50% of Caucasians carry a Thr300Ala variant (T300A) in the protein encoded by the macroautophagy/autophagy gene ATG16L1. Here, we show that the T300A variant confers protection against urinary tract infections (UTIs), the most common infectious disease in women. Using knockin mice carrying the human T300A variant, we show that the variant limits the UTI-causing bacteria, uropathogenic Escherichia coli (UPEC), from establishing persistent intracellular reservoirs, which can seed UTI recurrence. This phenotype is recapitulated in mice lacking Atg16l1 or Atg7 exclusively in the urothelium. We further show that mice with the T300A variant exhibit urothelial cellular abnormalities, including vesicular congestion and aberrant accumulation of UPK (uroplakin) proteins. Importantly, presence of the T300A variant in humans is associated with similar urothelial architectural abnormalities, indicating an evolutionarily conserved impact. Mechanistically, we show that the reduced bacterial persistence is independent of basal autophagic flux or proinflammatory cytokine responses and does not involve Atg14 or Epg5. However, the T300A variant is associated with increased expression of the small GTPase Rab33b; RAB33B interacts with ATG16L1, as well as other secretory RABs, RAB27B and RAB11A, important for UPEC exocytosis from the urothelium. Finally, inhibition of secretory RABs in bladder epithelial cells increases intracellular UPEC load. Together, our results reveal that UPEC selectively utilize genes important for autophagosome formation to persist in the urothelium, and that the presence of the T300A variant in ATG16L1 is associated with changes in urothelial vesicle trafficking, which disrupts the ability of UPEC to persist, thereby limiting the risk of recurrent UTIs. Abbreviations: 3-PEHPC: 3-pyridinyl ethylidene hydroxyl phosphonocarboxylate; ATG: autophagy; ATG16L1: autophagy related 16 like 1; BECs: bladder epithelial cells; dpi: days post infection; hpi: hours post infection; IF: immunofluorescence; IL1B: interleukin 1 beta; IL6: interleukin 6; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MVB: multivesicular bodies; T300A: Thr300Ala; TNF: tumor necrosis factor; QIR(s): quiescent intracellular reservoir(s); siRNA: short interfering RNA; UPEC: uropathogenic Escherichia coli; UTI(s): urinary tract infection(s); TEM: transmission electron microscopy; WT: wild type.

中文翻译：

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ATG16L1T300A变体在尿路上皮囊泡运输和尿路致病性大肠杆菌持续中的非典型自噬依赖性作用。

50％的白种人在大自噬/自噬基因ATG16L1编码的蛋白质中携带Thr300Ala变体（T300A）。在这里，我们显示T300A变体可针对妇女最常见的传染病-尿路感染（UTI）提供保护。使用携带人T300A变体的敲除小鼠，我们显示出该变体限制了引起UTI的细菌，尿路致病性大肠杆菌（UPEC），从建立持久的细胞内储库开始，该储库可以播种UTI复发。在仅在尿路上皮中缺少Atg16l1或Atg7的小鼠中概括了这种表型。我们进一步表明，具有T300A变体的小鼠表现出尿路上皮细胞异常，包括囊泡充血和UPK（尿激酶）蛋白异常积累。重要的，T300A变异体在人类中的存在与类似的尿道上皮结构异常有关，表明在进化上是保守的。从机理上讲，我们表明减少的细菌持久性与基础自噬通量或促炎性细胞因子反应无关，并且不涉及Atg14或Epg5。但是，T300A变体与小GTPase Rab33b的表达增加有关。RAB33B与ATG16L1以及其他分泌型RAB，RAB27B和RAB11A相互作用，这对于尿路上皮中UPEC的胞吐作用很重要。最后，抑制膀胱上皮细胞中分泌型RAB会增加细胞内UPEC负荷。总之，我们的结果表明UPEC选择性地利用了对自噬​​小体形成很重要的基因来持久存在于尿路上皮中，并且ATG16L1中T300A变体的存在与尿路上皮小泡运输的变化有关，这改变了UPEC持续存在的能力，从而限制了复发性UTI的风险。缩写：3-PEHPC：3-吡啶基亚乙基羟基膦酸酯基羧酸盐；ATG：自噬；ATG16L1：自噬相关16像1；BEC：膀胱上皮细胞；dpi：感染后天数；hpi：感染后数小时；如果：免疫荧光；IL1B：白介素1 beta；IL6：白介素6；MAP1LC3B / LC3B：微管相关蛋白1轻链3 beta；MVB：多囊体；T300A：Thr300Ala；TNF：肿瘤坏死因子；QIR：静止的细胞内储层；siRNA：短干扰RNA；UPEC：尿路致病性大肠杆菌；尿路感染：尿路感染；TEM：透射电子显微镜；WT：野生型。