Gonzales-Huerta L E, Williams T J, Aljohani R, Robertson B, Evans C A, Armstrong-James Dph
Department of Infectious Diseases, Imperial College London, SW7 2BX, UK.
Carrera de Medicina Humana, Facultad de Ciencias de la Salud, Universidad San Ignacio de Loyola, Lima 15024 Peru.
bioRxiv. 2024 Nov 20:2024.11.18.623945. doi: 10.1101/2024.11.18.623945.
Over 1 million people have chronic pulmonary aspergillosis (CPA) secondary to pulmonary tuberculosis. Additionally, () has been reported as one of the most common pathogens associated with mycobacteria in patients with cystic fibrosis. Mycobacterial virulence factors, like lipoarabinomannan, have been shown to interfere with host's intracellular pathways required for an effective immune response, however, the immunological basis for mycobacterial-fungal coinfection is still unknown. We therefore investigated the effect of lipoarabinomannan on macrophage responses against .
Bone marrow-derived macrophages (BMDMs) were stimulated with non-mannose-capped lipoarabinomannan (LAM) from or mannose-capped lipoarabinomannan (ManLAM) from for 2 hours and then infected with swollen conidia. Cell death was assessed by lactate dehydrogenase release. Cytokine release was measured in supernatant using Enzyme Linked Immuno-Sorbent Assay (ELISA). Colony forming units counting and time-lapse fluorescence microscopy was performed for studying conidia killing by macrophages.
BMDMs stimulated with LAM showed increased cell death and inflammatory cytokine release in a dose-dependent manner, characterised by a significant increase of IL-1β release. Time-lapse fluorescence microscopy and CFUs revealed that both LAM and ManLAM significantly decrease the capacity of macrophages to kill conidia within the first 6 hours of infection.
The mycobacterial virulence factor, lipoarabinomannan, disrupts macrophage capacity to efficiently clear at early stages of infection .
超过100万人患有继发于肺结核的慢性肺曲霉病（CPA）。此外，（）已被报道为囊性纤维化患者中与分枝杆菌相关的最常见病原体之一。分枝杆菌毒力因子，如脂阿拉伯甘露聚糖，已被证明会干扰宿主有效免疫反应所需的细胞内途径，然而，分枝杆菌 - 真菌合并感染的免疫基础仍然未知。因此，我们研究了脂阿拉伯甘露聚糖对巨噬细胞抗（）反应的影响。
用来自（）的非甘露糖封端的脂阿拉伯甘露聚糖（LAM）或来自（）甘露糖封端的脂阿拉伯甘露聚糖（ManLAM）刺激骨髓来源的巨噬细胞（BMDM）2小时，然后用肿胀的（）分生孢子感染。通过乳酸脱氢酶释放评估细胞死亡。使用酶联免疫吸附测定（ELISA）在上清液中测量细胞因子释放。进行菌落形成单位计数和延时荧光显微镜检查以研究巨噬细胞对分生孢子的杀伤作用。
用LAM刺激的BMDM以剂量依赖性方式显示细胞死亡增加和炎性细胞因子释放增加，其特征在于IL-1β释放显著增加。延时荧光显微镜检查和CFU显示，LAM和ManLAM在感染的前6小时内均显著降低巨噬细胞杀死（）分生孢子的能力。
分枝杆菌毒力因子脂阿拉伯甘露聚糖在感染早期破坏巨噬细胞有效清除（）的能力。
