Cellularly defined minor histocompatibility antigens are differentially expressed on human hematopoietic progenitor cells

Previously, five CTL lines directed against minor histocompatibility (mH) antigens designated HA-1-5 have been established from peripheral blood of patients after allogeneic bone marrow transplantation (BMT), and have been characterized using population and family studies. All cell lines showed specific HLA class I-restricted lysis of PHA-stimulated peripheral blood target cells from donors positive for the particular mH antigens. After 4 h of incubation of the mH antigen HA-3-specific CTL line with bone marrow cells from HA-3+ donors, complete class I-restricted inhibition of colony growth of the hematopoietic progenitor cells was observed even at low E/T ratios, indicating that the HA-3 antigen is strongly expressed on hematopoietic stem cells. Therefore, this antigen may be a target structure in the immune-mediated rejection of the hematopoietic graft in case of incompatibility for this determinant between donor and recipient in allogeneic BMT. In contrast, incubation of bone marrow cells with the antigen-specific anti-HA-1, -2, -4, and -5 CTL lines did not result in growth inhibition of the hematopoietic progenitor cells tested. After a prolonged incubation time and using a very high E/T ratio, progenitor cells from HA-2+ or HA-5+ donors were killed to some extent by the anti-mH-specific CTL lines, although the growth inhibition observed was minor and variable. Our results show that mH antigens are differentially expressed on human hematopoietic progenitor cells. Therefore, only some of these antigens may be targets in immune-mediated rejection of the bone marrow graft.     

MHC class II presentation of endogenously expressed antigens by transfected dendritic cells

Dendritic cells (DC) present immunogenic epitopes of antigens in the context of MHC class I and class II molecules in association with costimulatory molecules, and efficiently activate both cytotoxic T cells and T helper cells. Gene modified DC expressing antigen encoding cDNA represent a particularly attractive approach for the immunotherapy of disease. We previously described a gene delivery system for DC based on receptor-mediated endocytosis of ligand/polyethylenimine (PEI) DNA transfer complexes that target cell surface receptors which are abundantly expressed on DC. Employing this gene delivery system, DC were generated that express chicken ovalbumin (OVA) cDNA as a model antigen and introduce antigen into the MHC class I presentation pathway. We demonstrate here that modification of OVA cDNA as transferrin receptor (TfR) or invariant chain (Ii) fusions effectively generate MHC class II specific immune responses in addition to MHC class I responses. TfR-OVA contains the membrane anchoring region of transferrin receptor and represents a membrane-bound form of OVA for access to the MHC class II compartment. Ii-OVA fusions directly target the MHC class II processing pathway. Thus, modification of antigen encoding cDNA represents a convenient and effective means to direct antigens to MHC class II presentation and thus to generate T cell help.     

Calcium signals are affected by ciprofloxacin as a consequence of reduction of mitochondrial DNA content in Jurkat cells

The effects of ciprofloxacin on mitochondrial DNA (mtDNA) content, oxygen consumption, mitochondrial membrane potential, cellular ATP formation, and capacitative Ca(2+) entry into Jurkat cells were investigated. In cells incubated for several days with 25 mug/ml ciprofloxacin, a 60% reduction of mtDNA content, inhibition of the respiratory chain, and a significant decrease in mitochondrial membrane potential were observed. These changes led to a decrease in the calcium buffering capacity of mitochondria which, in turn, resulted in a gradual inhibition of the capacitative Ca(2+) entry. On days 4, 7, and 11 of incubation with ciprofloxacin, the initial rates of Ca(2+) entry were reduced by 33%, 50%, and 50%, respectively. Ciprofloxacin caused a transient decrease in the cellular capability for ATP formation. In cells incubated for 15 min with glucose, pyruvate, and glutamine as exogenous fuel, ciprofloxacin reduced ATP content by 16% and 35% on days 4 and 7, respectively, of incubation with the drug. However, on day 11 of incubation with ciprofloxacin, a recovery of cellular ATP formation was observed. In conclusion, long-term exposure of Jurkat cells to ciprofloxacin at a concentration of 25 mug/ml seriously affects cellular energy metabolism and calcium homeostasis.     

