寄生虫IgE依赖组胺释放因子抗体抑制致敏肥大细胞释放组胺作用的研究

目的 观察抗寄生虫IgE依赖组胺释放因子(HRF)抗体对重组大鼠IgE依赖组胺释放因子(rRHRF)诱导致敏吧大细胞释放组胺功能的影响.方法 用纯化的日本血吸虫和华支睾吸虫IgE依赖组胺释放因子重组蛋白rSjHRr和rCsHRF分别免疫大鼠,分离免疫血清并通过亲和层析纯化出总IgG.将rRHRF(终浓度为75 μg/mL)分别与2种纯化抗体(浓度梯度为3/5,2/5,1/5,0)37℃预先反应30 min后,再加入卵清蛋白变应原致敏的大鼠肺肥大细胞,利用荧光分光光度法测定rRHRF诱导吧大细胞组胺释放量.实验中采用未致敏大鼠血清纯化所得总IgG作为对照.结果 得到了纯化的抗rSjHRF IgG和抗rC-sHRF LgG,抗rCsHRF IgG和抗rSjHRF IgG可明显抑制大鼠内源性IgE依赖HRF诱导致敏肥大细胞释放组胺的功能,但抗体抑制作用的强弱与抗体浓度之间的剂量依赖关系还需进一步实验验证.结论 抗寄生虫IgE依赖组胺释放因子抗体具有抑制大鼠IgE依赖组胺释放因子诱导致敏肥大细胞释放组胺的作用,可能是参与寄生虫感染抑制宿主Ⅰ型超敏反应发生的免疫学机制之一,为预防和控制Ⅰ型超敏反应提供了新的思路.     

合成人IgE肽抗血清抑制Ⅰ型变态反应的实验研究

作者设计合成了5个人IgE多肽片段,分别交联载体蛋白后免疫小鼠,诱生的抗血清有2个在ELISA中对人与鼠IgE分子有交叉反应,3个无反应。5个抗血清均显示有中等程度的被动皮肤过敏反应（PCA）抑制作用。被测试的2个抗血清在大鼠肥大细胞被动致敏试验中也显示了抑制作用。研究结果初步表明,采用人IgE分子受体结合部位的适当残基序列的合成肽疫苗,免疫动物所诱导的抗体可抑制Ⅰ型变态反应。     

热致死发酵乳杆菌对牛乳β-乳球蛋白过敏小鼠的免疫调节作用

目的:观察热致死的发酵乳杆菌对牛乳β-乳球蛋白(BLG)致敏小鼠Th1/Th2细胞平衡、血清抗体水平及T细胞亚群数量的影响,探讨其缓解过敏反应的作用。方法:用牛乳BLG和弗氏佐剂的混合液腹腔注射诱发BALB/c小鼠致敏,建立动物过敏模型。将实验动物随机分为空白组、致敏组和不同剂量的热致死发酵乳杆菌组。采用ELISA法测定各组小鼠血清总IgE、BLG特异性IgE和总IgG含量。体外分离培养各组小鼠脾细胞,采用ELISA法检测细胞上清液中Th1型细胞因子(IL-12、IFN-γ)和Th2型细胞因子(IL-4)水平,采用流式细胞术检测脾淋巴细胞中CD3+、CD4+和CD8+T百分含量。结果:发酵乳杆菌组小鼠脾细胞培养上清液中IFN-γ/IL-4比值为13.53,显著高于致敏组的3.34(P<0.05);血清总IgE、BLG特异性IgE和总IgG水平显著降低(P<0.05);脾细胞中CD3+和CD4+T细胞比例升高,CD4+/CD8+比值趋近正常组。特别是高剂量的热致死发酵乳杆菌组小鼠脾细胞培养上清液中抑制IL-4分泌的效果显著优于致敏组(P>0.05),且该组小鼠血清的抗体水平和CD4+/CD8+比值与空白组相比无差异(P>0.05)。结论:热致死的发酵乳杆菌干预可改善小鼠的BLG过敏症状,其作用可能与促进Th1占优势的Th1/Th2细胞平衡,阻断IgE、IgG分泌及平衡T细胞亚群数量相关。     

