温度对mPEG-BTC修饰HLA抗原效果的影响

目的　寻找mPEG BTC修饰淋巴细胞表面HLA A2抗原的最适温度 ,及如何在 37℃条件下保持修饰物的稳定。方法　在不同温度条件下 ,用终浓度为 12mmol/L的mPEG BTC在pH7.4的PBS中对淋巴细胞表面HLA A2抗原进行修饰。结果　 4～ 2 5℃mPEG BTC对淋巴细胞有良好的修饰效果 ,可完全阻断淋巴细胞表面HLA A2抗原与其相应抗体的反应 ;在 30℃及 37℃条件下不利于修饰 ;在 2 2℃条件下经mPEG BTC修饰后的淋巴细胞在 37℃条件下72h内可以完全阻断HLA A2抗原与其抗体的反应。结论　在室温下经mPEG BTC修饰的淋巴细胞可以在 37℃中保持稳定。     

mPEG-BTC对淋巴细胞表面HLA-A2抗原化学修饰效果评价

目的　研究mPEG BTC有效修饰淋巴细胞表面HLA A2抗原、阻断其与相应抗体间特异性结合的方法。方法　在室温下、pH 7.4的磷酸盐溶液中 ,采用浓度梯度法修饰淋巴细胞表面HLA A2抗原 ,用微量淋巴细胞毒试验检测其修饰效果。结果　经mPEG BTC处理后的淋巴细胞微量淋巴细胞毒试验为阴性。结论　在本实验条件中 ,mPEG BTC对淋巴细胞表面HLA A2抗原具有良好的化学修饰作用 ,可以完全阻断其与HLA A2抗体的反应。     

何谓抗原？抗原具有什么性能？

答：抗原是一类能够刺激机体免疫系统，使之发生免疫应答，产生抗体和／或致敏淋巴细胞等免疫物质，同时又能在体内外与相应抗体或致敏淋巴细胞发生特异性结合的物质。抗原具有两种性能：（1）刺激机体产生免疫反应的免疫原性；（2）与相应抗体和／或致敏淋巴细胞发生特异性结合的反应原性。在某些特定条件下，抗原也可引起机体产生免疫耐受性。     

CTL表位预测的研究进展

细胞毒性T淋巴细胞(CTL)表位是抗原蛋白中经抗原提呈细胞(APCs)处理,与MHC-Ⅰ类分子结合并共同被T细胞抗原受体(TCR)特异性识别从而诱导相应的CTL克隆产生免疫应答的短肽.     

甲氧基聚乙二醇修饰改造RhD(+)血型的初步研究

Rh血型与ABO血型一样是重要的血型系统，Rh血型不符会引起严重的输血反应及新生儿溶血病。中国人群中RhD阴性血型的比例仅为0．2％-0．5％，将RhD阳性红细胞改造成RhD阴性红细胞在临床输血中有重要的意义。本研究用4种不同端基的甲氧基聚乙二醇(mPEG)，修饰A型、B型、AB型和O型的RhD( )红细胞，比较4种mPEG衍生物对RhD抗原的修饰效果。同时观察mPEG修饰对红细胞形态、结构和功能的影响。结果表明，mPEG—BTC(苯并三唑端基PEG)较其他3种PEG的修饰效果好，在1mmol／L时可以有效地遮蔽红细胞表面RhD抗原，而对红细胞形态、渗透脆性、自身溶血、乙酰胆碱酯酶、胆固醇、ATP、2，3-DPG含量以及变形性无影响。结论：初步实现了将RhD( )红细胞修饰改造成RhD(-)红细胞的目的。     

血小板减少性疾病PAIgG的测定

人类血小板膜上有多种抗原,产生的血小板相关抗体（PAIgG）主要有红细胞血型（ABH）抗体、白细胞（HIA—Ⅰ类）抗体和血小板特异性抗体（HPA）。PAIgG的测定对于诊断原发性血小板减少性紫癜（ITP）、血小板输注无效、免疫性血小板减少性紫癜、再生障碍性贫血等血小板减少性疾病有重要意义。采用血清学技术和DNA分型技术对190例血小板减少性疾病患者血清中PAIgG进行测定。     

