Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico.
Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico.
Cells. 2023 Aug 17;12(16):2079. doi: 10.3390/cells12162079.
is a facultative intracellular bacterium that produces cellular necrosis in granulomatous lesions in bovines. Although -induced inflammation actively participates in granuloma development, its role in necrotic cell death and in bovine macrophages has not been fully explored. In this study, we evaluate the effect of AN5 and its culture filtrate protein extract (CFPE) on inflammasome activation in bovine macrophages and its consequences on cell death. Our results show that both stimuli induce necrotic cell death starting 4 h after incubation. CFPE treatment and infection also induce the maturation of IL-1β (>3000 pg/mL), oligomerization of ASC (apoptosis-associated speck-like protein containing CARD), and activation of caspase-1, following the canonical activation pathway of the NLRP3 inflammasome. Inhibiting the oligomerization of NLRP3 and caspase-1 decreases necrosis among the infected or CFPE-stimulated macrophages. Furthermore, histological lymph node sections of bovines naturally infected with contained cleaved gasdermin D, mainly in macrophages and giant cells within the granulomas. Finally, the induction of cell death (apoptosis and pyroptosis) decreased the intracellular bacteria count in the infected bovine macrophages, suggesting that cell death helps to control the intracellular growth of the mycobacteria. Our results indicate that induces pyroptosis-like cell death that is partially related to the NLRP3 inflammasome activation and that the cell death process could control bacterial growth.
是一种兼性细胞内细菌，可在牛的肉芽肿病变中引起细胞坏死。虽然 诱导的炎症积极参与肉芽肿的发展，但它在坏死细胞死亡和牛巨噬细胞中的作用尚未得到充分探索。在这项研究中，我们评估了 AN5 及其培养滤液蛋白提取物 (CFPE) 对牛巨噬细胞中炎症小体激活及其对细胞死亡影响的作用。我们的结果表明，这两种刺激物在孵育 4 小时后开始引起坏死细胞死亡。CFPE 处理和 感染也诱导 IL-1β 的成熟（>3000 pg/mL）、ASC（含 CARD 的凋亡相关斑点样蛋白）的寡聚化和 caspase-1 的激活，遵循 NLRP3 炎症小体的经典激活途径。抑制 NLRP3 和 caspase-1 的寡聚化可减少感染或 CFPE 刺激的巨噬细胞中的坏死。此外，天然感染 的牛淋巴结组织切片中含有裂解的 GSDMD，主要存在于肉芽肿中的巨噬细胞和巨细胞中。最后，细胞死亡（凋亡和焦亡）的诱导降低了感染牛巨噬细胞中的胞内细菌数量，表明细胞死亡有助于控制分枝杆菌的细胞内生长。我们的结果表明， 诱导类似于细胞焦亡的细胞死亡，这部分与 NLRP3 炎症小体的激活有关，细胞死亡过程可能控制细菌的生长。
