UNASSIGNED: In this study, we used patients\' samples together with transgenic mouse models carrying pathogenic CARD11 mutations from patients to explore their effects on Treg development. Immunoblotting and a GFP receptor assay were used to evaluate the activation effect of CARD11 mutants on NF-κB signaling. Then the suppressive function of Tregs carrying distinct CARD11 mutations was measured by in vitro suppression assay. Finally, we applied the retroviral transduced bone marrow chimeras to rescue the Treg development in an NF-κB independent manner.
UNASSIGNED: We found CARD11 mutations causing hyper-activated NF-κB signals also gave rise to compromised Treg development in the thymus, similar to the phenotype in Card11 deficient mice. This observation challenges the previous view that CARD11 regulates Treg lineage dependent on the NF-kB activation. Mechanistic investigations reveal that the noncanonical function CARD11, which negatively regulates the AKT/ FOXO1 signal pathway, is responsible for regulating Treg generation. Moreover, primary immunodeficiency patients carrying CARD11 mutation, which autonomously activates NF-κB, also represented the reduced Treg population in their peripheral blood. Our results propose a new regulatory function of CARD11 and illuminate an NF-κB independent pathway for thymic Treg lineage commitment.
■在这项研究中,我们使用患者样本和携带来自患者的致病性CARD11突变的转基因小鼠模型来探讨其对Treg发育的影响.免疫印迹和GFP受体测定用于评估CARD11突变体对NF-κB信号传导的激活作用。然后通过体外抑制测定测量携带不同CARD11突变的Treg的抑制功能。最后,我们应用逆转录病毒转导的骨髓嵌合体以独立于NF-κB的方式挽救Treg的发育。
■我们发现导致NF-κB信号过度激活的CARD11突变也导致胸腺中Treg发育受损,与Card11缺陷小鼠的表型相似。该观察结果挑战了先前的观点,即CARD11调节依赖于NF-kB活化的Treg谱系。机制研究表明,负调节AKT/FOXO1信号通路的非规范功能CARD11,负责调节Treg的产生。此外,携带CARD11突变的原发性免疫缺陷患者,自主激活NF-κB,也代表了外周血中Treg数量的减少。我们的结果提出了CARD11的新调节功能,并阐明了胸腺Treg谱系定型的NF-κB独立途径。