艾滋病患者T淋巴细胞表面归巢分子的表达在抗病毒治疗后升高

目的 探讨艾滋病(AIDS)患者高效抗反转录病毒治疗(HAART)前后T淋巴细胞表面归巢分子CD49d、CCR9、CD62L表达的变化情况.方法 采用流式细胞术检测42例艾滋病患者和18例HIV阴性健康对照的外周血T淋巴细胞表面CD49d、CCR9和CD62L表达,用BD FACSDiva软件分析计算各组细胞表达的百分率.结果 治疗后组外周血的平均CD4~+T淋巴细胞明显高于治疗前组(P<0.01);治疗前组CD3~+CD49d~+、CD3~+ CCR9~+、CD3~+CD62L~+、CD3~+CD4~+、CD4~+CD49d~+、CD4~+CCR9~+、CIM~+CD62L~+、CD8~+CD49d~+、CD8~+CD62L~+T淋巴细胞的百分率显著低于治疗后组和阴性对照组(P<0.05);CD3~+CD8~+T淋巴细胞的百分率高于治疗后组(P<0.05).治疗后组CD3~+CCR9~+、CD8~+CCR9~+、CD8~+CD62L~+T淋巴细胞的百分率均低于阴性对照组(P均<0.001).结论 AIDS患者外周血T淋巴细胞亚群不仅比例失调,而且其表面表达肠道归巢分子CD49d、CCR9,淋巴结归巢分子CD62L的数量发生异常改变.抗病毒治疗可以逆转以上部分免疫病理变化.建议肠道归巢分子CD49d、CCR9和淋巴结归巢分子CD62L可作为艾滋病疾病进展和评价机体HAART后免疫重建的指标.     

人初始和记忆CD4+T细胞信使RNA基因芯片检测结果分析

目的探讨健康成人外周血初始和记忆CD4~+T细胞静息状态下表面分子、趋化因子受体、细胞因子和转录因子mRNA表达的差异。方法抽取健康成年人外周血,分离PBMC,染色后流式分选出CD45RO-的初始和CD45RO+的记忆CD4~+T细胞,裂解细胞,进行mRNA表达谱芯片检测。结果相比初始T细胞,静息状态下记忆CD4~+T细胞表达高水平的表面分子CTLA-4、PD-1、FAS、CD25,趋化因子受体CCR4、CCR6、CXCR3、CXCR5,细胞因子IFN-γ、TNF-α、IL-17和转录因子T-bet、EOMES、STAT4、GATA3和RORγt,并表达低水平的表面分子CD62L、CCR7、ICAM-I、CD40L,细胞因子IL-1β和转录因子NF-κB。结论静息状态下,与初始CD4~+T细胞相比,记忆CD4~+T细胞高表达某些活化分子、细胞因子、转录因子mRNA,可能是记忆CD4~+T细胞发生快速免疫应答的关键因素。     

人肠道正常粘膜组织与外周血中记忆性IL-22~+T淋巴细胞频率及表型的比较

目的比较人肠道正常粘膜组织与外周血中IL-22+T淋巴细胞的频率及其表型特征。方法分离人肠道正常粘膜与外周血中单个核细胞,anti-CD3+anti-CD28刺激后,采用流式细胞术(FACS)检测IL-22的产生及其与IFN-γ、IL-17的关系,分析IL-22+T淋巴细胞CD45RO,CD62L,CCR7,CCR6,CCR10,CCR4等表面分子的表达。结果与anti-CD3+anti-CD28刺激外周血中CD4+和CD8+T淋巴细胞产生少量的IL-22(0.6%;0.57%)相比,肠道粘膜CD4+T细胞产生大约3.15%的IL-22,CD8+T淋巴细胞产生4%左右的IL-22。此外,肠道粘膜CD4+和CD8+T细胞中存在一群产生IL-22并独立于Th1、Th17,Tc1、Tc17的细胞亚群。肠道粘膜IL-22+T细胞表达较高比例的CD45RO,其中部分细胞表达CCR7,而较少表达CD62L。进一步研究表明,肠道粘膜CD4+IL-22+和CD8+IL-22+T细胞表达较高水平的CCR10(55.3%;73.9%),部分细胞表达CCR6或CCR4。结论人肠道正常粘膜组织中IL-22主要由效应型或中央型记忆T细胞产生,部分IL-22+T细胞独立于Th1、Th17,Tc1、Tc17细胞亚群。     

