural killer (NK) cell cytotoxic activity and induction of intracellular Ca²⁺ flux. In this study, we evaluated whether CD44 plays a stimulatory role in NK cell functions, such as cytokine production and activation antigen expression. Our results indicate that ligation of the CD44 receptor results in the induction of expression of the CD69 surface activation antigen as well as in the enhancement of phorbol ester-induced TNF-α secretion. We report also evidence for the coupling of CD44 receptor to a protein tyrosine kinase(s) pathway. CD44 engagement rapidly stimulates the tyrosine phosphorylation of several cellular substrates. Pretreatment of NK cells with the tyrosine kinase inhibitor herbimycin A resulted in marked decrease of CD44-stimulated phosphorylation, indicating that it activates tyrosine kinase(s). Furthermore, the drug also prevents CD44-mediated TNF-α production and CD69 expression. These findings indicate that protein tyrosine phosphorylation is an early and critical event in CD44-mediated activation of NK cell functions.     

膜型/分泌型MICA对NK细胞受体NKG2D的相反调节效应及其对NK细胞受体谱的影响

目的　观察膜型和分泌型MICA对NK细胞受体表达的影响 ,以探讨NK细胞抗肿瘤活化机制及肿瘤细胞表达MICA分子的意义。方法　用MTT法测定人NK细胞系 (NK92 )的细胞毒活性 ;用RT PCR或FACS检测NK细胞受体 (NKG2D ,NKG2A B ,KIR2DL1,KIR2DS1)及NKG2D的识别配体MICA的表达。结果　肿瘤细胞表面的MICA分子可上调NKG2D的表达 ,下调抑制性受体NKG2A B和KIR2DL1的表达 ;而分泌型MICA (sMICA)分子对NKG2D及抑制性受体的表达均有抑制作用。结论　膜型MICA分子可上调NKG2D的表达 ,激发NK细胞对肿瘤细胞的细胞毒效应 ;分泌型MICA分子则通过降低NKG2D的表达下调机体的抗肿瘤免疫效应 ,肿瘤细胞分泌sMICA分子为肿瘤发生免疫逃逸的机制之一。