【作者】 赵志海；

【导师】 程云；

【作者基本信息】 中国人民解放军军医进修学院 ， 内科学传染病， 2008， 博士

【摘要】 慢性丙型肝炎是严重危害人类健康的疾病之一。免疫应答在丙型肝炎的发病机制中起重要作用。辅助性T淋巴细胞Thl/2细胞失平衡在丙型肝炎发病中有重要作用。我们检测了64份慢性HCV感染者血清Thl/2相关细胞因子及其动态变化。结果肝炎和肝硬化组患者IL-2,IFN-Y无明显差别;肝硬化组患者IL-4,IL-10表达增强;TNF-α表达减弱。对6名患者动态血清检测发现IL-4,IL-10有逐渐增高趋势,IL-2,TNF-α,IFN-γ表达有下降趋势;急性发作时,IL-2,TNF-α,IFN-y增高;IL-4,IL-10维持在一定水平;1名患者接受peg-IFN-α2a治疗后,血清IL-2,TNF-α,IFN-γ增高,IL-4,IL-10下降。提示慢性HCV感染者外周血Th1/Th2细胞失平衡,以Th2细胞因子为主,干扰素治疗有利于恢复Th1/Th2失衡。通过调节Th相关细胞因子纠正Th1/Th2失平衡可能成为慢性HCV感染新的治疗思路。为了解慢性HCV感染者肝脏内免疫状态,对30例慢性HCV感染者的肝穿标本进行了研究,用原位杂交法检测HCV RNA表达,发现HCV RNA阳性表达在肝组织内呈散在分布,周围可伴随单个核细胞浸润。HCV RNA复制活跃可加重肝脏损伤。用免疫组化方法检测肝脏中IFN-γ、TNF-α、IL-10的表达。观察到IFN-γ、TNF-α、IL-10在肝内主要表达于淋巴细胞和窦内皮细胞等,另外炎症、坏死、脂肪变性周围的部分肝细胞也可见IFN-γ、TNF-α、IL-10表达。慢性HCV感染者肝组织中的IFN-γ、TNF-α、IL-10较正常肝组织增强。随炎症程度的增加IL-10、TNF-α表达逐渐增强,IFN-γ表达无明显增加。TNF-α与IL-10表达有较高相关性,TNF-α和IL-10与IFN-γ表达有相关性,但相关系数较低。TNF-α、IL-10与HCVRNA表达相关性较高,IFN-γ与HCVRNA相关性稍低。提示慢性HCV感染者肝内促炎因子TNF-ct和抗炎因子IL-10表达均增强,可能是HCV感染慢性化的原因之一。用免疫组化法检测了慢性HCV感染者肝脏内CD4+、CD8+、Foxp3+T细胞的分布特点,观察到CD4+、CD8+、Foxp3+T淋巴细胞主要分布于汇管区和部分胆管增生区,肝小叶内也可见散在分布。CD4+、CD8+、Foxp3+T阳性细胞分布部位与HCVRNA阳性部位较为一致。CD8+T淋巴细胞在肝小叶内炎性坏死灶及窦周炎部位增多明显。慢性HCV感染者肝脏Foxp3+表达增强,随炎症程度增加,Foxp3+表达逐渐增强,由于Foxp3+特异性地表达于Treg,推测Treg细胞可能在HCV感染慢性化中发挥重要作用。慢性HCV感染者患者肝内存在抑制HCV特异性CTL功能的机制:如调节性T淋巴细胞、IL-10等,可能是HCV慢性感染持续存在的重要原因之一。随着慢性HCV免疫学研究的进一步深入,将为临床治疗和预防HCV感染提供新的思路和方法。更多还原

【Abstract】 Hepatitis C is an important infectious disease of human beings and immune response may play an important role in HCV infection.Th0 lymphocytes resemble functionally both Th1 and Th2 lymphocytes.Th1 lymphocytes produce cytokines such as IL-2,IFN-γ,TNF-α,which possess a potent antiviral activity.The Th2-type pattern of cytokine secretion(IL-4,IL-5,IL-6,IL-10 and IL-13)is able to activate mainly B cells and inhibit Th1 type immune responses.We detected Th1/Th2-type pattern cytokines in patients with chronic HCV.We found that IL-2,IFN-γserum levels are similar in hepatitis and cirrhosis group,IL-4,10 serum levels in cirrhosis group are hinger than hepatitis goup,but TNF-αserum level is lower.We also observed the dynamic cytokines secretion changes of six patients with chronic HCV and founded that along with the development of hepatitis,IL-4,IL-10 serum levels increases gradually, IL-2,IFN-γ,TNF-αdecreased gradually but increased in acute episode of chronic HCV infection.In an patient who received peg-IFN-α2a therapy, IL-2,IFN-γ, TNF-αincreased and IL-4,10 decreased.It is supposed that Th1/Th2 imbalance in periphery blood,espeically increased Th2-type pattern cytokines secretion may play an importment role in chronic HCV infection.Cytokines theraphy to rectificate the Th1/Th2 imbalance may be an new strategy of hepatitis C treatment.We also used in situ hybridization method to detect the expression of HCVRNA in liver biopsies of 30 patients with chronic HCV.We founded that HCVRNA positive signals are single or in some hepatic cells,dispersaled in lobuli hepatis.Little positive cells are in or near the necrosis,infiltrated by lymph cells or mononuclear cells.Increased expression of HCVRNA always raisd the hepatic damage. Regulatory T cells are able to suppress HCV-specific T lymphocyte proliferation and cytokine secretion during chronic HCV infection. We wished to address to what extent regulatory T cells exist in the livers of HCV+ individuals, and what the role of such cells might be in disease progression. We analysed the frequency and distribution of FOXP3+ cells, along with CD4+, CD8+ cells, IL-10,TNF-α,IFN-γ,in liver biopsies of 30 patients with chronic HCV and correlated these data with histological parameters. We found that CD4+, CD8+,FOXP3+,IL-10, TNF-α,IFN-γexpressed mainly in portal tract,folliculus lymphaticus and CD8+ expressed predominantly near necrosis area.When liver damage increased, expression of CD8+, FOXP3+,IL-10,TNF-αincreased,but CD4+,IFN-γdid not increased obversiously. Because FOXP3+ expresses specificially in Treg,it is supposed that the ratio of CD4+/CD8+ degradation revealed dysfunction of CD8+T lymphocyte and Treg may play a critical role in intrahepatic immune regulation of chronic HCV infection. Advanced understanding of immune pathogenesis of chronic HCV infection may provide new strategy and treatment to therapy or prevent HCV infection.更多还原