IPC-1/IPC-2在猫过敏患者减敏治疗中血清IGE水平测定及过敏原因分析

目的:分析高免疫活性的合成过敏原IPC-1/IPC-2(ALLERVAX⁴ CAT)在猫过敏患者减敏治疗中血清特异性IgE水平变化及过敏原因。方法:通过双盲,安慰剂对照实验检测27例猫过敏患者减敏治疗中血清IgE水平变化及其中1例超敏患者血特异性IgG 、IgG₄、特异性IgE、总IgE、组胺水平动态分析。结果:实验组与对照组IgE水平差异无显著性。动态检测血清特异性IgG ,IgG₄,组胺水平明显升高而血清总IgE和特异性IgE水平无变化。结论:IPC-1/IPC-2引起过敏反应与IgE无关,可能与非IgE依赖的组胺释放有关系。表明在部分人群中IgG、IgG₄可能作为致敏抗体起类似IgE的作用。     

小鼠抵抗射线的IgE分泌细胞:对抑制性T细胞的敏感性

作者用氢氧化铝-卵清蛋白结合物(AH-OA)免疫Balb/c小鼠,并用800R或1000Rx-射线照射。分别用被动皮肤过敏(PCA)和血凝(HA)试验测定抗OA的IgE类及IgG类抗体。结果观察到,对OA表现持续高效价IgE应答的Balb/c小鼠经800R或1000R     

IgE及其介导的Ⅰ型变态反应对免疫复合物在肾脏沉积的影响

本文采用豚鼠血清过敏症的动物模型,以热凝聚IgG(HAG)代替免疫复合物(IC),用直接免疫荧光技术,测检了IC在豚鼠肾脏的沉积情况。结果表明,在血清IgE水平增高的豚鼠和发生血清过敏症的豚鼠的肾脏中,IC的沉积量明显高于对照组。这说明,血清IgG水平增高及其介导的Ⅰ型变态反应均可促进IC在肾脏的沉积。从而提示,IgE及其介导的Ⅰ型变态反应可能参与某些免疫复合物性疾病的发病过程。     

短期致敏IgG抗体的出现频率

本文作者选择收集了对一种或多种食物或环境中过敏原有临床过敏史病人的血清标本84份。用放射过敏原吸附试验,按Seska的直接法,以过敏原致敏的纸片测定IgE抗体浓度;用在猴身上的被动转移法测定短期致敏IgG(IgG(s-Ts))抗体。实验中所用过     

IgG 型抗登革病毒NS1 抗体介导被动系统性过敏反应的研究

目的:明确登革病毒玉型(Dengue virus serotype 1,DENV1)非结构蛋白1(Non-structure protein 1, NS1)与其IgG 型抗体的免疫复合物(Immune complexes,ICs)能否诱导机体产生被动系统性过敏反应(Passive systmic anaphylaxis,PSA),为阐明登革出血热与登革休克综合征(DHF/ DSS)的发病机制提供依据。方法:从本课题组现有的多株抗NS1 单克隆抗体中,筛选能够与纯化NS1 结合并形成免疫复合物进而诱导小鼠产生被动系统性过敏反应(PSA)和被动皮肤过敏反应(Passive cu-taneous anaphylaxis,PCA)的单抗或单抗组合;并观察体内氯化钆(GdCl3 )和血小板活化因子受体(PAFR)拮抗剂CV-3988 处理对PSA 的影响。结果:用亲和层析纯化的DENV1 NS1,从本室制备的20 株IgG 型抗DENV1 NS1 单抗中仅筛选出2 组单抗组合制备免疫复合物(NS1-IgG ICs)能成功诱导小鼠的PCA 和PSA 反应,而其他抗体或抗体组合并无此反应;用GdCl3 抑制单核巨噬细胞或CV-3988 阻断PAFR 处理可抑制或减轻小鼠PSA 反应。结论:DENV1 NS1 结合两个IgG 型单抗组合的免疫复合物可诱发PSA 与PCA,但并非所有的抗NS1 单抗或抗体组合与NS1 结合都能诱发PSA,推测与识别表位不同有关;初步证明DENV1 NS1-IgG ICs 诱发PSA 的主要效应细胞是巨噬细胞,主要效应分子是PAF。     