两种念珠菌DNA探针的研制及应用

目的：制备两种念珠菌DNA探针并应用于临床诊断。方法：对聚合酶链反应扩增的白色念珠菌标准株的E03基因的125bp片段，用半抗原地高辛标记；合成仪合成的E03基因中25bp特异寡核苷酸，用生物素标记。检测两种探针显色敏感度，并与23株临床分离的白色念珠菌、热带念珠菌，近平滑念珠菌、克柔念珠菌、星形念珠菌及大肠埃希菌等细菌进行斑点杂交试验。结果：Dig-125bpDNA探针显色敏感度为0.01pg，仅与白色念珠菌杂交，且对临床分离株检测的结果与传统厚膜孢子鉴定法相符。Bio-25bpDNA探针显色敏感度为20pg，与白色念珠菌、近平滑念珠菌及星形念珠菌杂交。结论：Bio-25bp DNA探针可用于念珠菌初步鉴定，而Dig-125bp DNA探针可用于白色念珠菌的鉴定。     

两种黑色素瘤B16细胞肺转移小鼠模型的构建和比较

目的采用尾静脉接种法建立C57BL/6小鼠和KM小鼠两种黑色素瘤B16细胞肺转移动物模型,观察小鼠肺部成瘤过程,并对两种模型进行比较。制作肿瘤切片,通过HE染色分析两种肿瘤模型的组织病理学特征。方法培养B16黑色素瘤细胞至对数生长期时收集细胞,用生理盐水调整浓度为5×106/ml备用。将备好的B16细胞通过尾静脉接种小鼠,每只注射0.2 ml。接种后,两种小鼠每隔一定时间随机各取一只小鼠处死,解剖取肺,观察成瘤情况,计数肺表面的瘤结节数,测量瘤结节大小。以出现瘤结节开始计时,记录小鼠荷瘤时间。形成稳定的肿瘤模型后,制作肿瘤组织切片,HE染色进行病理学观察分析。结果 B16细胞尾静脉接种C57BL/6小鼠和KM小鼠,均能形成肺转移模型,但两种小鼠成瘤情况差异较大。KM小鼠的荷瘤时间比C57BL/6小鼠荷瘤时间长。HE染色结果显示黑色素瘤B16细胞在两种小鼠的肺组织中均形成巢团状的转移瘤,且两种模型肺转移瘤均多分布在支气管周围。结论通过对C57BL/6小鼠和KM小鼠两种黑色素瘤B16细胞肺转移小鼠模型的成瘤特点的分析比较,可以看出KM小鼠更适合用于研究新的肺肿瘤治疗药物,为研究黑色素瘤的发生发展提供依据。     

Invariant NKT cells are required for airway inflammation induced by environmental antigens

Invariant NKT cells (iNKT cells) are a unique subset of T lymphocytes that rapidly carry out effector functions. In this study, we report that a majority of sterile house dust extracts (HDEs) tested contained antigens capable of activating mouse and human iNKT cells. HDEs had adjuvant-like properties in an ovalbumin (OVA)-induced asthma model, which were dependent on Vα14i NKT cells, as vaccinated animals deficient for iNKT cells displayed significantly attenuated immune responses and airway inflammation. Furthermore, the administration of HDEs together with OVA mutually augmented the synthesis of cytokines by Vα14i NKT cells and by conventional CD4(+) T cells in the lung, demonstrating a profound immune response synergy for both Th2 cytokines and IL-17A. These data demonstrate that iNKT cell antigens are far more widely dispersed in the environment than previously anticipated. Furthermore, as the antigenic activity in different houses varied greatly, they further suggest that iNKT cell responses to ambient antigens, particular to certain environments, might promote sensitization to conventional respiratory allergens.     

Localization of H-2 antigens on mouse trophoblast cells

The presence of H-2 antigens of the paternal and maternal haplotypes on mouse trophoblast cells was examined at several stages of pregnancy by using a sensitive immunolabeling technique followed by quantitative radioautography. Results revealed the presence of H-2 antigens (determined by the K or D loci) of both parental haplotypes on the F1 trophoblast cells. At 14-16 d of gestation, the antigen density was equivalent to that on adult thymocytes and there was a further 50% increase on day 18. H-2 antigens of both parental haplotypes are also found to be expressed on 11-13 d trophoblast cells.     

