Qaseem Asif S, Singh Iesha, Pathan Ansar A, Layhadi Janice A, Parkin Rebecca, Alexandra Fedina, Durham Stephen R, Kishore Uday, Shamji Mohamed H
1 Allergy and Clinical Immunology, Inflammation, Repair and Development, and Immune Modulation and Tolerance Group, National Heart and Lung Institute, Imperial College London, Medical Research Council and Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom; and.
2 Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.
Am J Respir Crit Care Med. 2017 Dec 15;196(12):1526-1534. doi: 10.1164/rccm.201701-0225OC.
Recombinant fragment of human surfactant protein D (rfhSP-D) has been shown to suppress house dust mite- and Aspergillus fumigatus-induced allergic inflammation in murine models.
We sought to elucidate the effect of rfhSP-D on high-affinity IgE receptor- and CD23-mediated, grass pollen-induced allergic inflammatory responses.
rfhSP-D, containing homotrimeric neck and lectin domains, was expressed in Escherichia coli BL21(λDE3)pLysS cells. Peripheral blood mononuclear cells and sera were obtained from individuals with grass pollen allergy (n = 27). The effect of rfhSP-D on basophil activation and histamine release was measured by flow cytometry. IgE-facilitated allergen binding and presentation were assessed by flow cytometry. T-helper cell type 2 (Th2) cytokines were measured in cell culture supernatants. The effect of rfhSP-D on IgE production by B cells when stimulated with CD40L, IL-4, and IL-21 was also determined.
rfhSP-D bound to Phleum pratense in a dose- and calcium-dependent manner. Allergen-induced basophil responsiveness and histamine release were inhibited in the presence of rfhSP-D, as measured by CD63, CD203c (P = 0.0086, P = 0.04205), and intracellularly labeled diamine oxidase (P = 0.0003, P = 0.0148). The binding of allergen-IgE complexes to B cells was reduced by 51% (P = 0.002) in the presence of rfhSP-D. This decrease was concomitant with reduction in CD23 expression on B cells (P < 0.001). rfhSP-D suppressed allergen-driven CD27CD4CRTh2 T-cell proliferation (P < 0.01), IL-4, and IL-5 levels (all P < 0.01). Moreover, rfhSP-D inhibited CD40L/IL-4- and IL-21-mediated IgE production (77.12%; P = 0.02) by B cells.
For the first time, to our knowledge, we show that rfhSP-D inhibited allergen-induced basophil responses at a single-cell level and suppressed CD23-mediated facilitated allergen presentation and Th2 cytokine production. In addition, rfhSP-D inhibited IgE synthesis by B cells, which is also a novel observation.
人表面活性蛋白D重组片段（rfhSP-D）已被证明在小鼠模型中可抑制屋尘螨和烟曲霉诱导的过敏性炎症。
我们试图阐明rfhSP-D对高亲和力IgE受体和CD23介导的草花粉诱导的过敏性炎症反应的影响。
包含同源三聚体颈部和凝集素结构域的rfhSP-D在大肠杆菌BL21(λDE3)pLysS细胞中表达。从草花粉过敏个体（n = 27）获取外周血单核细胞和血清。通过流式细胞术检测rfhSP-D对嗜碱性粒细胞活化和组胺释放的影响。通过流式细胞术评估IgE促进的过敏原结合和呈递。在细胞培养上清液中检测2型辅助性T细胞（Th2）细胞因子。还确定了rfhSP-D对用CD40L、IL-4和IL-21刺激时B细胞产生IgE的影响。
rfhSP-D以剂量和钙依赖性方式与早熟禾结合。如通过CD63、CD203c（P = 0.0086，P = 0.04205）和细胞内标记的二胺氧化酶（P = 0.0003，P = 0.0148）测量，在rfhSP-D存在下，过敏原诱导的嗜碱性粒细胞反应性和组胺释放受到抑制。在rfhSP-D存在下，过敏原-IgE复合物与B细胞的结合减少了51%（P = 0.002）。这种减少与B细胞上CD23表达的降低同时发生（P < 0.001）。rfhSP-D抑制过敏原驱动的CD27CD4CRTh2 T细胞增殖（P < 0.01）、IL-4和IL-5水平（均P < 0.01）。此外，rfhSP-D抑制B细胞由CD40L/IL-4和IL-21介导的IgE产生（77.12%；P = 0.02）。
据我们所知，我们首次表明rfhSP-D在单细胞水平抑制过敏原诱导的嗜碱性粒细胞反应，并抑制CD23介导的促进过敏原呈递和Th2细胞因子产生。此外，rfhSP-D抑制B细胞产生IgE，这也是一项新的观察结果。
