University Children's Hospital Munich, Department of Pulmonary and Allergy, LMU Munich, Germany.
J Allergy Clin Immunol. 2011 Jun;127(6):1587-94.e6. doi: 10.1016/j.jaci.2011.03.015. Epub 2011 May 4.
In a genome-wide association study, genetic variants on chromosome 17q21 were strongly associated with childhood asthma and orosomucoid 1-like 3 (ORMDL3) gene expression. Regulation of the 17q21 locus and its immunologic relevance early in life have not been well characterized.
We investigated the relation between polymorphisms and mRNA expression of 17q21 locus genes and their influence on T-cell subsets in cord blood.
In 200 children of our cord blood study, 17q21 polymorphisms were genotyped by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Gene expression was assessed for ORMDL3; gasdermin A (GSDMA, alias GSDM1); gasdermin B (GSDMB, alias GSDML); Ikaros family zinc finger 3 (ZNFN1A3), zona pellucida binding protein 2 (ZPBP2); and proteasome (prosome, macropain) 26S subunit, non-ATPase, 3 (PSMD3), in cord blood mononuclear cells (CBMCs) and for ORMDL3 in peripheral blood (real-time RT-PCR). Mononuclear cells were assessed before and after microbial (lipid A/peptidoglycan), phytohemagglutinin, or allergen (Der p 1) stimulation. Regulatory T-associated markers (forkhead box protein 3, glucocorticoid-induced TNF receptor, lymphocyte activation gene 3 mRNA expression) and T(h)2/T(h)1/T(h)17 cytokines were examined.
In CBMCs, single genetic risk variants within 17q21 were associated with increased ORMDL3 (Der p 1 stimulation; P ≤ .01) and GSDMA expression (phytohemagglutinin/Der p 1 stimulation; P ≤ .05). Children homozygous for all 4 risk alleles for 17q21 tagging single nucleotide polymorphisms showed increased expression for ORMDL3 (Der p 1; P = .002) and GSDMA (phytohemagglutinin; P = .0009/Der p 1; P = .004). CBMC ORMDL3 expression was lower compared with PBMCs (P ≤ .0003) and increased in both CBMC and PBMC after stimulation (phytohemagglutinin/lipid A/peptidoglycan/Der p 1; P ≤ .006 and phytohemagglutinin/peptidoglycan; P < .05, respectively). No correlation between 17q21 polymorphisms and regulatory T/T(h)2/T(h)1 lineages was detectable. However, 17q21 risk allele carriers showed significantly increased IL-17 secretion (unstimulated, phytohemagglutinin-stimulated).
Our results suggest an association of 17q21 polymorphisms with ORMDL3, GSDMA expression, and IL-17 secretion early in life. These observations may imply a functional role of the 17q21 locus affecting T-cell development during immune maturation.
在全基因组关联研究中，染色体 17q21 上的遗传变异与儿童哮喘和粘蛋白 1 样 3（ORMDL3）基因表达强烈相关。17q21 基因座的调控及其在生命早期的免疫相关性尚未得到很好的描述。
我们研究了 17q21 基因座基因的多态性和 mRNA 表达与脐带血 T 细胞亚群之间的关系。
在我们的脐带血研究的 200 名儿童中，通过基质辅助激光解吸电离飞行时间质谱法对 17q21 多态性进行了基因分型。评估了 ORMDL3、gasdermin A（GSDMA，也称为 GSDM1）、gasdermin B（GSDMB，也称为 GSDML）、Ikaros 家族锌指 3（ZNFN1A3）、透明带结合蛋白 2（ZPBP2）和蛋白酶体（蛋白酶体，大分子蛋白酶）26S 亚基，非 ATP 酶，3（PSMD3）在脐带血单核细胞（CBMCs）中的基因表达，并通过实时 RT-PCR 检测外周血中的 ORMDL3 基因表达。在微生物（脂 A/肽聚糖）、植物血凝素、或过敏原（Der p 1）刺激前后，评估单核细胞。检查了调节性 T 相关标志物（叉头框蛋白 3、糖皮质激素诱导的 TNF 受体、淋巴细胞激活基因 3 mRNA 表达）和 T(h)2/T(h)1/T(h)17 细胞因子。
在 CBMCs 中，17q21 内的单一遗传风险变异与 ORMDL3（Der p 1 刺激；P ≤.01）和 GSDMA 表达（植物血凝素/Der p 1 刺激；P ≤.05）增加有关。携带 17q21 标记单核苷酸多态性的所有 4 个风险等位基因的儿童，ORMDL3（Der p 1；P=.002）和 GSDMA（植物血凝素；P=.0009/Der p 1；P=.004）的表达增加。与 PBMCs 相比，CBMCs 的 ORMDL3 表达较低（P ≤.0003），且刺激后 CBMC 和 PBMC 中的表达均增加（植物血凝素/脂 A/肽聚糖/Der p 1；P ≤.006 和植物血凝素/肽聚糖；P<.05，分别）。17q21 多态性与调节性 T/T(h)2/T(h)1 谱系之间未检测到相关性。然而，携带 17q21 风险等位基因的携带者表现出明显增加的 IL-17 分泌（未刺激、植物血凝素刺激）。
我们的研究结果表明，17q21 多态性与 ORMDL3、GSDMA 表达和生命早期的 IL-17 分泌有关。这些观察结果可能表明 17q21 基因座影响免疫成熟过程中 T 细胞发育的功能作用。
