慢性HBV感染不同临床表型的免疫因子表达模式及免疫遗传特征研究

发布时间：2018-09-10 13:09

【摘要】：慢性HBV（hepatitis B virus，乙型肝炎病毒）感染多种临床表型的形成机制一直为研究者广为关注。一般认为，宿主遗传因素决定的个体免疫差异在慢性HBV感染的临床转归中起决定作用。慢性HBV感染时机体免疫系统的两大核心改变是树突状细胞激活初始型T细胞能力降低和Th分化失衡。在众多的细胞因子中，尚不清楚何种免疫因素在慢性HBV感染临床表型多样性中起主导作用。全基因组关联研究发现HLA-DQ、HLA-DP基因多态性与持续HBV感染存在关联，但尚无机制上的进一步解释。对HBeAg阴性慢性乙型肝炎的免疫发病机制和宿主遗传发病机制尚无深入研究。慢性HBV感染个体化治疗也迫切需要对其进行免疫状态的评估和宿主遗传特征筛选。本研究通过包括30个细胞因子/趋化因子的蛋白质芯片来评估慢性HBV感染者不同临床表型的免疫因子表达模式；通过蛋白质相互作用分析评估免疫因子的效应差异；在此基础上筛选出与慢性HBV感染临床转归密切相关的免疫分子；通过病例-对照的遗传关联研究观察这些因子的基因多态性与慢性HBV感染临床表型之间的关联。研究将丰富慢性HBV感染临床表型多样性形成的机制，并为预测慢性HBV感染的临床转归及早期干预治疗提供策略。主要研究结果如下： 1.对持续ALT（alanine aminotransferase，丙氨酸氨基转移酶）正常的慢性HBV感染者而言，JAK-STAT信号通路的细胞因子表达普遍上调是其重要的免疫特征；较高的表达水平提示较佳的预后；γ链细胞因子、IL-12p70、IL-23p19和IL-29升高引起的免疫效应改变可能对促进自发性HBeAg血清转换和HBV清除发挥重要作用。 2.对慢性乙型肝炎患者而言，炎性趋化因子CXCL9、CXCL10、CXCL11和CCL20适合作为活动性肝炎的免疫评估指标；ALT5×ULN（upper limit of normal，正常上限值）的HBeAg阳性慢性乙型肝炎与非活动性HBV携带有较多相似的免疫基础可能是这部分人群可以获得较高血清免疫学应答的基础；与HBeAg阳性慢性乙型肝炎相比，IL-29、IL-17、IFN-γ、IL-6、CCL5等上调表达缺陷和IL-21的表达上调所引起免疫效应改变可能与HBeAg阴性慢性乙型肝炎形成机制有关；IL-29和IFN-γ等因子表达上调可作为评价HBeAg阴性慢性乙型肝炎血清免疫学应答的标志。 3.通过HBV清除者与持续HBV感染者的对照遗传关联研究，发现天然免疫、炎症应答和炎性趋化因子等免疫环节的基因多态性与持续HBV感染的易感性密切关联；HLA-DQ、HLA-DP基因多态性与持续HBV感染密切关联最显著；HLA-DQ rs7453920、IL10rs1800872和MX1rs467960呈显著协同遗传，GTC基因型为持续HBV感染的高危基因型；TLR9rs352140与持续HBV感染单独关联。 4.通过HBeAg阳性慢性乙型肝炎与HBeAg阴性慢性乙型肝炎的对照遗传关联研究，发现IL1B、IRAK1、IL4基因多态性与HBeAg阴性慢性乙型肝炎存在关联；男性IL12A基因多态性、女性IL6R基因多态性可能与不同性别HBeAg阴性慢性乙型肝炎的易感性存在关联。 5.通过活动性HBV感染与非活动性HBV携带的对照遗传关联研究，发现IFNG、IL12B、IL15、IL17A、IL1B、IL28B、IL6ST、IL9、TNFRSF18基因多态性与非活动性HBV携带存在关联；IFNG rs2069705独立与非活动性HBV携带关联；IL15rs10833、IL28B rs8099917、IL6ST rs2112979和TNFRSF18rs3819001协同一致遗传，女性CTGC型和TTAC基因型更倾向于发生非活动性HBV携带；女性SLC10A1rs12882299与非活动性HBV携带存在关联。总之，本研究通过蛋白质芯片技术较为全面的对慢性HBV感染不同临床表型的免疫因子表达模式进行了评估，获得了一些有利于HBV清除的免疫特征，明确了细胞因子与炎症活动程度的关联；并通过病例-对照遗传关联研究筛选出了与持续HBV感染、HBeAg阴性慢性乙型肝炎、非活动性HBV携带等存在关联的基因多态性位点；研究丰富了慢性HBV感染临床表型多样性形成的机制，所筛选出来的免疫特征和基因多态性位点可用于慢性HBV感染的预后评估。
[Abstract]:It is generally believed that the individual immune differences determined by host genetic factors play a decisive role in the clinical outcome of chronic HBV infection. The two core changes in the body's immune system during chronic HBV infection are dendritic fineness. Among many cytokines, it is not clear which immune factors play a leading role in the clinical phenotypic diversity of chronic HBV infection. Genome-wide association studies have found that HLA-DQ, HLA-DP gene polymorphisms are associated with persistent HBV infection, but there is no further explanation for the mechanism. The immunopathogenesis and host genetic pathogenesis of HBeAg-negative chronic hepatitis B have not been thoroughly studied. Individualized treatment of chronic HBV infection also requires the evaluation of its immune status and screening of its host genetic characteristics.
In this study, 30 cytokine/chemokine protein microarrays were used to evaluate the expression patterns of immune factors in different clinical phenotypes of chronic HBV infections, and the effects of immune factors were evaluated by protein interaction analysis. The study will enrich the mechanism of clinical phenotypic diversity formation in chronic HBV infection and provide strategies for predicting the clinical outcome of chronic HBV infection and early intervention therapy.
The main findings are as follows:
