内体 Toll 样受体 (eTLR) 对于通过 RNA 和 DNA 检测来感知非自身至关重要。在这里，利用囊泡动力学的时空分析、超分辨率显微镜研究和功能测定，我们发现与小 GTPase Rab27a 缺陷相关的内膜缺陷会导致 eTLR 配体识别延迟、早期信号传导缺陷和细胞因子分泌受损。 Rab27a 缺陷的中性粒细胞显示 eTLR 保留在两栖体中，并且配体内化受损。 Rab27a 缺陷导致细胞外信号调节激酶 (ERK) 信号传导和 β2 整合素上调以及对 TLR7 和 TLR9 配体的早期反应出现缺陷。 CpG 刺激的 Rab27a 缺陷型中性粒细胞呈现肿瘤坏死因子 α (TNF-α) 分泌增加和选定的一组介质（包括白细胞介素 (IL)-10）分泌减少。在体内，CpG 攻击的 Rab27a-null 小鼠表现出 I 型干扰素 (IFN) 和 IFN-γ 的产生减少，并且在 Rab27a-null 浆细胞样树突细胞中证实了 IFN-α 分泌缺陷。我们的研究结果对免疫缺陷、炎症和 CpG 辅助疫苗接种具有重要意义。版权所有 © 2024 作者。由爱思唯尔公司出版。保留所有权利。

Endosomal Toll-like receptors (eTLRs) are essential for the sensing of non-self through RNA and DNA detection. Here, using spatiotemporal analysis of vesicular dynamics, super-resolution microscopy studies, and functional assays, we show that endomembrane defects associated with the deficiency of the small GTPase Rab27a cause delayed eTLR ligand recognition, defective early signaling, and impaired cytokine secretion. Rab27a-deficient neutrophils show retention of eTLRs in amphisomes and impaired ligand internalization. Extracellular signal-regulated kinase (ERK) signaling and β2-integrin upregulation, early responses to TLR7 and TLR9 ligands, are defective in Rab27a deficiency. CpG-stimulated Rab27a-deficient neutrophils present increased tumor necrosis factor alpha (TNF-α) secretion and decreased secretion of a selected group of mediators, including interleukin (IL)-10. In vivo, CpG-challenged Rab27a-null mice show decreased production of type I interferons (IFNs) and IFN-γ, and the IFN-α secretion defect is confirmed in Rab27a-null plasmacytoid dendritic cells. Our findings have significant implications for immunodeficiency, inflammation, and CpG adjuvant vaccination.Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.