Caspase-11非经典炎症小体对问号钩端螺旋体诱导J774A.1细胞炎性细胞因子分泌水平的影响

Effects of caspase-11 non-canonical inflammasome on Leptospira interrogans-induced secretion of inflammatory cytokines in J774A.1 cells

目的:了解caspase-11非经典炎症小体对问号钩端螺旋体(钩体)诱导J774A.1细胞分泌炎性细胞因子的影响。方法:采用钩体56601株感染小鼠单核-巨噬细胞株(J774A.1)建立细胞模型,应用real-time RT-PCR检测J774A.1细胞caspase-11、IL-1β、IL-1α和IL-18 mRNA水平,采用ELISA定量检测J774A.1细胞上清液中caspase-11、IL-1β、IL-1α和IL-18水平。结果:Real-time RT-PCR检测结果显示,钩体感染J774A.1细胞1、2、4、8、12和24 h后,caspase-11 mRNA水平分别为未感染细胞的5.12、14.21、8.94、14.06、18.58和0.93倍,caspase-11阻断后分别下降至0.10、0.07、0.10、0.09、0.07和0.45倍( P<0.05);钩体感染后,IL-1β、IL-1α和IL-18 mRNA水平均显著上调,caspase-11阻断后IL-1β mRNA水平分别下降至0.05、0.03、0.02、0.05、0.06和0.02倍( P<0.05);IL-1α mRNA分别下降至0.14、0.07、0.15、0.10、0.03和0.06倍( P<0.05);IL-18 mRNA分别下降至0.08、0.10、0.16、0.18、0.10和0.07倍( P<0.05)。ELISA检测结果显示,钩体感染J774A.1细胞后细胞上清液中caspase-11、IL-1β、IL-1α和IL-18水平均显著上调,caspase-11阻断后caspase-11分别下降至43.07、41.64、51.96、86.56、105.36和129.95 pg/ml( P<0.05);IL-1β分别下降至15.01、14.19、68.02、31.20、173.13和104.98 pg/ml( P<0.05);IL-1α分别下降至12.14、15.40、38.01、21.97、24.48和27.09 pg/ml( P<0.05);IL-18分别下降至96.27、102.21、85.34、116.28、155.36和114.03 pg/ml( P<0.05)。 结论:Caspase-11非经典炎症小体参与介导问号钩体诱导小鼠单核-巨噬细胞IL-1β、IL-1α和IL-18的分泌。

Objective To investigate the effects of caspase-11 non-canonical inflammasome on the Leptospira interrogans(L.interrogans)-induced secretion of inflammatory cytokines in J774A.1 cells.Methods Murine mononuclear macrophage cells(J774A.1)were infected with L.interrogans strain 56601.Expression of caspase-11,IL-1β,IL-1αand IL-18 at mRNA level in J774A.1 cells were detected by real-time RT-PCR.The levels of caspase-11,IL-1β,IL-1αand IL-18 in the culture supernatants of J774A.1 cells were detected by ELISA.Results Real-time RT-PCR showed that caspase-11 expression at mRNA level was 5.12,14.21,8.94,14.06,18.58 and 0.93 times of that in uninfected cells after 1,2,4,8,12 and 24 h of L.interrogans infection,and respectively decreased to 0.10,0.07,0.10,0.09,0.07 and 0.45 times after caspase-11 inhibitor intervention(P<0.05).Expression of IL-1β,IL-1αand IL-18 at mRNA level was significantly increased after infection(P<0.05).After the intervention with caspase-11 inhibitor,IL-1βmRNA decreased to 0.05,0.03,0.02,0.05,0.06 and 0.02 times(P<0.05);IL-1αmRNA decreased to 0.14,0.07,0.15,0.10,0.03 and 0.06 times(P<0.05);IL-18 mRNA decreased to 0.08,0.10,0.16,0.18,0.10 and 0.07 times(P<0.05).ELISA results showed that the expression of caspase-11,IL-1β,IL-1αand IL-18 at protein level was significantly increased.After the intervention with caspase-11 inhibitor,caspase-11 level decreased to 43.07,41.64,51.96,86.56,105.36,and 129.95 pg/ml(P<0.05);IL-1βlevel decreased to 15.01,14.19,68.02,31.20,173.13 and 104.98 pg/ml(P<0.05);IL-1αlevel decreased to 12.14,15.40,38.01,21.97,24.48 and 27.09 pg/ml(P<0.05);IL-18 level decreased to 96.27,102.21,85.34,116.28,155.36 and 114.03 pg/ml(P<0.05).Conclusions Caspase-11 non-canonical inflammasome was involved in the mediation of IL-1β,IL-1αand IL-18 secretion in mouse mononuclear macrophages after L.interrogans infection.