ELISPOT方法检测SIVmac239感染猴特异性细胞免疫水平

目的为了完善现有的SIV／恒河猴模型,掌握恒河猴被SIV感染后体内细胞免疫应答状态,为评价HIV疫苗提供方法和数据上的参考,我们测定了SIV感染猴体内病毒特异性的细胞免疫水平。方法实验前选出4只无SIV、sTLV、SRV／D和B病毒感染的恒河猴,用SIVmac239病毒液静脉感染实验猴,使用RT-PCR、流氏细胞术和ELISPOT等方法,监测SIVmac239病毒在恒河猴体内复制情况、感染猴的外周免疫损伤情况和细胞免疫情况,持续测定一年。结果实验结果显示IFN-γ ELISPOT方法能有效的评估实验猴的细胞免疫情况,IFN—YELISPOT结果和CD4＋T细胞数无相关性,与血浆病毒载量稍有相关。结论本实验明确了SIVmac239感染中国恒河猴体内CTL的基本趋势和范围,了解了外周血病毒载量、外周免疫损伤与细胞免疫状况之间的联系,完善了SIV／SAIDS模型评价指标,为使用此模型评价抗病毒药物或疫苗提供了基础条件。     

恒河猴Mamu-A^＊01基因与SIV／SHIV感染相关的研究进展

SIV／SHIV感染的恒河猴是研究艾滋病及艾滋病药物筛选、疫苗评价较理想的动物模型。MHC在细胞免疫中起着关键作用,研究表明,MHC-I类分子的多态性与SIV／SHIV感染者的疾病进展有着明显的关联作用,Mamu-A^＊01是恒河猴中的一种MHC-I类分子,它可以呈递特定的病毒蛋白片段到细胞的表面,从而激发CTL反应。国外发现Mamu-A^＊01阳性的猴艾滋病恒河猴会出现疾病进展缓慢,存活时间长等特征。本文就恒河猴Mamu-A^＊01基因与SIV／SHIV感染相关的研究进展做一综述,以期进一步加深对MHC在疫苗研究中的作用的了解,并促进更行之有效地对HIV／AIDS疫苗进行评价。     

PCR技术在猴免疫缺陷病毒(SIV)感染模型中的应用

目的(1)建立RT PCR方法,定性测定SIV感染猴血浆中病毒RNA,比较其与传统血浆病毒分离方法的敏感性;(2)建立DNA PCR方法,检测SIV感染猴外周血淋巴细胞(PBMCs)中的前病毒DNA。(3)检验DNA PCR和RNA PCR方法在猴SAIDS模型应用中的实用性和可操作性。方法用SIVmac251静脉感染恒河猴,定期采血,从血浆中提取病毒RNA,以RNA为模板通过RT PCR法扩增,凝胶电泳定性;从感染猴PBMC中提取带有整合的SIV前病毒DNA的细胞基因组DNA,巢式PCR扩增,凝胶电泳定性。结果DNA PCR和RNA PCR经两轮扩增后均得到一长度为477bp的特异条带,测序鉴定确为目的片段。9只实验猴感染SIV后7d,RNA PCR结果为79阳性,DNA PCR结果为100%阳性,而血浆病毒分离只有59阳性;此后一直到感染后的42d,RNA PCR和DNA PCR的结果一直为100%阳性,而血浆病毒分离阳性率在感染后35d下降到49,到42d时下降为零。结论PCR方法比病毒分离方法的敏感性高。尤其是DNA PCR,既可检测具有活跃病毒复制的受感染细胞,又可检测那些携带病毒处于转录休眠期的细胞,所以在感染的早期和中后期———血浆病毒水平较低的情况下或病毒处于潜伏感染的阶段,它作为猴艾滋病(SAIDS)模型病毒学指标之一有其必要性和重要性。这个指标的检测方法应该是较血浆病毒RNA检测更为敏感。     

实验用猴脑脊液采集技术方法的创新

脑脊液在艾滋病的研究中有着重要的意义。近年来脑脊液的检测逐步成为SIV/SHIV感染猴模型研究和应用中的重要指标。传统的采集方法不易学习和掌握。针对上述情况我们优化了脑脊液的采集方法,优化后的方法明显缩短穿刺时间,显著提高成功率。     

