Stopinšek Sanja, Ihan Alojz, Salobir Barbara, Terčelj Marjeta, Simčič Saša
Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia.
Department for Respiratory and Allergic Diseases, University Medical Centre, Zaloška 2, SI-1000 Ljubljana, Slovenia.
J Occup Med Toxicol. 2016 Sep 21;11:46. doi: 10.1186/s12995-016-0135-4. eCollection 2016.
Composition of organic dust is very complex, involving particles of microbial, animal and plant origin. Several environmental exposure studies associate microbial cell wall agents in organic dust with various respiratory symptoms and diseases. The aim of the present study was to investigate the in vitro effects of the co-exposure of fungal cell wall agents (FCWAs) and bacterial lipopolysaccharide (LPS) on inflammatory immune responses of peripheral blood mononuclear cells (PBMCs) from patients with pulmonary sarcoidosis.
PBMCs from 22 patients with pulmonary sarcoidosis and 20 healthy subjects were isolated and stimulated in vitro with FCWAs (soluble and particulate (1 → 3)-β-D-glucan, zymosan and chitosan) and/or LPS. Subsequently, cytokines were measured by ELISA and the mRNA expression of dectin-1, toll-like receptor 2 (TLR2), TLR4 and mannose receptor (MR) was analysed by real-time RT-PCR.
Patients with sarcoidosis had a significantly higher secretion of inflammatory cytokines tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-10 and IL-12 (1.7-fold, 2.0-fold, 2.2-fold, and 2.8-fold, respectively; all p < 0.05) after in vitro co-stimulation of PBMCs with FCWAs and LPS. We showed that PBMCs from patients with sarcoidosis had a higher baseline mRNA expression of dectin-1, TLR2, TLR4 and MR (6-fold, 11-fold, 18-fold, and 4-fold, respectively). Furthermore, we found a reduced expression of dectin-1, TLR2 and TLR4 after stimulation with FCWAs and/or LPS, although the reduction was significantly weaker in patients than in healthy subjects.
In conclusion, co-stimulation with FCWAs and LPS of PBMC from patients with sarcoidosis caused a weaker reduction of dectin-1, TLR2, TLR4 receptors expression, which could increase the sensitivity of PBMCs, leading to excessive inflammatory cytokine responses and result in the development or progression of pulmonary sarcoidosis.
有机粉尘的成分非常复杂，包括微生物、动植物来源的颗粒。多项环境暴露研究表明，有机粉尘中的微生物细胞壁成分与各种呼吸道症状和疾病有关。本研究的目的是调查真菌细胞壁成分（FCWAs）和细菌脂多糖（LPS）共同暴露对外周血单核细胞（PBMCs）炎症免疫反应的体外影响。
分离22例结节病患者和20例健康受试者的PBMCs，并在体外使用FCWAs（可溶性和颗粒状（1→3）-β-D-葡聚糖、酵母聚糖和壳聚糖）和/或LPS进行刺激。随后，通过ELISA检测细胞因子，并通过实时RT-PCR分析dectin-1、Toll样受体2（TLR2）、TLR4和甘露糖受体（MR）的mRNA表达。
结节病患者的PBMCs在体外与FCWAs和LPS共同刺激后，炎症细胞因子肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、IL-10和IL-12的分泌显著增加（分别为1.7倍、2.0倍、2.2倍和2.8倍；均p<0.05）。我们发现，结节病患者的PBMCs中dectin-1、TLR2、TLR4和MR的基线mRNA表达较高（分别为6倍、11倍、18倍和4倍）。此外，我们发现用FCWAs和/或LPS刺激后，dectin-1、TLR2和TLR4的表达降低，尽管患者的降低程度明显弱于健康受试者。
总之，结节病患者的PBMCs与FCWAs和LPS共同刺激导致dectin-1、TLR2、TLR4受体表达的降低较弱，这可能会增加PBMCs的敏感性，导致过度的炎症细胞因子反应，并导致结节病的发生或进展。
