Table_1_Downregulation of monocyte miRNAs: implications for immune dysfunction and disease severity in drug-resistant tuberculosis.xlsx

BackgroundMonocyte miRNAs govern both protective and pathological responses during tuberculosis (TB) through their differential expression and emerged as potent targets for biomarker discovery and host-directed therapeutics. Thus, this study examined the miRNA profile of sorted monocytes across the TB disease spectrum [drug-resistant TB (DR-TB), drug-sensitive TB (DS-TB), and latent TB] and in healthy individuals (HC) to understand the underlying pathophysiology and their regulatory mechanism.
MethodsWe sorted total monocytes including three subsets (HLA-DR+CD14+, HLA-DR+CD14+CD16+, and HLA-DR+CD16+cells) from peripheral blood mononuclear cells (PBMCs) of healthy and TB-infected individuals through flow cytometry and subjected them to NanoString-based miRNA profiling.
ResultsThe outcome was the differential expression of 107 miRNAs particularly the downregulation of miRNAs in the active TB groups (both drug-resistant and drug-sensitive). The miRNA profile revealed differential expression signatures: i) decline of miR-548m in DR-TB alone, ii) decline of miR-486-3p in active TB but significant elevation only in LTB iii) elevation of miR-132-3p only in active TB (DR-TB and DS-TB) and iv) elevation of miR-150-5p in DR-TB alone. The directionality of functions mediated by monocyte miRNAs from Gene Set Enrichment Analysis (GSEA) facilitated two phenomenal findings: i) a bidirectional response between active disease (activation profile in DR-TB and DS-TB compared to LTB and HC) and latent infection (suppression profile in LTB vs HC) and ii) hyper immune activation in the DR-TB group compared to DS-TB.
ConclusionThus, monocyte miRNA signatures provide pathological clues for altered monocyte function, drug resistance, and disease severity. Further studies on monocyte miRNAs may shed light on the immune regulatory mechanism for tuberculosis.

研究背景
单核细胞微小RNA（miRNA）可通过差异表达调控结核病（TB）进程中的保护性与病理性免疫应答，现已成为生物标志物发掘及宿主导向治疗的重要靶点。本研究针对覆盖结核病疾病谱的样本（包括耐药结核病（DR-TB）、药物敏感性结核病（DS-TB）及潜伏性结核病患者，以及健康个体（HC））的分选单核细胞miRNA表达谱进行分析，以解析其潜在的病理生理机制及调控通路。

研究方法
本研究通过流式细胞术，从健康个体及结核病感染者的外周血单个核细胞（PBMCs）中分选得到总单核细胞，涵盖三个亚群：HLA-DR+CD14+、HLA-DR+CD14+CD16+及HLA-DR+CD16+细胞；随后采用基于NanoString技术的miRNA表达谱检测技术对样本进行分析。

研究结果
本研究共鉴定出107个差异表达的miRNA，其中活动性结核病组（含耐药及药物敏感性结核病组）的miRNA整体呈下调趋势。miRNA表达谱呈现四类特征性差异模式：① 仅在耐药结核病组中出现miR-548m表达下调；② miR-486-3p在活动性结核病中表达降低，但仅在潜伏性结核病组中显著升高；③ miR-132-3p仅在活动性结核病组（耐药及药物敏感性结核病）中表达上调；④ 仅在耐药结核病组中出现miR-150-5p表达上调。通过基因集富集分析（GSEA）解析单核细胞miRNA介导的功能方向，得到两项核心发现：其一，活动性疾病与潜伏感染存在双向应答特征：与潜伏性结核病及健康个体相比，耐药与药物敏感性结核病组呈现免疫激活谱，而潜伏性结核病组与健康个体相比则呈现免疫抑制谱；其二，与药物敏感性结核病组相比，耐药结核病组呈现更为显著的免疫激活状态。

研究结论
综上，单核细胞miRNA表达特征可为单核细胞功能异常、结核病耐药性及疾病严重程度提供病理线索。后续针对单核细胞miRNA的相关研究，可进一步阐明结核病的免疫调控机制。