Vaccination with chimeric protein induces protection in murine model against ascariasis

An estimated 400 million people are infected by parasites of the genus Ascaris and the existing control measures are inefficient. Vaccine development using B cell antigens is a promising strategy for increased protection against this parasite. The present study aimed at developing a chimeric protein capable of conferring protection against infection by Ascaris sp. For this purpose, we performed B-cell epitope predictions on previously described vaccine candidate proteins from Ascaris suum and the corresponding peptides were used to construct a chimeric protein. Female BALB / c mice were immunized subcutaneously in three doses at 10 day intervals with a vaccine formulation comprised of the chimeric protein together with monophosphoryl lipid A (MPLA). Control groups included protein alone, MPLA, or PBS. After challenge infection, animals vaccinated with chimeric protein plus MPLA showed a reduction of 73.54% of larval load in the lung compared to control group animals. Animals immunized with chimeric protein plus MPLA also display higher IgG response and a reduction in lung inflammation. Our study highlights how chimeric proteins containing more than one B cell epitope can enhance immune protection against helminthic infection and offer new approaches to the development of Ascaris vaccines.     

The Subclass Nature and Clinical Significance of the IgG Antibody Response in Patients Undergoing Allergen-Specific Immunotherapy

The purpose of this paper is to discuss the methodological difficulties in quantitation of human IgG subclass antibodies to allergens, to describe the subclass nature of the IgG antibody response in patients undergoing allergen-specific immunotherapy, and to discuss the possible immunological functions and clinical significance of allergen-specific IgG antibodies of different subclasses. Based on results obtained by use of assays with documented specificity it is concluded that the IgG antibody response during allergen-specific immunotherapy is IgG1 and IgG4 restricted, although low levels of IgG2 and IgG3 antibodies to some allergens may occur. In most patients the early IgG antibody response is IgG1 dominated and the late IgG4 dominated. A too early or too pronounced IgG4 dominated antibody response seems to indicate a poor clinical outcome of immunotherapy with inhalant allergens, whereas a pronounced early IgG1 antibody production has been found to be associated with a decrease in synthesis of IgE antibodies to an insect venom. It is therefore proposed that an early IgG1 dominated response is necessary to induce suppression of the ongoing IgE antibody production, which in its turn may be a prerequisite for long-lasting clinical effect. The possibility of induction of an early IgG1 dominated response in every patient by use of alternative immunotherapy procedures is discussed.     

Immunoassays at a quartz-liquid interface: theory, instrumentation and preliminary application to the fluorescent immunoassay of human immunoglobulin G

The theoretical basis and instrumental requirements of an optical detection technique for monitoring antibody-antigen reactions at a quartz-liquid interface are described. The antibody is covalently immobilized on the optical surface of a planar, fused-quartz waveguide and reacted with antigen solution. A light beam is internally reflected within the waveguide and penetrates into the solution only a fraction of the wavelength of the incident light. This is the evanescent wave which interacts optically with the growing number of antigen-antibody complexes but minimally with the bulk solution. A two-site immunofluorescent assay for human IgG measurement is described using fluorescein as the label. The assay detection limit is approximately 0.8 micrograms/ml and individual fluorescence measurements are completed within 10 min. It is expected that this evanescent wave immunoassay should have wide applicability in both routine and research fields.     

Human Peripheral Eosinophils with Receptors for IgM: Demonstration and Ultrastructural Morphology

Receptors for IgM were detected on peripheral blood human eosinophils by a rosette technique with ox red blood cells coated with the IgM fraction of the specific immunserum. Between 14 % and 43 % (mean 27 %) FcµR positive cells were found after an overnight incubation period at 37°C by using this technique. The specificity of the receptors for IgM was assessed by studying the inhibitory capacity of purified human IgM in the rosette assay. From an ultrastructural point of view, the EA^M rosette-forming cells are mature eosinophlic granulocytes characterized by a nucleus with a variable number of lobes and a certain number of «first type» granules partially or totally devoid of their content.     

Exposure to formaldehyde and phenol during an anatomy dissecting course: sensitizing potency of formaldehyde in medical students

BACKGROUND: The sensitizing potency of formaldehyde and phenol during anatomy dissecting was investigated. The objective was to determine whether exposure induces specific IgE or IgG against formaldehyde-albumin or phenol-albumin. METHODS: In 27 medical students, specific IgE against formaldehyde-albumin by RAST plus ELISA and specific IgE against phenol-albumin by ELISA were assessed. In addition, specific IgG against formaldehyde-albumin was assessed in 23 students. Symptoms before and during dissecting were assessed, and indoor formaldehyde and phenol were measured. RESULTS: Mean indoor formaldehyde was 0.265 +/- 0.07 mg/m3, and mean indoor phenol was 4.65 +/- 2.96 mg/m3. Specific IgE/IgG against formaldehyde-albumin was not found at the beginning. Four students developed specific IgE against formaldehyde-albumin (RAST classes of > or =2.0), and all four also had specific IgE in the ELISA, but IgG against formaldehyde-albumin was not found. Specific IgE against phenol-albumin was not seen. Itch and paresthesia of the hands (P<0.00001), dizziness (P<0.008), burning eyes (P<0.01), headache, sneezing, epistaxis, gingival bleeding, oral or pharyngeal itch, and shortness of breath were experienced. CONCLUSIONS: Formaldehyde exposure during dissecting may induce specific IgE, but not IgG, against formaldehyde-albumin. Sensitization did not correlate with symptoms.     