八色流式细胞术检测人外周血BCG特异性效应型记忆CD4+T细胞的表型特征

目的:检测BCG刺激后,PPD+正常人外周血中细胞因子产生及其亚群.方法:分离PPD+正常人外周血单个核细胞(PBMC),BCG刺激后检测CD4+和CD8+T细胞细胞因子分泌,并用八色流式细胞术分析BCG特异性T细胞亚群.结果:BCG刺激PBMC后,主要是CD4+T细胞分泌Th1细胞因子(IFN-γ、IL-2和TNF-α),而CD8+T细胞几乎不产生细胞因子.进一步分析分泌细胞因子的细胞亚群,主要是CD4+CD45RO+ CD62L(-)CD27(-)和CD4+ CD45RO+ CD62L(-)CD27+分泌细胞因子.结论:BCG刺激PPD+正常人外周血PBMC后,主要诱导CD4+T细胞分泌细胞因子,且该细胞表现出CD4+CD45RO+ CD62L(-)效应型记忆细胞特征,可能在预防结核感染中发挥重要作用.     

多色流式细胞术检测人外周血BCG特异性效应型记忆γδT细胞的表型特征

目的检测卡介苗(BCG)刺激后,PPD+正常人外周血中分泌IFN-γ的TCRγδ亚群及其表型特征。方法分离PPD+正常人外周血单个核细胞(PBMCs),用多色流式细胞术检测TCRγδ亚群;BCG刺激PBMCs后检测γδT细胞IFN-γ分泌水平,并分析BCG特异性γδT细胞表型特征。结果依据PBMCs中TCRγδ和δ2的表达,可将γδT细胞分为3个亚群,即δ2high、δ2low和TCRγδ中非δ2T细胞(non-δ2-γδT)细胞。其中,δ2high和δ2lowT细胞几乎全部(>98%)为CD45RO+,而non-δ2-γδT细胞中只有少部分表达CD45RO,其余大部分不表达CD45RO。δ2high和δ2lowT细胞表型类似,主要为CD45RO+CD62L-CD27-,而non-δ2CD45RO+细胞主要为CD62L-CD27+,non-δ2CD45RO-细胞几乎全部为CD62L-CD27-。BCG刺激PBMCs后,可诱导γδT细胞分泌IFN-γ,且主要为δ2high和δ2low细胞,而non-δ2-γδT几乎不产生IFN-γ。进一步分析BCG特异性γδT细胞的表型特征,结果表明,δ2high-CD45RO+IFN-γ+和δ2lowCD45RO+IFN-γ+细胞主要为CD62L-CD27-和CD62L-CD27+,为效应型记忆细胞。结论 BCG刺激PPD+正常人外周血PBMCs后,主要诱导δ2T细胞分泌IFN-γ,且该细胞表现出CD45RO+CD62L-效应型记忆细胞特征,可能在预防结核早期感染中发挥重要作用。     

早、中、晚孕期胎盘因子对人外周血淋巴细胞CD4、CCR5和CXCR4表达的影响

目的 通过研究早、中、晚孕期胎盘因子(PF)对人外周血淋巴细胞(PBLs)中CD4、CCR5和CXCR4表达的作用,探讨PF在人免疫缺陷病毒-1(HIV-1)垂直传播中的作用及其机理.方法 制备早、中、晚孕期PF.分离人外周血单个核细胞,并分别与相对浓度为25%的早、中、晚孕期PF作用,培养24 h后收集细胞,荧光抗体标记,流式细胞术检测外周血淋巴细胞(PBLs)中CD4、CCR5和CXCR4表达,以及CD4 T细胞中CCR5 细胞、CXCR4 细胞、CCR5 CXCR4 细胞所占的百分率.结果 各孕期PF均可显著降低PBLs中CCR5的表达,其中早孕期PF的作用明显强于中、晚孕期PF的作用;各孕期PF组CD4 T细胞中CCR5 细胞的百分率均显著低于对照组,早孕期PF组CD4 T细胞中CCR5 细胞的百分率明显低于中、晚孕期PF组;各孕期PF组CD4 T细胞中CCR5 CXCR4 细胞的百分率均显著低于对照组,早孕期PF组CD4 T细胞中CCR5 CXCR4 细胞的百分率显著低于晚孕期PF组.结论 各孕期PF均可显著降低PBLs中CCR5的表达,以及CD4 T细胞中CCR5 细胞和CCR5 CXCR4 细胞的百分率,早孕期PF作用最强,中、晚孕期PF效应相当,PF可能通过抑制R5病毒的人胞而具有抗R5病毒的作用,并可能在阻断HIV-1宫内感染中具有重要作用.     

