中国HIV感染长期不进展者CD4+CD25+Foxp3+调节性T细胞变化研究

目的 对中国HIV感染长期不进展者(LTNP)CD4+CD25+Foxp3+调节性T细胞水平及其与疾病进展相关性进行研究,探讨CD4+CD25+Foxp3+ 调节性T细胞在LTNP保护机制中发挥的作用.方法 选取74名HIV-1感染者(LTNP、典型进展HIV组、AIDS组)及16名健康对照,应用流式细胞仪胞内染色技术在单细胞水平检测CD4+CD25+Foxp3+调节性T细胞表达水平,分析其与CD4+ T细胞数量、病毒载量、淋巴细胞活化、凋亡水平的相关性.结果 中国HIV感染LTNP CD4+CD25+Foxp3+ T细胞百分率明显低于典型进展HIV、AIDS组及健康对照组(P<0.05).HIV/AIDS患者CD4+CD25+Foxp3+ T细胞百分率与CD4+ T细胞显著负相关(r=-0.509,P<0.001),与病毒载量明显正相关(r=0.414,P<0.01),与CD4、CD8+ T细胞表面CD38、CD95表达水平明显正相关(P<0.05),与CD4、CD8+ T细胞表面HLA-DR表达无显著相关性.结论 中国HIV感染LTNP CD4+CD25+Foxp3+ 调节性T细胞百分率明显低于典型进展者,提示调节性T细胞与LTNP保护机制相关.     

中国经采供血HIV感染长期不进展者CD4~+T淋巴细胞趋化因子受体表达研究

目的:了解中国经采供血HIV感染长期不进展者CD4+T淋巴细胞趋化因子受体表达,分析其与疾病不进展的关系。方法:收集43例经采供血HIV感染长期不进展者、82例无症状HIV感染者、35例AIDS病人及40例健康对照的抗凝全血,用流式细胞仪检测趋化因子受体CCR5、CXCR4的表达,并分析其与病毒载量、CD4+T淋巴细胞绝对值及T淋巴细胞活化的相关性。结果:长期不进展组CD4+T细胞表面CCR5的表达明显低于无症状HIV感染组及AIDS组(P0.01),与健康对照无显著差异;CD4+T细胞表面CXCR4的表达各组无显著差异。CD4+T细胞表面CCR5的表达与CD4+T细胞数量显著负相关(r=-0.498,P0.05),与病毒载量无显著相关性。CD4+T细胞表面CCR5的表达与HLA、CD38在CD4+、CD8+T细胞的表达水平显著正相关(P0.001,CD38在CD4+T细胞的表达除外),CD4+T细胞表面CXCR4的表达与HLA在CD4、CD8+T细胞的表达水平显著负相关(P0.01)。结论:HIV感染长期不进展者CD4+T细胞趋化因子受体CCR5表达维持较低水平,与疾病不进展相关。     

