粉尘螨变应原明胶微球口服免疫动物的脱敏效果

目的　研究粉尘螨变应原明胶微球经口服免疫小白鼠后的脱敏疗效。　方法　以粉尘螨变应原明胶微球 (含粉尘螨变应原 2× 10 -5mg )口服免疫小白鼠 ,以ELISA法检测 3 5d内血清特异性IgG水平变化。并以腹腔注射相同剂量的粉尘螨变应原浸液的小白鼠为对照实验 ,以口服不含粉尘螨变应原的空白明胶微球的小白鼠为空白实验。　结果口服粉尘螨变应原微球的小白鼠实验组可产生高水平的血清抗体 ,在给药后第 14d抗体最高值为 2 .45× 10 5Au/ml(Ar bitraryunitspermilliliter) ,高于腹腔注射相同剂量的粉尘螨变应原浸液小白鼠的最高抗体水平 (4 .2 7× 10 4Au/ml)。结论　在给予相同剂量粉尘螨变应原的前提下 ,明胶微球口服制剂的免疫效果优于变应原浸液腹腔注射剂。     

粉尘螨Der f4变应原的提纯及其淀粉酶活性分析

采用上海医科大学医学螨类研究室培养的粉尘螨提纯粉尘螨４类变应原，并对其作淀粉活性分析。     

3 种常见尘螨分子进化关系的初步探讨

为探讨粉尘螨（Dermatophagoides farinae）、屋尘螨（Dermatophagoides pteronyssinus）和梅氏嗜霉螨（Euroglyphus maynei）的分类，采用PCR扩增获得粉尘螨1类(Der f 1)和2类变应原(Der f 2)的cDNA片段，经测序后推导氨基酸序列, 与GenBank中的屋尘螨Der p 1、Der p 2和梅氏嗜霉螨Eur m 1、Eur m 2氨基酸序列进行比对，分别构建1类和2类变应原分子进化树。结果显示变应原之间相似度，Der p 1与Eur m 1为86%，Der p 1与Der f 1为83%；Der p 2与Eur m 2为87%，Der p 2与Der f 2为67%。用变应原氨基酸序列构建分子进化树，1类变应原Der p 1与Eur m 1聚成一簇，2类变应原Der p 2与Eur m 2聚成一簇。结果表明屋尘螨和梅氏嗜霉螨亲缘关系较近，而与粉尘螨较远。     

粉尘螨Der fI变应原的免疫化学特征鉴定

作者在原制备Der f Ⅰ变应原基础上进行其免疫化学特征鉴定。Der fⅠ的交叉免疫电泳(CIE)结果证实提纯的Der f Ⅰ为均质性。Der f Ⅰ氨基酸组成与Dandeu(1982)、Heymann(1986)报道的Der f Ⅰ相应结果相关性比较表明,三者在氨基酸组成上有相似性。采用放射性变应原吸附试验(RAST)检测55份螨过敏性患者血清抗Der f ⅠIgE抗体水平,其中49.09％病人RAST阳性,平均阳性特异性IgE水平为6.58±3.90百分结合率。结果表明Der f Ⅰ是粉尘螨主要的变应原。     

T-cell sensitization to epitopes from the house dust mites Dermatophagoides pteronyssinus and Euroglyphus maynei

Background Dermatophagoides pteronyssinus and Euroglyphus maynei frequently occur in house dust but little is known about primary sensitization to the less abundant E. maynei. Objective To determine the occurrence of primary sensitization to E. maynei by T-cell responses and the crossreactivity to D. pteronyssinus. Methods The proliferative response ot peripheral blood cells to overlapping peptides from Derp I and Eur m 1 were measured as well as to peptides from Der f 1, an allergen not found in the study environment. Results The most frequent and strongest responses were to Der p 1 peptides especially in the region 105–133. However, 3/17 responders to mite peptides were stimulated predominantly by Eur m 1 peptides and a further two had their highest response to an Eur m 1 peptide. There was very little crossreactivity between Der p 1 and Eur m 1 peptides and very little response to peptides from Der f 1. Conclusion E. maynei group 1 allergens are a significant source of primary T-cell sensitization and have little T-cell crossreactivity with D. pteronyssinus or D. farinae.     