中国恒河猴Mamu-A*01基因筛查及其对抗原肽p11C的特异性CTL反应

目的 筛查中国恒河猴Mamu-A*01基因,比较中国恒河猴和印度恒河猴的Mamu-A*01基因序列和功能是否相同.方法 PCR方法检测128只中国恒河猴,用特异性引物扩增Mamu-A*01基因,将PCR扩增后的产物克隆测序后与印度恒河猴的Mamu-A*01基因进行同源比对;酶联免疫斑点检测 (ELISPOT) 方法分别检测5只Mamu-A*01基因阳性和5只阴性恒河猴针对SIV、SHIV抗原肽p11C的特异性CTL反应.结果 共筛查出5 只Mamu-A*01基因阳性恒河猴 (3.91%),经测序分析后与印度恒河猴的同源性可达99.1 %.这5只均为SIV/SHIV感染恒河猴,其中四只SIV感染的猴的ELISPOT结果显示针对p11C的高频CTL反应,斑点数在500-1400/106 PBMCs之间,而另1只SHIV感染的恒河猴及5只阴性猴没有斑点出现.结论 中国恒河猴含有Mamu-A*01基因,基因频率有区域性差异,中国恒河猴的Mamu-A*01可提呈特异性抗原肽p11C.     

猴免疫缺陷病毒（SIV）感染恒河猴血液学和血液生化的动态变化

目的探讨SIVmac239感染中国恒河猴的血液学和血清生物化学的变化,研究艾滋病的发生机制。方法 20只恒河猴感染SIVmac239后分别在感染前和感染后2、6、9、12、15和18个月在猴空腹状态用盐酸氯胺酮麻醉下静脉釆血。抗凝血用全自动血液细胞分析仪检测血液常规,血清用全自动生化分析仪检测生化指标。结果SIV感染猴红白细胞计数呈逐渐的减少。淋巴细胞计数有较明显减/增的波动。血清酶类ALT和AST没有明显的上升,但在15月时均有所下降P〈0.05～P〈0.01。LDH持续降低,原因未明。CK则逐月上升,至12月时达高峰,后又有所下降。血尿素氮逐月上升,并在6～18个月时P〈0.01。总蛋白量上升,白蛋白逐月降低,球蛋白升高,白蛋白/球蛋白比率倒置。SIV感染猴2个月后总胆固醇、甘油三脂、低密度脂蛋白和高密度脂蛋白均呈上升,至12月时略有下降,但到18月又上升。血糖（GLU）在SIV感染后逐月上升,后期上升更为明显,这可能与胰岛的损害有关。结论 SIVmac239感染猴后,通过SIV侵入相关的器官病变和体液调节失衡导致血液学和血液生物化学产生异常,从而提供有关猴艾滋病的一些基础资料,这将对研究人的艾滋病也许有所帮助。     

SHIV-KB9感染中国恒河猴动物模型的建立

目的为了进一步确证SHIV-KB9感染中国恒河猴的病毒浓度范围,测试动物对病毒的适应性,明确该动物模型的可重复性。方法实验前采集猴血清并进行血清学检查。选出4只无SIV、STLV、SRV/D和B病毒感染的恒河猴,分别用10倍系列稀释的病毒液静脉感染实验猴,使用流氏细胞术、血常规、病毒分离、DNA-PCR和RT-PCR等方法确定实验猴是否被感染,以及感染后恒河猴体内病毒复制和免疫细胞损伤情况。结果实验猴的血浆病毒载量、病毒分离结果、CD4＋/CD8＋比值和CD4＋T细胞数等证实,4.8×105 copies/mL以上浓度的SHIV-KB9病毒液能成功感染中国恒河猴。结论本研究进一步明确了SHIV-KB9感染中国恒河猴的有效病毒浓度范围,确定了SHIV-KB9病毒感染中国恒河猴的病毒学、免疫学的测定指标,成功的建立了SHIV-KB9/中国恒河猴动物模型。     

