近日,，日本慶應(yīng)大學(xué)等機構(gòu)參加的一個國際研究小組在動物實驗中發(fā)現(xiàn),，生長體毛的毛囊在感知到外部刺激或炎癥風(fēng)險時,，會“召集”免疫細(xì)胞并使其分布到表皮中去,，觸發(fā)免疫反應(yīng),。過敏性皮炎等疾病或許與這種機理有關(guān)。
研究人員在實驗鼠的耳朵上貼,、撕膠條以刺激其耳部毛囊,，并用特殊的顯微鏡觀察其皮膚內(nèi)免疫細(xì)胞的動向。結(jié)果發(fā)現(xiàn),，約1小時之后毛囊處就集結(jié)了大批免疫細(xì)胞,。其中，能夠吸收異物,、然后給其他免疫細(xì)胞標(biāo)示攻擊對象的樹狀細(xì)胞還經(jīng)過毛囊向皮膚表皮移動,。
研究小組在最新一期《自然—免疫學(xué)》（Nature Immunology）雜志網(wǎng)絡(luò)版上報告說，他們研究毛囊組織后發(fā)現(xiàn),，有部分特定的毛囊細(xì)胞生成了能夠“召集”免疫細(xì)胞的趨化因子,。人類身上也有相同的現(xiàn)象。
以前,，人們知道哺乳動物的體毛能夠緩解外部撞擊和紫外線的影響,，具備物理防御功能，此次研究則表明,，生長體毛的毛囊會將外部刺激視為異物入侵的征兆,，從而觸發(fā)免疫反應(yīng)。這一發(fā)現(xiàn)將有助于開發(fā)治療過敏性皮炎的方法,。（生物谷Bioon.com）
doi:10.1038/ni.2353
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Stress-induced production of chemokines by hair follicles regulates the trafficking of dendritic cells in skin
Keisuke Nagao,1 Tetsuro Kobayashi,1 Kazuyo Moro,2 Manabu Ohyama,1 Takeya Adachi,1 Daniela Y Kitashima,1 Satoshi Ueha,3 Keisuke Horiuchi,4, 5 Hideaki Tanizaki,6 Kenji Kabashima,6 Akiharu Kubo,1, 5 Young-hun Cho,7 Bj?rn E Clausen,8 Kouji Matsushima,3 Makoto Suematsu,9, 10 Glaucia C Furtado,11 Sergio A Lira,11 Joshua M Farber,12 Mark C Udey7 & Masayuki Amagai1
Langerhans cells (LCs) are epidermal dendritic cells with incompletely understood origins that associate with hair follicles for unknown reasons. Here we show that in response to external stress, mouse hair follicles recruited Gr-1hi monocyte-derived precursors of LCs whose epidermal entry was dependent on the chemokine receptors CCR2 and CCR6, whereas the chemokine receptor CCR8 inhibited the recruitment of LCs. Distinct hair-follicle regions had differences in their expression of ligands for CCR2 and CCR6. The isthmus expressed the chemokine CCL2; the infundibulum expressed the chemokine CCL20; and keratinocytes in the bulge produced the chemokine CCL8, which is the ligand for CCR8. Thus, distinct hair-follicle keratinocyte subpopulations promoted or inhibited repopulation with LCs via differences in chemokine production, a feature also noted in humans. Pre-LCs failed to enter hairless skin in mice or humans, which establishes hair follicles as portals for LCs.