HIV/HCV合并感染者淋巴细胞活化及第二受体表达的研究

目的了解中国不同疾病进展阶段人类免疫缺陷病毒和丙型肝炎病毒（HIV／HCV）合并感染者T淋巴细胞与自然杀伤细胞（natural killer cells，NK）数量变化及T淋巴细胞活化、受体表达情况，并探讨HCV感染对HIV感染免疫指标及疾病进展的影响。方法应用流式细胞术分析228例不同疾病进展阶段的HIV／HCV合并感染者及101例单纯HIV感染者外周血T淋巴细胞、NK细胞数量及T淋巴细胞活化受体（HLA-DR、CD38）、第二受体（CCR5、CXCR4）表达情况。结果（1）HIV／HCV合并感染组中，CD4^＋T淋巴细胞、NK细胞数量随疾病进展持续下降，其中艾滋病组（AIDS）明显低于无症状HIV感染组（HIV）（P〈0．05），HIV组明显低于长期不进展组（LTNP）（P〈0．01），LTNP组与健康对照组差异无统计学意义。LTNP组、HIV组及AIDS组CD4^＋、CD8^＋T细胞表面活化受体HLA-DR、CD38的表达依次升高，其中各组间CD8／CD38的升高差异均有统计学意义（P〈0．05），AIDS组CD4／HLA-DR、CD8／HLA-DR的升高明显高于LTNP组和HIV组（P〈0．01）。LTNP组、HIV组及AIDS组CD4^＋、CD3^＋T细胞表面CCR5的表达亦依次升高，各组间差异均有统计学意义（P〈0．05）；CD3^＋T细胞表面CXCR4的表达依次升高，AIDS组明显高于HIV组和LTNP组（P〈0．01）。（2）HIV／HCV合并感染组与单纯HIV感染组相比，AIDS组NK细胞明显下降（P〈0．05），CD4^＋T细胞下降，但无统计学意义，CD4／HLA-DR、CD8／HLA-DR、CD4／CXCR4、CD3／CXCR4明显升高（P〈0．01）；HIV组NK细胞明显下降（P〈0．01），CD4／CXCR4明显升高（P〈0．05）；LTNP组各项指标与单纯HIV感染组相比差异无统计学意义。（3）HIV／HCV合并感染组的HIV病毒载量随疾病进展不断升高，与单纯HIV感染组相比差异无统计学意义；HCV病毒载量在疾病不同阶段差异无统计学意义（P〉0．05）。结论随疾病进展，HIV／HCV合并感染者的免疫功能逐渐下降，HIV病毒载量逐渐升高。与单纯HIV感染相比，合并HCV感染可通过破坏机体天然免疫功能、促进免疫系统活化和受体表达，加速HIV感染的疾病进展。     

HIV/AIDS患者CCR5、CXCR4的表达与疾病进展的关系

目的　了解HIV AIDS患者淋巴细胞表面第二受体CCR5、CXCR4的表达 ,分析其与疾病进展的关系 ,探讨HIV感染的免疫基础。方法　收集 33例HIV AIDS患者及 13例健康对照的抗凝全血 ,用流式细胞仪检测第二受体CCR5、CXCR4的表达 ,并分析第二受体表达与病毒载量、CD4 + T淋巴细胞绝对值及T淋巴细胞活化 (HLA DR+ CD38+ )的相关性。结果　艾滋病组CD4 + 、CD8+ T淋巴细胞表面CCR5表达高于无症状HIV 1感染组及健康对照 (P <0 .0 0 1) ;艾滋病组CD8+ T淋巴细胞表面CXCR4表达低于健康对照 (P <0 .0 1)。HIV AIDS患者CD4 + 、CD8+ T淋巴细胞表面CCR5的表达与病毒载量明显正相关 (P <0 .0 1) ;与CD4 + T淋巴细胞绝对值明显负相关 (P <0 .0 1) ,与T淋巴细胞活化(HLA DR+ CD38+ )水平明显正相关 (P <0 .0 0 1)。结论　HIV 1感染者第二受体CCR5的表达与机体对HIV的免疫反应及疾病进展密切相关。     

中国HIV/AIDS患者T细胞及调节性T细胞CTLA-4表达与疾病进展关系研究

目的 对中国HIV感染者T细胞及凋节性T细胞CTLA-4表达与HIV疾病进展的相关性进行研究,探讨CTLA-4在HIV感染中的作用.方法 选取58名HIV/AIDS患者(长期不进展组、无症状HIV组、AIDS组),应用流式细胞仪胞内染色技术检测T细胞及CD4+CD25+Foxp3+调节性T细胞内CTLA-4表达水平,分析其与CD4+T细胞、病毒载量、淋巴细胞活化凋亡水平的相关性.结果 长期不进展组、无症状HIV组、AIDS组CD4+T细胞内CTLA-4表达水平依次增岛(P<0.05);与CD+T细胞显著负相关(P<0.01),与CD8+T细胞活化(CD38表达)、凋亡水平(CD95表达)及CD4+T细胞凋亡水平显著相关(P<0.05),与病毒载量无显著相关性.长期不进展组、无症状HIV组、AIDS组CD8+T细胞内CTLA-4表达水平差异无统计学意义;与CD4+T细胞、病毒载量、CD4,'+>、CD8+T细胞活化及凋亡水平均无显著相关性.CD4+CD25+Foxp3+T细胞内CTLA-4表达水平长期不进展组明显低于无症状HIV组及AIDS纽(P<0.05);与CD4+T细胞显著负相关(P<0.05);与CD4+、CD8+T淋巴细胞活化(HLA-DR表达)显著相关(P<0.01).结论 中国HIV感染者CD4+T细胞及CD4+CD25+Foxp3+调节性T细胞内CTLA-4表达水平与疾病进展及免疫活化状态显著相关,参与HIV感染免疫平衡的调节.     