GD患者外周血CD4+CD28-T细胞亚群的表型特征及临床意义

检测Graves病(GD)患者外周血CD4~+CD28-T细胞水平及其表面CD45RO/CD45RA及ICOS的表达,探讨CD4~+ CD28-T细胞亚群在GD免疫致病机制中的作用。采用三色荧光抗体染色及流式细胞术检测了42例初发GD患者和30例健康者外周血中CD4~+CD28-T细胞的百分率及其表面CD45RO/CD45RA和ICOS表达水平,同时检测其甲状腺功能并进行相关性分析。结果GD患者外周血中CD4~+CD28-T细胞百分率明显高于健康对照组,并高表达ICOS分子,与FT3水平显著正相关;与健康对照组相比,GD患者CD4~+CD28~-CD45RO~+T细胞百分率也显著增高,而CD4~+CD28~-CD45RA~+T细胞呈下降趋势,FT3、FT4水平与CD4~+CD28-T细胞表面CD45RO的表达率呈正相关,而FT3水平与CD45RA表达呈负相关。结论GD患者外周血CD4~+CD28~-T细胞异常增高,表面高表达ICOS分子,具有记忆性细胞的表型特征,与甲状腺功能异常有一定的相关性,CD4~+CD28-T细胞可能是参与GD免疫病理反应的自身反应性T细胞。     

正常人周围血初始和记忆T细胞亚群及细胞因子表达的探讨

目的：利用多色流式检测技术探讨初始和记忆T细胞亚群与细胞因子表达之间的关系。方法：自正常人静脉血中分离PBMC,经超抗原（SEB）刺激5h后,加入多种抗细胞表面标记和抗细胞因子抗体进行染色,利用流式细胞术检测,并利用Flow Jo软件分析结果。结果：根据CD45RO表达与否,将CD4^＋和CD8^＋T细胞分为初始和记忆T细胞,再根据归巢受体（CD62L）和趋化因子受体（CCR7）的表达与否,将初始和记忆T细胞进一步分为不同的亚群。当T细胞受到SEB激活后,CD45RO^＋和CD45RO^-的CD4^＋或CD8^＋T细胞均表达IL-2、IFN-γ和TNF-α。进一步分析结果表明,CD62L^hi和CD62L^hiCCR7^＋细胞不表达细胞因子,而CD62L^loCCR7^lo和CCR7^＋T细胞均表达细胞因子,其中CD62L^loCCR7^lo细胞表达细胞因子的阳性率明显高于CCR7^＋细胞亚群。结论：只利用CD45RO表达与否区分初始和记忆T细胞是不够准确的,同时检测CD62L的表达,可明显地提高其准确性。     