Clonally restricted insulin autoantibodies in a cohort of 2200 healthy blood donors

Summary Serum samples of 2200 blood donors were screened for anti-insulin IgG by enzyme-linked immunosorbent assay. Specificity of detected antibodies was verified by competition with an excess of insulin and observation that saturated anti-insulin IgG were no longer measurable. The upper limit of measured signal in the population was defined as the mean plus three SD. In the direct assay, 32 sera were positive. Among these, 22 (1%) contained saturable insulin antibodies (true positive) and 10 were non-saturable and considered as non-insulin-specific. The positive blood donors were requested to answer a questionnaire and according to their answers, none had ever received insulin, was a first degree relative of a Type 1 (insulin-dependent) diabetic patient or had experienced a hypoglycaemic episode. None of the 22 true positive sera detected by enzyme-immunosorbent assay bound ¹²⁵-I-insulin to any significant extent. The nine sera yielding the highest signal were further characterized with regard to heavy and light chains as well as species specificity of ligand. Anti-insulin IgG from healthy blood donors contained only one heavy (1 2/9; 3 7/9) and one light ( 8/9; 1/9) chain. Three sera were human insulin specific; two were non-species-specific; the other four bound insulin in the order human = porcine > bovine. These results indicate that low affinity clonally restricted antibodies against insulin are present in unselected blood donors with a prevalence of 1%.     

91例免疫相关性皮肤病患者血清花粉IgG抗体检测结果分析

目的：检测免疫相关性皮肤病患者血清花粉IgG阳性情况。方法：采用Dot-ELISA法检测受检患者血清花粉IgG抗体。结果：56％受检患者血 清花粉IgG抗体阳性,其中荨麻疹、湿疹、接触性皮炎和过敏性紫癜等过敏性皮肤病患者血清花粉IgG抗体阳性率为83．0％,其它免疫相关性皮肤病为18．4％（P＜0．005）。血清花粉IgG抗体阳性的34例荨麻疹患者中,早春花粉抗体阳性高达91．2％,晚春花粉52．9％,夏秋花粉29．4％（P＜0．005）。结论：致敏性花粉与过敏性皮肤病有较大关系。春季花粉,特别是早春花粉,是本地区花粉相关性荨麻疹的主要致敏花粉。     

生前与死后伤的区别——用免疫组化法检测损伤组织中的免疫球蛋白G

目的 :研究损伤组织中的免疫球蛋白 G(Ig G)的分布以区别生前与死后伤。方法 :卵白素—生物素过氧化物酶复合物技术 (ABC法 ) ,直接用辣根过氧化物酶标记单一特异性抗体 (直接法 )检测人体生前与死后损伤皮肤组织中的 Ig G。结果 :生前损伤标本均阳性 ,死后损伤标本均阴性。应用本方法可以检测极短时间 (<1 0 min)内死亡的生前伤。钝器伤 Ig G阳性反应分布范围比锐器伤广。结论 :应用 ABC法、直接法的免疫组化技术检测人体损伤皮肤组织中的 Ig G比较简便 ,该方法适用基层推广应用。     

单纯IgG型冷凝集素致聚凝胺配血不合一例

患者 ,男 ,6 0岁。因直肠癌手术申请输血 40 0 ml。定型 :患者与献血员两者 ABO正、反定型一致 ,均为 A型 ,Rh(D)阳性。交叉配血 :1盐水法 :主次侧均未见凝集。 2聚凝胺法 :(室温 15℃左右 ,以下同 ) :主侧 ;次侧 。上述所有凝集管置 37℃水浴 5 m in后 ,凝集均消失。抗体筛选 :1患者血清与自身红细胞 O型谱细胞、供者红细胞同时分别作聚凝胺法 ,抗人球法配合试验 ,结果为 :聚凝胺法室温显示 ,37℃水浴5 min后凝集消失 ;抗人球法则不显示凝集。 2供者血清与 O型谱细胞、供者红细胞同时分别作聚凝胺法、抗人球法配合试验 ,结果均未出…     

IgG antibodies, chronic bronchitis, and pulmonary function values in farmer's lung patients and matched controls

We measured IgG antibody levels against eight different microbes in farmer's lung (FL) patients an average of 14 years after the first diagnosed episode of FL and in matched controls. The study population consisted of 87 FL patients and 81 control farmers, matched by age, sex, and smoking habits. Clinical studies included the measurement of IgG antibody levels against Absidia corymbifera, Aspergillus umbrosus, A. fumigatus, Humicola grisea, Saccharopolyspora rectivirgula, Penicillium brevicompactum, Rhodotorula glutinis, and Thermoactinomyces vulgaris, in addition to spirometry, pulmonary diffusing capacity (DL(CO)), and the evaluation of chronic bronchitis. Median IgG antibody levels were two or more times higher in FL patients than control farmers against Ab. corymbifera, S. rectivirgula, and T. vulgaris (P<0.001). Against A. fumigatus, H. grisea, and R. glutinis, FL patients also had significantly higher antibody levels. FL patients often had positive antibody titers against several microbes, whereas control farmers usually had a positive titer against one or two microbes. A positive association between IgG antibody levels and chronic bronchitis and DL(CO) was observed in FL patients, but not in control farmers. It is suggested that the high antibody levels noted in FL patients were due not only to high exposure but also to individual sensitivity to environmental microbes.