miR-146a负向调控表皮朗格汉斯细胞抗原提呈功能  

miR-146a downregulates epidermal Langerhans cell-mediated antigen presentation

作　　者：张晓茜 张君 徐英萍 Zhang Xiaoqian;Zhang Jun;Xu Yingping(Institute of Dermatology and Venereal Diseases,Dermatology Hospital of Southern Medical University,Guangzhou 510091,China)

机构地区：[1]南方医科大学皮肤病医院皮肤病研究所,广州510091

出　　处：《中华微生物学和免疫学杂志》2023年第5期360-365,共6页Chinese Journal of Microbiology and Immunology

基　　金：国家自然科学基金(81471553, 81872530);广东省自然科学基金(2023A1515010490)。

摘　　要：目的探讨小分子miR-146a对表皮朗格汉斯细胞(Langerhans cells, LCs)稳态和功能的调控作用。方法流式细胞术(flow cytometry, FCM)分选纯化新鲜分离及体外培养成熟后的表皮LCs, 荧光定量PCR(quantitative PCR, qPCR)分析LCs中miR-146a的表达水平。FCM分析野生型和miR-146a条件性敲除(miR-146a conditional knockout, miR-146a cKO)小鼠表皮LCs数量差异。FCM分析组织相容性复合体Ⅱ(major histocompatibility complex Ⅱ, MHCⅡ)分子和共刺激分子(CD86、CD80)表达水平以及LCs吞噬Dextran-FITC的阳性细胞比例以评价miR-146a对LCs成熟和吞噬功能的影响。采用体内外试验分析miR-146a缺失的LCs刺激CD8+OT-Ⅰ T细胞和CD4+OT-Ⅱ T细胞增殖的能力以评价其对LCs的抗原提呈能力的影响。结果与新鲜分离的LCs比较, miR-146a在成熟LCs中表达水平显著上调。与野生型组比较, miR-146a缺失不影响表皮LCs的数量。分离表皮细胞在体外培养48 h后, miR-146a cKO小鼠与野生小鼠表皮LCs中MHCⅡ、CD86及CD80分子表达水平差异无统计学意义, 且miR-146a缺失不影响LCs摄取抗原的能力, 但miR-146a cKO小鼠表皮LCs刺激OVA蛋白特异性CD8+OT-Ⅰ T细胞和CD4+OT-Ⅱ T细胞增殖的能力显著增强。结论 miR-146a不影响表皮LCs稳态、成熟及吞噬能力, 但抑制LCs的抗原提呈功能。Objective To investigate the role of miR-146a in regulating the homeostasis and function of epidermal Langerhans cells(LCs).Methods Fresh and in vitro cultured epidermal LCs were isolated and purified by flow cytometry(FCM).The expression of miR-146a in LCs was detected by quantitative PCR(qPCR).The percentages of epidermal LCs in wild-type(WT)and miR-146a conventional knockout(miR-146a cKO)mice were analyzed by FCM.The expression of major histocompatibility complexⅡ(MHCⅡ)and co-stimulatory molecules(CD86 and CD80)was analyzed by FCM to evaluate the effect of miR-146a on the maturation of LCs.The percentage of Dextran-FITC+LCs was detected by FCM to evaluate the effect of miR-146a on the phagocytic function of LCs.In vitro and in vivo experiments were used to analyze the ability of miR-146a-deficient and-sufficient LCs to stimulate the proliferation of CD8+OT-ⅠT cells and CD4+OT-ⅡT cells.Results The expression of miR-146a was significantly increased in mature LCs than in the freshly isolated LCs.There was no significant difference in the number of epidermal LCs between wild-type(WT)and miR-146a cKO mice.After a 48 h culture in vitro,the expression of MHCⅡ,CD86 and CD80 in the epidermal LCs of miR-146a cKO mice was similar to that of WT mice.Moreover,miR-146a deletion had no significant influence on antigen uptake by LCs.However,miR-146a deficiency enhanced the antigen-presenting ability of LCs that could stimulate the proliferation of OVA-specific CD8+OT-ⅠT cells and CD4+OT-ⅡT cells.Conclusions miR-146a had no influence on the homeostasis,maturation and phagocytosis of LCs,but enhanced the antigen-presenting function.

关 键 词：MIR-146A 朗格汉斯细胞 CD8+OT-ⅠT细胞 CD4+OT-ⅡT细胞 抗原提呈 

分 类 号：R392[医药卫生—免疫学]