Singh Bhawana, Singh Siddharth Sankar, Sundar Shyam
Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
Parasite Immunol. 2019 Jan;41(1):e12601. doi: 10.1111/pim.12601. Epub 2018 Dec 3.
Iron is key ingredient for immunosurveillance and host-pathogen interaction. Intracellular pathogen steals the iron from the host, but how parasite orchestrates iron acquisition and affects immune responses remains controversial. We aimed to study the iron homoeostasis in visceral leishmaniasis (VL) and its influence on immune machinery.
This study was performed on purified monocytes and T cells, peripheral blood mononuclear cells and splenic aspirates for transcriptional analyses of iron homoeostasis (hepcidin, DMT1, transferrin receptor, ferroportin) and immune modulations (IFN-γ, HLA-DR, IL-10, iNOS, IL-6). Serum/plasma was used for determination of iron, total/transferrin iron-binding capacity and anti-leishmania antibody titres in cases. We report that VL-induced perturbation in iron homoeostasis may cause immune dysfunctions. VL cases had decreased iron uptake by transferrin-dependent and transferrin-independent routes while elevated hepcidin, degraded sole iron exporter ferroportin. Therefore, it appears that perturbation in iron homoeostasis has essential role in HLA-DR mediated antigen presentation and innate armoury by downregulating iNOS as well as altering IFN-γ, IL-6 and IL-10 profiles.
The iron homoeostasis by hepcidin can serve as one of the crucial determinants for regulating immune cell signalling; therefore, targeting iron metabolism, specifically hepcidin alone or in combination with agonists, can serve to clear infection.
铁是免疫监视和宿主-病原体相互作用的关键成分。细胞内病原体从宿主窃取铁,但寄生虫如何协调铁的获取并影响免疫反应仍存在争议。我们旨在研究内脏利什曼病(VL)中的铁稳态及其对免疫机制的影响。
本研究对纯化的单核细胞和T细胞、外周血单核细胞和脾穿刺液进行了铁稳态(铁调素、二价金属离子转运体1、转铁蛋白受体、铁转运蛋白)和免疫调节(干扰素-γ、人类白细胞抗原-DR、白细胞介素-10、诱导型一氧化氮合酶、白细胞介素-6)的转录分析。用血清/血浆测定病例中的铁、总/转铁蛋白铁结合能力和抗利什曼原虫抗体滴度。我们报告,VL引起的铁稳态紊乱可能导致免疫功能障碍。VL病例通过转铁蛋白依赖性和非转铁蛋白依赖性途径的铁摄取减少,而铁调素升高,唯一的铁输出蛋白铁转运蛋白降解。因此,铁稳态的紊乱似乎在人类白细胞抗原-DR介导的抗原呈递和固有免疫中起着重要作用,通过下调诱导型一氧化氮合酶以及改变干扰素-γ、白细胞介素-6和白细胞介素-10的水平。
铁调素介导的铁稳态可作为调节免疫细胞信号传导的关键决定因素之一;因此,针对铁代谢,特别是单独使用铁调素或与激动剂联合使用,可有助于清除感染。