Detection of intracellular IFN‐γ and IL‐4 cytokines in CD4+ and CD8+ T cells in the peripheral blood of dogs naturally infected with Leishmania infantum

Canine leishmaniosis (CanL) is a systemic zoonotic disease the clinical manifestations of which can range from self‐healing cutaneous lesions to disseminated visceral disease. Effective activation of cellular immunity is the cornerstone of resistance against Leishmania infantum in infected dogs. The aim of this cross‐sectional, controlled study was the intracellular detection of interleukin 4 (IL‐4) and interferon‐γ (IFN‐γ) in CD4+ and CD8+ lymphocytes in the peripheral blood of 40 dogs naturally infected with L. infantum by applying flow cytometry. The percentage of CD4+IL‐4+ and CD8+IL‐4+ lymphocytes (with or without immunostimulation) was low in the clinically healthy and subclinically infected dogs in contrast to clinically affected ones. In the same groups of dogs, the percentage of CD4+IFN‐γ+ and CD8+IFN‐γ+ T cells in their resting phase and following specific immunostimulation with Leishmania soluble antigen (LSA) was also low. CD4+IL‐4+ and CD8+IL‐4+ T cell percentage was higher in sick compared to clinically healthy and subclinically infected dogs, after immunostimulation. The corresponding figure of CD8+IL‐4+ cells in sick dogs after LSA immunostimulation was also increased thus underlining the important role these cells may play in humoral immunity and perhaps the progression of CanL.     

慢性乙型肝炎外周血中T细胞亚群和NK细胞的变化及临床意义

目的观察慢性乙型肝炎患者外周血中T细胞亚群及NK细胞含量的变化,进一步了解慢性乙型肝炎患者的免疫功能状况。方法收集48例慢性乙型肝炎患者作为实验组,其中HBe Ag阳性20例,阴性28例,选择26名健康人群作为正常对照组,采用流式细胞仪检测两组血清中CD3+T细胞、CD4+T细胞、CD8+T细胞和NK细胞的含量。结果与正常对照组比较,慢性乙型肝炎患者外周血中CD3+T细胞、CD4+T细胞和NK细胞的含量明显降低,而CD8+T细胞含量升高,差异具有统计学意义(P0.05),而HBe Ag阳性和阴性的慢性乙型肝炎患者之间的差异无统计学意义(P0.05)。结论慢性乙型肝炎患者免疫功能低下,这对患者免疫功能的判断、疾病进展、治疗及预后有一定的指导意义。     

肺结核患者外周血CD_4~+、CD_8~+T细胞Blimp-1表达下降

目的研究活动性肺结核患者外周血单个核细胞(PBMCs)Blimp-1的表达及临床意义。方法采集31例活动期肺结核患者和45位健康对照组外周血,纯化PBMCs,用结核分枝杆菌ESAT-6和CFP-10混合性抗原肽库刺激,通过细胞表面标记和细胞内细胞因子染色技术,采用流式技术检测CD+4、CD+8T细胞Blimp-1的表达。结果与对照组比较,肺结核患者PBMCs中的CD+4、CD+8T细胞亚群分布出现显著性下降,且肺结核患者CD+4T细胞中Blimp-1的表达比例(%)下降(肺结核组89.5%(83.8%,95.7%),对照组94.5%(89.8%,98.7%),P0.05),且CD+4、CD+8T细胞中Blimp-1的表达量(平均荧光强度)也显著性下降(CD+4T细胞:肺结核组9.28(7.5,18.9),对照组15.4(11,25.4),P0.05);CD+8T细胞:肺结核组9.01(6.08,14.7),对照组14.2(9.53,23.1),P0.05)。结论活动期肺结核CD+4、CD+8T细胞群内Blimp-1的表达下降可能会使效应性和调节性T细胞的分化出现异常。Blimp-1可能参与结核病的疾病进程,这为研究结核病的诊断和治疗提供了线索。     

