急性期/早期HIV-1感染的临床研究进展

原发Ⅰ型艾滋病病毒(HIV-1)感染(PHI)包括急性期感染(AHI)和早期感染(EHI)。AHI通常与急性的"反转录病毒综合征"有关,包括一系列非特异的症状和实验室检测异常。AHI和EHI的分界点在于HIV抗体的阳转,而PHI和其后的慢性感染阶段的临界点在于体内何时达到HIV-1的调定点。早期诊断有赖于检测HIV-1RNA和P24抗原。大约50%经性传染HIV发生在急性期阶段,对急性期/早期感染者尽早诊断并给予抗病毒治疗,能明显减少HIV的传播。一些研究显示,早期抗病毒治疗能够使病毒得以长期抑制,并能保持甚至增加HIV-1特异性T细胞免疫应答,但早期治疗和治疗中断的临床益处还没有足够数据支持。     

一例HIV-1急性感染者奠基病毒的gp160基因序列特征及其假病毒构建

目的观察急性感染期艾滋病病毒I型（HIV-1）gp160的全长基因序列及感染特征。方法从一例处于Feibig I期HIV-1感染者血浆中提取RNA,扩增gp160全长基因并测序,分析其生物学信息;将gp160全长基因与pcDNA3.1His/V5真核表达载体连接,构建Env-pcDNA3.1真核表达质粒,与骨架质粒pNL4-3.Luc.R-E-共转染293细胞,包装出假病毒。用包装的假病毒感染ghost细胞,测定感染细胞的荧光素酶活性（RLU）,鉴定假病毒的感染活性。结果成功扩增出gp160全长基因,嗜性预测为CCR5,N-糖基化位点数与标准株HXB2相同,但gp120糖基化程度更高,氨基酸变异主要集中在V1-V5区。假病毒感染试验显示,RLU值达到7log。结论获得了处于急性感染期的HIV-1gp160基因序列和高感染活性的假病毒。     

高效抗逆转录病毒治疗后HIV感染者CTL应答研究现状

高效抗逆转录病毒治疗（Highly active antiretroviral therapy，HAART）明显降低了艾滋病病毒Ⅰ型（HIV-1）感染者的发病率和死亡率，随着HIV-1被抑制于不可检测水平，CD4T细胞数明显增加，部分免疫功能重建，肺孢子虫、弓型虫、分支杆菌、真菌等并发感染明显得到控制。虽已在猴免疫缺陷病毒（SIV）感染猿猴的模型以及人体实验中证实，HIV特异性细胞毒性T细胞（CTL）在控制HIV感染中起着关键作用，     

HIV感染者pDC功能与TLR7／9介导的信号转导

类浆细胞样的树突状细胞（pDC）是一种重要的免疫细胞,在联结初始免疫应答和获得性免疫应答中发挥重要的作用。pDC高表达Toll样受体（TLR）7和9,脱氧核糖核酸（DNA）或者核糖核酸（RNA）病毒通过TLR7／9激活pDC,启动下游信号转导通路的改变,最终引起pDC活化成熟状态的改变以及细胞因子的分泌,因此TLR7／9信号转导通路出现障碍,将直接影响pDC的功能。pDC在艾滋病（AIDS）疾病进展中发挥着重要的作用,艾滋病病毒（HIV）感染后,pDC的数量和功能都发生改变,pDC通过其中的TLR7识别HIV的单链RNA（ssRNA）,HIV-1感染后所引起的pDC的功能变化与TLR7／9信号通路密切相关。     

HIV-1慢性感染Jurkat细胞系的建立及其特性研究

目的建立艾滋病病毒Ⅰ型（HIV-1）慢性感染Jurkat细胞系,研究其生物学特性。方法参照文献方法改良,建立HIV-1ⅢB慢性感染Jurkat细胞系。其细胞系特性采用以下方法检测：光学显微镜观察细胞形态;流式细胞仪检测HIV-1ⅢB感染细胞的阳性率;噻唑蓝（MTT）法检测抗病毒药物对慢性感染细胞的毒性作用;酶联免疫吸附试验（ELISA）检测药物对慢性感染细胞中病毒复制的影响;合胞体形成方法检测药物对HIV-1ⅢB慢性感染细胞与正常细胞融合的阻断作用。结果成功建立了HIV-1慢性感染Jurkat细胞系（Jurkat/HIV-1ⅢB）,感染细胞阳性率〉90%。检测影响病毒复制各周期的抗病毒药物对Jurkat/HIV-1ⅢB细胞的作用,发现Jurkat/HIV-1ⅢB细胞具有HIV-1慢性感染细胞的生物学特征。结论成功建立Jurkat/HIV-1ⅢB细胞系,为抗HIV-1药物的研发和病毒感染机制研究提供了新的工具。     