Human B-lymphocyte antigens expressed by lymphocytic and myelocytic leukemia cells. I. Detection by rabbit antisera

A previously uncharacterized human B-lymphocyte antigen has been detected by rabbit antisera raised to papain digests of spleen cell membranes. The unabsorbed sera reacted in both cytotoxicity and immunofluorescent tests with normal B lymphocytes and cultured B-cell lines but not with normal T lymphocytes or cultured T-cell lines. The cytotoxicity titers against B cells were as high as 1:32,000, whereas the same sera undiluted were negative against T cells. By immunofluorescent staining 6-14% of unfractionated normal lymphocytes and 48-85% of B-rich lymphocyte preparations were positive. Normal peripheral blood granulocytes, platelets, erythrocytes, and phytohemagglutinin blasts were negative. The antisera reacted with the same high titers against leukemia cells from approximately 70% of the patients with acute lymphocytic leukemia, acute myelocytic leukemia, chronic myelocytic leukemia, and seven of eight cases of chronic lymphocytic leukemia. From absorption studies it appeared that the same antigen was being expressed by leukemia cells and normal B lymphocytes. Using immunofluorescent staining the anti-B-cell antisera were able to detect positive leukemia cells in the bone marrow of patients with advanced leukemia and to monitor the elimination of these cells after chemotherapy. Soluble B-cell antigen was found in the serum of some leukemia and lymphoma patients do but not in normal serum.     

人白细胞抗原B位点基因芯片分型技术研究

目的 探讨基因芯片技术在进行北方汉族人群人白细胞抗原B位点（HLA-B）分辨度分型的价值.方法 根据中国北方汉族人群HLA-B常见基因位点及临床分型分辨度特征,设计特异性寡核苷酸中分辨度分型探针,制成HLA-B基因分型芯片.采用荧光标记引物和不对称聚合酶链反应（PCR）扩增HLA-B 2、3外显子,产物与芯片探针杂交后经荧光扫描,并用特定软件分析判断阳性探针,以确定样品基因型.结果 用中分辨度探针从30份北方汉族人标本中可分出HLA-B 7～83范围的42个B抗原等位基因,与顺序特异引物聚合酶链反应（PCR-SSP）分型方法对比,多检出3个HLA-B14、73和82新等位基因.结论 HLA-B基因芯片具有较高的精确度和特异性,可一张芯片多人份检测,适合用于临床HLA-B抗原分型.     

两种前处理流程检测HBV DNA的重复性比较

目的比较修改前后两种前处理流程检测HBV-DNA的变异系数(CV),以确定重复性更好的检测流程。方法采用修改前后两种前处理流程,对标称1×105IU/ml的阳性定量参考品、自制室内质控血清进行日内重复检测;对两个批号的自制室内质控血清进行日间重复检测,比较两种前处理流程检测结果的变异系数。结果以HBV DNA IU/ml的自然对数值进行统计分析,前处理流程修改前后,标称1×105的阳性定量参考品的日内CV分别为4.26%、1.38%,差异有统计学意义(u=2.564,P=0.0103);室内质控血清的日内CV分别为7.85%、2.14%,差异有统计学意义(u=2.792,P=0.0052);室内质控血清的日间CV分别为9.62%、3.40%,差异有统计学意义(u=7.358,P=1.9×10-13)。修改前处理操作流程后两个批号室内质控血清日间CV为3.40%、2.84%,差异无统计学意义(u=1.522,P=0.1281)。结论采用修改后的前处理流程检测HBV-DNA重复性更好。     

Longitudinal increases in mitochondrial DNA levels in blood cells are associated with survival in critically ill patients

Background  

Mitochondrial dysfunction may be causally related to the pathogenesis of organ failure in critically ill patients. Decreased mitochondrial DNA (mtDNA) levels have been associated with mitochondrial dysfunction and were investigated here in relation to short-term (31-day) survival.     

Tumor antigens defined by cloned immunological probes are highly polymorphic and are not detected on autologous normal cells

