■有机磷酸酯(OPEs)是消费品中使用的阻燃剂和增塑剂。OPEs在整个环境中随处可见,在室内室内灰尘中浓度很高。暴露于单个OPEs与免疫功能障碍有关,特别是在巨噬细胞中。然而,OPEs以复杂混合物的形式存在,尚未研究与环境相关的混合物对免疫系统的影响。
■本研究的目的是评估OPEs的环境相关混合物的毒性,该混合物使用体外表型和功能评估对巨噬细胞上的加拿大房屋灰尘进行建模。
■在用OPE混合物处理的THP-1巨噬细胞中进行毒性的表型生物标志物的高含量活细胞荧光成像。我们使用共聚焦显微镜和胆固醇分析来验证和扩展观察到的OPE诱导的脂质表型。然后,我们使用流式细胞术和活细胞成像技术进行了功能测试,并揭示了OPE诱导的吞噬抑制机制.最后,我们在人原代外周血单核细胞(hPBMC)来源的巨噬细胞中验证了THP-1的发现.
■暴露于OPE混合物的非细胞毒性稀释液导致更高的氧化应激并破坏THP-1和原代巨噬细胞中的溶酶体和脂质稳态。我们进一步观察到,在暴露于OPE的细胞中,THP-1和原代巨噬细胞中凋亡细胞的吞噬作用较低。controls.在THP-1巨噬细胞中,与OPE暴露细胞相比,革兰氏阳性和革兰氏阴性细菌的吞噬作用也较低controls.此外,OPE混合物改变了与磷脂酰丝氨酸识别和病原体相关分子模式相关的吞噬受体的表达。
■这项体外研究的结果表明,暴露于与环境相关的OPEs混合物会导致巨噬细胞中更高的脂质保留和较差的白细胞反应。这些效应可以转化为增强的泡沫细胞生成,导致更高的心血管死亡率。此外,在体外环境中,暴露于OPE的巨噬细胞的细菌吞噬作用较低,这可能表明感染模型中细菌清除率降低的可能性。一起来看,我们的数据提供了强有力的证据,证明OPEs的混合物可以影响巨噬细胞的生物学,并为OPE混合物对免疫系统的影响提供了新的机制见解.https://doi.org/10.1289/EHP13869.
UNASSIGNED: Organophosphate esters (OPEs) are flame retardants and plasticizers used in consumer products. OPEs are found ubiquitously throughout the environment with high concentrations in indoor house dust. Exposure to individual OPEs is associated with immune dysfunction, particularly in macrophages. However, OPEs exist as complex mixtures and the effects of environmentally relevant mixtures on the immune system have not been investigated.
UNASSIGNED: The objectives of this study were to evaluate the toxicity of an environmentally relevant mixture of OPEs that models Canadian house dust on macrophages using phenotypic and functional assessments in vitro.
UNASSIGNED: High-content live-cell fluorescent imaging for phenotypic biomarkers of toxicity in THP-1 macrophages treated with the OPE mixture was undertaken. We used confocal microscopy and cholesterol analysis to validate and expand on the observed OPE-induced lipid phenotype. Then, we used flow cytometry and live-cell imaging to conduct functional tests and uncover mechanisms of OPE-induced phagocytic suppression. Finally, we validated our THP-1 findings in human primary peripheral blood mononuclear cells (hPBMC) derived macrophages.
UNASSIGNED: Exposure to non-cytotoxic dilutions of the OPE mixture resulted in higher oxidative stress and disrupted lysosome and lipid homeostasis in THP-1 and primary macrophages. We further observed that phagocytosis of apoptotic cells in THP-1 and primary macrophages was lower in OPE-exposed cells vs. controls. In THP-1 macrophages, phagocytosis of both Gram-positive and Gram-negative bacteria was also lower in OPE-exposed cells vs. controls. Additionally, the OPE mixture altered the expression of phagocytic receptors linked to the recognition of phosphatidylserine and pathogen-associated molecular patterns.
UNASSIGNED: The results of this in vitro study suggested that exposure to an environmentally relevant mixture of OPEs resulted in higher lipid retention in macrophages and poor efferocytic response. These effects could translate to enhanced foam cell generation resulting in higher cardiovascular mortality. Furthermore, bacterial phagocytosis was lower in OPE-exposed macrophages in an in vitro setting, which may indicate the potential for reduced bacterial clearance in models of infections. Taken together, our data provide strong evidence that mixtures of OPEs can influence the biology of macrophages and offer new mechanistic insights into the impact of OPE mixtures on the immune system. https://doi.org/10.1289/EHP13869.