Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA; Department of Immunology, Duke University Medical Center, Durham, NC, USA.
Cell Host Microbe. 2022 Dec 14;30(12):1671-1684.e9. doi: 10.1016/j.chom.2022.08.008. Epub 2022 Sep 8.
Chlamydia trachomatis is the leading cause of sexually transmitted bacterial infections and a major threat to women's reproductive health in particular. This obligate intracellular pathogen resides and replicates within a cellular compartment termed an inclusion, where it is sheltered by unknown mechanisms from gamma-interferon (IFNγ)-induced cell-autonomous host immunity. Through a genetic screen, we uncovered the Chlamydia inclusion membrane protein gamma resistance determinant (GarD) as a bacterial factor protecting inclusions from cell-autonomous immunity. In IFNγ-primed human cells, inclusions formed by garD loss-of-function mutants become decorated with linear ubiquitin and are eliminated. Leveraging cellular genome-wide association data, we identified the ubiquitin E3 ligase RNF213 as a candidate anti-Chlamydia protein. We demonstrate that IFNγ-inducible RNF213 facilitates the ubiquitylation and destruction of GarD-deficient inclusions. Furthermore, we show that GarD operates as a cis-acting stealth factor barring RNF213 from targeting inclusions, thus functionally defining GarD as an RNF213 antagonist essential for chlamydial growth during IFNγ-stimulated immunity.
沙眼衣原体是性传播细菌感染的主要原因，特别是对女性生殖健康构成重大威胁。这种专性细胞内病原体存在于并在称为包含体的细胞隔室中复制，在该隔室中，它通过未知机制免受γ干扰素（IFNγ）诱导的细胞自主宿主免疫的影响。通过遗传筛选，我们发现沙眼衣原体包涵体膜蛋白γ抗性决定簇（GarD）是一种保护包涵体免受细胞自主免疫的细菌因子。在 IFNγ 引发的人细胞中，garD 功能丧失突变体形成的包涵体被线性泛素化修饰，并被消除。利用细胞全基因组关联数据，我们鉴定出泛素 E3 连接酶 RNF213 是候选的抗衣原体蛋白。我们证明 IFNγ 诱导的 RNF213 促进 GarD 缺陷包涵体的泛素化和降解。此外，我们表明 GarD 作为一种顺式作用的隐身因子发挥作用，阻止 RNF213 靶向包涵体，从而将 GarD 功能定义为 IFNγ 刺激免疫期间衣原体生长所必需的 RNF213 拮抗剂。
