Poulsen L K, Stahl Skov P, Mosbech H, Weeke B
Medical Department TTA, State University Hospital, Copenhagen, Denmark.
Int Arch Allergy Appl Immunol. 1988;86(4):383-90. doi: 10.1159/000234623.
Several conflicting reports on the ability of IgG4 to mediate type I allergic reactions have appeared lately. We have developed a model system for testing this possibility, using passive sensitization of basophil leucocytes from normal individuals. At first, the system was optimized with regard to donor cells and anti-IgG4 antibody: among 3 normal individuals with cells showing high, medium and low responses to anti-IgE, only the high responder showed a reproducible, but low response to anti-IgG4. This response was consistent when testing anti-IgG4 from different sources, and could be potentiated by a phorbol ester TPA, although not up to the level of anti-IgE. The cells from the high responding donor and a monoclonal anti-IgG4 were selected for further studies. Serum pools from patients allergic to house dust mite (Dermatophagoides pteronyssinus) were used for passive sensitization. The pools contained allergen-specific IgE with or without concomitant IgG4 of the same specificity. The sensitized basophils reacted to anti-IgE and allergen, but to anti-IgG4 only to a small extent. However, when these serum pools were fractionated by affinity chromatography, only the IgE fractions and not the IgG4 fractions made the cells reactive towards specific allergen. It was still possible to elicit a reaction by triggering IgE with anti-IgE, whereas only a small reaction was seen, when IgG4-sensitized basophils were provoked with anti-IgG4. We conclude that IgG4 does not sensitize normal basophils.
最近出现了几篇关于IgG4介导I型过敏反应能力的相互矛盾的报道。我们开发了一个模型系统来测试这种可能性，采用对正常个体的嗜碱性粒细胞进行被动致敏的方法。起初，该系统在供体细胞和抗IgG4抗体方面进行了优化：在3名对抗IgE反应呈高、中、低水平的正常个体中，只有高反应者对抗IgG4表现出可重复但较低的反应。当测试来自不同来源的抗IgG4时，这种反应是一致的，并且可以被佛波酯TPA增强，尽管达不到抗IgE的水平。选择来自高反应供体的细胞和一种单克隆抗IgG4进行进一步研究。使用对屋尘螨（粉尘螨）过敏患者的血清池进行被动致敏。这些血清池中含有过敏原特异性IgE，伴有或不伴有相同特异性的IgG4。致敏的嗜碱性粒细胞对抗IgE和过敏原产生反应，但对抗IgG4仅产生很小程度的反应。然而，当这些血清池通过亲和层析进行分离时，只有IgE组分而不是IgG4组分使细胞对特异性过敏原产生反应。用抗IgE触发IgE仍有可能引发反应，而当用抗IgG4刺激IgG4致敏的嗜碱性粒细胞时，只观察到很小的反应。我们得出结论，IgG4不会使正常嗜碱性粒细胞致敏。
