人自然杀伤细胞抑制性受体P58.2基因克隆与鉴定

目的：P58．2基因克隆与鉴定。方法：采用RT—PCR技术，从正常人外周血单个核细胞中扩增自然杀伤细胞抑制性受体P58．2基因全长cDNA，经酶切后构建重组克隆载体，双酶切和测序鉴定。结果：RT—PCR获得了预期的扩增产物P58．2全长cDNA，成功构建了pSPORT1-P58．2重组克隆载体，酶切、酶谱分析与预期结果相符。DNA测序结果与GenBank登记的人P58．2cDNA全长碱基序列一致。结论：pSPORT1-P58．2重组克隆载体构建成功；P58．2基因序列与文献报道一致，为下一步构建表达载体和基因转染等工作打下良好的基础。     

赖型钩端螺旋体重组DNApCX7的特异性鉴定和限制性内切酶谱分析

本实验将赖型钩端螺旋体（简称钩体）ＤＮＡ基因库的克隆ｐＣＸ７制备成￣（３２）Ｐ－重组ＤＮＡ探针，对８个不同血清群的１７株问号状钩体、双曲钩体ＰａｔｏｃⅠ株以及细螺旋体３０５５株ＤＮＡ进行打点杂交；同时用１５种ＤＮＡ片断进行限制性内切酶谱分析。结果表明，该重组ＤＮＡ具有问号状钩体种（Ｓｐｅｃｉｅｓ）特异性，但与不同问号状钩体之间的同源性程度有差别；限制性内切酶谱分析发现ｐＣＸ７重组ＤＮＡ片段长约１．７ｋｂ，具有１个Ｂｇ１Ⅱ识别位点和３个ＢｓｔＢ１识别位点。     

大鼠子宫内膜抗菌成分的初步分析

作者以１％乙酸冲洗ＳＤ大鼠子宫内膜，获得子宫内膜酸溶性提取物。利用琼脂糖弥散法和电泳凝胶琼脂糖弥散法抗菌试验发现，子宫内膜提取物有三条主蛋白带对致病性大肠杆菌ＭＬ－３５Ｐ耐药株有强抗菌活性，这三条抗菌蛋白带命名为ＲａｔＵＰ－１，ＲａｔＵＰ－２和ＲａｔＵＰ－３，分别占子宫内膜提取物总蛋白量的４．５％，５．７％和６．６％。虽然提取物存在溶菌的活性，但其含量甚微，在ＡＵ一ＰＡＧＥ图谱上亦未能显现溶菌酶条带。本实验的结果提示子宫内膜合成一类抗菌多肽，可能在子宫抗菌机制中发挥重要作用。     

Analysis of Killer Cell Activities in Epstein-Barr Virus Infections

Using spontaneously established autologous lymphoblastoid B cell lines (LCL), killer cell activities were studied in children with severe infectious mononucleosis (IM), chronic IM, and acute IM, and compared with those in EBV-seropositive normal controls. Natural killer (NK) cell activity of fresh peripheral blood mononuclear cells (PBMC) was normal in acute IM patients, but it was low in four of six patients with severe or chronic IM. Recombinant inter-leukin 2 (rIL-2)-activated PBMC from normal controls showed lymphokine-activated killer (LAK) cell activity against the respective autologous LCL. The levels of LCL lysis by LAK cells were significantly higher in acute IM patients, lower in chronic IM patients, and much lower in severe IM patients. In contrast to the fact that PBMC stimulated in vitro with autologous LCL (IVS cells) from normal controls and acute IM patients showed potent killing of autologous LCL, IVS cells from severe or chronic IM patients showed lower levels of LCL lysis, which were markedly augmented in three patients by rIL-2 addition to the cultures. These killer cell dysfunctions appear to be responsible for the severe or chronic course of EBV infection.     

新疆塔城地区多房棘球蚴的鼠类宿主考察

1989～1991年由新疆的塔城、裕民、额敏和托里等4个县市采集各类鼠类4科11属14种共9832只。剖检结果发现有0.014％(1/6980)小家鼠(Mus musculus)和0.09％(2/2211)赤颊黄鼠(Citellus erythrogenys)自然感染多房棘球蚴。二者发育的多房棘球蚴均系不育囊,囊内没有原头节。小家鼠和赤颊黄鼠均是本虫在我国的鼠类宿主新记录,而赤颊黄鼠又是本虫鼠类宿主的首次报道。     

