Kojima Naoya, Kojima Shohei, Hosokawa Shin, Oda Yoshiki, Zenke Daisuke, Toura Yuta, Onohara Emi, Yokota Shin-Ichi, Nagaoka Masato, Kuroda Yasuhiro
Department of Applied Biochemistry, Tokai University, Hiratsuka, Japan.
Technology Joint Management Office, Tokai University, Hiratsuka, Japan.
Front Microbiol. 2022 Aug 9;13:986396. doi: 10.3389/fmicb.2022.986396. eCollection 2022.
Selected lactic acid bacteria can stimulate macrophages and dendritic cells to secrete IL-12, which plays a key role in activating innate and cellular immunity. In this study, we investigated the roles of cell wall teichoic acids (WTAs) displayed on whole intact cell walls (ICWs) of in activation of mouse macrophages. ICWs were prepared from whole bacterial cells of several lactobacilli without physical disruption, and thus retaining the overall shapes of the bacteria. WTA-displaying ICWs of several strains, but not WTA-lacking ICWs of strains of other lactobacilli, elicited IL-12 secretion from mouse bone marrow-derived macrophages (BMMs) and mouse macrophage-like J774.1 cells. The ability of the ICWs of to induce IL-12 secretion was abolished by selective chemical elimination of WTAs from ICWs, but was preserved by selective removal of cell wall glycopolymers other than WTAs. BMMs prepared from TLR2- or TLR4-deficient mouse could secret IL-12 upon stimulation with ICWs of and a MyD88 dimerization inhibitor did not affect ICW-mediated IL-12 secretion. WTA-displaying ICWs, but not WTA-lacking ICWs, were ingested in the cells within 30 min. Treatment with inhibitors of actin polymerization abolished IL-12 secretion in response to ICW stimulation and diminished ingestion of ICWs. When overall shapes of ICWs of were physically disrupted, the disrupted ICWs (DCWs) failed to induce IL-12 secretion. However, DCWs and soluble WTAs inhibited ICW-mediated IL-12 secretion from macrophages. Taken together, these results show that WTA-displaying ICWs of can elicit IL-12 production from macrophages actin-dependent phagocytosis but TLR2 signaling axis independent pathway. WTAs displayed on ICWs are key molecules in the elicitation of IL-12 secretion, and the sizes and shapes of the ICWs have an impact on actin remodeling and subsequent IL-12 production.
选定的乳酸菌可刺激巨噬细胞和树突状细胞分泌白细胞介素-12（IL-12），其在激活先天性免疫和细胞免疫中起关键作用。在本研究中，我们调查了几种乳酸菌完整细胞壁（ICW）上展示的细胞壁磷壁酸（WTA）在激活小鼠巨噬细胞中的作用。ICW是从几种乳酸菌的完整细菌细胞制备而来，未经过物理破坏，从而保留了细菌的整体形状。几种乳酸菌菌株展示WTA的ICW，而非其他乳酸菌菌株缺乏WTA的ICW，可诱导小鼠骨髓来源的巨噬细胞（BMM）和小鼠巨噬细胞样J774.1细胞分泌IL-12。通过从ICW中选择性化学去除WTA，可消除乳酸菌ICW诱导IL-12分泌的能力，但通过选择性去除除WTA以外的细胞壁糖聚合物，该能力得以保留。从TLR2或TLR4缺陷小鼠制备的BMM在用乳酸菌ICW刺激后可分泌IL-12，并且MyD88二聚化抑制剂不影响ICW介导的IL-12分泌。展示WTA的ICW，而非缺乏WTA的ICW，在30分钟内被细胞摄取。用肌动蛋白聚合抑制剂处理可消除对ICW刺激的IL-12分泌反应，并减少ICW的摄取。当乳酸菌ICW的整体形状受到物理破坏时，破坏的ICW（DCW）无法诱导IL-12分泌。然而，DCW和可溶性WTA可抑制巨噬细胞ICW介导的IL-12分泌。综上所述，这些结果表明，乳酸菌展示WTA的ICW可通过肌动蛋白依赖性吞噬作用但不依赖TLR2信号轴途径诱导巨噬细胞产生IL-12。ICW上展示的WTA是诱导IL-12分泌的关键分子，ICW的大小和形状对肌动蛋白重塑及随后的IL-12产生有影响。