We have isolated UV light-induced and spontaneous tumors along with nonmalignant cells and tissues from each host. CD8+ CTL clones generated to a number of highly immunogenic UV-induced tumors did not react with autologous normal fibroblasts nor with autologous second tumors. Using up to 25 independently induced tumors as targets, these CTL clones were found to be uniquely specific for the particular tumor used for immunization even when multiple tumors isolated from the same animals were used as targets. In addition to this extensive antigenic diversity of independently induced tumors, we found that a single cancer cell can express multiple independent antigens that were uniquely expressed on the tumor but were not detectable on autologous nonmalignant fibroblasts. A poorly immunogenic spontaneous tumor was also found to express an antigen that was uniquely specific for the immunizing tumor in that it was absent from any of 25 other tumors tested. This antigen was recognized by a mAb and not detected on autologous nonmalignant fibroblasts or on an autologous second spontaneous tumor. These findings demonstrate that syngeneic CTL clones or mAbs can define unique antigens on UV-induced or spontaneous tumors. The use of autologous nonmalignant fibroblast targets made it unlikely that these antigens were widely expressed on normal cells. The availability of cloned immunological probes to antigens on tumors isolated with autologous normal cells will allow a reliable identification of the genetic origins of unique antigens on experimentally induced and spontaneous tumors and permit a decisive answer to whether these unique antigens are encoded by normal genes or by genes that have undergone somatic mutations; i.e., whether these antigens are truly tumor specific.     

两种血液分析仪性能评价

目的评价两种全自动血细胞分析仪（KX一21与ABXPENTRA60）的性能,以验证不同仪器测定结果的准确性和一致性。方法按照国际血液学标准化委员会（ICSt[）有关规定,对KX一21与ABXPENTRA60KX一21全自动血细胞分析仪从携带污染率、精密度、线性、及与ABXPENTRA60A全自动血细胞分析仪相关性和白细胞分类准确性等方面进行评价。结果KX一21的批间、批内精密度及总精密度变异系教（CV％）均在可接受范围内;各分析参数的携污带染率均〈1．O％;与ABXPENTBA60对比分析,各项参数相关性良好;白细胞分类准确性符合要求。结论KX一21与ABXPENTRA60血液分析仪性能良好,检测结果准确可靠,在临床应用中结果可以互认。     

肿瘤细胞线粒体DNA的研究进展

线粒体是哺乳动物细胞中唯一含有自身遗传物质的细胞器 ,肿瘤细胞mtDNA的突变包括结构的改变和拷贝数的增加 ;另外 ,肿瘤细胞mtDNA的核内整合也可能是导致细胞癌变的重要因素。研究某些致癌剂对mtDNA的影响可间接了解其对肿瘤的作用机制 ;而肿瘤细胞mtDNA的状态可直接影响某些化疗药物的疗效。随着线粒体基因组结构及表达调控研究的深入 ,mtDNA与肿瘤发病关系的研究必将成为肿瘤病因学研究的又一热点。     

Differences in maternal lineages of New Zealand Black mice defined by restriction endonuclease analysis of mitochondrial DNA and by expression of maternally transmitted antigen

Two substrains of New Zealand Black (NZB) mice have been compared with respect to expression of a maternally transmitted cell surface antigen, Mta, defined by cloned cytolytic T cells, and for restriction enzyme polymorphisms of mitochondrial DNA (mtDNA). These independent assays of maternal cytoplasmic inheritance provide strong evidence for genetic contamination of the NZB/BlPt substrain (NZB/Bl mice from Michael Potter's separate colony at the National Institutes of Health), in which the typical NZB immunologic abnormalities are at least partially ameliorated. The decisive data are the restriction enzyme maps of mtDNA for NZB/BlPt, which were identical with those of the common "old inbred" strains and quite different from those of NZB/BlN (NZB/Bl mice from the breeding facility at the National Institutes of Health). It is probable that the contamination of the NZB/BlPt substrain is related to phenotypic changes in their autoimmune state. More interestingly, the data are consistent with, although they do not prove, involvement of the mitochondrial genome in expression of a cell surface molecule.     

Biochemical transformation of mouse cells by a purified fragment of marmoset herpesvirus DNA

Although the size of marmoset herpesvirus (MarHV) DNA, estimated by velocity sedimentation in sucrose gradients, was similar to that of herpes simplex virus type 1 (HSV-1) DNA, the restriction endonuclease sites of MarHV and HSV-1 DNAs were quite different. A specific BamHI restriction fragment (6.2 x 10(6) daltons) of MarHV DNA biochemically transformed LM(TK-) mouse fibroblasts to the thymidine kinase(TK)-positive phenotype. Rabbit antisera, prepared against MarHV TK, inhibited MarHV-induced TK, but not HSV-1, HSV-2, or cellular TKs. Disc PAGE analyses and enzyme neutralization experiments with the anti-MarHV TK sera demonstrated that the TK expressed in MarHV transformants was MarHV-specific.     

