■内源性大麻素系统(ECS),以大麻植物中发现的化学物质命名,是一个神经递质的调节网络,受体,以及在皮肤健康和疾病中起关键作用的酶。ECS的内源性配体,称为内源性大麻素,已被证明是免疫反应的重要调节因子。最普遍的内源性大麻素之一,花生四烯酸乙醇胺(也称为anandamide),以其抗炎作用而闻名。朗格汉斯细胞(LC)是存在于人表皮中的唯一抗原呈递细胞。它们是抵御病原体的第一道防线,对皮肤的特异性免疫反应至关重要,在维持组织稳态方面发挥着关键作用;然而,关于内源性大麻素对这些细胞的影响知之甚少。我们的研究旨在提供单核细胞衍生的朗格汉斯细胞(moLCs)和ECS之间的联系,阐明它们在免疫稳态和炎症中的协同作用。
■使用建立的方案将人单核细胞分化成moLC。在分化过程中应用Anandamide以测试其对生存力的影响,标记表达,和细胞的细胞因子产生,以及细胞内钙测量的短期治疗。分化方案后应用的TLR配体用于激活moLC。使用大量RNA-Seq数据的差异基因表达分析进一步评估了anandamide对moLCs功能的影响,moLC-T细胞共培养,而ELISpot用于确定上述共培养物中激活的T细胞的极化。
■Anandamide不会显着影响高达10µM的moLCs的活力。当在分化过程中应用时,它对CD207表达的影响可以忽略不计,LCs的原型标记;然而,观察到moLCs的CD1a表达减少。Anandamide对moLCs的成熟状态没有显著影响,也不影响TLR3和TLR7/8激动剂诱导的成熟。然而,在anandamide存在下分化的MoLC确实显示由TLR3和TLR7/8活化诱导的CXCL8、IL-6、IL-10和IL-12细胞因子的产生减少。Anandamide处理的moLCs显示出增强的激活幼稚T细胞的能力;然而,没有达到合并TLR激动的水平。与对照细胞相比,用anandamide分化的moLC的RNA测序分析显示出适度的变化,但确实揭示了对激活的moLC中特定的氧化磷酸化的抑制作用。Anandamide还促进了初始T细胞向Th1表型的极化。
■我们的结果表明,anandamide对分化有细微的影响,成熟,细胞因子分泌,激活的moLCs的代谢和功能。在这些变化中,moLCs上CD1a表达的减少有望选择性抑制CD1a限制性T细胞诱导的炎症,它们被认为是牛皮癣等常见炎性皮肤病中炎症的驱动因素,特应性皮炎和接触性皮炎。
UNASSIGNED: The endocannabinoid system (ECS), named after the chemical compounds found in the cannabis plant, is a regulatory network of neurotransmitters, receptors, and enzymes that plays crucial roles in skin health and disease. Endogenous ligands of the ECS, called endocannabinoids, have proven to be important regulators of immune responses. One of the most prevalent endocannabinoids, arachidonoylethanolamide (also known as anandamide), is known for its anti-inflammatory effects. Langerhans cells (LCs) are the sole antigen-presenting cells present in the human epidermis. They serve as the first line of defense against pathogens and are essential for the skin\'s specific immune responses and play a critical role in maintaining tissue homeostasis; however, little is known about the effect of endocannabinoids on these cells. Our research aimed to provide the connection between monocyte-derived Langerhans cells (moLCs) and the ECS, shedding light on their collaborative roles in immune homeostasis and inflammation.
UNASSIGNED: Human monocytes were differentiated into moLCs using established protocols. Anandamide was applied during the differentiation process to test its effect on the viability, marker expression, and cytokine production of the cells, as well as in short term treatments for intracellular calcium measurement. TLR ligands applied after the differentiation protocol were used to activate moLCs. The impact of anandamide on the functionality of moLCs was further assessed using differential gene expression analysis of bulk RNA-Seq data, moLC-T cell cocultures, while ELISpot was employed to determine polarization of T cells activated in the aforementioned cocultures.
UNASSIGNED: Anandamide did not significantly affect the viability of moLCs up to 10 µM. When applied during the differentiation process it had only a negligible effect on CD207 expression, the prototypic marker of LCs; however, there was an observed reduction in CD1a expression by moLCs. Anandamide had no significant effects on the maturation status of moLCs, nor did it affect the maturation induced by TLR3 and TLR7/8 agonists. MoLCs differentiated in the presence of anandamide did however show decreased production of CXCL8, IL-6, IL-10 and IL-12 cytokines induced by TLR3 and TLR7/8 activation. Anandamide-treated moLCs showed an increased capability to activate naïve T cells; however, not to the level seen with combined TLR agonism. RNA sequencing analysis of moLCs differentiated with anandamide showed modest changes compared to control cells but did reveal an inhibitory effect on oxidative phosphorylation specifically in activated moLCs. Anandamide also promoted the polarization of naïve T cells towards a Th1 phenotype.
UNASSIGNED: Our results show that anandamide has nuanced effects on the differentiation, maturation, cytokine secretion, metabolism and function of activated moLCs. Among these changes the decrease in CD1a expression on moLCs holds promise to selectively dampen inflammation induced by CD1a restricted T cells, which have been implicated as drivers of inflammation in common inflammatory skin conditions such as psoriasis, atopic dermatitis and contact dermatitis.