Purpose

The immune response induced by nucleotide-binding oligomerization domain-2(NOD2) is associated with the production of cytokines affected by the host's genetic background. The present study aimed to examine the effects of NOD2; 802C > T, 2105G > A polymorphisms associated with altered cytokine levels in patients with active pulmonary tuberculosis disease, Latent TB subjects (household contacts(HHC) and healthy controls(HC).

Methods

Genetic polymorphisms were analyzed by Restriction Fragment Length Polymorphism(RFLP) in 102-PTB patients, 102-HHC, and 132-HC. QuantiFERON-TB Gold In-Tube test was performed to identify latent TB infection in 60-HHC. Estimated their cytokine levels by ELISA in MDP (muramyl dipeptide) stimulated culture supernatants of all the groups. Further, we studied pre-mRNA structures by insilico analysis and relative gene expression by RT-PCR.

Results

Recessive genetic models of NOD2 802C > T SNP with TT genotype and AA genotype of NOD2 2105G > A SNP were significantly associated with increased TB risk in PTB patients and HHC compared with HC. In vitro stimulations were performed with NOD2 ligand MDP in PTB patients and latent TB subjects: QuantiFERON positive household contacts (QFT + ve HHC)and QuantiFERON negative household contacts(QFT-ve HHC). The results showed that reduced TNF-α and enhanced IL-12, IL-1β indicate that these cytokines may play an essential role in the initial maintenance of cell-mediated immunity. Our study demonstrated the correlation between NOD2 polymorphism with IL-1β, TNF-α, IL-12 levels. Insilico analysis represents the pre-mRNA secondary structures affected by NOD2 SNPs. We also observed the difference in m RNA levels in variant and wild genotypes.

Conclusion

This finding may lead to the forthcoming development of immunotherapy and may be used as predictive markers to identify high-risk individuals for TB disease.

中文翻译：

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NOD样受体2基因多态性对活动性肺结核患者及家庭接触者胞壁酰二肽诱导的促炎反应的影响

目的

核苷酸结合寡聚结构域 2 (NOD2) 诱导的免疫反应与受宿主遗传背景影响的细胞因子的产生有关。本研究旨在检查 NOD2 的影响；802C > T, 2105G > A 多态性与活动性肺结核病患者、潜伏性结核病患者（家庭接触者（HHC）和健康对照者（HC）的细胞因子水平改变相关）。

方法

通过限制性片段长度多态性（RFLP）分析102-PTB患者、102-HHC和132-HC的遗传多态性。进行 QuantiFERON-TB Gold In-Tube 测试以识别 60-HHC 中的潜伏 TB 感染。通过 ELISA 在 MDP（胞壁酰二肽）刺激的所有组的培养上清液中估计它们的细胞因子水平。此外，我们通过 insilico 分析和 RT-PCR 的相对基因表达研究了前 mRNA 结构。

结果

与 HC 相比，NOD2 802C > T SNP 的 TT 基因型和 AA 基因型 NOD2 2105G > A SNP 的隐性遗传模型与 PTB 患者和 HHC 的 TB 风险增加显着相关。在 PTB 患者和潜伏性 TB 受试者中使用 NOD2 配体 MDP 进行体外刺激：QuantiFERON 阳性家庭接触者 (QFT + ve HHC) 和 QuantiFERON 阴性家庭接触者 (QFT-ve HHC)。结果表明，TNF-α减少和IL-12、IL-1β增强表明这些细胞因子可能在细胞介导免疫的初始维持中发挥重要作用。我们的研究证明了 NOD2 多态性与 IL-1β、TNF-α、IL-12 水平之间的相关性。Insilico 分析代表受 NOD2 SNP 影响的前 mRNA 二级结构。我们还观察到变异和野生基因型中 m RNA 水平的差异。

结论

这一发现可能导致免疫疗法的即将发展，并可用作预测标记物来识别结核病高危个体。