食物特异性IgG抗体在青霉素过敏患者血清中的检测

目的:探讨IgG抗体在过敏反应中的作用及食物特异性IgG抗体与青霉素过敏是否有关。方法:采用酶联免疫吸附试验(ELISA)检测99例青霉素过敏者血清花生、鸡蛋、牛奶3种常见食物过敏原特异性IgG、IgE抗体。结果:99例青霉素过敏者3种食物抗原特异性IgG、IgE抗体水平均显著高于正常对照组,且其IgG抗体水平显著高于食物过敏组(P<0.05);青霉素抗体阳性组花生、牛奶特异性IgG抗体阳性率显著高于青霉素抗体阴性组(P<0.05);鸡蛋特异性IgG抗体水平在青霉素过敏者不同症状组间有显著性差异(P<0.05)。结论:研究结果:提示,IgG抗体为保护性抗体;青霉素过敏者过敏症状与鸡蛋特异性IgG抗体有关。     

发酵乳杆菌干预对牛乳β-乳球蛋白过敏小鼠模型的免疫调节作用

目的观察活的/热致死发酵乳杆菌对牛乳β-乳球蛋白(BLG)致敏小鼠Th1/Th2细胞平衡、血清抗体水平及T淋巴细胞亚群数量的影响,探讨其缓解过敏反应的作用。方法用牛乳BLG和弗氏佐剂的混合液腹腔注射诱发Balb/c小鼠致敏,建立动物过敏模型。将实验动物随机分为空白组、致敏组、活的与热致死发酵乳杆菌组。采用ELISA法测定各组小鼠血清总IgE和BLG特异性IgE含量。体外分离培养各组小鼠脾淋巴细胞,采用ELISA法检测细胞上清液中Thl型细胞因子(IL-12、IFN-γ)和Th2型细胞因子(IL-4)的水平,采用流式细胞术检测脾淋巴细胞中CD3+、CD4+和CD8+的百分含量。结果与致敏组相比,活的/热致死发酵乳杆菌组小鼠的IFN-γ/IL-4比值(代表Thl/Th2细胞平衡)显著增高(P<0.05);血清总IgE和BLG特异性IgE水平显著降低(P<0.05);脾淋巴细胞中的CD4+细胞比例升高,CD4+/CD8+比值得到优化。特别是热致死的发酵乳杆菌组抑制IL-4分泌的效果显著优于活菌组(P>0.05),且该组的抗体水平和CD4+/CD8+比值与空白组相比无差异(P>0.05)。结论发酵乳杆菌干预可改善小鼠的BLG过敏症状,其作用可能与促进Thl占优势的Thl/Th2细胞平衡,阻断IgE分泌及平衡T淋巴细胞亚群数量相关。     

Relationship between IgG1 levels and airway responses in guinea pigs actively and passively sensitized to hexahydrophthalic anhydride

Organic acid anhydrides (OAAs) are industrial chemicals that may cause induction of specific IgE and airway symptoms in exposed workers. They are a good model for studies of relationships between chemical structure and the sensitizing potential of reactive low-molecular-weight compounds. Hexahydrophthalic anhydride (HHPA) is such a compound. This study aimed to evaluate the relationship between specific IgG1 levels and airway responses in a model to predict the sensitizing potential of OAAs. Guinea pigs were either actively or passively sensitized to HHPA. For active sensitization, guinea pigs were injected i.d. with 0.1 ml of olive oil (vehicle) or 0.05, 0.5, or 5% HHPA in olive oil. Passive sensitization was performed by i.p. injection of different volumes of antisera (0.75–6 ml, either unheated to keep IgE or heated to destroy IgE) taken form HHPA-sensitized guinea pigs. Specific antibody levels were evaluated with ELISA and passive cutaneous anaphylaxis. Animals were challenged 16–18 days after active sensitization, or 2 days after passive sensitization, by interatracheal instillation with HHPA conjungated to guinea pig serum albumin (HHPA-GPSA; 0.05% in saline), and the immediate effects on lung resistance (R¹), and plasma extravasation, measured as Evans blue dye extravasation, for up to 6 min were recorded. Active sensitization caused production of specific IgG1. Provocation with HHPA-GPSA caused an increase of both (R¹), and Evans blue dye extravasation, which was dependent upon the active sensitization dose. Challenge with HHPA-GPSA in passively sensitized guinea pigs also produced an increase in both (R¹), and Evans blue dy extravasation which was related to IgG1 level. In the guinea pig model of HHPA-induced airway allergy, the airway responses are closely related to the serum levels of specific IgG1. Thus, the IgG1 levels induced by the immunization may reflect the sensitizing potential of HHPA.     

