Loharungsikul Somying, Troye-Blomberg Marita, Amoudruz Petra, Pichyangkul Sathit, Yongvanitchit Kosol, Looareesuwan Sornchai, Mahakunkijcharoen Yuvadee, Sarntivijai Suphannee, Khusmith Srisin
Department of Clinical Microbiology, Faculty of Medical Technology, Mahidol University, 2 Prannok Road, Bangkok-Noi, Bangkok 10700, Thailand.
Acta Trop. 2008 Jan;105(1):10-5. doi: 10.1016/j.actatropica.2007.08.002. Epub 2007 Aug 9.
The continuous release of blood-stage malaria parasites and their products can activate components of the innate immune system and induce the production of proinflammatory cytokines. Toll-like receptors (TLRs) have emerged as pattern-recognition receptors, residing on/in innate immune cells whose function is recognizing specific conserved components on different microbes. The aim of this study was to determine the expression of TLR2, TLR4 and TLR9 on antigen-presenting cells (APCs) in patients with mild and severe forms of falciparum malaria. Healthy individuals were used as controls. Peripheral blood mononuclear cells (PBMCs) were stained with specific monoclonal antibodies (mAbs) to investigate the percentage and the level of TLR expression by flow cytometry. Patients with severe and mild malaria showed increased surface expression of TLR2 and TLR4 on CD14(+)monocytes and myeloid dendritic cells (MDCs) and decreased intracellular expression of TLR9 on plasmacytoid dendritic cells (PDCs), compared to those of healthy controls. A significant decrease in the percentage of circulating CD14(+)monocytes and MDCs expressing TLR2 was found in both severe and mild malaria patients. These findings suggested that TLRs might play role in innate immune recognition in which the differential expression of TLRs on APCs could be regulated by the P. falciparum parasite.
血液阶段疟原虫及其产物的持续释放可激活先天性免疫系统的成分并诱导促炎细胞因子的产生。Toll样受体（TLRs）已成为模式识别受体，存在于先天性免疫细胞上或细胞内，其功能是识别不同微生物上的特定保守成分。本研究的目的是确定轻度和重度恶性疟患者抗原呈递细胞（APC）上TLR2、TLR4和TLR9的表达情况。以健康个体作为对照。用特异性单克隆抗体（mAb）对外周血单核细胞（PBMC）进行染色，通过流式细胞术研究TLR表达的百分比和水平。与健康对照相比，重度和轻度疟疾患者CD14(+)单核细胞和髓样树突状细胞（MDC）上TLR2和TLR4的表面表达增加，浆细胞样树突状细胞（PDC）上TLR9的细胞内表达降低。在重度和轻度疟疾患者中均发现表达TLR2的循环CD14(+)单核细胞和MDC的百分比显著降低。这些发现表明，TLRs可能在先天性免疫识别中发挥作用，其中疟原虫可调节APC上TLRs的差异表达。