表达SIV Gag/Env基因的DNA疫苗、重组腺病毒和重组痘苗病毒三载体疫苗联合免疫小鼠的细胞免疫研究

获得性免疫缺陷综合征即艾滋病是人类面临的严重公共卫生威胁,目前常用的药物疗法仍存在一定的缺陷,尚不能彻底治愈AIDS并阻断HIV的传播。将治疗型疫苗用于HIV感染的治疗具有一定的发展潜力,但缺乏适宜的HIV感染动物模型阻碍了治疗型HIV疫苗的研制。SIV能够感染非人灵长动物并引起类似AIDS的猴免疫缺陷病,因而常被用作研究HIV及其疫苗的替代动物模型。为了对SIV疫苗在猴感染模型中治疗SIV感染的效果进行评价,我们分别构建了表达SIV gag和env基因的DNA疫苗、重组腺病毒和重组痘苗病毒疫苗,并联合使用这三种疫苗免疫小鼠,对包括不同抗原组合、不同免疫次序及间隔的免疫策略进行探索和优化。IFN-γ酶联免疫斑点和小鼠体内杀伤试验的结果显示,通过三载体疫苗联合免疫,能够在小鼠体内诱导出强度较高、持续时间较长的SIV Gag/Env特异性细胞免疫反应。并且,重复免疫后仍可以诱导较高水平的免疫反应。该结果为在SIV感染猴模型中评价多载体疫苗序贯和重复免疫治疗SIV感染的研究奠定了基础,也为治疗型HIV疫苗的研究提供了参考。     

用于猕猴的艾滋疫苗研制成功

波士顿哈佛医学院免疫学家 Norman L .Letvin及其同事研制成功一种基于 DNA的疫苗来抵抗猕猴的艾滋病 .这种猕猴感染的艾滋病毒是猴免疫缺陷病毒 (SIV)与人免疫缺陷病毒 (HIV)的融合物 .这种疫苗编码 2种蛋白质 ,一种在 SIV中找到 ,另一种在 HIV中找到 .疫苗吸引免疫系统注意 ,激发免疫反应 ,只形成少量抗体 ,主要是加强细胞免疫 ,即形成 T杀伤细胞 .为了加强该疫苗 ,研究者加入白细胞介素 - 2 (IL- 2 )以及免疫球蛋白 G(Ig G) ,或是加入编码它们的 DNA.IL- 2加速大量制造 T杀伤细胞 ,而 Ig G则延长 IL- 2的半衰期 .用该新疫…     

猴艾滋病急性期肠粘膜相关淋巴组织NK细胞表型及功能

目的研究猴艾滋病毒感染急性期恒河猴肠道相关淋巴组织（mucosal associated lymphoid tissues,MALTs）NK细胞亚群和功能变化。方法 SIV静脉感染恒河猴后,定期进行动物感染指标测定,并在感染后不同时间点取肠组织,分离派氏淋巴结单个核细胞（peyer＇s patch mononuclear cells,PPMC）和粘膜固有层单个核细胞（lamina propria mononuclear cells,LPMC）,进行T细胞和NK细胞表面抗体染色,流式分析。结果 SIV感染急性期MALTs CD56CD16＋NK细胞亚群比例增幅明显,同时细胞毒性功能增强;CD56-CD16-NK细胞亚群数量减少,功能无明显变化;CD56＋CD16＋和CD56＋CD16-NK细胞数量比例略有增加趋势,但免疫调节功能显著降低。结论SIV感染急性期恒河猴肠道MALTs中NK细胞脱颗粒作用增强,表型功能呈现出较强可塑性。该研究对探索艾滋病粘膜免疫机理、抗病毒治疗及药物研发具有参考意义。     