中国HIV感染长期不进展者T细胞表面IL-7受体表达研究

目的:了解中国HIV感染长期不进展者(Long-Term Non-Progressor,LTNP)T细胞表面IL-7(Interleukin-7,IL-7)受体的表达,分析其与疾病进展的关系。方法:收集LTNP组、HIV组、AIDS组及健康对照组(每组各20例)的抗凝全血,用流式细胞仪检测IL-7受体的表达,并分析IL-7受体表达与血浆中IL-7水平的相关性。结果:LTNP组CD4+T、CD8+T、中枢记忆T细胞(Central memory T cells,Tcm)、效应记忆性T细胞(Effector memory T cells,Tem)表面IL-7受体表达水平明显高于无症状HIV感染组(HIV组)、AIDS病人组(AIDS组)(P<0.05),LTNP组初始T细胞(Na ve T cells,Na ve)、终末分化效应记忆型T细胞(Terminallydifferentiated effector memory T cells,Tem/td)表面IL-7受体表达水平与HIV组、AIDS组间差异无统计学意义。HIV/AIDS患者IL-7受体在CD4+T和CD8+T细胞上表达的百分率与血浆IL-7水平呈明显负相关(P<0.05),与CD4+T细胞数量呈明显的正相关(P<0.05),与病毒载量呈明显负相关(P<0.05)。结论:外周血T细胞表面IL-7受体表达与HIV疾病进展密切相关,LTNP组T细胞保持较高水平的IL-7受体表达,可能是保护因素之一。     

HIV-1感染疾病缓慢进展者CD8+T淋巴细胞非细胞毒性免疫应答作用的研究

目的 探讨HIV-1感染疾病缓慢进展者CD8+T淋巴细胞非细胞毒性抗病毒应答功能(CNAR)的变化.方法 应用密度梯度离心法、免疫磁珠法纯化健康人CD4+T淋巴细胞和HIV感染者CD8+T淋巴细胞,用HIV毒株SF-33感染健康人CD4+T淋巴细胞,并加入不同疾病进程HIV感染者CD8+T淋巴细胞共培养,收集培养上清,应用ELISA方法测定上清中HIV-1 p24含量.结果 我们研究发现缓慢进展组(slow progressors,SP)、HIV典型进展组(typical progressors,TP)、健康对照组及AIDS组中CNAR功能依次下降(89%>77%>73%>61%),各组间的下降差异均有统计学意义(P<0.05);在HIV感染者中,CNAR功能与CD4+T细胞绝对计数呈显著正相关;与病毒载量无显著相关性.结论 CNAR功能对HIV感染疾病不进展可能具有保护作用.     

中国HIV-1感染者CD4+CD25+Foxp3+调节性T细胞与疾病进展相关性研究

目的对中国HIV-1感染者CD4~ CD25~ Foxp3~ 调节性T细胞水平及与疾病进展相关性进行研究,探讨CD4~ CD25~ Foxp3~ 调节性T细胞在HIV-1疾病进程中发挥的作用。方法选取35名HIV-1感染者及14名健康对照,应用流式细胞仪胞内染色技术在单细胞水平检测CD~ CD25~ Foxp3~ 调节性T细胞表达及淋巴细胞活化、凋亡水平。结果中国HIV-1感染者CD4~ CD25~ Foxp3~ T细胞水平与CD4~ T细胞显著负相关(r=-0.544,P=0.001),与病毒载量明显正相关(r=0.484,P= 0.026),与CD4~ T细胞凋亡(CD95表达)水平明显正相关(r=0.431,P=0.011)。艾滋病人CD4~ CD25~ Foxp3~ T细胞水平明显高于无症状HIV感染者(P<0.05),与健康人相比差异无统计学意义。艾滋病人CD4~ 、CD8~ T细胞凋亡水平明显高于无症状HIV感染者及健康人(P<0.05),艾滋病人及无症状HIV感染者CD4~ 、CD8~ T细胞活化明显高于健康人(P<0.05)。结论中国HIV-1感染者CD4~ CD25~ Foxp3~ 调节性T细胞水平与疾病进展明显相关。     

