【作者】 王月云；

【导师】 聂绍发； 程锦泉；

【作者基本信息】 华中科技大学 ， 流行病与卫生统计学， 2009， 博士

【摘要】 研究背景性传播途径已经成为全球人类免疫缺陷病毒Ⅰ型(human immunodeficiency virusType 1，简称HIV-1)的主要传播途径，大约70％～80％感染者通过性接触感染HIV-1。HIV-1是一种具有高度变异性的逆转录病毒，其感染与疾病进展过程尚有很多问题需要阐明。在艾滋病的分子流行病学研究领域，有两类人群值得关注：一类是较高频率暴露于HIV-1但未感染，血清呈阴性反应，该类人群被称为暴露HIV-1后血清阴性者(HIV-1-exposed seronegative subjects，简称ESNs或ES人群)或HIV-1高暴露持续血清阴性者(higly exposed and persistently seronegative，简称HEPS人群)；另一类为感染HIV-1后长期不进展者(long-term no-progressors，LTNP)。目前，对HIV-1不易感性机理及其影响因素尚不明确，国内外关于HEPS人群不易感HIV-1的研究报道并不多见。因此，我们选择经性传播途径高暴露HIV-1持续血清阴性的人群作为研究对象，探讨其对HIV-1不易感性的影响因素。研究目的1．探讨经性传播途径高暴露HIV-1的HEPS人群HIV-1感染相关基因CCR5-Δ32、CCR2b-64I和SDF1-3’A多态性与HIV-1不易感性的关系。2．了解经性传播途径高暴露HIV-1的HEPS人群与HIV-1感染者、无HIV暴露史健康对照人群的淋巴细胞亚群分布差异，分析其与HIV-1不易感性的关系。3．了解经性传播途径高暴露HIV-1的HEPS人群淋巴细胞亚群表达及其免疫活化状态，探讨经性途径高暴露HIV-1不易感性的免疫学机制。研究方法本研究采用流行病学病例对照研究方法，在深圳市疾病预防与控制中心2006年01月1日～2007年12月31日的自愿咨询检测(voluntary counselling and test，简称VCT)人群中选择经性传播途径高暴露HIV-1的HEPS人群作为病例组，选择经性途径感染HIV-1者及无HIV暴露史的健康对照人群作对照组。按年龄相差小于5岁、性别和民族相同的匹配条件选取对照。采用统一的调查问卷对病例组和对照组进行调查，并收集生物样本。用PCR／RFLP技术分析基因多态性的基因型；采用流式细胞术分析淋巴细胞亚群及其表面活化标志的表达。主要研究结果1．CCR5-⊿32等位基因突变HEPS人群(n=52)、健康对照人群(n=104)和HIV-1感染者(n=104)三组人群(n=260)中均未检测到；CCR2b-64I等位基因突变频率在这三组人群中分别为21．57％、22．12％和22．12％，三者之间的差异没有统计学意义；SDF1-3’A等位基因突变频率在这三组人群中分别是20．19％、28．37％和29．33％。HEPS人群的SDF1-3’A等位基因突变频率显著低于健康对照人群和HIV-1感染人群，差异具有统计学意义(P=0．023，P=0．049)。2．HEPS人群与健康对照人群外周血淋巴细胞亚群差异没有统计学意义；HPES人群和健康对照人群的CD4~+T淋巴细胞数量、CD4~+／CD8~+比值显著高于HIV-1感染者(P＜0．001)，而该两类人群的CD8~+T淋巴细胞数量则显著低于HIV-1感染者(P＜0．001)；HIV-1感染者外周血CD19~+B淋巴细胞、CD16~+CD56~+NK细胞数量显著低于HEPS人群和健康对照人群。淋巴细胞亚群相关性分析结果显示，HIV-1感染者和健康对照人群的CD19~+B淋巴细胞、CD16~+ CD56~+ NK细胞数量均与其CD4~+、CD8~+ T淋巴细胞数量呈一定程度正相关，HEPS人群的CD19~+ B淋巴细胞数量与CD4~+、CD8~+T淋巴细胞数量呈显著正相关，而CD16~+ CD56~+ NK细胞数量与其CD4~+、CD8~+ T淋巴细胞数量无相关性。3．HEPS人群和健康对照人群的CD38~+／CD4~+、HLA-DR~+ CD38~+／CD4~+百分比显著低于HIV-1感染者(P＜0．001)，同时HEPS人群的HLA-DR~+ CD38~+／CD4~+百分比显著低于健康对照人群(P＜0．05)；HEPS人群的HLA-DR~+／CD4~+百分比显著低于HIV-1感染者和健康对照人群(P＜0．001)。研究结论1．CCR5-Δ32和CCR2b-64I等位基因突变与中国汉族人群通过性传播途径感染HIV-1的关系不大，SDF1-3’A等位基因突变可能增加经性传播途径感染HIV-1危险性。2．经性传播途径高暴露HEPS人群淋巴细胞亚群和健康对照人群比较差异无统计学意义，HIV-1感染可明显降低单位体积CD4~+ T淋巴细胞、CD19~+ B淋巴细胞和CD16~+ CD56~+ NK细胞数量。3．HEPS人群对HIV-1的不易感性可能与其T淋巴细胞表面标志活化抗原表达水平处于较低水平状态有关。更多还原