The guinea pig model of diisocyanate sensitization. I. Immunologic studies

Two strains of guinea pigs were parenterally immunized with well-characterized diisocyanate-protein conjugates. Hapten-specific IgE antibodies were detected in the sera of English short-hair strain guinea pigs immunized with either toluene diisocyanate-human serum albumin (TDI-HSA) or hexamethylene diisocyanate-HSA (HDI-HSA) when these sera were analyzed by the 168 hr passive cutaneous anaphylaxis (PCA) technique followed by intravenous challenges with conjugates of respective ligands coupled to an unrelated carrier protein, transferrin. IgG1 antibodies and precipitating antibodies were demonstrated in Hartley strain guinea pigs immunized with TDI/HDI-HSA conjugates. The hapten specificity of these antibodies was proved by PCA inhibition experiments and antibody absorption experiments. In the precipitating antibody system, this was further confirmed by immunoelectrophoretic analysis. Cross-reactivity between HDI and TDI was not observed in the PCA experiments. However, apparent cross-reactivity in the double gel diffusion experiments was due to new antigenic determinants formed by isocyanates after conjugation with proteins. It was therefore apparent that immune responses of guinea pigs immunized with protein conjugates of bifunctional isocyanates were heterogeneous and involved multiple specificities for hapten, carrier protein, and new antigenic determinants. It was postulated that the complex nature of the immune response generated by diisocyanate compounds in the guinea pig may also serve as a more appropriate model of isocyanate-induced human sensitivity reactions, which are known to involve diverse immunologic and nonimmunologic mechanisms.     

Systemic persistence of homologous guinea pig skin-sensitizing antibodies.

Homologous guinea pig skin-sensitizing antibodies of the IgG1 class (as characterized by heat stability and persistence in skin for 7 days) were shown to persist systemically for 28-35 days. Persistence was shown by the anaphylaxis induced in guinea pigs following the intracardiac administration of the antiboy and subsequent antigenic challeng by aerosol. Skin-sensitizing antibody of the IgE class, characterized by heat lability and persistence in skin for 14 days, still caused systemic anaphylaxis for 42 days after the intracardiac administration of antibody. The IgG serum fraction from nonimmunized rabbits blocked systemic anaphylaxis in the guniea pig induced by aerosol following the passive transfer of heterologous (rabbit) and homologous IgG antibodies to ovalbumin, but not following the passive transfer of homologous IgE antibodies to ovalbumin.     

IgG2 antibodies block IgE antibody-induced asthma in guinea pigs

In order to examine the blocking activity of IgG2 antibodies to guinea pig for IgE antibodies-induced guinea pig asthma, experiments were carried out as follows. Guinea pigs were passively sensitized intravenously with guinea pig serum containing IgE antibodies to ovalbumin (OA). 8 days after sensitization, IgG2 purified from guinea pigs hyperimmunized with OA was intravenously injected. One hour later, the guinea pigs were challenged by inhalation of OA solution. Asthma attacks were not observed in the guinea pigs, whereas the attacks were observed in guinea pigs passively sensitized with the IgE antibodies but injected IgG2 fraction from normal guinea pigs 1 h before inhalation. These observations suggested that IgG antibodies that increased after immunotherapy might block asthma caused by inhalation of allergens in humans.     

Incidence of IgG short-term sensitizing antibodies in an allergic population.

Heat-stable, immunoglobulin G, short-term sensitizing antibodies (IgG S-T S) were sought in serum from 149 allergic patients who had strongly positive immediate skin tests to inhalant allergens. The sera were tested by passive cutaneous anaphylaxis (PCA) in monkeys. No IgG S-T S antibodies were demonstrated in 169 tests with a variety of allergens. Antibody with the characteristics of IgE was demonstrated in 47% of monkey PCA tests and, in an additional 34% of sera. IgE antibody to the same allergen was demonstrated by radioallergosorbent testing (RAST).     