用CyQuant法观察免疫缺陷病毒对中性粒细胞存活率的影响

目的 观察猴免疫缺陷病毒（SIV）感染中性粒细胞（PMN）后对PMA生长率的影响，以及粒细胞巨噬细胞集落刺激因子（GM-CSF）在PMN生存中的作用。方法 用台酚蓝染色和CyQuant法同时对不同时间SIV感染PMN生存率进行测定。结果 2种测定结果是一致的，但CyQuant法结果显示较好的线形关系。GM-CSF对正常PMN的存活有一定程度的维持作用，但对SIV感染PMN不起明显作用。结论 SIV感染的PMN对GM-CSF的敏感性下降可能是造成PMN功能障碍的原因之一。     

6种细胞因子对巨细胞病毒感染人胚肺成纤维细胞的影响

目的 研究6种细胞因子（IL－1β、IFN－α、IFN－γ、GM－CSF、TGF－β1、bFGF）对人巨细胞病毒（HCMV）感染人胚肺成纤维细胞（HEL）的影响,探讨细胞因子在HCMV感染免疫中的作用。方法 用不同浓度的6种细胞因子分别作用于HEL,24h后感染病毒,研究6种细胞因子对HCMV感染HEL的影响。结果 在病毒感染前,IL－1β、IFN－α、INF－γ、bFGF作用于HEL可抑制HCMV的增殖;TGF－β1作用于HEL可增加HCMV的增殖,上述细胞因子对病毒复制的影响与细胞因子的浓度有关。GM－CSF地人巨细胞病毒感染人胚肺成纤维细胞无明显影响。结论 细胞因子在HCMV感染免疫过程中起重要作用。     

HIV急性期/早期感染者合并HBV感染的临床特征

目的探讨艾滋病病毒(HIV)急性期/早期感染者合并感染乙型肝炎病毒(HBV)的临床特点及实验室特征,进一步明确影响HIV/HBV重叠感染疾病进展的关键因素。方法采用回顾性分析的方法,了解单独HIV急性期/早期感染者(单独HIV感染组)和合并HBV的HIV急性期/早期感染者(HIV/HBV重叠感染组)的初始CD+4T淋巴细胞(简称CD4细胞)计数和病毒载量调定点,以及两组病人感染HIV一年内CD4细胞计数和HIV病毒载量的动态变化,和HIV急性期/早期合并HBV感染的临床特征。结果 20例HIV/HBV重叠感染组的初始CD4细胞计数平均值为(443.55±197.00)个/μL(213~985个/μL),病毒载量调定点(4.34±0.99)Log10拷贝/mL(1.82~5.47Log10拷贝/mL)。30例单独HIV感染组病人的初始CD4细胞计数平均值为(497.37±121.29)个/μL(196~792个/μL),病毒载量调定点(3.87±0.62)Log10拷贝/mL(2.77~5.19Log10拷贝/mL)。HIV/HBV重叠感染组的初始CD4细胞计数明显低于单独HIV感染组,两组比较差异有统计学意义(P0.05)。HIV/HBV重叠感染组的病毒载量调定点明显高于单独HIV感染组,两组间差异有统计学意义(P0.05)。结论在我国HIV急性期/早期感染者中,HIV/HBV重叠感染者与单独HIV感染者比较,初始CD4细胞计数明显降低,病毒载量调定点明显升高,HIV病毒复制更为活跃。     

人类免疫缺陷病毒感染者重叠输血传播病毒感染的临床研究

目的 了解中国地区人类免疫缺陷病毒（HIV-1）感染者重叠输血传播病毒（TTV）感染的流行情况，并探讨重叠感染TTV对CD4^＋T淋巴细胞计数及HIVRNA病毒载量的影响。方法收集55例HIV-1感染者的血浆标本，采用荧光定量PCR法检测TTVDNA，流式细胞法检测T淋巴细胞亚群，bDNA方法检测HIVRNA。结果HIV感染者中TTVDNA检出率及TTVDNA滴度明显高于健康对照组（P〈0．05）。HIV／TTV重叠感染者CD4^＋T淋巴细胞计数低于单纯HIV感染者。HIVRNA病毒载量高于单纯HIV感染者，两组比较差异有统计学意义（P〈0．05）。结论中国地区HIV感染者易重叠感染TTV，且滴度较高。重叠感染TTV可能导致细胞免疫功能进一步下降，加快病毒复制，促进HIV病程的进展。     