【Abstract】 BackgroundSexual transmission is the major route of HIV-1 infection in the world. About 70% to80% of HIV-1-infected cases occured through sexual transmission. HIV-1 is a highvariability retrovirus, which infection and disease progression process still need to beclarified. In AIDS molecular epidemiology studies, two kinds of populations are worthpaying attention to, one of which is HIV-exposed seronegative individuals (ESNs or ES) orhighly HIV-1-exposed and persistently seronegative (HEPS) individuals, the other infectedHIV-1 with long-term no-progressors (LTNP). At present, the mechanism of HIV-1non-susceptivity and its influential factors in HEPS individuals are still unclear, and thereare few reports on it in the world. Therefore, we select the HEPS individuals of HanChinese as the subjects and explore influential factors of HIV-1 non-susceptivity by sexualtransmission in our study.Objective1. To determine the genetic polymorphisms of CCR5-A32, CCR2b-64I and SDF1-3’Ain highly HIV-1-exposed and persistently seronegative (HEPS) individuals, and analyzetheir correlations with HIV-1 non-susceptibility.2. To detect the distribution of lymphocyte subsets in highly HIV-l-exposed andpersistently seronegative (HEPS) individuals, and analyze their correlations with HIV-1non-susceptibility.3. To detect the distribution and immune activation status of T lymphocyte subsets inhighly HIV-1-exposed and persistently seronegative (HEPS) individuals, and explore the immunologic mechanism of HIV-1 non-susceptibility by sexual transmission in HEPSindividuals.MethodsCase-control study was desiged in this study. Highly HIV-1-exposed persistentlyseronegative individuals by sexual transmission were enrolled as the cases, andHIV-1-seropositive individuals and healthy HIV-unexposed individuals were choosen as thecontrols. All subjects were voluntary counseling and test (VCT) individuals enrolled inShenzhen Center for Disease Control and Prevention from January 1, 2006 to December 31,2007. The cases and controls were matched by gender, ethnic, and age (within 5 years). Allof them were interviewed using the same questionnaire, whose blood samples were drawnin terms of the same conditions and standards. Polymerase chain reaction (PCR) andrestriction fragment length polymorphism (PCR/RFLP) analysis were used for genotypedetermination. Flow cytometry was used to analyze lymphocyte subsets and the expressionof activation markers.Results1. The CCR5-A32 mutation was not detected in HEPS, healthy HIV-unexposedindividuals and HIV-1-seropositive individuals (n=260). The allelic frequencies ofCCR2b-64I were 21.57%, 22.12%, 22.12% in the three groups respectively. There was notsignificant difference among the three groups on CCR2b-64I distribution. The allelicfrequencies of SDF1-3’A were 20.19%, 28.37% and 29.33% in the three groupsrespectively. There was significant difference in the allelic distribution of SDF1-3’Abetween HEPS and healthy HIV-unexposed individuals (P=0.023), also between HEPS andHIV-1-seropositive individuals (P=0.049).2. The differences in distributions of lymphocyte subsets were not significant betweenHEPS individuals and healthy HIV-unexposed individuals. CD4~+ counts, CD4/CD8 ratiowere higher in HEPS individuals and healthy HIV-unexposed individuals than those inHIV-1-seropositive individuals (P＜0.001), but CD8~+ counts were significantly lower in thetwo groups than that in HIV-1-seropositive individuals (P＜0.001); CD19~+ counts on B lymphocytes and CD16~+ CD56~+ counts on NK cells in HIV-1-seropositive individuals weresignificantly lower than those in I-IEPS individuals and healthy HIV-unexposed individuals.Correlation analysis showed that there were significantly positive correlations betweenCD19~+ counts on B lymphocytes, CD16~+ CD56~+ counts on NK cells and CD4~+ counts,CD8~+ counts in HIV-1-seropositive individuals and healthy HIV-unexposed individuals tosome extent. There were significantly positive correlations between CD19~+ counts on Blymphocytes and CD4~+ counts, CD8~+ counts, but significant correlations did not existbetween CD16~+ CD56~+ counts on NK cells and CD4~+ counts, CD8~+ counts in HEPSindividuals.3. Percentages of CD38~+/CD4~+, HLA-DR~+ CD38~+/CD4~+ were significantly lower inHEPS and healthy HIV-unexposed individuals than those in HIV-1-seropositive individuals(P＜0.001). Meanwhile, the percentage of HLA-DR~+ CD38~+/CD4~+ in HEPS individuals waslower than that in healthy HIV-unexposed individuals (P＜0.05). The percentage ofHLA-DR~+/CD4~+ in HEPS individuals was significantly lower than that inHIV-1-seropositive individuals and healthy HIV-unexposed individuals (P＜0.001).Conclusions1. The mutant genotypes on CCR5-A32 and CCR2b-64I were not correlated withHIV-1 infection through sexual transmission in Han Chinese. SDF1-3’A was associatedwith high risk of HIV-1 infection by sexual transmission in Han Chinese.2. There are no differences in distributions of lymphocyte subsets between HEPSindividuals and healthy HIV-unexposed individuals; CD4~+ counts on T lymphocytes,CD19~+ counts on B lymphocytes and CD16~+ CD56~+ counts on NK cells significantlydecrease for HIV-1-seropositive individuals.3. The expression of activation antigen marker HLA-DR on CD4~+ T cells was at a lowlevel, which probably was correlated with HIV-1 non-susceptibility in HEPS individuals bysexual transmission.更多还原