1. For chronic HBV infections with persistent normal ALT (alanine aminotransferase), a general up-regulation of cytokine expression in JAK-STAT signaling pathway is an important immune feature; a high level of JAK-STAT signaling indicates a better prognosis; immune effects induced by elevated levels of gamma-chain cytokines, IL-12p70, IL-23p19 and IL-29 Alterations may play an important role in promoting spontaneous HBeAg seroconversion and HBV clearance.
2. For patients with chronic hepatitis B, inflammatory chemokines CXCL9, CXCL10, CXCL11 and CCL20 are suitable for evaluating the immune response to active hepatitis B, and ALT5 *ULN (upper limit of normal) HBAg-positive chronic hepatitis B may have more similar immune basis to inactive HBV carriers. Compared with HBeAg-positive chronic hepatitis B, the up-regulation of IL-29, IL-17, IFN-gamma, IL-6, CCL5 and the up-regulation of IL-21 may be related to the formation mechanism of HBeAg-negative chronic hepatitis B, and the up-regulation of IL-29 and IFN-gamma may be used to evaluate HBeAg-negative chronic hepatitis B. Markers of serum immune response in chronic hepatitis B.
3. The genetic polymorphisms of natural immunity, inflammatory response and inflammatory chemokines were closely related to the susceptibility to persistent HBV infection. HLA-DQ, HLA-DP gene polymorphisms were most significantly associated with persistent HBV infection. MX1rs467960 was significantly co-inherited, GTC genotype was a high-risk genotype for persistent HBV infection, and TLR9rs352140 was independently associated with persistent HBV infection.
4. The genetic association between HBeAg-positive chronic hepatitis B and HBeAg-negative chronic hepatitis B was studied. It was found that IL-1B, IRAK1, IL-4 gene polymorphisms were associated with HBeAg-negative chronic hepatitis B; IL-12A gene polymorphisms in males and IL-6R gene polymorphisms in females might be associated with susceptibility to HBeAg-negative chronic hepatitis B in different gender. Relation.
5. Through the comparative genetic association study between active HBV infection and inactive HBV carriers, we found that IFNG, IL12B, IL15, IL17A, IL1B, IL28B, IL6ST, IL9, TNFRSF18 gene polymorphisms were associated with inactive HBV carriers; IFNG rs2069705 was independently associated with inactive HBV carriers; IL15rs10833, IL28B rs8099917, IL6ST rs2112979 and TNFRSF18rs3 819001 was co-inherited, and female CTGC and TTAC genotypes were more likely to have inactive HBV carriers, while female SLC10A1rs12882299 was associated with inactive HBV carriers.
In summary, this study assessed the expression patterns of immune factors in different clinical phenotypes of chronic HBV infection by protein chip technology, obtained some immune features that are conducive to HBV clearance, clarified the correlation between cytokines and inflammatory activity, and screened and maintained by case-control genetic association study. The study enriched the mechanism of phenotypic diversity formation in chronic HBV infection, and the immune characteristics and gene polymorphisms screened can be used to evaluate the prognosis of chronic HBV infection.
【学位授予单位】：第三军医大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：R512.62

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