中国HIV/AIDS典型进展者与疾病长期不进展者中和抗体保守表位氨基酸变异比较研究

目的 研究中国HIV/AIDS典型进展者及疾病长期不进展者(LTNP)中和抗体保守表位氨基酸变异,探讨中和抗体表位变异与疾病进展关系,为开展中和抗体免疫治疗和疫苗设计奠定理论基础.方法 RT-PCR及巢式PCR扩增HIV/AIDS典型进展者及LTNP的HIV-1 gp120 C2～C3区基因,双脱氧终止法进行核酸序列测定,翻译为氨基酸序列,与HIV-1 Sequence Database参考毒株比对识别中和抗体保守表位氨基酸变异.结果 HIV/AIDS典型进展者CD4结合位点(CD4BS)、CD4诱导(CD4i)、2G12中和抗体保守表位氨基酸均存在变异,LTNP 2G12中和抗体保守表位氨基酸存在变异;LTNP各表位突变率较典型进展的HIV感染者/AIDS患者有降低趋势,但差异无统计学意义(P＞0.05);CD4BS、CD4i、2G12变异表位构成比分别为25.0%、22.9%、52.1%,2G12表位变异明显高于CD4BS和CD4i表位,差异有统计学意义(P＜0.01);CD4BS和CD4i保守表位变异多见于E370Q(10.8%),2G12保守表位变异多见于N295V(18.9%)和T297I(9.5%).结论 中国HIV感染人群中,LTNP中和抗体保守表位氨基酸构成相对稳定,变异较典型进展的HIV感染者/AIDS患者少见,目前发现2G12中和抗体表位存在较低水平变异.中和抗体表位中,2G12表位变异较CD4BS和CD4i表位多见,各类型中和抗体保守表位氨基酸位点的变异程度存在差异.     

共抑制分子BTLA在慢性HIV-1感染中的特点及与疾病进展的相关性研究

目的:观察慢性HIV-1感染者中CD4~+和CD8~+ T淋巴细胞上BTLA(B and T lymphocyte attenuator,CD272)分子的表达及临床意义.方法:采集34例慢性HIV-1感染者和15例健康人的外周血,分离外周血单个核细胞,用间接免疫荧光染色方法标记并用流式细胞术检测T淋巴细胞上BTLA表达的百分比及平均荧光强度,并将BTLA的表达水平与患者CD4~+ T淋巴细胞计数和病毒载量做相关性分析.结果:与健康对照相比,HIV-1慢性感染者中CD4~+和CD8~+ T细胞上的BTLA表达均明显下降,且BTLA的下降在各组HIV-1慢性感染者中也有明显差异,随着疾病进展,BTLA表达进行性下降.CD4~+ T细胞上BTLA表达比率与平均荧光强度均与CD4~+T淋巴细胞计数呈明显正相关,而与病毒载量呈负相关.结论:在慢性HIV-1感染中,随着疾病进展,BTLA的进行性下降可能是机体活化和抑制信号失衡、导致免疫系统广泛活化的重要因素,恢复BTLA抑制信号的强度可能是治疗HIV感染的新策略.     

Immunogenic and tolerogenic signatures in human immunodeficiency virus (HIV)-infected controllers compared with progressors and a conversion strategy of virus control

Epidemiological studies have identified a small cohort of controllers of human immunodeficiency virus (HIV)-1 infection, who without treatment have no detectable virus, and others who progress at a variable rate. The objective of this study was to distinguish immune signatures in HIV controllers and progressors, by evaluating tolerogenic and immunogenic factors in untreated HIV-1 infected individuals. The recruited population was divided into putative elite controllers (PEC), long-term non-progressors (LTNP), normal progressors (NP) and fast progressors (FP). The proportion of regulatory T cells [T(regs) , CD4+ CD25+ forkhead box P3 (FoxP3+)], programmed death (PD)-1 and cytotoxic T lymphocyte antigen (CTLA)-inhibitory molecules and CD40L, CD69 and Ki67 activation markers were evaluated in peripheral blood mononuclear cells (PBMC) by flow cytometry. Significant differences were found between HIV controllers and HIV progressors, with up-regulation of T(regs) , PD-1 and CTLA-4 and decrease of CD40L expression in progressors compared with controllers. Expression of CD40L and concentrations of interleukin (IL)-6, CCL-3, and CCL-4 were significantly higher in PEC and LTNP than in NP and FP. In an attempt to convert immune signatures of progressors to those of controllers, seven agents were used to stimulate PBMC from the four cohorts. Treatment with CD40L and IL-4 or PD-1 antibodies in vitro were most effective in converting the immune signatures of progressors to those observed in controllers by down-regulating T(regs) and up-regulating CD40L expression in CD4+ T cells. The conversion concept merits translation to in vivo immune control of HIV infection.     