模拟HIV性传播特点的SIVmac239恒河猴直肠黏膜感染

目的制备SIVmac239恒河猴(Macaca mulatta)细胞适应株病毒,模拟HIV性传播感染特点进行恒河猴直肠黏膜感染研究,探索引起系统性感染的病毒阈值水平与机体病毒、免疫学之间相关性,为我国艾滋病黏膜疫苗等生物制剂有效性评价提供新的模型构建思路。方法参照HIV性传播自然感染剂量范围,选用SIVmac239连续升高的3种剂量直肠黏膜途径感染两只恒河猴,采取多种方法进行病毒血症和免疫反应特点分析。结果两只恒河猴经2×101TCID50和2×102TCID50病毒滴度2次攻击后45d,经检测均未建立系统性感染,病毒特异性免疫反应均为阴性;第3次2×103TCID50病毒滴度攻击后,M296猴表现出典型的系统性感染特点,并诱导特异性免疫反应。结论确认了HIV性传播过程中的病毒剂量效应关系,为预防性生物制剂的猴体有效性评价提供了新的思路。同时,发现SIVmac239Gag区特异性的T细胞免疫反应在病毒控制过程中发挥了关键作用,对于新一代艾滋病黏膜疫苗的抗原选择具有指导性意义。     

Synthetic peptides containing T and B cell epitopes from human immunodeficiency virus envelope gp120 induce anti-HIV proliferative responses and high titers of neutralizing antibodies in rhesus monkeys.

We have previously described a synthetic peptide (T1-SP10) derived from two noncontiguous regions of HTLVIIIB envelope gp120 (T1, amino acids 428-443; SP10, amino acids 303-321) that induced type-specific anti-HIV neutralizing antibodies and T cell proliferative responses against native HIV gp120 when used as a carrier-free immunogen in goats. In this study, HTLVIIIB T1-SP10 synthetic peptides were used to immunize rhesus monkeys to determine if the peptides were capable of eliciting HIV-specific neutralizing antibody and proliferative responses in primates. Four compounds (alum, polyA:polyU, threonyl-muramyldipeptide (MDP) and IFA) were also compared for efficacy as adjuvants in this system. Rhesus monkeys immunized with T1-SP10 peptides generated high titers of antibodies against the immunogens and also against HTLVIIIB gp120. Sera from all four animals given T1-SP10 in IFA or threonyl-MDP neutralized infection by HTLVIIIB and blocked virus-dependent cell fusion events. A peak neutralization titer of 1:940 was seen in one animal given IFA (19600) and a titer of 1:900 was seen in one of the monkeys (17371) given threonyl-MDP. Proliferative responses of immune rhesus PBMC to T1-SP10 appeared after the first injection. After eight immunizations, two of eight monkeys (one injected with peptides in threonyl-MDP and one given peptides in IFA) had PBMC proliferative responses to native HTLVIIIB gp120. These data demonstrate that the carrier-free T1-SP10 synthetic peptide construct can induce high titers of neutralizing anti-HIV antibody responses and PBMC proliferative responses to HIV in primates.     

SIVmac239感染恒河猴急性期回肠派氏淋巴结中淋巴细胞亚群的变化

目的分析SIVmac239感染早期中国恒河猴回肠派氏淋巴结淋巴细胞数量及亚群的变化,探讨这些变化与疾病进展的可能关系。方法以静脉注射SIVmac239制备恒河猴AIDS模型,对回肠派氏淋巴结进行CD4和CD8免疫组化标记,分离Peyer’s集合淋巴结淋巴细胞,分别标记CD3、CD4、CD8、CD28、CD95单克隆抗体,以流式细胞仪检测T细胞及其亚群的表达情况。结果 SIVmac239感染急性期中国恒河猴Peyer淋巴结中CD4＋/CD8＋比值持续下降,记忆性细胞比例升高,但Peyer淋巴结形态及CD4＋T细胞数量未见明显变化,CD8＋T细胞从第5天开始持续升高。结论 SIVmac239感染急性期,中国恒河猴回肠派氏淋巴结形态及CD4＋T细胞数量基本维持,向记忆性细胞的转化增加,但是CD4＋/CD8＋比值下降。     

The simultaneous ex vivo detection of low-frequency antigen-specific CD4+ and CD8+ T-cell responses using overlapping peptide pools