应用四聚体酶联免疫斑点法和细胞内细胞因子染色法检测HIV-1感染者体内特异性细胞毒性T淋巴细胞的研究

目的应用四聚体（tetramer）、酶联免疫斑点法（ELISPOT）和细胞内细胞因子染色（ICCS）方法研究HIV-1感染者细胞毒性T淋巴细胞（CTLs）的数量和功能。方法应用三种tetramer检测14例HLA-A2阳性的HIV-1感染者外周血中特异性CTLs的频率，同时采用SL9（SLYNTVATL）体外冲击HIV-1感染者的外周血单核细胞（PBMCs）。通过EL／SPOT和ICCS方法检测产生卜干扰素（IFN—γ）的CTLs，初步分析特异性CTLs在HIV-1感染中的作用。结果Tetramer SL9、IV9和Y19检测出的特异性CTLs占CDs^＋T细胞的百分比范围分别为0．06％～3．27％，0．05％～0．57％和0．09％～0．66％；其检出阳性率分别为11／14、10／14和5／7。ELISPOT和ICCS检测的产生IFN-γ的细胞近似，但远低于tetramer检测出的病毒特异性CTLs的数量。结论Tetramer可以敏感地检测出特异性CTLs。ELISPOT和ICCS则是研究CTLs功能的重要手段。联合使用三种方法可以更准确地评价HIV-1感染者体内CTLs的特征及其临床意义。     

A stochastic model for primary HIV infection: optimal timing of therapy

OBJECTIVE: To investigate the optimal time point for the initiation of therapy in HIV infection from the perspective of drug resistance. BACKGROUND: The enormous genetic diversity of HIV within an infected individual represents one of the greatest challenges for effective therapy, because the viral population may harbour drug-resistant mutants that rapidly outgrow the wild-type virus once the patient starts treatment. To determine the optimal timing of therapy it is crucial to know how long it takes for the viral population to build up sufficient diversity to enable the virus to escape from therapy. METHOD: A stochastic model of the viral diversification during primary infection was used to study the behaviour of small population sizes of mutant virus. RESULTS AND CONCLUSIONS: The simulations suggest that from the perspective of viral diversity, therapy should be started at the viral set-point. Starting treatment earlier involves a risk of the selective outgrowth of drug-resistant mutants, which are transiently present at the viral peak during primary infection.     

The central nervous system as a reservoir for simian immunodeficiency virus (SIV): steady-state levels of SIV DNA in brain from acute through asymptomatic infection

Latent reservoirs of human immunodeficiency virus (HIV) present significant challenges for eradicating HIV from infected persons, particularly reservoirs in the brain established during acute infection. A simian immunodeficiency virus (SIV)/macaque model of HIV dementia was used to show that viral DNA levels in the brain remained at constant levels from acute through asymptomatic infection, despite significant down-regulation of viral RNA in the brain after the acute phase of infection. Viral replication in the brain coincided with activation of macrophages and microglia in the central nervous system; down-regulation of viral replication coincided with increased infiltration of cytotoxic lymphocytes and reduced activation of macrophages and microglia in the brain. Comparison of viral genotypes in the central nervous system and peripheral blood mononuclear cells suggests that recrudescence of viral replication in brain occurs by reactivation of latent viral DNA. Latent virus in the brain must be considered in therapeutic strategies to eliminate HIV from infected persons.     

Variation in HIV-1 set-point viral load: epidemiological analysis and an evolutionary hypothesis

The natural course of HIV-1 infection is characterized by a high degree of heterogeneity in viral load, not just within patients over time, but also between patients, especially during the asymptomatic stage of infection. Asymptomatic, or set-point, viral load has been shown to correlate with both decreased time to AIDS and increased infectiousness. The aim of this study is to characterize the epidemiological impact of heterogeneity in set-point viral load. By analyzing two cohorts of untreated patients, we quantify the relationships between both viral load and infectiousness and the duration of the asymptomatic infectious period. We find that, because both the duration of infection and infectiousness determine the opportunities for the virus to be transmitted, this suggests a trade-off between these contributions to the overall transmission potential. Some public health implications of variation in set-point viral load are discussed. We observe that set-point viral loads are clustered around those that maximize the transmission potential, and this leads us to hypothesize that HIV-1 could have evolved to optimize its transmissibility, a form of adaptation to the human host population. We discuss how this evolutionary hypothesis can be tested, review the evidence available to date, and highlight directions for future research.     

