Saini S S, Klion A D, Holland S M, Hamilton R G, Bochner B S, Macglashan D W
Department of Medicine, Division of Clinical Immunology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
J Allergy Clin Immunol. 2000 Sep;106(3):514-20. doi: 10.1067/mai.2000.108431.
Expression of receptors for IgE (FcepsilonR) have been mainly studied on mast cells and blood basophils in the context of allergic disease. Some reports have noted limited expression of FcepsilonR on other leukocytes, including blood monocytes and eosinophils in certain patients. An association between human blood basophil expression of FcepsilonRIalpha and serum IgE has been noted among allergic subjects.
Recent evidence supports regulation of FcepsilonRIalpha by free IgE on both mast cells and basophils. We hypothesized that this relationship would exist across an extremely wide range of IgE levels for human basophils, irrespective of underlying disease. We further examined whether a similar relationship existed between serum IgE and FcepsilonRIalpha or FcepsilonRII (CD23) expression on monocytes and eosinophils in these same subjects.
Blood was obtained from nonallergic subjects (n = 3) and subjects with allergic asthma (n = 5), atopic dermatitis (n = 3), hypereosinophilic syndromes (n = 7), hyper-IgE syndrome (n = 6), helminth infestation (n = 6), or IgE myeloma (n = 1). Levels of serum IgE were determined by using RIA and ranged from 3 to 4.7 mg/mL. Levels of cell surface FcepsilonRIalpha, FcepsilonRII, and IgE were measured by using immunofluorescence and flow cytometry.
Basophil surface IgE density and FcepsilonRIalpha expression correlated with serum IgE levels (r = 0. 67 and r = 0.46, respectively; P <.01; n = 31) regardless of the disease state. In contrast, monocyte FcepsilonRIalpha expression did not correlate with serum IgE (r = 0.09, P >.5, n = 29), and low-level eosinophil FcepsilonRIalpha expression was only detected in a single asthmatic subject. CD23 expression was not detected on basophils or eosinophils, except for the eosinophils from the donor with IgE myeloma. CD23 was present on monocytes from some donors but did not correlate with serum IgE levels.
In a variety of disease states, FcepsilonRIalpha expression by basophils, but not monocytes or eosinophils, correlated with serum IgE levels across a 6-log range of IgE. These data support the concept of in vivo regulation of FcepsilonRIalpha on basophils by serum IgE and further demonstrate that this is independent of allergic disease per se.
在过敏性疾病的背景下，主要在肥大细胞和血液嗜碱性粒细胞上研究了IgE受体（FcepsilonR）的表达。一些报告指出，在某些患者中，包括血液单核细胞和嗜酸性粒细胞在内的其他白细胞上FcepsilonR的表达有限。在过敏性受试者中，已注意到人类血液嗜碱性粒细胞FcepsilonRIα的表达与血清IgE之间存在关联。
最近的证据支持游离IgE对肥大细胞和嗜碱性粒细胞上FcepsilonRIα的调节作用。我们假设，对于人类嗜碱性粒细胞，无论潜在疾病如何，这种关系在极宽的IgE水平范围内都存在。我们进一步研究了在这些相同受试者中，血清IgE与单核细胞和嗜酸性粒细胞上FcepsilonRIα或FcepsilonRII（CD23）表达之间是否存在类似关系。
从非过敏性受试者（n = 3）和患有过敏性哮喘（n = 5）、特应性皮炎（n = 3）、高嗜酸性粒细胞综合征（n = 7）、高IgE综合征（n = 6）、蠕虫感染（n = 6）或IgE骨髓瘤（n = 1）的受试者中采集血液。使用放射免疫分析法测定血清IgE水平，范围为3至4.7mg/mL。使用免疫荧光和流式细胞术测量细胞表面FcepsilonRIα、FcepsilonRII和IgE的水平。
无论疾病状态如何，嗜碱性粒细胞表面IgE密度和FcepsilonRIα表达均与血清IgE水平相关（r分别为0.67和0.46；P <.01；n = 31）。相比之下，单核细胞FcepsilonRIα表达与血清IgE无相关性（r = 0.09，P >.5，n = 29），仅在一名哮喘受试者中检测到低水平嗜酸性粒细胞FcepsilonRIα表达。除来自IgE骨髓瘤供体的嗜酸性粒细胞外，在嗜碱性粒细胞或嗜酸性粒细胞上未检测到CD23表达。一些供体的单核细胞上存在CD23，但与血清IgE水平无关。
在多种疾病状态下，嗜碱性粒细胞而非单核细胞或嗜酸性粒细胞的FcepsilonRIα表达与跨越6个对数范围的IgE血清水平相关。这些数据支持血清IgE在体内对嗜碱性粒细胞上FcepsilonRIα进行调节的概念，并进一步证明这与过敏性疾病本身无关。