HIV-1 RNA被有效抑制下T细胞与外周血中HIV-1前病毒DNA

目的:考察HIV-1 RNA被有效抑制下T细胞与外周血中HIV-1前病毒DNA的相关性。方法:对云南地区90例确诊为AIDS,HAART持续治疗时间超过6个月,血浆HIV RNA<50 Copies/ml的患者进行研究,采用Spearmans秩和相关回顾性分析CD4+、CD3+、CD8+、CD4+CD28+、CD4+CD45RA+、CD4+CD45RO+、CD38+、CD8+CD38+T细胞的绝对计数和相对计数与外周血中HIV-1前病毒DNA的相关性,同时考察HIV-1前病毒DNA拷贝数与HAART持续治疗时间的相关性。将90例患者根据HAART后CD4+T细胞绝对计数分为A(CD4+<200 cells/μl)、B(200≤CD4+≤349 cells/μl)、C(CD4+≥350 cells/μl)3组,考察3组间T细胞亚群的差别。结果:HIV-1前病毒DNA的log拷贝数与CD4+CD45RA+T细胞绝对计数呈负相关(r=-0.231,P<0.05),与CD4+CD45RA+T细胞相对计数呈明显负相关(r=-0.270,P<0.01);与CD38+T细胞绝对计数呈正相关(r=0.250,P<0.05);与HAART持续治疗时间无相关性。B、C组的CD3+T细胞绝对计数明显高于A组(P<0.01);C组的CD8+T细胞绝对计数高于B组的(P<0.05);B、C组的CD4+CD28+T细胞绝对计数和相对计数明显高于A组(P<0.01),C组的CD4+CD28+T细胞绝对计数高于B组(P<0.05);B、C组的CD4+CD45RA+T细胞、CD4+CD45RO+T细胞绝对计数明显高于A组(P<0.01),C组的CD4+CD45RA+T细胞、CD4+CD45RO+T细胞绝对计数高于B组(P<0.05),B、C组的CD4+CD45RO+T细胞相对计数高于A组(P<0.05);B、C组的CD8+CD38+T细胞绝对计数低于A组(P<0.05),B组的CD8+CD38+T细胞相对计数低于A组(P<0.05);C组的CD38+T细胞绝对计数高于A组(P<0.05)。A、B、C组的HIV-1前病毒DNA的log拷贝数分别为3.561±0.297 9,3.605±0.277 6,3.434±0.289 1(copies/ml),3组间无显著性差异(P>0.05)。结论:经过HAART治疗后HIV-1前病毒DNA可能处于稳定状态,HIV-1前病毒DNA拷贝数只是某些T细胞亚群数量改变的原因之一。     

CHOP方案治疗前后外周T细胞淋巴瘤患者外周血CD45RA~+ T和CD45RO~+ T的变化特点

目的:探讨CHOP方案对外周T细胞淋巴瘤(PTCL)患者外周血中初始和记忆T细胞水平的变化及其临床意义。方法:采用流式细胞术检测20例PTCL患者CHOP方案化疗前后外周血中CD4+CD45RA+、CD4+CD45RO+、CD8+CD45RA+和CD8+CD45RO+T细胞的比例,分析疗效与T细胞亚群的关系。结果:PTCL患者化疗前外周血中CD4+T细胞、CD4+CD45RO+细胞的比例明显降低,CD4+CD45RA+、CD8+、CD8+CD45RO+和CD8+CD45RA+T细胞的比例均明显升高(P<0.05),而化疗后PTCL患者CD4+、CD4+CD45RO+细胞的比例较治疗前升高,CD4+CD45RA+、CD8+、CD8+CD45RO+和CD8+CD45RA+T细胞比例则较治疗前稍下降(P<0.05)。治疗前后化疗有效组的CD4+CD45RA+均明显高于化疗无效组(P<0.05)。结论:CHOP治疗对PTCL患者胸腺输出功能有一定的影响,伴有较高胸腺输出功能者对化疗效果更好。     

CCR5 and CXCR4 expression on memory and naive T cells in HIV-1 infection and response to highly active antiretroviral therapy

OBJECTIVE: To measure CCR5 and CXCR4 chemokine receptor expression on CD4 and CD8 T cells in HIV-1 infection and to relate levels to the distribution of CD45RO memory and CD45RA-naive subsets, measures of disease activity, and response to highly active antiretroviral therapy (HAART). DESIGN: Fourteen untreated HIV-1-infected patients, 18 patients at 3-to 4-weeks after beginning HAART, and 35 uninfected control subjects were studied. METHODS: Four-color cytofluorometry with appropriate conjugated monoclonal antibodies (mAbs) was performed to define CD45RA and CD45RO subsets of CD4 and CD8 T cells and measure their expression of CCR5, CXCR4, and CD38. RESULTS: HIV-1-infected patients had higher CCR5 levels and lower CXCR4 levels on CD4 and CD8 T cells and their CD45RO/CD45RA subsets than control subjects did. However, CCR5 elevation was statistically significant only for CD4 T cells and their subsets, and CXCR4 depression was significant for CD8 T cells and their subsets (and for CD4:CD45RO cells). The elevation of CCR5 and depression of CXCR4 were not due to shifts in CD45RO/CD45RA subset proportions but to upregulation or downregulation within the subsets. CCR5 elevation on CD4 T cells was significantly restored toward normal by HAART, but the CXCR4 depression was not. CCR5 expression but not CXCR4 expression correlated with other measures of immunodeficiency (CD4 T-cell levels), active infection (viral load), and cellular activation (CD38). CONCLUSIONS: CCR5 elevation is a concomitant of immune activation and viral replication that occurs in HIV-1 infection, but the relation of CXCR4 depression to severity of infection, disease progression, and response to therapy remains undefined.     

