Husby S
Institute of Medical Microbiology, Odense University, Denmark.
APMIS Suppl. 1988;1:1-40.
This thesis is based on 9 papers on the uptake of dietary antigens and on the humoral immune responses to dietary antigens, in healthy subjects and in patients with coeliac disease or atopic eczema. Work in experimental animals have indicated that dietary antigens are taken up in amounts, which are nutritionally insignificant, but may be of immunological importance. Local or systemic antibodies may retard the uptake, but in addition may increase the uptake of unrelated antigens. In humans the uptake of intact dietary antigen, free or in immune complexes, was reported in studies in healthy subjects and in patients with immune deficiency or atopy. We investigated the uptake of dietary antigen in 8 healthy subjects after a test meal, using ELISA methods and high performance liquid chromatography (HPLC) for the fractionation of serum samples. A significant finding was that ovalbumin (OA) was taken up as intact antigen or as a high MW immune complex constituent in all the 8 subjects. IgG was the only isotype demonstrable in the OA-containing aggregates, which were detected in particular in the subjects with high anti-OA antibody levels. The antigen was measurable in serum in up to 48 h after the meal. We studied with the same methods the uptake of OA and beta-lactoglobulin (BLG) in children with coeliac disease on a gluten-free diet and after gluten challenge, and in controls with a normal gut mucosa. Both OA and BLG was mostly present in high MW fractions of the sera, presumably as immune complexes. The levels of antigens in serum did not differ between the children with coeliac disease and the controls. However, in 4/5 coeliac children the uptake of both antigens was increased after gluten challenge, indicating increased antigen uptake in coeliac disease. Increased gut permeability has been suggested as a pathogenic factor in food allergy. At present, there is in this condition no direct evidence for altered uptake of dietary antigens. Dietary antigens have been detected in the mother's milk and may be important for the development of normal immunity to dietary antigens and in particular of cow's milk allergy in the infant. Antibodies to dietary antigens have previously been detected in a major proportion of healthy subjects. In a limited number of sera from normals, analysed by electrophoretic techniques, we detected antibodies to bovine serum albumin and OA predominantly in the IgG class. Interestingly, these antibodies were restricted to the IgG subclasses IgG1, IgG2 and IgG4.(ABSTRACT TRUNCATED AT 400 WORDS)
本论文基于9篇关于健康受试者、乳糜泻患者或特应性皮炎患者对膳食抗原的摄取以及对膳食抗原的体液免疫反应的论文。对实验动物的研究表明，膳食抗原的摄取量在营养方面微不足道，但可能具有免疫学重要性。局部或全身性抗体可能会阻碍摄取，但此外也可能会增加无关抗原的摄取。在人类中，完整膳食抗原（游离或处于免疫复合物中）的摄取情况已在健康受试者以及免疫缺陷或特应性疾病患者的研究中有所报道。我们使用酶联免疫吸附测定（ELISA）方法和高效液相色谱法（HPLC）对血清样本进行分离，研究了8名健康受试者在试餐后对膳食抗原的摄取情况。一个重要发现是，在所有8名受试者中，卵清蛋白（OA）均作为完整抗原或高分子量免疫复合物成分被摄取。IgG是在含OA的聚集体中唯一可检测到的同种型，尤其在抗OA抗体水平高的受试者中可检测到这些聚集体。餐后长达48小时血清中均可检测到该抗原。我们用相同方法研究了无麸质饮食的乳糜泻儿童在麸质激发前后以及肠道黏膜正常的对照儿童对OA和β-乳球蛋白（BLG）的摄取情况。OA和BLG大多存在于血清的高分子量组分中，推测为免疫复合物。乳糜泻儿童和对照儿童血清中的抗原水平没有差异。然而，在4/5的乳糜泻儿童中，麸质激发后两种抗原的摄取均增加，表明乳糜泻中抗原摄取增加。肠道通透性增加被认为是食物过敏的一个致病因素。目前，在这种情况下，尚无膳食抗原摄取改变的直接证据。已在母乳中检测到膳食抗原，其可能对膳食抗原正常免疫的发展尤其对婴儿牛奶过敏的发展很重要。先前已在大部分健康受试者中检测到针对膳食抗原的抗体。在通过电泳技术分析的少数正常受试者血清中，我们主要在IgG类中检测到针对牛血清白蛋白和OA的抗体。有趣的是，这些抗体仅限于IgG亚类IgG1、IgG2和IgG4。（摘要截选至400词）
