G-test positive serum inhibits ROS-dependent killing of Candida albicans by interfering with internal- ized expression of neutrophil Dectin-1
10.3760/cma.j.issn.0254-5101.2013.11.011
- VernacularTitle:G 试验阳性血清通过干扰 Dectin-1的内在化表达抑制 ROS 依赖性杀伤白念珠菌
- Author:
Bilin DONG
;
Ming WANG
;
Weihuang LIU
;
Dongsheng LI
;
Zhongsheng TONG
;
Yiqun DUAN
;
Wei LIU
- Publication Type:Journal Article
- Keywords:
G-test;
Dectin-1;
Reactive oxygen species ( ROS);
Candida albicans;
Human neu-trophils
- From:
Chinese Journal of Microbiology and Immunology
2013;(11):856-864
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanism of soluble β-1, 3-D-glucan in G-test positive serum in inhibiting ROS-dependent killing of Candida albicans ( C.albicans ) mediated by neutrophil Dectin-1.Methods The expression and distribution of internalized Dectin-1 and triggered ROS in human neutrophils were detected by using confocal/two-photon laser scanning microscopy upon stimulation with C.albicans (MOI=10) which was pretreated with β-1, 3-D-glucanase (10 U/ml) or not.Abrogation test was used to analyze whether intracellular Dectin-1 was involved in C.albicans-triggered ROS production in human neutrophils.Furthermore, flow cytometry analysis was performed to detect the expression of intracel-lular Dectin-1 and ROS in neutrophils which were pretreated respectively with G-test positive serum at differ-ent dilutions for 60 min and then stimulated with C.albicans for another 60 min at 37℃.Results After stimulated with C.albicans (MOI=10) for 60 min, the expression of Dectin-1 in neutrophils was recruited to the spores of opsonophagocytized C.albicans, and partly co-localized with the triggered ROS production . However, the expression of intracellular Dectin-1 was not observed in neutrophils when stimulated with β-1, 3-D-glucanase pretreated C.albicans for 60 min at 37℃.Abrogation test further showed that C.albicans-trig-gered ROS production in neutrophils was partly and irreversibly inhibited by adding Dectin -1 blocking mAb of 5 μg/ml.In addition , both the triggered expression of intracellular Dectin-1 and ROS production in neu-trophils stimulated with C.albicans ( MOI=10 ) in the presence of G-test positive serum were significantly lower than those of neutrophils stimulated only with C.albicans (LSD-t test, P<0.01).Linear regression a-nalysis suggested that the triggered intracellular Dectin-1 and ROS production in neutrophils upon stimulation with C.albicans were both inhibited by soluble β-1, 3-D-glucan in a dose-dependent manner (Dectin-1,R2=0.702,P<0.01;ROS,R2=0.588,P<0.01 ).Conclusion Taken together, these results demonstrated that the soluble β-1, 3-D-glucan in G-test positive serum may play a role in inhibiting the ROS-dependent killing of C.albicans by interfering with internalized expression of neutrophil Dectin-1.