CD4 responses to conserved HIV-1 T helper epitopes show both negative and positive associations with virus load in chronically infected subjects

Characterization of immune responses to immunodominant CD4 epitopes in HIV-1 that are associated with control of HIV infection could be used to strengthen the efficacy of polyepitope HIV vaccines. We measured both the proliferative and the CD4 interferon (IFN)-gamma and interleukin (IL)-2 cytokine responses specific for 11 previously identified HIV-1 T helper epitopes in 10 HIV-infected non-progressors (LTNPs) (infected for a median of 15 years with a stable CD4 count of >500 cells x 10(6)/l), and seven slow progressors (SPs) (infected for a median of 15 years with a CD4 count that had declined to <500 cells x 10(6)/l). Both groups were antiretroviral treatment-naive at the time of evaluation. The median virus load of SP group was higher than that of the LTNP group (P = 0.0002). The CD4 response to a peptide pool representing all potential CD4 Gag epitopes and to Gag p24 protein was also studied. Compared to SPs, LTNPs had higher numbers of Gag-specific IFN-gamma+IL-2+ CD4s (P = 0.0059). The Gag-specific cytokine and proliferative responses correlated inversely with virus load (P = 0.03 and 0.0002, respectively), highlighting the potential importance of this response in immunity to HIV. A direct correlation was noted between proliferation and the Gag-specific IL-2 (P = 0.0053) rather than IFN-gamma response (P = 0.1336), demonstrating that the proliferation assay reflected the IL-2 rather than the IFN-gamma secreting capacity of CD4 cells. Several subjects with diverse class II DRB1 alleles responded, confirming the 11 selected peptides to be both antigenic and conserved. CD4 cytokine responses to one Gag and two conserved Pol peptides correlated negatively with virus load. The cytokine response to two additional Pol peptides correlated positively with virus load. The data indicate that there is not an absolute correlation between the CD4 immune response to conserved and broadly antigenic helper T cell epitopes in HIV non-progression.     

Low Relative Frequencies of CD26+ CD4+ Cells in Long-Term Nonprogressing Human Immunodeficiency Virus Type 1-Infected Subjects

A broad antibody panel was used for immunophenotyping of human immunodeficiency virus type 1 (HIV-1)-infected patients who were long-term nonprogressors (LTNP). The LTNP were compared with patients in the early phase of infection and patients who had progressed to advanced immunodeficiency. Changes in CD8⁺ subset distribution were observed mainly at acquisition of HIV-1 infection, whereas CD4⁺ subset changes appeared during progression of HIV-1 infection. The decreasing levels of CD4⁺ cells were characterized by an increasing frequency of cells expressing the activation markers HLA-Dr and CD45RO but not the CD28 surface antigen. The LTNP exhibited significant changes compared to HIV-negative patients in almost all markers. Compared to patients in the early phase of infection, the only difference was a relatively lower frequency of CD4⁺ cells expressing CD26 among the LTNP. The results show that HIV-1-infected persons who have no signs of immunodeficiency despite many years of infection have an immunophenotypic pattern that is substantially different from that of noninfected persons. Despite the long duration of infection, the LTNP exhibit a pattern similar to that of newly infected persons, with the exception of lower expression of CD26 on CD4⁺ cells.     