免疫检验学试题参考答案

一、名词解释1、间接凝集抑制试验：将引起致敏载体发生凝集反应的抗原或抗体，用相应的抗体或抗原中和后再加入致敬载体，此时致敬我体不发生凝集，故称间接凝集抑制试验。2、29℃花环试验：将淋巴细胞与绵羊红细胞况和离心沉淀后，放置29C并温1小时所形成的T淋巴细胞花环．称谓29℃花环试验。3、葡萄球菌A蛋白：葡萄球菌A蛋白（SPA）是金黄色葡萄球菌细胞壁上的一种特殊的蛋白质。具有与人和某些动物的IgGFc段结合的特性，同时仍保留IgG与相应抗原结合的Fab段的反应特住。4、多克隆抗体：每一种抗原分子常有多个抗原决定读，可刺激…     

Ⅰ型IFN对体外培养树突状细胞的影响

树突状细胞(dendritic cells，DC)能够刺激并致敏初始T细胞和启动早期免疫反应而被认为是最重要的抗原呈递细胞。存在于外周组织中的未成熟DC主要参与捕获、加工处理抗原的过程，之后则进入淋巴器官分化为成熟DC并上调HIA—Ⅰ、Ⅱ类分子，CD80、CD86等共刺激分子及粘附分子的表达，诱导CD4^ 和CD8^ T细胞反应。国外研究表明，Ⅰ型IFN可以加速DC的分化和成熟。在Ⅰ型IFN存在下体外培养诱生的DC高表达HLA—Ⅰ、Ⅱ类分子、共刺激分子及粘附分子，刺激同种混合淋巴细胞反应的能力增强。本文对这一领域研究进展作一综述。     

IL-4基因修饰HL-60细胞增强CTL杀伤活性机制初探

目的 进一步探讨IL－4基因修饰瘤苗增强细胞毒性T淋巴细胞（CTL）杀伤活性的机制。方法 通过逆转录病毒载体PL－IL－4－SN将人IL－4基因导入白血病细胞系HL－60细胞,以IL－4基因修饰瘤苗和野生型瘤细胞作刺激细胞诱导CTL反应,通过流式细胞仪检查肿瘤细胞表面MHC－Ⅰ、MHC－Ⅱ类抗原及B7－1、ZCAM－1等分子表达。结果 IL－4基因修饰诱导瘤细胞表达MHC－Ⅱ类抗原、B7－1及ICAM－1等细胞表面分子,对MHC－Ⅰ类抗原表达无影响,其瘤苗诱导的CTL杀伤活性为野生型瘤细胞的7倍（P＜0．01）,加入抗IL－4单抗可完全阻断IL－4诱声细胞表面MHC－Ⅱ类抗原及B7－1、ICAM－1分子的表达,IL－4基因修饰瘤苗诱导CTL反应时培养上清可测及IL－2产生。抗IL-4灌抗细胞MHC－Ⅱ类抗原等表面分子单抗可降低IL－2产生及抑制CTL反应。结论 诱导MHC－Ⅱ类抗原等表面分子表达,促进IL－2产生,可能是IL－4基因修饰增强CTL杀伤活性的作用机制之一。     

mPEG修饰红细胞Rh抗原稳定性的研究

本研究旨在探究mPEG修饰的红细胞Rh抗原的稳定性。利用红细胞膜蛋白SDS—PAGE电泳技术分析mPEG修饰后红细胞膜蛋白与mPEG结合情况，用红细胞血影凝集实验及40cCPD保养液保存的修饰红细胞与匹配血液体外混血实验，观察mPEG修饰后红细胞Rh抗原被遮蔽的稳定性。结果发现：不同保存时间的mPEG修饰的红细胞在模拟输血（即混血前后）的血型保持不变，同时mPEG修饰的红细胞在保存过程中游离血红蛋白水平正常，并且混血后经37℃孵育的mPEG修饰的红细胞游离血红蛋白水平低于不混合的修饰的红细胞。比较分析PEG特异的碘染和考马斯亮蓝染的显色图谱发现，特殊的碘染显示出mPEG与红细胞膜蛋白结合的条带，mPEG—SPA与红细胞膜蛋白结合后导致蛋白分子迁移速度发生改变。mPEG修饰的红细胞血影凝集实验证实，修饰红细胞在质膜裂损后mPEG仍有效地遮蔽抗原。结论：mPEG—SPA不论在红细胞膜蛋白被单独提取后，还是膜破损后以及存活状态下，均能与红细胞膜蛋白稳固结合。     

Acid pH-induced changes in the immunoreactivity of specific antigen and antibody in circulating immune complexes from tuberculosis sera.