Positive Epstein-Barr virus heterophile antibody tests in patients with primary human immunodeficiency virus infection

PURPOSE: To describe three cases of primary human immunodeficiency virus (HIV) infection in patients who had laboratory studies consistent with infectious mononucleosis. SUBJECTS: We describe 3 patients who presented with a viral syndrome, had a positive heterophile antibody test, and were diagnosed with primary HIV infection. RESULTS: The results of Epstein-Barr virus serology studies in each of these patients were consistent with chronic, but not acute, Epstein-Barr virus infection. HIV antibody tests were negative, and HIV RNA was >500,000 copies/mL in each patient. CONCLUSIONS: Clinicians should recognize that a positive heterophile antibody test in the setting of an acute viral illness does not exclude the diagnosis of primary HIV infection, although reactivation of latent Epstein-Barr virus infection cannot be ruled out. Patients presenting with nonspecific viral syndromes should be assessed for HIV risk behaviors and tested for primary HIV infection when appropriate.     

Administration of Fozivudine tidoxil as a single-agent therapeutic during acute feline immunodeficiency virus infection does not alter chronic infection

Initiating combination antiretroviral therapy (ART) during acute HIV infection has been correlated with decreased viral set point and improved lymphocyte function. However, the long term effects of single-agent therapy administered only during the acute stage of infection (interrupted treatment) remain largely uncharacterized. In this study we provide longitudinal data using the feline immunodeficiency virus (FIV) model for HIV infection. Infected cats were treated with a prophylactic single-agent therapy, Fozivudine tidoxil (FZD), for six weeks, starting one day before infection. The initial acute infection study, reported elsewhere, demonstrated a decrease in plasma- and cell-associated viremia at two weeks post-infection (PI) in FZD-treated cats as compared to placebo-treated cats. We hypothesized that this early alteration in plasma- and cell-associated viremia would alter the virus set point and ultimately affect the outcome of chronic infection. Here we provide data at one, two and three years PI for plasma- and/or cell-associated viremia, total lymphocyte counts and CD4:CD8 ratios. There was no difference in viremia or cell counts between treated and nontreated groups at all time points tested. Contrary to our hypothesis, these results suggest that treatment with a single agent anti-retroviral drug during acute lentivirus infection does not significantly alter viral load and immune function during the chronic, asymptomatic stage of infection.     

Loss of viral control in early HIV-1 infection is temporally associated with sequential escape from CD8+ T cell responses and decrease in HIV-1-specific CD4+ and CD8+ T cell frequencies

The outcome of human immunodeficiency virus type 1 (HIV-1) infection is related to the set-point plasma virus load (pVL) that emerges after primary HIV-1 infection (PHI). This set-point pVL generally remains stable but eventually increases with progression to disease. However, the events leading to loss of viremic control are poorly understood. Here, we describe an individual who presented with symptomatic PHI and subsequently progressed rapidly, after an initial period of 1 year during which viral replication was well controlled. Escalation of viral replication in this atypical case was preceded by the emergence of escape variants in many epitopes targeted by dominant CD8+ T cell responses and a marked decrease in HIV-1-specific CD4+ and CD8+ T cell frequencies. There were no changes in viral tropism, replication kinetics, or neutralizing antibody titers. These findings demonstrate the temporal relationship between viral escape from CD8+ T cell activity, decrease in HIV-1-specific T cell frequencies, and loss of control of viral replication.     

CD4 antigen-based antireceptor peptides inhibit infectivity of human immunodeficiency virus in vitro at multiple stages of the viral life cycle.

