Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Infect Immun. 2011 Oct;79(10):3966-77. doi: 10.1128/IAI.05493-11. Epub 2011 Aug 1.
We have previously reported that compromised interleukin 17A (IL-17A) production in the lungs increased susceptibility to infection with the invasive fungal pathogen Aspergillus fumigatus. Here we have shown that culturing lung cells from A. fumigatus-challenged mice ex vivo demonstrated Dectin-1-dependent IL-17A production. In this system, neutralization of IL-23 but not IL-6, IL-1β, or IL-18 resulted in attenuated IL-17A production. Il23 mRNA expression was found to be lower in lung cells from A. fumigatus-challenged Dectin-1-deficient mice, whereas bone marrow-derived dendritic cells from Dectin-1-deficient mice failed to produce IL-23 in response to A. fumigatus in vitro. Addition of recombinant IL-23 augmented IL-17A production by wild-type (WT) and Dectin-1-deficient lung cells, although the addition of IL-6 or IL-1β did not augment the effect of IL-23. Intracellular cytokine staining of lung cells revealed lower levels of CD11b(+) IL-17A(+) and Ly-6G(+) IL-17A(+) cells in A. fumigatus-challenged Dectin-1-deficient mice. Ly-6G(+) neutrophils purified from the lungs of A. fumigatus-challenged Dectin-1-deficient mice displayed lower Il17a mRNA expression but surprisingly had intact Rorc and Rora mRNA expression. We further demonstrated that Ly-6G(+) neutrophils required the presence of myeloid cells for IL-17A production. Finally, upon in vitro stimulation with A. fumigatus, thioglycolate-elicited peritoneal neutrophils were positive for intracellular IL-17A expression and produced IL-17A in a Dectin-1- and IL-23-dependent manner. In summary, Dectin-1-dependent IL-17A production in the lungs during invasive fungal infection is mediated in part by CD11b(+) Ly-6G(+) neutrophils in an IL-23-dependent manner.
我们之前曾报道过，肺部白细胞介素 17A（IL-17A）产生受损会增加对侵袭性真菌病原体烟曲霉感染的易感性。在这里，我们已经表明，从烟曲霉挑战的小鼠的肺细胞进行离体培养证明了 Dectin-1 依赖性的 IL-17A 产生。在这个系统中，中和 IL-23 但不是 IL-6、IL-1β 或 IL-18 导致 IL-17A 产生减弱。我们发现，在烟曲霉挑战的 Dectin-1 缺陷型小鼠的肺细胞中，Il23 mRNA 的表达较低，而 Dectin-1 缺陷型骨髓来源的树突状细胞在体外对烟曲霉没有产生 IL-23。添加重组 IL-23 增强了野生型（WT）和 Dectin-1 缺陷型肺细胞的 IL-17A 产生，尽管添加 IL-6 或 IL-1β 并没有增强 IL-23 的作用。对肺细胞进行细胞内细胞因子染色显示，在烟曲霉挑战的 Dectin-1 缺陷型小鼠中，CD11b（+）IL-17A（+）和 Ly-6G（+）IL-17A（+）细胞的水平较低。从烟曲霉挑战的 Dectin-1 缺陷型小鼠的肺部纯化的 Ly-6G（+）中性粒细胞显示较低的 Il17a mRNA 表达，但令人惊讶的是，其 Rorc 和 Rora mRNA 表达完整。我们进一步证明，Ly-6G（+）中性粒细胞需要髓样细胞的存在才能产生 IL-17A。最后，在体外用烟曲霉刺激时，硫代乙醇酸盐诱导的腹腔中性粒细胞对细胞内 IL-17A 表达呈阳性，并以 Dectin-1 和 IL-23 依赖性的方式产生 IL-17A。总之，在侵袭性真菌感染期间，肺部的 Dectin-1 依赖性 IL-17A 产生部分是通过 IL-23 依赖性方式由 CD11b（+）Ly-6G（+）中性粒细胞介导的。