The effect of acid pH treatment of circulating immune complexes (CIC) derived from tuberculosis sera was studied on the relative titers of specific antibody (CIC Ab) and mycobacterial antigen (CIC Ag) in the complexes. While the specific antibody titers increased, the titers of CIC Ag declined as a result of acid pH treatment of CIC, both changes being highly significant statistically. Direct exposure of TB sera to pH 2.8 also resulted in significant enhancements in the titers of antibodies directed against Mycobacterium tuberculosis (M.tb.). Competition experiments indicated that the acid pH-treated antibodies retained their antigen specificity. TB sera treated with pH 2.8 for 30 min and then neutralized back to pH 7.4 retained the enhanced antibody reactivity even after 7 days of storage at 4 degrees C. Our results indicate that acid pH treatment induces higher antigen binding ability in anti-M.tb. antibodies, present in free or complexed form in TB sera. These changes appear to be irreversible. Dissociation of CIC and analyzing the titers of released antibody and antigen components offered no advantage with respect to the immunodiagnosis of tuberculosis, as compared to the levels of undissociated CIC components or the serum antibody.     

mPEG修饰解决血型匹配困难的体外研究

本研究的目的是通过nPEG修饰红细胞表面抗原以期找到一种解决临床疑难配血的方法。收集了含高效价抗体及发生临床配血困难病例的血清共29例，分析了病因及所含的抗体，并采用1．0mmol／L的mPEG-BTC与献血者红细胞混合，25℃孵育1小时，用聚凝胺法和抗人球蛋白法检测对比mPEG修饰前后的红细胞与29例血清的凝集情况。结果表明：临床配血困难及血清含高效价抗体的病例主要发生在血液系统疾病和肿瘤及新生儿溶血病产妇，所含的抗体主要是Rh血型系统的抗体和自身抗体。1．0mmol／L mPEG-BTC修饰的红细胞后，不会与这些病例血清中的抗体发生反应，达到了临床配血输用的要求。结论：mPEG修饰红细胞可能是解决临床输血血型匹配困难的一种有效方法。     

血小板HLA抗原修饰动物实验研究

目的探讨mPEG-BTC对HLA修饰的生物学意义及机理及其用于“通用”血小板开发的可行性。方法以HLA-A2型淋巴细胞为指示细胞,微量淋巴细胞毒试验研究mPEG修饰HLA的效果,检测修饰对血小板聚集、粘附、释放功能的影响,兔和猴动物试验观察修饰血小板的效果。结果mPEG-BTC修饰血小板HLA抗原成功,修饰血小板的粘附、聚集功能有所增强,分泌功能不受影响,实验动物输注修饰血小板后无不良反应,24h血小板升高指数及血小板回收率显示输注有效。结论MPEG-BTC可以修饰血小板HLA抗原,提示制备“通用”血小板可能可行。     

Degradation of and drug release from a novel 2,2-bis(2-oxazoline) linked poly(lactic acid) polymer.

The degradation rate of poly(lactic acid) (PLA) is typically modified by copolymerization of the glycolide with lactide. In the present study, the degradation rate of PDLLA was modified by a novel linking of PLA with 2,2'-bis(2-oxazoline). This modification resulted in formation of a more rapidly degrading poly(ester amide) (PEA) for controlled drug release. The hydrolytic degradation of PDLLA and PEA films was studied in PBS (pH 7.4, USP XXIV, 37 degrees C); the resulting decrease in molecular weight was determined by size exclusion chromatography and the weight loss of films was measured. Drug releases of guaifenesin (mw 198.2), timolol (mw 332.4), sodium salicylate (mw 160.1) and FITC-dextran (mw 4400) from PDLLA and PEA films and microspheres were examined in PBS (pH 7.4, 37 degrees C). The degradation rate of PEA was substantially greater than that of PDLLA. The release profiles of all small model drugs (mw <332.4) from PDLLA films were biphasic or triphasic, while the release profiles of small model drugs from PEA films varied extensively. Due to the faster weight loss of PEA, FITC-dextran (mw 4400) was released substantially more rapidly from PEA microspheres than from PDLLA microspheres. In conclusion, all model drugs, except guaifenesin, were released faster from PEA preparations than from PDLLA preparations.     

