Heymann P W, Chapman M D, Platts-Mills T A
J Immunol. 1986 Nov 1;137(9):2841-7.
The physicochemical and antigenic properties of an allergen purified from Dermatophagoides farinae, Der f I, were compared with Der p I from Dermatophagoides pteronyssinus. On SDS-PAGE, Der f I migrated as a single polypeptide chain with the same m.w. as Der p I (24,000). Two isoallergenic peaks of Der f I were identified on preparative isoelectric focusing (pI 5.7 to 6.3 and pI 6.6 to 6.95). Fractions from each peak were shown to have an identical amino acid composition (which was similar but not identical to Der p I) and the same N-terminal amino acid sequence. There was a good correlation between quantitative intradermal skin tests to both purified allergens and to D. farinae extract in mite-allergic patients, with positive results when using as little as 10(-5) micrograms/ml of Der f I. The majority of sera with detectable IgE antibody to D. farinae also had IgE antibody to Der f I both among children (29/42 = 69%) and adults (55/63 = 87%). By RAST, there was an excellent correlation between IgE antibody to Der f I and Der p I in sera from 42 mite-allergic children (n = 0.94, p less than 0.001). Polyclonal IgG antibodies from six mice immunized with Der f I showed preferential binding to that allergen, and most monoclonal antibodies (16 of 18) raised against Der f I did not bind Der p I. However, two monoclonal antibodies from this fusion showed cross-reactive binding to both allergens. Immunoabsorption experiments, using D. pteronyssinus and D. farinae extracts coupled to Sepharose, showed that a large proportion of murine antibodies (74% to Der p I and 60 to 93% to Der f I) could not be absorbed by the heterologous extract on the immunosorbent. In contrast, in sera from seven mite-allergic patients, most of the specific IgE and IgG antibody (i.e., greater than or equal to 82%) was removed by either immunosorbent. Thus, Der f I and Der p I represent a homologous pair of major allergens which possess both cross-reacting and species-specific epitopes. The antibody response in mice immunized with either allergen in complete Freund's adjuvant was largely directed against species-specific epitopes, whereas in allergic humans, IgE- and IgG-specific antibodies bound predominately to cross-reacting epitopes.
将从粉尘螨中纯化得到的变应原Der f I的物理化学和抗原特性与来自屋尘螨的Der p I进行了比较。在SDS - PAGE上，Der f I以单条多肽链形式迁移，其分子量与Der p I相同（24,000）。在制备性等电聚焦过程中鉴定出Der f I的两个等变应原峰（pI 5.7至6.3和pI 6.6至6.95）。每个峰的组分显示具有相同的氨基酸组成（与Der p I相似但不相同）和相同的N端氨基酸序列。在螨过敏患者中，针对两种纯化变应原以及粉尘螨提取物的定量皮内皮肤试验之间存在良好的相关性，当使用低至10^(-5)微克/毫升的Der f I时结果为阳性。在儿童（29/42 = 69%）和成人（55/63 = 87%）中，大多数可检测到针对粉尘螨的IgE抗体的血清也具有针对Der f I的IgE抗体。通过RAST检测，42名螨过敏儿童血清中针对Der f I和Der p I的IgE抗体之间存在极好的相关性（n = 0.94，p < 0.001）。用Der f I免疫的6只小鼠产生的多克隆IgG抗体显示出对该变应原的优先结合，并且针对Der f I产生的大多数单克隆抗体（18个中的16个）不与Der p I结合。然而，来自该融合的两种单克隆抗体显示出与两种变应原的交叉反应性结合。使用偶联到琼脂糖凝胶上的屋尘螨和粉尘螨提取物进行的免疫吸附实验表明，很大一部分鼠抗体（针对Der p I的74%以及针对Der f I的60%至93%）不能被免疫吸附剂上的异源提取物吸附。相反，在7名螨过敏患者的血清中，大多数特异性IgE和IgG抗体（即≥82%）可被任一种免疫吸附剂去除。因此，Der f I和Der p I代表一对同源的主要变应原，它们具有交叉反应性和种特异性表位。在用完全弗氏佐剂中任一种变应原免疫的小鼠中，抗体反应主要针对种特异性表位，而在过敏的人类中，IgE和IgG特异性抗体主要结合到交叉反应性表位上。
