Yang W, Wardlaw A J, Bradding P
Department of Infection, Immunity, and Inflammation, University of Leicester Medical School, Leicester, UK.
Allergy. 2006 May;61(5):569-75. doi: 10.1111/j.1398-9995.2006.01041.x.
Human lung mast cells (HLMC) lie in close proximity to the bronchial epithelium in asthma and adhere with high affinity to bronchial epithelial monolayers in vitro. We investigated the consequences of this adhesive interaction on HLMC activation in response to Fc epsilon RI cross-linking.
Human lung mast cells were cultured with the bronchial epithelial cell line BEAS-2B or plastic control for either 30 min or 16 h and then activated with anti-IgE. Histamine was measured by radioenzymatic assay.
After co-culture for 30 min, IgE-dependent histamine release from HLMC was identical on both BEAS-2B and plastic. After 16 h of co-culture, there was a marked decrease in constitutive and IgE-dependent histamine release from HLMC cultured on BEAS-2B compared with those cultured on plastic or fibronectin. In contrast, the Ca(2+)/ATPase inhibitor thapsigargin produced concentration-dependent histamine release that was significantly increased on BEAS-2B compared with plastic. IgE-dependent degranulation was not significantly affected by BEAS-2B-conditioned medium.
BEAS-2B bronchial epithelial cells attenuate IgE-dependent but not thapsigargin-induced histamine release from HLMC. The differential effect with anti-IgE compared with thapsigargin suggests that the mechanism includes interference with the proximal Fc epsilon RI signalling pathway.
在哮喘中，人肺肥大细胞（HLMC）紧邻支气管上皮，并且在体外与人支气管上皮单层具有高亲和力的黏附作用。我们研究了这种黏附相互作用对HLMC因FcεRI交联而激活产生的影响。
将人肺肥大细胞与支气管上皮细胞系BEAS - 2B或塑料对照培养30分钟或16小时，然后用抗IgE激活。通过放射酶法测定组胺。
共培养30分钟后，HLMC中IgE依赖性组胺释放量在BEAS - 2B和塑料上相同。共培养16小时后，与在塑料或纤连蛋白上培养的HLMC相比，在BEAS - 2B上培养的HLMC中组成性和IgE依赖性组胺释放量显著降低。相反，Ca(2+)/ATP酶抑制剂毒胡萝卜素产生浓度依赖性组胺释放，与塑料相比，在BEAS - 2B上显著增加。BEAS - 2B条件培养基对IgE依赖性脱颗粒没有显著影响。
BEAS - 2B支气管上皮细胞减弱HLMC中IgE依赖性组胺释放，但不减弱毒胡萝卜素诱导的组胺释放。与毒胡萝卜素相比，抗IgE的不同作用表明该机制包括干扰近端FcεRI信号通路。