Autoantibodies to B Lymphocytes in a Patient with Hypoimmunoglobulinemia: CHARACTERIZATION AND PATHOGENIC ROLE

In a young woman with ulcerative colitis, hypoimmunoglobulinemia, and humoral immunodeficiency, lymphocyte counts vary between 600 and 1,000 per mm(3) with 0.5-1.5% bone marrow-derived (B) cells and 98-99% thymus-derived (T) cells. Anti-lymphocyte antibodies were detected by immunofluorescence and by microlymphocytotoxicity with increased reactivity at +4 degrees C. They belonged to the IgM class and were polyclonal. Studies performed with various normal lymphocyte subpopulations, several lymphoblastoid cell lines and lymphocytes from immunodeficiency patients showed that these antibodies reacted with B cells. The corresponding antigen(s) is distinct from membrane-bound immunoglobulins, is not an alloantigen, and is probably unrelated to the la-like molecules. Pokeweed mitogen stimulated B cells appear to lose this antigen. Cells from various lymphoproliferative disorders were tested. T-derived and "non T-non-B" leukemic cells did not react with the antibody. Malignant cells from B-derived lymphomas and prolymphocytic leukemias were reactive. The incidence of positivity of the leukemic cells among patients with common B chronic lymphocytic leukemia was surprisingly low (one-third of the patients).The autoantibody nature of the anti-B-cell antibodies and their pathogenic role in the genesis of the patient's hypoimmunoglobulinemia was demonstrated by the effect of removal of antibodies by massive plasmaphereses which were followed by a dramatic and transitory increase of B-cell figures. Whereas most primary immunodeficiency syndromes appear to result from an arrest in the differentiation capabilities of immunologically competent cells, autoantibodies to circulating B lymphocytes may be incriminated in the pathogenesis of some cases of hypogammaglobulinemia.     

猪红细胞表面抗原化学修饰后应用于异种输血的初步体外研究

目的使化学修饰的猪红细胞(pRBC)呈现出与人红细胞(hRBC)相似的血清学特性,减弱或消除人体对pRBC的免疫排斥。方法采用双修饰法即rSα-GalE酶解法(100U/mL的rSα-GalE处理)修饰改造pRBC表面的Gal抗原,再用mPEG包裹法(3mmol/L的mPEG-BTC)修饰遮蔽pRBC的non-αGal表面抗原。结果修饰后的pRBC与人混合血浆的盐水交叉配血试验为阴性;修饰后pRBC的结构、功能等指标基本正常。结论经rSα-GalE和mPEG双修饰法修饰改造的pRBC呈现出与hRBC相似的血清学特性。     

Primary polyclonal human T lymphocytes targeted to carcino-embryonic antigens and neural cell adhesion molecule tumor antigens by CD3zeta-based chimeric immune receptors

Antigen-specific T lymphocytes are attractive as potential anticancer agents. The generation of large numbers of antigen-specific T cells is possible through the use of gene therapy to express targeting receptors on the T lymphocyte. Activated T lymphocytes were transduced to express carcino-embryonic antigen or neural cell adhesion molecule targeted CD3zeta chimeric immune receptors. The chimeric receptors were expressed as homodimers and also as heterodimers with the native CD3zeta. T lymphocyte populations were expanded in the absence of selection for the modified cells and were shown to produce cytokines when cultured in the presence of immobilized purified protein antigen. These lymphocytes also responded by cytokine production and cytolytic activity when challenged with tumor-cell lines expressing the antigen recognized by the chimeric immune receptor. The cytolytic activity appears to be largely perforin mediated. Furthermore, soluble carcino-embryonic antigen did not interfere with the functional activity of the carcino-embryonic antigen-targeted lymphocytes. Long-term (5-day) stimulation of the modified lymphocytes by protein antigen resulted in reduced viability similar to that induced by anti-CD3 antibodies alone. Viability was improved by a costimulatory signal indicating that such signals may be vital in the maintenance of long-term functional activity of receptor modified T lymphocytes.     