The ability to measure antigen-specific T cells at the single-cell level by intracellular cytokine staining (ICS) is a promising immunomonitoring tool and is extensively applied in the evaluation of immunotherapy of cancer. The protocols used to detect antigen-specific CD8+ T-cell responses generally work for the detection of antigen-specific T cells in samples that have undergone at least one round of in vitro pre-stimulation. Application of a common protocol but now using long peptides as antigens was not suitable to simultaneously detect antigen-specific CD8+ and CD4+ T cells directly ex vivo in cryopreserved samples. CD8 T-cell reactivity to monocytes pulsed with long peptides as antigens ranged between 5 and 25?% of that observed against monocytes pulsed with a direct HLA class I fitting minimal CTL peptide epitope. Therefore, we adapted our ICS protocol and show that the use of tenfold higher concentration of long peptides to load APC, the use of IFN-α and poly(I:C) to promote antigen processing and improve T-cell stimulation, does allow for the ex vivo detection of low-frequency antigen-specific CD8+ and CD4+ T cells in an HLA-independent setting. While most of the improvements were related to increasing the ability to measure CD8+ T-cell reactivity following stimulation with long peptides to at least 50?% of the response detected when using a minimal peptide epitope, the final analysis of blood samples from vaccinated patients successfully showed that the adapted ICS protocol also increases the ability to ex vivo detect low-frequency p53-specific CD4+ T-cell responses in cryopreserved PBMC samples.     

Antibodies and reactive T cells against the malaria heat-shock protein Pf72/Hsp70-1 and derived peptides in individuals continuously exposed to Plasmodium falciparum.

Pf72/Hsp70-1, a heat-shock protein of m.w. 72 kDa from Plasmodium falciparum is one of the Ag of interest to be included in a polyvalent vaccine against malaria. It is one of the major immunogens present in a fraction of purified blood stage parasites that elicited protection against experimental infection of Saimiri monkeys with blood stages of P. falciparum. It is present at all blood stages and one of its B cell epitopes is also detected on the surface of the infected hepatocyte. Moreover, Pf72 appears to be well conserved among different isolates of P. falciparum. We have examined the immune response against Pf72/Hsp70-1 in individuals from different age groups living in a holoendemic area (West Africa). The immune response against the native Ag (purified from schizonts and called Pf/Hsp70) was analyzed both at the humoral level by ELISA and at the cellular level by assessing in vitro proliferation and IFN-gamma production of PBMC. Of the individuals studied 52% had a statistically significant level of anti-Pf/Hsp70 antibodies as compared with unexposed individuals. These positive individuals showed a heterogeneous distribution because significant levels of antibodies were found in 70% of the adults but in only 26% of the children. The presence of Pf/Hsp70-specific reactive T cells in the blood was detected in 32% of the individuals. The total anti-Pf/Hsp70 antibody level (IgG+IgM) appeared strongly age related and correlated positively with parasite exposure, whereas the T cell response failed to correlate either with the antibody level or with age. Moreover, PBMC of donors responded to the Pf/Hsp70 in a dissociated way, namely, by either T cell proliferation or IFN-gamma production. Ten synthetic peptides based on sequences found in the C-terminal part of Pf72/Hsp70-1 were further tested as potential T cell epitopes. The proliferative response of PBMC from individuals continuously exposed to the parasite showed that three peptides more frequently trigger significant T cell proliferation (in 21% to 27% of the individuals) and three others less frequently (10%). None of these peptides allowed detection of reactive T cells in PBMC of Europeans with no previous exposure to malaria. Some of the stimulating peptides are highly similar to human heat-shock Hsc and Hsp70 with large stretches of identical amino acids.(ABSTRACT TRUNCATED AT 400 WORDS)     

Nested-PCR检测恒河猴泡沫病毒

目的用nested-PCR检测恒河猴泡沫病毒SFV的前病毒形式。方法从SFV-1的pol区域选择两对引物分别对原代猴肾细胞（rhesus monkey kidney,RMK）及猴外周血淋巴细胞（peripheral blood lymphocytes,PBLs）进行体外扩增,扩增产物经1.0%的琼脂糖凝胶电泳,证实其特异性。阳性对照使用具有典型泡沫样病变的RMK377细胞株的前病毒DNA,阳性对照的PCR扩增产物经测序证实,阴性对照为恒河猴的SRV-1cDNA。结果nested-PCR能快速灵敏的直接从猴外周血淋巴细胞检出SFV的前病毒形式,与RMK细胞培养结果基本相一致。结论本实验所建立的检测SFV的nested-PCR法能快速准确的检测猴群中的SFV的带毒情况,对于提高实验猴的质量具有重要意义。     