艾滋病HAART治疗免疫重建炎性综合征的免疫机制初步研究

目的 为探讨我国艾滋病病人(AIDS)启动高效抗反转录病毒治疗(HAART)后,发生免疫重建炎性综合征(IRIS)的免疫学发病机制,在前瞻性研究队列中对启动HAART的AIDS病人部分淋巴细胞亚群、调节性T细胞和部分Th1和Th2细胞因子等进行追踪分析.方法 将接受HAART初始治疗的238例AIDS病人建立前瞻性研究队列,分为在24周内发生IRIS的47例病人(IRIS组)和未发生IRIS的191例病人(非IRIS组).在HAART的0周、12周和24周采集两组血标本,对47例IRIS病例及随机选择的50例非IRIS病例进行免疫机制的研究分析,检测HIV病毒载量和CD4+细胞计数;使用流式细胞术检测部分淋巴细胞亚群和调节性T细胞(CD4+CD25+Foxp3+).在HAART的0周、4周、12周、24周及发生IRIS时分别采集全部238例患者的血标本,使用ELISA法测定血浆细胞因子IL-2、IFN-γ、IL-4、IL-10以及IL-7水平.结果 两组感染者的CD4+、CD8+纯真细胞和记忆细胞比例在0周、12周、24周及发生IRIS时比较差异均无统计学意义,但CD4+记忆细胞和CD8+记忆细胞比例在启动HAART后均明显上升.两组感染者CD4+CD38+活化细胞和CD8+CD38+活化细胞比例在基线时均较正常值明显升高,治疗后均有下降趋势.在0周、12周、24周及发生IRIS时CD4+CD25+Foxp3+调节性T细胞在IRIS组中均较非IRIS组要低.两组IL-2及IFN-γ在HAART后均呈上升趋势,且IRIS组在4周及发生IRIS时更明显高于非IRIS组;两组IL-4及IL-10在HAART后均呈下降趋势,IRIS组中IL-10在4周及发生IRIS时更明显低于非IRIS组.IL-7在两组中基线时均较正常值升高,并随HAART进程逐渐降低,其中IRIS组在各随访点IL-7均要高于非IRIS组.结论 接受HAART治疗者早期即出现记忆T细胞快速上升,在IRIS炎症反应中可能起重要作用.IL-2、IL-10和IFN-γ在发生IRIS时的水平差别,提示IRIS的发生与炎性细胞因子大量增加,炎性抑制因子相对不足有一定关系.IL-7也可能参与到IRIS的发病机制中.

