Jullien D, Sieling P A, Uyemura K, Mar N D, Rea T H, Modlin R L
Division of Dermatology, University of California School of Medicine, Los Angeles 90095, USA.
J Immunol. 1997 Jan 15;158(2):800-6.
IL-15 is a novel cytokine with potent T cell growth factor activity. Here, we investigated the role of IL-15 in the human immune response to intracellular infection by studying patients leprosy. We found that IL-15 mRNA and protein were more strongly expressed in immunologically resistant tuberculoid patients than in with unresponsive and susceptible lepromatous patients. In vitro, Mycobacterium leprae induced IL-15 secretion from peripheral blood monocytes. Furthermore, rIL-15 by itself and in combination with rIL-2 or rIL-7 augmented PBMC proliferative responses to the pathogen. Although rIL-15 expanded the CD3-CD56+ (NK) subset, rIL-15 combined with M. leprae induced the expansion of CD3+CD56+ T cells. Immunohistologic analysis of leprosy skin lesions indicated that the frequency of CD56+ cells was greatest in the group of patients with high IL-15 expression, and that >90% of the CD56+ cells in lesions were CD3+ T cells. Therefore, IL-15 augments the local T cell response to human intracellular pathogen.
白细胞介素-15是一种具有强大T细胞生长因子活性的新型细胞因子。在此，我们通过研究麻风病患者来调查白细胞介素-15在人体对细胞内感染的免疫反应中的作用。我们发现，与无反应性和易感性瘤型患者相比，免疫抵抗性结核样型患者中白细胞介素-15的信使核糖核酸和蛋白质表达更强。在体外，麻风杆菌可诱导外周血单核细胞分泌白细胞介素-15。此外，重组白细胞介素-15单独以及与重组白细胞介素-2或重组白细胞介素-7联合使用时，可增强外周血单个核细胞对该病原体的增殖反应。虽然重组白细胞介素-15可使CD3-CD56+（自然杀伤细胞）亚群扩增，但重组白细胞介素-15与麻风杆菌联合使用可诱导CD3+CD56+ T细胞扩增。麻风病皮肤病变的免疫组织学分析表明，白细胞介素-15高表达患者组中CD56+细胞的频率最高，且病变中>90%的CD56+细胞为CD3+ T细胞。因此，白细胞介素-15可增强局部T细胞对人体细胞内病原体的反应。