Detection of antilymphocyte antibodies in patients with systemic lupus erythematosus by indirect immunofluorescence on acetone-fixed lymphocytes.

Antilymphocyte antibodies in normal and SLE sera were found to react with lymphocytes fixed in acetone at -30 degrees C. for 10 minutes. At a dilution of 1:40, 3.7 per cent of normal and 90.9 per cent of SLE sera were positive with the use of indirect immunofluorescence with a pepsin-digested, FITC-labeled anti-Fab serum. The reaction was independent of temperature between 4 degrees and 37 degrees C. Three patterns of staining were seen in the lymphocyte surface: reticular, ring, and globular. The ring pattern appeared to correlate with IgM, and the reticular and globular patterns with IgG antilymphocyte antibodies. Absorption with lymphocytes, insolubilized extracts of rat liver and kidney, and human brain revealed that antilymphocyte and ANA activity could be independently removed. Variation in reactivity with cells from different normal donors was similar to that seen with the microcytotoxicity test. Acetone-fixed lymphocytes appear to be a much more sensitive target than viable cells in suspencion in IIF tests for antilymphocyte antibodies. The IIF test with fixed cells also appears slightly more sensitive than cytotoxicity testing and has the advantage of allowing storage of target cells.     

The amount of surface HLA-I on T lymphocytes decreases in breast infiltrating ductal carcinoma patients

Human leucocyte antigen class I (HLA-I), which includes HLA-A, -B and -C, is an essential immune factor participating in the antitumour immune response. The changes in HLA-I expression in peripheral blood T lymphocytes in cancer patients have yet to be defined. This study examined the expression of HLA-I on CD4(+) and CD8(+) T lymphocytes in female patients with stage I - IV breast infiltrating ductal carcinoma, benign breast tumour diseases (mammary intraductal papilloma or breast fibroadenoma), and in healthy controls. HLA-I was down-regulated on CD4(+) T lymphocytes from patients with stage III and IV cancer, and on CD8(+) T lymphocytes in patients with stage I - IV cancer compared with healthy controls. HLA-I expression in T lymphocytes may contribute towards immune-balance disorders in tumour patients.     

Chlamydia pneumoniae reactive T lymphocytes in the walls of abdominal aortic aneurysms.

BACKGROUND: The presence of Chlamydia pneumoniae in the walls of abdominal aortic aneurysms (AAAs) has been demonstrated recently, but its role in the cause and/or maintenance of aortic wall inflammation is not known. In the present study, we have investigated the possible relationship between C. pneumoniae and the antigen specificity of T lymphocytes mediating inflammation in AAA tissue. MATERIALS AND METHODS: Tissue specimens were obtained from 22 consecutive AAA patients undergoing elective surgery (mean age 67 +/- 1 year). Immunohistochemical analysis of the formalin-fixed tissue was performed using the streptavidin-biotin-peroxidase method. In vivo activated T lymphocytes were propagated from the specimens with interleukin (IL) 2, and antigen specificity of the established T-cell lines was analysed in the presence of autologous antigen-presenting cells using radioactive thymidine labelling. RESULTS: Immunohistological staining of AAA tissue showed the presence of C. pneumoniae antigen in 55% (6/11) of the samples studied. The inflammatory cell infiltrate of the AAA tissue contained 60-90% T (CD45RO) and 0-10% B (CD20) cells. When the tissue specimens were cultured without antigen in the presence of IL-2, lymphocyte propagation was achieved in 17 out of the 22 samples. Chlamydia pneumoniae antigen was found to induce a positive proliferative response in 8 of the 17 lines. CONCLUSIONS: The presence of C. pneumoniae specific T lymphocytes among in vivo activated cells from the AAA tissue specimens suggests that C. pneumoniae participates in the maintenance of the inflammatory response in the tissue and may thus be involved in the progression of the disease.