Benzylated derivatives of peptides corresponding to residues 81 through 92 of the CD4 molecule [CD4-(81-92)] inhibit human immunodeficiency virus 1 (HIV-1)-induced cell fusion and infection in vitro. If such peptides are to be considered as candidates in the therapy of HIV infection, it is crucial to know if the anti-HIV efficacy of CD4-based peptides is limited to blockade of infection and virus-induced cell fusion or if other stages of the viral life cycle are affected by these compounds. Accordingly, an in vitro quantitative microassay for acute HIV infection was divided into two kinetic phases corresponding to the two general stages of the viral life cycle: (i) viral infection and (ii) transmission of virus and viral protein products through cell contact or release of free virions. CEM-SS cell cultures were treated with peptide during either the infection or the transmission phase of the assay. When peptides were present during the infection phase, inhibition of syncytium formation correlated with decreased expression of viral core protein p24 and lack of infectious cell centers when cells exposed to virus were washed and replated onto fresh uninfected indicator cells. These data are consistent with complete inhibition of viral infection when peptide is present only during initial exposure to virus. Unexpectedly, parallel inhibition of syncytium formation, decreased p24 levels, and inhibition of infectious cell center formation were also seen even when peptides were added as late as 48 hr after inoculation, during the transmission period of the assay. Since viral binding and penetration are completed well before 48 hr in this assay system, CD4-(81-92) peptide derivatives appear to exert a virostatic effect on cultures already infected with HIV-1, decreasing p24 production, cytopathicity, and cell-mediated infectivity.     

Modelling the Course of an HIV Infection: Insights from Ecology and Evolution

The Human Immunodeficiency Virus (HIV) is one of the most threatening viral agents. This virus infects approximately 33 million people, many of whom are unaware of their status because, except for flu-like symptoms right at the beginning of the infection during the acute phase, the disease progresses more or less symptom-free for 5 to 10 years. During this asymptomatic phase, the virus slowly destroys the immune system until the onset of AIDS when opportunistic infections like pneumonia or Kaposi’s sarcoma can overcome immune defenses. Mathematical models have played a decisive role in estimating important parameters (e.g., virion clearance rate or life-span of infected cells). However, most models only account for the acute and asymptomatic latency phase and cannot explain the progression to AIDS. Models that account for the whole course of the infection rely on different hypotheses to explain the progression to AIDS. The aim of this study is to review these models, present their technical approaches and discuss the robustness of their biological hypotheses. Among the few models capturing all three phases of an HIV infection, we can distinguish between those that mainly rely on population dynamics and those that involve virus evolution. Overall, the modeling quest to capture the dynamics of an HIV infection has improved our understanding of the progression to AIDS but, more generally, it has also led to the insight that population dynamics and evolutionary processes can be necessary to explain the course of an infection.     

Acute HIV infection among Kenyan infants.

BACKGROUND: Clinical signs and symptoms of acute human immunodeficiency virus (HIV) infection in infants are not well characterized. METHODS: Serial clinical assessments and HIV PCR assays were conducted in a cohort of children born to HIV-seropositive mothers from birth to 2 years of age. Acute HIV infection visits were defined as those up to 3 months prior to and including the visit at which HIV DNA was first detected. Noninfection visits included all visits at which the child had test results negative for HIV, including the last visit at which a test result negative for HIV DNA was obtained in children who later acquired HIV infection. Differences in the prevalence of symptoms at acute infection versus noninfection visits were determined overall and were stratified by age at infection (<2 months vs. >or=2 months). HIV RNA was measured serially in infected infants and was compared between infants with and infants without symptoms of acute HIV infection. RESULTS: There were 125 acute infection visits (among 56 infants) and 3491 noninfection visits (among 306 infants). Acute HIV infection was associated with rash (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-2.8), failure to thrive (OR, 1.9; 95% CI, 1.0-3.5), and lymphadenopathy (OR, 2.5; 95% CI, 1.4-4.8). Acute HIV infection was associated with lymphadenopathy (OR, 2.6; 95% CI, 1.3-5.0) in infants <2 months of age and with pneumonia (OR, 3.2; 95% CI, 1.1-9.3) and dehydration (OR, 6.0; 95% CI, 1.9-18.5) in infants >or=2 months of age. Infant peak viral load and mortality were not associated with symptoms of acute HIV infection. However, infants with symptoms had higher viral levels later in the course of infection than did those without symptoms (P=.05). CONCLUSIONS: Infants may manifest symptoms early during the course of HIV infection, and symptoms of acute HIV infection may correlate with poor viral control. Rash, failure to thrive, lymphadenopathy, pneumonia, and dehydration may signify acute HIV infection in infants.     

Effect of GB virus C viremia on HIV acquisition and HIV set-point

We performed both a case-control study and a cohort study to determine whether GB virus C (GBV-C) viremia prevents the acquisition of HIV infection or alters the HIV set-point after infection. The prevalence of GBV-C viremia in HIV-uninfected individuals who did and did not acquire HIV were similar (odds ratio 1.32; 95% confidence interval 0.6-2.6). Pre-existing GBV-C viremia at the time of HIV acquisition was also not associated with lower plasma HIV-RNA levels.