Allergen-containing immune complexes used for immunotherapy of allergic asthma

In a previous study guinea pigs inbred for their ability to develop respiratory anaphylaxis to experimental antigens have been used for comparison of different forms of immunotherapy (IT). Passive, active and combined (immune complexes prepared from antigen and specific IgG) IT was compared with placebo. In the present study methods were evaluated for determination of the allergen-specific IgE and IgG. IgE was determined by the passive cutaneous anaphylactic test (PCA) and the variability of this test on different strains of the recipient guinea pig was investigated. The same strain as used for the IT study was found to produce the most potent response. Radioimmunometric assays (RIA) were developed and validated for determination of specific IgG1 and IgG2. The IgE and IgG immune response in animals from the IT study were then evaluated by means of PCA and RIA. Animals from all four treatment groups were sensitized during the first part of the IT study, and responded with a marked IgE synthesis which later stabilized on a more moderate level. In spite of notably reduced symptoms in groups treated with active and combined IT, no difference in the IgE level was found between the four groups. In contrast to IgE, mean group titers of IgG1 and IgG2 in the groups receiving active or combined IT rose drastically during the first part of therapy and closely paralleled the clinical response during the rest of the study period. However, in the individual animals, no correlations were found between immune response and clinical symptoms. Thus, the strong IgG response during immunotherapy may not be causally related to the outcome of treatment.     

Production and isolation of guinea pig IgE antibody

Immunoglobulins of the IgE and IgG classes have been causally associated with hypersensitivity reactions in man and in numerous animal species including mice, rats and guinea pigs. The use of the guinea pig as an animal model for both pulmonary and dermal hypersensitivity reactions, and the recent recognition of the importance of IgE antibodies in both early- and late-onset hypersensitivity responses, has heightened interest in production, separation, and isolation of this immunoglobulin class from the guinea pig. IgE antibodies were produced by treatment of strain 13 guinea pigs with cyclophosphamide followed by injection with S. aureus enterotoxin. Serum was obtained and the globulin fraction isolated by addition of caprylic acid then ammonium sulfate. Immunoglobulins were separated into classes using fast protein liquid chromatography (FPLC) employing a Mono Q column and a linear gradient of 0.01-0.3 M Na,K phosphate buffer, pH 7.5 (buffer B). IgG eluted in two major peaks. IgG2 was not retained on the column and emerged with the starting buffer; IgG1 was eluted with 15-20% buffer B. IgE, detected as heat labile homocytotropic antibody, was found in the fraction eluting with 30-35% buffer B. The elution profile of the guinea pig immunoglobulins was predicted from the pattern obtained with immunoglobulin classes from other species. This chromatographic procedure enabled rapid isolation of immunoglobulin classes from guinea pig sera and effectively separated IgG1 from IgE, the two classes associated with hypersensitivity reactions.     

Immunoglobulin-G-dependent stimulation of guinea pig lung mast cells and macrophages

Alveolar macrophages and mast cells isolated from guinea pig lung were passively sensitized with IgG1, IgG2, or serum obtained from guinea pigs actively sensitized with ovalbumin. The release of histamine by mast cells and of thromboxane A2 by alveolar macrophages upon ovalbumin challenge indicated that both antibodies and serum were capable of sensitizing these cells with similar effectiveness. Heating the scrum at 56°C for 4 h to inactivate IgE did not modify the antigen-dependent response of lung cells. These results suggest a predominant role for IgG in the allergic response of the guinea pig through the activation of different cell types such as lung mast cells and alveolar macrophages.     

Effect of Trichinella spiralis infection on passive cutaneous anaphylaxis in mice.

Infection of CFW mice with Trichinella spiralis induced a state of relative unresponsiveness to passive cutaneous anaphylaxis (PCA) induced with hen egg albumin and its corresponding antibodies. The unresponsiveness was to PCA produced either with immunoglobulin G1 (IgG1) or IgE type of antibodies, but was more pronounced with the latter. As few as 25 larvae given by stomach tube 20 days before induced this resistance, although 400 larvae induced a greater resistance. When 400 to 600 larvae were fed to mice, the refractoriness of these mice to PCA was noticed 15 days later. The sera of infected mice had the ability to inhibit mainly PCA induced by IgE. This inhibitory property of sera from infected mice was more pronounced 35 days after infection than 10 months later, when only weak inhibitory activity was detected. Purified rat IgE inhibited the PCA reactions induced in both mice and rats with mouse IgE-type antibody. At high concentrations, evidence of inhibition of the IgG1-induced PCA in mice was also obtained. We believe that the relative unresponsiveness of infected mice is due to an increase in production of IgE which competitively blocks the mast cell sites for other IgE molecules.