Abstract：

Objective To investigate the immunological pathogenesis of immune reconstitution inflammatory syndrome (IRIS) during highly active antiretroviral therapy( HAART), in this prospective cohort study we analyzed the lymphocyte subsets, lymphocyte activation, changes in regulatory T cells, and levels of Th1 and Th2 cytokines in both IRIS and non-IRIS groups. Methods Two hundred and thirty-eight AIDS patients received HAART and participated prospective research cohort for 24 weeks follow-up. Forty-seven IRIS cases and 191 non-IRIS cases were enrolled in the IRIS group or non-IRIS group respectively. Blood samples were collected in both groups at pre- and post-HAART 12 weeks, 24 weeks. Using flow cytometer to detect the immunophenotypes of lymphocyte subsets (CD4 + CD45RA+ CD62L+, CD8+ CD45RA+ CD62L+naive T cells; CD4+ CD45RO+, CD8+ CD45RO+ memory T cells), activated T lymphocytes (CD4+CD38 +, CD8 + CD38 + cells), and regulatory T cell ( CD4 + CD25 + Foxp3 + ). Blood samples collected at pre-and post-HAART4 weeks, 12 weeks, 24 weeks and used ELISA to detect IL-2, IFN-γ, IL-4, IL-10and IL-7 cytokine serum levels. Results The percentages of CD4 + and CD8 + naive T cells and mlemory T cells exhibited no significant differences at the baseline, 12 weeks, 24 weeks of HAART initiation between both groups, but CD4 + and CD8 + memory T cells were demonstrated a trend towards to increase while compared to baseline during HAART. The percentages of CD4 + and CD8 + activated T cells are significantly higher at the baseline while compared to normal control and demonstrated a downward trend, but between both groups showed no significant difference. The percentages of CD4 + regulatory T cell was lower in IRIS group than non-IRIS group at the baseline, 12 weeks, 24 weeks and the onset of IRIS. Th1 cytokines, IL-2 and IFN-γshowed an upward trend during HAART at the levels of IRIS group had significantly increased at 4 weeks and the onset of IRIS. Th2 cytokines, IL-4 and IL-10 showed a downward trend during HAART,and the levels of IL-10 in IRIS group had significantly decreased at 4 weeks and the onset of IRIS. IL-7 was higher than normal control at the baseline in two groups and showed a downward trend during HAART. The level of IL-7 was higher than non-IRIS group at all follow-up points. Conclusion Memory T cells appear rapid increase in the early stage of HAART and may play a significant role in the inflammatory response of IRIS. CD4 + and CD8 + naive T cells, memory T cells and activated T cells showed no significant difference between IRIS and non-IRIS group within 24 weeks after HAART started. There was a significant reduction in the frequency of regulatory T cells in IRIS group without obvious upward trend during HAART, suggesting that the immune suppression function of regulatory T cells in IRIS was impaired. IL-2 and IFN-γ significantly increased while IL-10 significantly decreased at 4 weeks post-HAART initiation and onset of IRIS in IRISgroup than non-IRIS group, suggested that IRIS was related to cytokines environment disorder. That is, a significant increase in inflammatory cytokines, while the relative lack of non-inflammatory cytokines. The level of IL-7 decreased gradually after HAART started, and it was higher in IRIS group when compared to non-IRIS group in the first 24 weeks after HAART started. Also IL-7 may play a role in the pathogenesis of IRIS.     

Increased allergen concentration enhances IFN-gamma production by allergic donor T cells expressing a peripheral tissue trafficking phenotype

BACKGROUND: Clinically effective allergen-specific immunotherapy correlates with decreased circulating allergen-specific IL-4+ T cells but increased IFN-gamma+ cells at sites of allergen challenge. Whether immunotherapy promotes trafficking of IFN-gamma+ T cells to peripheral tissues is unknown. As aeroallergen is administered at higher concentrations during immunotherapy than those encountered naturally, the effect of allergen concentration on adhesion molecule (CD62L and CD49d) and chemokine receptor (CCR3 and CCR5) expression by peripheral-blood T cells was analysed in parallel with cytokine production. METHODS: House dust mite-allergic donor peripheral blood mononuclear cells were cultured for 14 days with different allergen concentrations. Cytokine profiles of were analysed by flow cytometry. RESULTS: Cultures stimulated with 100 microg/ml house dust mite extract compared with 1 microg/ml had increased proportions and numbers of CD62Llo, CD49dhi or CCR5+ T cells expressing IFN-gamma. CCR3-positive CD4+ and CD8+ T cell numbers were very low and did not differ between cultures. In contrast the proportions of 'peripheral tissue trafficking' CD4+ T cells expressing IL-4 were decreased in cultures stimulated with high in comparison with low allergen concentration. CONCLUSION: These results indicate the importance of achieving high allergen doses during immunotherapy to promote IFN-gamma production and expression of a 'peripheral tissue trafficking' phenotype by allergen-specific CD4+ and CD8+ T cells. The net change in cytokine milieu at sites of allergen encounter would then down-regulate clinical manifestations of allergic disease.     

CCR5 and CXCR4 chemokine receptor expression and beta-chemokine production during early T cell repopulation induced by highly active anti-retroviral therapy.