Frequency and function of HIV-specific CD8(+) T cells

The virus-specific CD8(+) T cell responses of 27 HIV-infected patients were studied, including a unique cohort of long term nonprogressors (LTNP) with normal CD4(+) T cell counts, low levels of plasma viral RNA, strong proliferative responses to HIV antigens and an over-representation of the HLA B*5701 class I allele. The frequencies of CD8(+) T cells specific to the majority of HIV gene products were measured by flow cytometric detection of intracellular interferon-gamma (IFN-gamma) in response to HIV-vaccinia recombinant infected autologous B cells. Very high frequencies (1.4-22%) of circulating CD8(+) T cells were found to be HIV-specific and were not only found in LTNP with reduced plasma virus. No correlation was evident between the frequency of HIV-specific CD8(+) T cells and levels of plasma viremia. In each case, the vast majority of cells (up to 17.2%) responded to Gag-Pol gene products. Although similar frequencies of Gag peptide-specific CD8(+) T cells were found in LTNP and progressors by either intracellular IFN-gamma or MHC class I tetramer staining, the breadth of these responses was greater in patients with progressive HIV infection compared with the LTNP group. The frequency of CD8(+) T cells specific for a single peptide was not representative of an individual patient's total HIV-specific CD8(+) T cell response. These data demonstrate that high numbers of HIV-specific CD8(+) T cells exist even in patients with high level viremia and progressive disease. Further, they suggest that other qualitative parameters of the CD8(+) T cell response may differentiate some patients with very low levels of plasma virus and nonprogressive infection.     

Persistent human immunodeficiency virus-1 antigenaemia affects the expression of interleukin-7Ralpha on central and effector memory CD4+ and CD8+ T cell subsets

Interleukin (IL)-7 and its receptor (IL-7Ralpha) play important roles in regulating lymphopoiesis. Previous studies have reported that human immunodeficiency virus-1 (HIV-1) viraemia affects the expression of IL-7Ralpha, but its effects on CD4+ and CD8+ T cell memory subsets have not been studied. Using eight-colour flow cytometry, we compared the immunophenotypic patterns of CD4+ and CD8+ T cell subsets expressing IL-7Ralpha and activation markers, as well as circulating IL-7 levels, in three well-defined groups of HIV-1-infected subjects: successfully treated, viraemic and long-term non-progressor (LTNP). Compared with successfully treated and LTNP subjects, viraemic patients had reduced expression of IL-7Ralpha on both CD4+ and CD8+ T cells, particularly on central and effector memory T cell compartments, and substantially elevated expression of activation markers on CD8+ T cell subsets. Circulating IL-7 levels were correlated negatively with the number of CD4+ and CD8+ T cell subsets expressing IL-7Ralpha; these associations were stronger with CD4+ T cell subsets and mainly with central and effector memory cells. The expression of activation markers on CD4+ and CD8+ cell T subsets was not related to circulating IL-7 levels. A strong negative correlation was observed between central memory CD4+ or CD8+ T cells expressing IL-7Ralpha and those expressing activation markers, independently of IL-7 levels. Collectively, these results provide further insight on the role of unsuppressed viral load in disrupting the IL-7/IL-7Ralpha system and contributing to HIV-1 disease progression.     

Spreading of HIV-specific CD8+ T-cell repertoire in long-term nonprogressors and its role in the control of viral load and disease activity

Long-term non-progressors (LTNP) represent a minority of human immunodeficiency virus (HIV) infected individuals characterized by stable or even increasing CD4+ T-cell count and by stronger immune responses against HIV than progressors. In this study, HIV-specific effector CD8+ T cells, as detected by both a sensitive ex vivo enzyme-linked immunospot (ELISPOT) assay and specific major histocompatibility complex (MHC) peptide tetramers, were at a low frequency in the peripheral blood of LTNP, and recognized a lower number of HIV peptides than their memory resting cell counterparts. Both factors may account for the lack of complete HIV clearance by LTNP, who could control the viral spread, and displayed a higher magnitude of cytotoxic T lymphocyte (CTL) responses than progressors. By combining cell purification and ELISPOT assays this study demonstrates that both effector and memory resting cells were confined to a CD8+ population with memory CD45RO+ phenotype, with the former being CD28- and the latter CD28+. Longitudinal studies highlighted a relatively stable HIV-specific effector repertoire, viremia, and CD4+ T-cell counts, which were all correlated with maintenance of nonprogressor status. In conclusion, the analysis of HIV-specific cellular responses in these individuals may help define clear correlates of protective immunity in HIV infection.