Influence of Mismatch of Env Sequences on Vaccine Protection by Live Attenuated Simian Immunodeficiency Virus

Vaccine/challenge experiments that utilize live attenuated strains of simian immunodeficiency virus (SIV) in monkeys may be useful for elucidating what is needed from a vaccine in order to achieve protective immunity. Derivatives of SIVmac239 and SIVmac239Δnef were constructed in which env sequences were replaced with those of the heterologous strain E543; these were then used in vaccine/challenge experiments. When challenge occurred at 22 weeks, 10 of 12 monkeys exhibited apparent sterilizing immunity despite a mismatch of Env sequences, compared to 12 of 12 monkeys with apparent sterilizing immunity when challenge virus was matched in its Env sequence. However, when challenge occurred at 6 weeks, 6 of 6 SIV239Δnef-immunized monkeys became superinfected by challenge virus mismatched in its Env sequence (SIV239/EnvE543). These results contrast markedly not only with the results of the week 22 challenge but also with the sterilizing immunity observed in 5 of 5 SIV239Δnef-immunized rhesus monkeys challenged at 5 weeks with SIV239, i.e., with no mismatch of Env sequences. We conclude from these studies that a mismatch of Env sequences in the challenge virus can have a dramatic effect on the extent of apparent sterilizing immunity when challenge occurs relatively early, 5 to 6 weeks after the nef-deleted SIV administration. However, by 22 weeks, mismatch of Env sequences has little or no influence on the degree of protection against challenge virus. Our findings suggest that anti-Env immune responses are a key component of the protective immunity elicited by live attenuated, nef-deleted SIV.     

Depo-Provera abrogates attenuated lentivirus-induced protection in male rhesus macaques challenged intravenously with pathogenic SIVmac239

BACKGROUND: Progesterone administration prior to intravaginal challenge with pathogenic SIVmac239 decreases the protective efficacy of live attenuated vaccines in rhesus macaques. METHODS: To determine if progesterone alters the efficacy of live attenuated vaccines through local or systemic effects, seven male rhesus macaques were immunized with SHIV89.6 and then challenged intravenously with SIVmac239. Three of these animals were treated with Depo-Provera 30 days prior to the SIV challenge. RESULTS: The SHIV animals had significantly lower plasma viral RNA levels than the unimmunized control monkeys, but the Depo-Provera treated, SHIV-immunized animals did not. Despite the lack of protection, the Depo-Provera SHIV animals had strong SIV specific T-cell responses. However, altered patterns of NK frequency and CD38 T-cell expression prior to SIV challenge were observed in Depo-Provera SHIV animals. CONCLUSIONS: Depo-Provera eliminates live-attenuated lentivirus vaccine efficacy in male rhesus monkeys through systemic effects on antiviral immunity and/or viral replication.     

Establishment of AIDS Animal Model with SIVmac239 Infected Chinese Rhesus Monkey

In the present research,two Chinese rhesus monkeys were inoculated intravenously with 5000 TCID50 of SIVmac239. The changes in the numbers of CD4 T lymphocyte in peripheral blood,plasma viral loads,proviral DNA and humoral antibodies against virus were periodically monitored during 121 days. At the early stage of infection,proviral DNA had been detected in PBMCs,and infectious SIVmac239 virus had been isolated from PBMCs. At the same period,the numbers of CD4 T lymphocytes were significantly decreased,and maintained at low level during the 121-day period of infection. Plasma viral loads reached the peak at week 2 post-inoculation and kept at a steady state subsequently. Moreover,antibodies against viral proteins were detected from plasma. All the results showed that the two Chinese rhesus monkeys had been infected with SIVmac239 successfully. This animal model can be applied for further AIDS researches.