流行性出血热自然状态监测研究

１９８６年１０月至１９９０年３月，先后在贵州省ＥＨＦ野鼠型疫区遵义、安顺两县和家鼠型疫区凯里市选点，监测丘陵地区自然状态下影响ＥＨＦ流行的主要因素，连续两年的逐月监测结果表明，人间流行的强度、临床表现和流行特征的不同与主要宿主动物种类、密度和带病毒率以及病原体的毒力和型别有关。     

The molecular basis of Natural Killer (NK) cell recognition and function

Natural Killer cells are likely to play an important role in the host defenses because they kill virally infected or tumor cells but spare normal self-cells. The molecular mechanism that explains why NK cells do not kill indiscriminately has recently been elucidated. It is due to several specialized receptors that recognize major histocompatibility complex (MHC) class I molecules expressed on normal cells. The lack of expression of one or more HLA class I alleles leads to NK-mediated target cell lysis. Different types of receptors specific for groups of HLA-C, HLA-B, and, very recently, HLA-A alleles have been identified. While in most instances, they function as inhibitory receptors, an activatory form of the HLA-C-specific receptors has been identified in some donors. Molecular cloning of HLA-C-, HLA-B- or HLA-A-specific receptors has revealed new members of the immunoglobulin superfamily with two or three Ig-like domains, respectively, in their extracellular portion. While the inhibitory form is characterized by a long cytoplasmic tail associated with a non-polar transmembrane portion, the activatory one has a short tail asociated with a Lys-containing transmembrane portion. Thus, these human NK receptors are different from the murine Ly49, that is a type II transmembrane protein characterized by a C-type lectin domain. A subset of activated T lymphocytes expresses NK-type class I-specific receptors. These receptors exert an inhibiting activity on T cell receptor-mediated functions and may provide an important mechanism of downregulation of T cell responses.     

Cryopreservation of human mononuclear cells for quality control in clinical immunology. I. Correlations in recovery of K- and NK-cell functions,surface markers,and morphology

Cryopreserved human peripheral blood mononuclear cells (PBMC) were tested for natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) and for high-affinity (29°C) and total (4°C) rosette formation with sheep erythrocytes. PBMC produced variable NK activity following freezing and thawing, but consistently reacted well in ADCC. A significant correlation was found between low NK activity and a decreased percentage of low-affinity rosette-forming cells. On the contrary, the number of large granular lymphocytes (LGL), among which NK cells are restricted, and the reactivity with the monoclonal antibody OKT10, which recognizes the majority of LGL in the peripheral blood, were not significantly altered by cryopreservation. Cryopreserved cells proved to be excellent controls for determining the day-to-day variability of the NK assay and for selecting optimum conditions for this test in the clinical immunology laboratory.     

Natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities can be differentiated by their different sensitivities to interferon and prostaglandin E1

Though purported to be identical cells (or in identical populations of cells), the natural killer (NK) cell mediating spontaneous natural cytotoxicity and the killer (K) cell mediating antibody-dependent cellular cytotoxicity (ADCC) may not be totally identical, at least in susceptibility to regulation by the immunomodulators prostaglandin E₁ (PGE₁) and interferon (IFN). We demonstrate here that NK cells are always enhanced by IFN, while K cells are inhibited from binding targets, resulting in fewer effectors at optimal concentrations of antibody. Only at 10- to 100-fold suboptimal concentrations of antibody is ADCC activity enhanced. As measured by magnitude of inhibition and dose-response titration, ADCC activity is less sensitive to the effects of PGE₁ than is NK activity in the⁵¹Cr release assay and single-cell assay. After overnight incubation with or without PGE₁, whatever sensitivity ADCC activity had to PGE₁ is lost. However, NK cells incubated in the presence of PGE₁ overnight are still sensitive to inhibition. Indomethacin boosts NK activity without having any effect on ADCC activity. Finally, NK activity is substantially reduced by overnight incubation of cells at room temperature, which has no effect on K cells.     

西部开发中的虫媒病传播问题

西部开发地区存在许多虫媒病 ,即昆虫和蜱螨传播的疾病 ,为了保障开发人群的健康 ,首先需要对这些疾病的传播 ,特别是有些疾病的自然疫源地或流行区有所了解。本文列述了 13种虫媒病及其在这个地区的分布 ,对其中值得我们更重视的 4类重要疾病 ,包括鼠疫、莱姆病、疟疾和登革热的病原体传播媒介或有的贮存宿主以及重要性等作了扼要的介绍。本文并提出了这类疾病在开发中和开发后可能产生的危害性 ,以及防止或减少它们危害的建议。作者认为从开发地区的长远利益出发 ,应该重视开发中自然环境改变对上述虫媒病传播影响的研究