Blanchard D K, Michelini-Norris M B, Pearson C A, Freitag C S, Djeu J Y
Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa 33612.
Blood. 1991 May 15;77(10):2218-24.
Mycobacterium avium-intracellulare (MAI) is an opportunistic pathogen commonly found in acquired immunodeficiency syndrome patients, whose immune systems are severely compromised. However, normal responses to this bacterium are apparently sufficient to prevent disseminated infection because disease is rarely found unless an immunocompromised state is present. Because interleukin-6 (IL-6) is an inflammatory cytokine with a multitude of activities, we investigated the potential of MAI to induce IL-6 from normal human leukocytes. Peripheral blood mononuclear cells were fractionated into monocytes (Mo), large granular lymphocytes (LGL), and T cells and stimulated with bacteria. Culture supernatants were collected and assayed for IL-6 activity by bioassay. Mo and LGL, but not T cells, were found to release IL-6 within 12 hours of stimulation, with optimal production occurring by 2 days of culture. Production of IL-6 from human leukocyte subsets was confirmed by Northern blot analysis and by neutralization of biologic function of the culture supernatants with specific antisera. Taken together, these results indicate that production of IL-6 is a key response of Mo and LGL to MAI. The role of IL-6 in MAI infection, therefore, needs to be further investigated.
鸟分枝杆菌-胞内分枝杆菌（MAI）是一种机会致病菌，常见于获得性免疫缺陷综合征患者中，这些患者的免疫系统严重受损。然而，对这种细菌的正常反应显然足以预防播散性感染，因为除非存在免疫受损状态，否则很少发现疾病。由于白细胞介素-6（IL-6）是一种具有多种活性的炎性细胞因子，我们研究了MAI诱导正常人白细胞产生IL-6的潜力。将外周血单核细胞分离为单核细胞（Mo）、大颗粒淋巴细胞（LGL）和T细胞，并用细菌进行刺激。收集培养上清液，并通过生物测定法检测IL-6活性。发现Mo和LGL在刺激后12小时内释放IL-6，培养2天时产量最佳。通过Northern印迹分析以及用特异性抗血清中和培养上清液的生物学功能，证实了人白细胞亚群产生IL-6。综上所述，这些结果表明IL-6的产生是Mo和LGL对MAI的关键反应。因此，IL-6在MAI感染中的作用需要进一步研究。
