Effects of Leptospira interrogans infection on the activation of NLRP3 in THP-1 and J774A. 1 cells
10.3760/cma.j.issn.0254-5101.2016.12.003
- VernacularTitle:问号钩端螺旋体对THP-1和J774A.1细胞NLRP3炎症小体活化的影响
- Author:
Ming WANG
;
Hong CHEN
;
Ying LIU
;
Qing MA
;
Xiaoyu WEI
;
Lyu YOU
;
Guangpeng TANG
;
Dingming WANG
;
Shijun LI
;
Bijun ZHOU
- Keywords:
Leptospira interrogans;
NLRP3 inflammasome;
Macrophage;
Inflammatory cytokine
- From:
Chinese Journal of Microbiology and Immunology
2016;36(12):894-899
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the effects of Leptospira interrogans ( L. interrogans) infection on the activation of NLRP3 in THP-1 and J774A. 1 cells and to further understand the mechanism of inflam-mation caused by L. interrogans in different hosts. Methods Human mononuclear macrophage cell line (THP-1) and murine mononuclear macrophage cell line (J774A. 1) were infected with L. interrogans strain 56601. The expression of NLRP3 at mRNA and protein levels were measured by using real-time RT-PCR and flow cytometry analysis, respectively. The NLRP3-mediated secretion of IL-1β, IL-18 and IL-33 was detec-ted by ELISA combined with the NLRP3 inhibitory test. Results Compared with the normal cells, the ex-pression of NLRP3 at mRNA level in L. interrogans-infected THP-1 cells was respectively increased by 4. 05, 0. 34, 0. 33, 0. 06 and 1. 66 times at the time points of 1 h, 2 h, 4 h, 12 h and 24 h after infection ( P<0. 05), while that in L. interrogans-infected J774A. 1 cells was respectively increased by 12. 98, 16. 19, 10. 68, 5. 8 and 0. 57 times (P<0. 05). The expression rates of NLRP3 protein in THP-1 and J774A. 1 cells respectively increased from 9. 26% to 94. 01%, 89. 24%, 31. 80%, 19. 74%, 11. 28% and from 18. 71%to 58. 78%, 43. 64%, 36. 42%, 76. 46%, 85. 21% at the time points of 1 h, 2 h, 4 h, 12 h and 24 h af-ter L. interrogans infection (P<0. 05). The level of IL-1β in L. interrogans-infected THP-1 cells was 73. 07 pg/ml, 939. 24 pg/ml, 939. 24 pg/ml, 843. 22 pg/ml and 851. 06 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, respectively (P<0. 05), while the level of IL-1β in L. interrogans-infected J774A. 1 cells began to rise at the time point of 12 h from 191. 17 pg/ml to 254. 4 pg/mL at the time point of 24 h (P<0. 05). The level of IL-18 in L. interrogans-infected THP-1 cells was 913. 89 pg/ml, 808. 19 pg/ml, 483. 54 pg/ml, 204. 19 pg/ml and 189. 09 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, re-spectively (P<0. 05), while the level of IL-18 in L. interrogans-infected J774A. 1 cells increased at the time point of 24 h, which was 113. 37 pg/ml (P<0. 05). A slight increase in the level of IL-33 was detected in L. interrogans-infected J774A. 1 cells at the time points of 12 h and 24 h to 201. 14 pg/ml and 155. 68 pg/ml, respectively (P<0. 05), but no significant change was detected in L. interrogans-infected THP-1 cells (P>0. 05). Results of the inhibitory test showed that the up-regulation of IL-1β , IL-18 and IL-33 in THP-1 and J774A. 1 cells were effectively inhibited by the specific inhibitor of NLRP3. Conclusion NL-RP3 inflammasome was activated and involved in the production of specific inflammatory cytokines IL-1βand IL-18 in both THP-1 and J774A. 1 cells after L. interrogans infection, but the inflammatory cytokines induced by L. interrogans infection varied in different cells. L. interrogans induced earlier and higher level of IL-1βand IL-18 production in human macrophages than in murine macrophages.