Dermatophagoides-induced interleukin-10 production by peripheral blood lymphocytes from patients with asthma in remission

Interleukin (IL)-10 is a cytokine that regulates inflammatory responses. We studied the role of IL-10 in the development of tolerance to Dermatophagoides farinae in asthma patients in remission, since asthma improves in most children during adolescence. The spontaneous production of IL-10 by cultured peripheral blood mononuclear cells (PBMC) was higher in patients with active asthma than in normal subjects. IL-10 production decreased when 1 microg/ml D. farinae was added to cultures, but increased again in a dose-dependent manner when higher concentrations of D. farinae were added. In patients with remission of asthma, IL-10 production was lower than in patients with active asthma. However, production of IL-10 showed a reciprocal increase in the presence of 1 microg/ml D. farinae, and decreased again at 10 and 50 microg/ml D. farinae. Such alterations were not observed in normal subjects. Cell lines established from patients asthma in remission showed higher IL-10 production when compared with that by cell lines from normal subjects or patients with active asthma when the cells were stimulated by D. farinae at 1 or 10 microg/ml. Neutralization of IL-10 led to revival of the D. farinae-specific proliferative response of PBMC from patients in remission, which was otherwise decreased. The increase of IL-10 production stimulated by D. farinae was inhibited by addition of an anti-IL-10 antibody. In contrast, antigen-induced interferon (IFN)-gamma production, which was increased by D. farinae stimulation when patients were in remission, did not increase after treatment with anti-IL-10, although spontaneous IFN-gamma production increased to the level seen after D. farinae stimulation. The reduced IL-4 production by cells from patients in remission after stimulation with D. farinae antigen, which was significantly higher in active patients, was not reversed by neutralization of IL-10. The D. farinae-induced IL-10/IL-4 production ratio, but not the IL-10/IL-5 production ratio, may be a significant indicator for evaluation of whether a patient has been in remission. In conclusion, D. farinae-specific anergy of T cells is likely to be induced by increased levels of IL-10 and IFN-gamma that are initially produced by specific T cells after exposure to relevant mite allergen in patients in remission.     

Biologic activity of Dermatophagoides siboney and Blomia tropicalis allergens in exposed and unexposed mite‐allergic individuals. Effect of patient selection on the biologic standardization of mite extracts

BACKGROUND: This study aimed to investigate the influence of patient selection criteria, i.e., mite-allergic individuals exposed and not exposed to Dermatophagoides siboney and Blomia tropicalis, on the biologic activity of mite extracts. Determination of the potency of mite extracts in vivo requires selection of patients with a clinical history of mite allergy. In Scandinavia, there are some anamnestic criteria for mite allergy, whereas in the tropics, where patients are continuously exposed to high levels of mites, selection of patients with mite allergy by clinical history is difficult. METHODS: A total of 210 Cuban asthmatics with continuous symptoms, and 43 Swedes with a clinical history of mite allergy were investigated. Skin prick tests were performed with D. siboney, D. pteronyssinus, D. farinae, B. tropicalis, Acarus siro, Lepidoglyphus destructor, and Tyrophagus putrescentiae extracts. For analysis of the biologic activity of mite extracts, Cuban patients were divided into four groups: 1) all patients skin-test-positive to mites 2) patients positive to mites, but not to other inhalant allergens 3) patients reacting most to the mite species analyzed 4) patients reactive only to mites and reacting most to the mite species analyzed. The biologic potency was calculated according to the Nordic Guidelines. RESULTS: Due to cross-reactivity between mites, Swedish mite-sensitive patients, with a clear clinical history of mite allergy, but not exposed to D. siboney and B. tropicalis, were more skin reactive to these mites than were Cubans. The estimated potency increased gradually to >200% in group 4. In group 1 Cubans, the reactivity to all mites but B. tropicalis was lower than that in mite-sensitive Swedes. CONCLUSIONS: According to the influence of patient selection criteria on the estimation of the potency of mite extracts, the determination of the biologic activity of allergenic extracts in subjects without a clear-cut clinical history should be replaced by new methods when available.     

Lymphocyte proliferative responses to the purified Dermatophagoides farinae major allergen in untreated and hyposensitized atopic patients

We investigated the proliferative response of lymphocytes from mite-sensitive patients (RAST D.far greater than 3.5 PRU/ml) in the presence of the major allergen Der.f.I purified from Dermatophagoides farinae. Comparative studies were carried out with peripheral blood mononuclear cells from non-atopic donors (RAST = 0), and from patients undergoing hyposensitization treatment (5 to 24 months). According to Student's t-test, there was no significant difference in the Der.f.I-induced proliferation of peripheral blood mononuclear cells from normal donors, untreated atopic patients and hyposensitized patients. In conclusion, it was impossible to discriminate between normal donors, atopic patients and hyposensitized patients with regard to their circulating lymphocyte responses to the purified major allergen Der.f.I.