Monteseirín J, Chacón P, Vega A, Sánchez-Monteseirín H, Asturias J A, Martínez A, Guardia P, Pérez-Cano R, Conde J
Servicio de Inmunología y Alergia, Hospital Universitario Virgen Macarena, Asunción 27, 41011 Seville, Spain.
Clin Exp Allergy. 2005 Sep;35(9):1204-13. doi: 10.1111/j.1365-2222.2005.02320.x.
L-selectin (CD62L) is an adhesion molecule involved in leucocyte attachment to endothelium at sites of inflammation, and it has been demonstrated that L-selectin is rapidly shed after neutrophil activation. Recently, it has been reported that there is increasing evidence of neutrophil participation in asthma and the allergic process.
The present study was designed to determine whether an IgE-dependent mechanism can modulate L-selectin expression on the surface of neutrophils. Moreover, we analyse the potential implication of intracellular signal-transduction pathways and whether specific immunotherapy (IT), glucocorticoids and antihistamines might regulate this process.
Peripheral blood neutrophils from three groups of donors (asthmatic group without IT treatment, IT-treated asthmatic group and healthy group) were used. Cells were challenged in vitro with the specific allergen that produced clinical symptoms in asthmatic patients and also with the allergen to which the patients were not sensitive. Neutrophils from healthy donors were also challenged with allergens. Expression of CD62L on the neutrophil surface was analysed by flow cytometry, and soluble CD62L (sCD62L) in culture supernatant by ELISA. In an attempt to discover which IgE receptor is involved, we also challenged the neutrophils with monoclonal antibody to FcepsilonRI, FcepsilonRII (CD23) and galectin-3 receptors.
When neutrophils from allergic patients were challenged with specific allergens that produce clinical allergy symptoms, L-selectin was down-regulated from the surface of those cells, accompanied by a concomitant up-regulation of soluble L-selectin in the supernatant. The challenge with antibodies against FCepsilonRI, FCepsilonRII (CD23) and galectin-3, induces down-modulation of L-selectin on the surface of the neutrophils in all three cases. Calphostin C, wortmannin and manoalide attenuated CD62L down-regulation, suggesting the potential implication of protein kinase C, phosphatidylinositol 3-kinase and phospholipase A(2) in the process. IT and glucocorticoids modulated allergen-dependent CD62L down-regulation, whereas antihistamines (terfenadine, loratadine and cetirizine) or nedocromil sodium did not affect the shedding of L-selectin.
We present evidence that the neutrophil surface expression of CD62L can be modulated by an allergen-dependent mechanism. The modulation of CD62L expression can be induced through the three receptors of IgE. This process can be affected by IT.
L-选择素（CD62L）是一种参与白细胞在炎症部位与内皮细胞黏附的黏附分子，并且已经证实中性粒细胞活化后L-选择素会迅速脱落。最近，有报道称越来越多的证据表明中性粒细胞参与哮喘和过敏过程。
本研究旨在确定IgE依赖机制是否能调节中性粒细胞表面L-选择素的表达。此外，我们分析细胞内信号转导途径的潜在影响以及特异性免疫疗法（IT）、糖皮质激素和抗组胺药是否可能调节这一过程。
使用三组供体（未接受IT治疗的哮喘组、接受IT治疗的哮喘组和健康组）的外周血中性粒细胞。用能使哮喘患者产生临床症状的特异性变应原以及患者不敏感的变应原在体外刺激细胞。也用变应原刺激健康供体的中性粒细胞。通过流式细胞术分析中性粒细胞表面CD62L的表达，并用ELISA法检测培养上清液中的可溶性CD62L（sCD62L）。为了试图发现涉及哪种IgE受体，我们还用抗FcepsilonRI、FcepsilonRII（CD23）和半乳糖凝集素-3受体的单克隆抗体刺激中性粒细胞。
当用能产生临床过敏症状的特异性变应原刺激过敏患者的中性粒细胞时，这些细胞表面的L-选择素下调，同时上清液中可溶性L-选择素上调。用抗FCepsilonRI、FCepsilonRII（CD23）和半乳糖凝集素-3的抗体刺激，在所有三种情况下均诱导中性粒细胞表面L-选择素的下调。钙泊三醇、渥曼青霉素和 manoalide减弱了CD62L的下调，提示蛋白激酶C、磷脂酰肌醇3-激酶和磷脂酶A(2)在此过程中的潜在影响。IT和糖皮质激素调节变应原依赖性CD62L的下调，而抗组胺药（特非那定、氯雷他定和西替利嗪）或奈多罗米钠不影响L-选择素的脱落。
我们提供证据表明CD62L在中性粒细胞表面的表达可通过变应原依赖机制进行调节。CD62L表达的调节可通过IgE的三种受体诱导。这一过程可受IT影响。
