Department of Internal Medicine I, LMU University Hospital, Munich, Germany.
Institute of Surgical Research at the Walter-Brendel-Centre of Experimental Medicine, LMU University Hospital, Munich, Germany.
PLoS Pathog. 2024 Sep 30;20(9):e1012580. doi: 10.1371/journal.ppat.1012580. eCollection 2024 Sep.
Helicobacter pylori (H. pylori) is a bacterial pathogen that exclusively colonizes the human gastric mucosa and can cause persistent infection. In this process, H. pylori employs various strategies to avoid recognition by the human immune system. These range from passive defense strategies (e.g., altered LPS or flagellin structures) that prevent recognition by pattern recognition receptors (PRRs) to more active approaches, such as inhibition of IL-2 secretion and proliferation of T cells via VacA. Despite the growing evidence that H. pylori actively manipulates the human immune system for its own benefit, the direct interaction of H. pylori with immune cells in situ is poorly studied. Here, we present a novel intravital imaging model of the murine stomach gastric mucosa and show for the first time the in situ recruitment of neutrophils during infection and a direct H. pylori-macrophage interaction. For this purpose, we applied multiphoton intravital microscopy adapted with live drift correction software (VivoFollow) on LysM-eGFP and CX3CR1-eGFP reporter mice strains in which specific subsets of leukocytes are fluorescently labeled. Multiphoton microscopy is proving to be an excellent tool for characterizing interactions between immune cells and pathogens in vivo.
幽门螺杆菌(H. pylori)是一种专性定植于人类胃黏膜的细菌病原体,可引起持续性感染。在这个过程中,H. pylori 采用了各种策略来避免被人体免疫系统识别。这些策略包括从阻止模式识别受体(PRRs)识别的被动防御策略(例如,改变 LPS 或鞭毛蛋白结构),到更主动的方法,例如通过 VacA 抑制 IL-2 的分泌和 T 细胞的增殖。尽管越来越多的证据表明 H. pylori 为了自身利益积极操纵人体免疫系统,但 H. pylori 与原位免疫细胞的直接相互作用研究甚少。在这里,我们提出了一种新型的活体成像模型,用于研究小鼠胃黏膜,并首次显示了感染过程中中性粒细胞的原位募集,以及 H. pylori 与巨噬细胞的直接相互作用。为此,我们在 LysM-eGFP 和 CX3CR1-eGFP 报告小鼠品系中应用了多光子活体显微镜,并采用了活漂移校正软件(VivoFollow),其中特定的白细胞亚群被荧光标记。多光子显微镜被证明是一种极好的工具,可用于研究体内免疫细胞与病原体之间的相互作用。