两种人羊膜细胞的表型鉴定和分化潜能测定(英文)

本研究旨在分离、培养和表型鉴定两种人羊膜细胞并分析其多向分化潜能。羊膜中可分离出来源于外胚层的羊膜上皮细胞和来源于中胚层的羊膜间充质细胞。用流式细胞术和免疫荧光法对其进行表型鉴定,同时用免疫荧光法分析其多向分化潜能。结果表明:两种人羊膜细胞阳性表达HLA-A,B,C和间充质干细胞的标志(CD29,CD73,CD44,CD59,CD90,CD105,CH166),不表达造血干细胞的标志(CD31,CD34,CD45,HLA-DR),弱表达协同刺激分子(CD40,CD40L,CD80,CD86),且这些表型的表达量在第3-7代都维持稳定。免疫荧光法显示羊膜上皮细胞表达角蛋白19,不表达波形蛋白,而羊膜间充质细胞则相反。对其多向分化潜能测定显示,羊膜间充质细胞更好地向心肌细胞分化,而羊膜上皮细胞更好地向神经细胞分化。结论:从羊膜中可分离出羊膜上皮细胞和羊膜间充质细胞,两种细胞的表型相似,多向分化潜能却不同。羊膜上皮细胞具有更好的外胚层分化潜能,而羊膜间充质细胞更好地向中胚层分化。此结论对细胞治疗有很好的指导作用。     

两种低张胶体液对失血并腹腔海水浸泡伤实验犬的救治作用

目的观察两种低张胶体液对失血并腹腔海水浸泡伤的救治效果。方法建立腹腔海水浸泡伤动物模型。42只犬随机均分为对照组(A组)、5%葡萄糖治疗组(B组)、045%氯化钠治疗组(C组)、09%氯化钠治疗组(D组)、低张胶体(右旋糖酐40)救治组(E组)及低张胶体(右旋糖酐70)救治组(F组),观察每一组腹腔海水浸泡后平均动脉压(MAP)、心输出量(CO)、尿量、血浆渗透压及脑肺病理学的变化。结果两种低张胶体液均可显著改善MAP及CO,增加尿量,降低血浆渗透压,预防脑肺水肿发生。伤后24h低张胶体(右旋糖酐70)改善MAP及CO作用优于低张胶体(右旋糖酐40)(P<005)。结论失血并腹腔海水浸泡伤后早期低张胶体(右旋糖酐40)与低张胶体(右旋糖酐70)有类似救治效果,伤后24h低张胶体(右旋糖酐70)改善血流动力学作用优于低张胶体(右旋糖酐40)。     

Small, clonally variant antigens expressed on the surface of the Plasmodium falciparum-infected erythrocyte are encoded by the rif gene family and are the target of human immune responses

Disease severity in Plasmodium falciparum infections is a direct consequence of the parasite's efficient evasion of the defense mechanisms of the human host. To date, one parasite-derived molecule, the antigenically variant adhesin P. falciparum erythrocyte membrane protein 1 (PfEMP1), is known to be transported to the infected erythrocyte (pRBC) surface, where it mediates binding to different host receptors. Here we report that multiple additional proteins are expressed by the parasite at the pRBC surface, including a large cluster of clonally variant antigens of 30-45 kD. We have found these antigens to be identical to the rifins, predicted polypeptides encoded by the rif multigene family. These parasite products, formerly called rosettins after their identification in rosetting parasites, are prominently expressed by fresh isolates of P. falciparum. Rifins are immunogenic in natural infections and strain-specifically recognized by human immune sera in immunoprecipitation of surface-labeled pRBC extracts. Furthermore, human immune sera agglutinate pRBCs digested with trypsin at conditions such that radioiodinated PfEMP1 polypeptides are not detected but rifins are detected, suggesting the presence of epitopes in rifins targeted by agglutinating antibodies. When analyzed by two-dimensional electrophoresis, the rifins resolved into several isoforms in the pI range of 5.5-6.5, indicating molecular microheterogeneity, an additional potential novel source of antigenic diversity in P. falciparum. Prominent polypeptides of 20, 22, 76-80, 140, and 170 kD were also detected on the surfaces of pRBCs bearing in vitro-propagated or field-isolated parasites. In this report, we describe the rifins, the second family of clonally variant antigens known to be displayed by P. falciparum on the surface of the infected erythrocyte.