Department of Chemotherapy and Mycoses, National Institute of Infectious Diseases, Tokyo, Japan.
Jpn J Infect Dis. 2012;65(6):522-6. doi: 10.7883/yoken.65.522.
Candida albicans is a major cause of invasive fungal infections. Mortality attributable to candidemia is very high, even when patients are treated with adequate antifungal agents. Therefore, it is important to investigate the mechanisms of immune response to C. albicans. Invariant natural killer T (iNKT) cells, innate lymphocytes that express an invariant T cell receptor α chain, participate in the response to various microbes, including two fungal pathogens, Aspergillus fumigatus and Cryptococcus neoformans. However, it is unknown whether iNKT cells play a role in the immune response to C. albicans. In this study, we have investigated the role of iNKT cells in the host defense against systemic C. albicans infection in mice. We compared the survival and fungal clearance between control mice and Jα18KO mice, which specifically lack iNKT cells, after intravenous C. albicans infection. There was no difference in the survival and fungal burden in the kidneys of the control and Jα18KO mice. Furthermore, production of inflammatory cytokines in several organs during C. albicans infection did not significantly differ between these two groups. These results suggest that iNKT cells play a minor role in controlling systemic C. albicans infections in mice.
白色念珠菌是侵袭性真菌感染的主要原因。即使患者接受了足够的抗真菌药物治疗，由念珠菌血症引起的死亡率仍然很高。因此，研究机体对白念珠菌免疫反应的机制非常重要。固有淋巴细胞中的不变自然杀伤 T(iNKT)细胞表达不变的 T 细胞受体α链，参与对包括两种真菌病原体烟曲霉和新生隐球菌在内的各种微生物的反应。然而，iNKT 细胞是否在对白念珠菌的免疫反应中发挥作用尚不清楚。在这项研究中，我们研究了 iNKT 细胞在宿主防御系统性白念珠菌感染中的作用。我们比较了静脉注射白念珠菌感染后，对照组小鼠和特异性缺乏 iNKT 细胞的 Jα18KO 小鼠的存活率和真菌清除率。对照组和 Jα18KO 小鼠的存活率和肾脏中的真菌负荷没有差异。此外，两组之间在几个器官中产生的炎症细胞因子的水平没有显著差异。这些结果表明，iNKT 细胞在控制小鼠系统性白念珠菌感染方面的作用较小。
