NLRP3、AIM2、IFI16炎症小体在慢性乙型病毒性肝炎患者PBMC中的活化水平和与HBV感染的相关性分析

Study of association of NLRP3,AIM2,IFI16 inflammasomes in PBMC with chronic hepatitis B infection

目的:探讨乙肝病毒(HBV)是否激活了慢性乙型病毒性肝炎(CHB)患者外周血单个核细胞(PBMCs)内核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、黑色素瘤缺乏因子2(AIM2)和干扰素诱导蛋白16(IFI16)炎症小体,分析HBV影响炎症小体活化的可能机制.方法:收集感染内科临床确诊CHB患者35例.同时选取健康住院医师28例为对照.以常规淋巴细胞分层液密度梯度离心法分离健康对照组和CHB患者组静脉血得到PBMCs,采用逆转录、实时荧光定量PCR检测CHB患者组和健康对照组PBMCs NLRP3、AIM2、IFI16、凋亡相关的斑点样蛋白(ASC)、半胱天冬酶1(CASP1)、IL-1β、IL-18 mRNA表达水平,ELISA法检测两组血清中IL-1β蛋白分泌水平.结果:CHB患者组和健康对照组PBMCs ASC、NLRP3、AIM2、IL-1β、IL-18 mRNA表达水平及两组血清IL-1β蛋白分泌水平无显著性差异.CHB患者组PBMCs IFI16、CASP1 mRNA表达水平显著上调,且IFI16 mRNA表达水平与患者血清HBV DNA载量显著正相关(r=0.699 8,P<0.01).结论:慢性HBV感染未导致CHB患者PBMCs NLRP3、AIM2炎症小体的活化;尽管HBV DNA可能诱导了CHB患者IFI16炎症小体的高表达,但通过抑制pro-caspase-1的活化、IL-1β的表达,HBV阻断了IFI16炎症小体的活化效应.

Aim： To investigate whether HBV can activate the NLRP3, AIM2, and IFI16 inflammasomes in peripheral blood mononuclear cells（PBMCs） of chronic hepatitis B（CHB） patients,and study the underlying mechanisms by which HBV affects the activation of inflammasomes. Methods：Thirty-five patients with CHB were enrolled in the study. Twenty-eight healthy volunteer residents were used as controls. PBMCs from patients and controls were isolated from the blood by Ficoll density gradient. Reverse transcription and real time PCR were used to determine the expressions of NLRP3,AIM2,IFI16,ASC,CASP1,IL-1β and IL-18 mRNAs in PBMCs. The levels of serum IL-1β in both groups were determined by ELISA kits. Results： No significant differences were observed in the expression levels of ASC,NLRP3,AIM2,IL-1β and IL-18 mRNA in PBMCs and serum IL-1β protein between CHB patients and healthy controls. However,the expression levels of IFI16 and CASP1 mRNA in CHB patients were significantly upregulated compared to the controls. Moreover,the levels of IFI16 mRNA in PBMCs were significantly and positively correlated with the virus load in serum（r = 0. 699 8,P〈0. 01）. Conclusion： Chronic HBV infection does not cause activation of NLRP3 and AIM2 inflammasomes in CHB patients. Although IFI16 inflammasome is upregulated by HBV DNA, the activation of pro-CASP1 and expression of IL-1β may be inhibited by HBV,resulting in suppression of the activation of IFI16 inflammasome.