Expression of chemokine receptors and beta-chemokine production by peripheral blood mononuclear cells (PBMC) were determined in HIV-1-infected individuals before and after highly active anti-retroviral therapy (HAART) and their relationship to viral load, T cell phenotype and the expression of immunological activation markers was examined. We found that the expression of CCR5 is up-regulated in HIV-1-infected individuals while CXCR4 appears down-regulated on both CD4 and CD8 T cells compared with normal controls. These alterations are associated with the high levels of viral load. In addition, a relationship was observed between the degree of immune activation and chemokine receptor expression on T cells. However, after 3 months of combined anti-retroviral regimen, expression of CXCR4 significantly increased while CCR5 decreased when compared with pretherapy determinations. This was seen in strict association with a dramatic decrease of viral load and an increase of both CD45RA+/CD62L+ (naive) and CD45RA-/CD62L+ or CD45RA+/CD62L- (memory) T cells accompanied by a significant decrease of the expression of immune activation markers such as HLA-DR and CD38. At enrolment, both spontaneous and lectin-induced RANTES, macrophage inflammatory protein-1alpha (MIP-1alpha) and MIP-1beta production by PBMC were higher in HIV-1-infected individuals compared with normal controls, although differences for MIP-1beta were not statistically significant. However, RANTES and MIP-1alpha production decreased during HAART at levels closer to that determined with normal controls, while MIP-1beta production was less consistently modified. These data indicate that the expression of chemokine receptors CCR5 and CXCR4 and the production of beta-chemokines are altered in HIV-infected individuals, and suggest that their early modifications during HAART reflect both the peripheral redistribution of naive/memory T cell compartments and the decrease in levels of T cell activation. Such modifications in the expression of host determinants of viral tropism and the production of anti-viral molecules may play a role in the emergence of virus variants when a failure of HAART occurs.     

Differential expression of the cytokine receptors for human interleukin (IL)-12 and IL-18 on lymphocytes of both CD45RA and CD45RO phenotype from tonsils, cord and adult peripheral blood

The objective of this study was to demonstrate the variable expression of cytokine receptors on naive versus memory human CD4+ T cell subpopulations in tonsillar tissue, cord blood and adult blood. We prove that the receptors for both interleukin (IL)-12 and IL-18 are expressed exclusively on memory T cells. This observation was seen not only on the CD45RO+ memory T cells but also on a significant percentage of the CD45RA+, CD62L-, CD27- and CCR7- populations. Furthermore, CD45RA+ CD62L+, CD27+ or CCR7+ CD4+ T cells that expressed IL-12Rbeta1 and IL-18Ralpha did not express CD31, a marker for recent thymic emigrants. We reveal that cord blood lymphocytes do not express IL-12Rbeta1 whereas IL-18Ralpha expression was detected at low levels. Importantly, the IL-12Rbeta2 signalling chain, which is absent in all resting T cells, was up-regulated in both CD45RA+ and CD45RO+ T cells as a result of stimulation with anti-CD3 and anti-CD28 in vitro. This observed up-regulation was, however, restricted to 80% of the total CD4+ population. Finally, a very small proportion of the CD4+ CD45RO+ tonsillar T cells expressed the IL-12 and IL-18 receptors, thereby establishing the differential expression of these receptors between peripheral and tonsillar memory T cell subpopulations.     

Effects of cryopreservation on lymphocyte immunophenotype and function

Cryopreservation of isolated peripheral blood mononuclear cells (PBMCs) for phenotypic and functional analyses is considered a standard procedure in order to minimize operator-dependent inter-assay variability and to optimize the use of available resources. However, only few and somewhat conflicting data are presently available on the effects of cryopreservation on PBMCs, especially in samples from HIV-infected patients in which assessment of lymphocyte phenotype and function is of the outmost importance. In this study, we compared fresh versus frozen/thawed (F/T) samples isolated from 19 healthy individuals and 21 HIV-infected patients, showing that cryopreservation induces: (i) a profound decrease of CD62L expression, with a consequent significant decline of the calculated proportions of "na?ve" (CD45RA+CD62L+) and "central memory" (CD45RO+CD62L+) T cells; (ii) an increase of the calculated proportions of "effector" CD8+ T cells (CD45RA+CD62L- and CD45RO+CD62L-) in the healthy subjects, while no changes were observed in the HIV-infected group; (iii) a significant decline of CC chemokine receptor 5 (CCR5) expression; (iv) a loss of proliferative responses to some HIV antigens (i.e. p24) and recall antigens [cytomegalovirus (CMV) and Influenza] in HIV-infected patients. We thus conclude that cryopreservation induces a consistent set of changes in PBMCs from both healthy and HIV-infected individuals, and that certain immunological studies of HIV-infected patients (i.e. studies of immune reconstitution following antiretroviral therapy in HIV-infected patients or studies of HIV-infectivity in vitro using CCR5-tropic strains) should be performed on fresh samples.