Pan Tingting, Tan Ruoming, Li Meiling, Liu Zhaojun, Wang Xiaoli, Tian Lijun, Liu Jialin, Qu Hongping
Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiaotong University School of Medicine Shanghai, China.
Front Cell Infect Microbiol. 2016 Dec 6;6:170. doi: 10.3389/fcimb.2016.00170. eCollection 2016.
The host acquired immune response, especially the humoral immunity, plays key roles in preventing bacterial pneumonia in the lung. Our previous research demonstrated that interleukin 17-producing γδ T cells (IL17-γδ T cells) have a protective effect on the early innate immune response during acute pulmonary infection. However, whether IL17-γδ T cells also play a role in humoral immunity is unknown. In this study, an acute pulmonary infection model was established in wild-type and γδ TCR C57BL/6 mice. The expression of IL-17 on γδ T cells isolated from infected lung tissues increased rapidly and peaked at day 7 after acute infection with . Compared with wild-type infected mice, the levels of total immunoglobulins including IgA, IgG, and IgM in the serum and BALF were significantly decreased in γδ TCR mice, with the exception of IgM in the BALF. Moreover, CD69 expression in B cells from the lungs and spleen and the level of BAFF in the plasma were also decreased in γδ TCR mice. IL17-γδ T cell transfusion significantly improved the production of immunoglobulins, B cell activation and BAFF levels in γδ TCR mice compared with γδ TCR mice without transfusion; this effect was blocked when cells were pretreated with an IL-17 antibody. Together, these data demonstrate that IL17-γδ T cells are involved in CD19 B cell activation and the production of immunoglobulins during acute pulmonary infection. Thus, we conclude that IL17-γδ T cells may facilitate the elimination of bacteria and improve survival through not only innate immunity but also humoral immunity.
宿主获得性免疫反应，尤其是体液免疫，在预防肺部细菌性肺炎中起关键作用。我们之前的研究表明，产生白细胞介素17的γδT细胞（IL17-γδT细胞）在急性肺部感染期间对早期固有免疫反应具有保护作用。然而，IL17-γδT细胞是否也在体液免疫中发挥作用尚不清楚。在本研究中，在野生型和γδTCR C57BL/6小鼠中建立了急性肺部感染模型。从感染肺组织中分离的γδT细胞上IL-17的表达迅速增加，并在急性感染后第7天达到峰值。与野生型感染小鼠相比，γδTCR小鼠血清和支气管肺泡灌洗液（BALF）中包括IgA、IgG和IgM在内的总免疫球蛋白水平显著降低，但BALF中的IgM除外。此外，γδTCR小鼠肺和脾中B细胞的CD69表达以及血浆中B细胞活化因子（BAFF）水平也降低。与未输血的γδTCR小鼠相比，IL17-γδT细胞输血显著改善了γδTCR小鼠免疫球蛋白的产生、B细胞活化和BAFF水平；当细胞用IL-17抗体预处理时，这种作用被阻断。总之，这些数据表明IL17-γδT细胞在急性肺部感染期间参与CD19 B细胞活化和免疫球蛋白的产生。因此，我们得出结论，IL17-γδT细胞不仅可以通过固有免疫，还可以通过体液免疫促进细菌清除并提高生存率。
