Division of ENT Diseases Huddinge, Karolinska Institutet, Stockholm, Sweden.
Int Arch Allergy Immunol. 2011;155(3):234-42. doi: 10.1159/000320480. Epub 2011 Feb 1.
Dendritic cells are antigen-presenting cells central to the immune system. They activate and orchestrate the innate and the adaptive immune systems. This phenotypically diverse group can be further divided into 2 subsets, the CD11c+ myeloid dendritic cells (mDCs) and the CD123+ plasmacytoid dendritic cells (pDCs). The aim of the study was to investigate the effect of allergen exposure on dendritic cells in subjects with allergic rhinitis.
Atopic and non-atopic subjects were challenged intranasally with birch or timothy allergen. Nasal biopsies were taken before and 24 h after challenge, and were, after CD68 exclusion, stained for expression of CD11c and CD123 to identify dendritic cell subsets. The effect of allergic mediators on CD68⁻,CD123+ cells was studied with flow cytometry analysis in peripheral blood.
The amount of CD68⁻,CD123+ cells increased in the nasal sub-epithelium upon allergen challenge, whereas the number of CD68⁻,CD11c+ cells was unaffected. In vitro study of the effect of inflammatory mediators on pDC phenotype showed an increased activation in response TNF-α, IL-4 and CpG. Furthermore, TNF-α caused a higher activation among atopic than non-atopic subjects.
An increased number of CD68⁻,CD123+ dendritic cells along with the positive pDC response following stimulation with inflammatory mediators suggest that the increased pDCs may be of an activated phenotype. It also suggests that the inflammatory response by pDCs to mediators such as TNF-α may be markedly higher in atopic subjects. These data support the notion of pDCs as important participants in allergic rhinitis.
树突状细胞是免疫系统中主要的抗原呈递细胞。它们激活并协调先天免疫和适应性免疫系统。这个表型多样的群体可以进一步分为 2 个亚群，即 CD11c+髓样树突状细胞（mDC）和 CD123+浆细胞样树突状细胞（pDC）。本研究旨在探讨变应原暴露对变应性鼻炎患者树突状细胞的影响。
对变应性和非变应性受试者进行桦树或豚草过敏原的鼻内激发。在激发前和激发后 24 小时取鼻活检，并在排除 CD68 后，用 CD11c 和 CD123 染色鉴定树突状细胞亚群。通过流式细胞术分析研究变应性介质对 CD68⁻、CD123+细胞的影响。
在变应原激发后，鼻黏膜下上皮中 CD68⁻、CD123+细胞的数量增加，而 CD68⁻、CD11c+细胞的数量则不受影响。体外研究炎性介质对 pDC 表型的影响表明，TNF-α、IL-4 和 CpG 可引起 pDC 的更高激活。此外，TNF-α在变应性受试者中引起更高的激活。
在炎性介质刺激下，CD68⁻、CD123+树突状细胞数量增加以及 pDC 反应阳性，表明增加的 pDC 可能具有激活表型。这也表明 pDC 对 TNF-α等介质的炎症反应在变应性受试者中可能明显更高。这些数据支持 pDC 作为变应性鼻炎重要参与者的观点。
