Th细胞极化群体在慢性乙型肝炎病毒感染中的作用

目的　了解慢性乙型肝炎病毒（HBV）感染者外周血中辅助性T细胞（Th）内干扰素-γ（IFN-γ）、白细胞介素-4（IL-4）和转化生长因子-β（TGF-β）的表达情况,以测定Th1/Th2 /Th3细胞的百分数,探明Th细胞各极化群体在慢性HBV感染中的作用.方法　常规分离外周血单个核细胞（PBMC）,在佛波脂（PMA）、钙离子导入剂伊屋诺霉素Ionomycin、细胞内转运阻断剂莫能星Monensin的刺激下,采用流式细胞分析术（FACS）对慢性HBV感染者外周血单个Th细胞内IL-4、IFN-γ和TGF-β的表达进行分析.结果　正常对照组,2.3%-18.6%的CD4+T细胞为Th1细胞,0.9%-9.2%为Th2细胞；0.7%-7.1%的细胞仅表达TGF-β, 为Th3细胞.在慢性HBV感染者外周血单个CD4+T细胞中,以Th0细胞居多；而Th1细胞则随着慢性乙型肝炎肝脏炎症活动的加剧而明显增多,在炎症活动明显的慢性乙型肝炎,其Th1百分数明显高于炎症活动呈静止状态的慢性乙型肝炎；Th2细胞在慢性HBV感染的不同阶段则较为恒定(P>0.05),但明显高于对照组(P<0.05).Th3细胞的百分数则随着肝组织炎症活动的加剧,其比例也明显减少(P<0.05),在无症状携带者（AsC）组,Th3细胞的百分数远高于慢性乙型肝炎组及对照组(P<0.05) .Th3细胞重叠于Th2细胞之中.结论　Th1细胞类因子与炎症活动呈正相关,Th2细胞可能与HBV感染的慢性化相关联.而Th3细胞与Th2细胞协同发挥负性免疫调节作用,并可能与慢性HBV感染的免疫耐受状态相关联.

T helper cells in patients with chronic hepatitis B virus infection

Objective To investigate the compositions of Th1/Th2/Th3 cells in chronic hepatitis B virus (HBV)-infected individuals by determining the expression of interleukin-4 (IL-4), inetrferon-γ (IFN-γ), and transform growth factor-β (TGF-β) in single CD4+ T cells isolated from peripheral blood mononuclear cells (PBMCs) and the role of polarized Th cell populations in chronic HBV-infection was discussed. Methods PBMCs from chronically infected HBV individuals were isolated, stimulated by PMA/Ionomycin/Monensin, and IL-4, IFN-γ and TGF-β production by CD4+ T cells was determined by using fluorescence activated cell sorter (FACS) analysis. Results The percentage of IFN-γ-producing T cells, IL-4-producing T cells and TGF-β-producing T cells ranged from 2.3%-18.6%, 1.1%-8.7% and 0.7%-7.1% respectively in CD4+ T cells from non-infected individuals. Most of CD4+ T cells from PBMCs in chronically infected HBV individuals were Th0 cells. The proportion of Th1 cells increased significantly with hepatic inflammatory activity, and in the active period of chronic hepatitis B infection were higher than those in the non-active period (P<0.05). Th2 cell percentage in CD4+ T cells from HBV-infected individuals did not differ significantly (P>0.05), but were higher than that from controls (P<0.05). Th3 cell percentage in CD4+ T cells from asymptomatic carrier (AsC) group was higher than that in the chronic hepatitis B (CHB) and control groups (P<0.05). Conclusions Th1 phenotype cytokines were positively correlated with hepatic inflammatory activity in chronic hepatitis B and Th2 cells may be associated with the persistence of HBV infection. Th3 cells cooperating with Th2 cells can negatively regulate immune responses and may be associated with the immune tolerant state of chronic HBV infection.