AIDS患者高效抗逆转录病毒联合治疗后外周血CD+8 CD+38T细胞与病毒载量同步变化

目的了解艾滋病(AIDS)患者高效抗逆转录病毒联合治疗(HAART)前后外周血CD+38抗原在CD+8T淋巴细胞上的表达情况.方法应用流式细胞仪采用双色荧光抗体检测技术检测CD+8 CD+38 T细胞;用罗式核酸扩增荧光定量聚合酶链反应(PCR)法检测血浆病毒载量(VL).结果 HAART后2周内CD+8 CD+38 T细胞数与VL开始同步下降,12周后83%AIDS患者的VL降至＜500拷贝/ml,同时CD+8 CD+38 T细胞计数与治疗前相比非常明显地降低(P＜0.001).而且63%的AIDS患者在血浆VL低于检测水平时,其CD+8 CD+38 T细胞数仍继续下降(与VL开始达到检测水平以下时相比,P＜0.001).结论 AIDS患者在HAART开始后,CD+8 CD+38 T细胞数与VL快速下降,在24周左右降至正常水平;并且CD+8 CD+38 T细胞数在VL达到检测不到时仍继续下降,提示在血浆VL低于检测水平时,CD+8 CD+38 T细胞数能够作为判断病毒是否复制的标记.     

Mechanisms regulating expansion of CD8+ T cells during HIV‐1 infection

Abnormal immune activation and expansion of CD8+ T cells, especially of memory and effector phenotypes, take place during HIV‐1 infection, and these abnormal features persist during administration of antiretroviral therapy (ART) to infected patients. The molecular mechanisms for CD8+ T‐cell expansion remain poorly characterized. In this article, we review the literature addressing features of CD8+ T‐cell immune pathology and present an integrated view on the mechanisms leading to abnormal CD8+ T‐cell expansion during HIV‐1 infection. The expression of molecules important for directing the homing of CD8+ T cells between the circulation and lymphoid tissues, in particular CCR5 and CXCR3, is increased in CD8+ T cells in circulation and in inflamed tissues during HIV‐1 infection; these disturbances in the homing capacity of CD8+ T cells have been linked to increased CD8+ T‐cell proliferation. The production of IL‐15, a cytokine responsible for physiological proliferation of CD8+ T cells, is increased in lymphoid tissues during HIV‐1 infection as result of microbial translocation and severe inflammation. IL‐15, and additional inflammatory cytokines, may lead to deregulated proliferation of CD8+ T cells and explain the accumulation of CD8+ T cells in circulation. The decreased capacity of CD8+ T cells to localize to gut‐associated lymphoid tissue also contributes to the accumulation of these cells in blood. Control of inflammation, through ART administration during primary HIV‐1 infection or therapies aimed at controlling inflammation during HIV‐1 infection, is pivotal to prevent abnormal expansion of CD8+ T cells during HIV‐1 infection.     

Comprehensive longitudinal analysis of hepatitis C virus (HCV)‐specific T cell responses during acute HCV infection in the presence of existing HIV‐1 infection

Summary. The aim of this study was to study the development of HCV‐specific T cell immunity during acute HCV infection in the presence of an existing HIV‐1 infection in four HIV‐1 infected men having sex with men. A comprehensive analysis of HCV‐specific T cell responses was performed at two time points during acute HCV infection using a T cell expansion assay with overlapping peptide pools spanning the entire HCV genome Three patients with (near) normal CD4+ T cell counts (range 400–970 × 10⁶/L) either resolved (n = 1) or temporary suppressed HCV RNA. In contrast, one patient with low CD4+ T cell counts (330 × 10⁶/L), had sustained high HCV RNA levels. All four patients had low HCV‐specific CD8+ T cell responses, and similar magnitudes of CD4+ T cell responses. Interestingly, individuals with resolved infection or temporary suppression of HCV‐RNA had HCV‐specific CD4+ T cell responses predominantly against nonstructural (NS) proteins. While the individual with high HCV RNA plasma concentrations had CD4+ T cell responses predominantly directed against Core. Our data show that an acute HCV infection in an HIV‐1 infected person can be suppressed in the presence of HCV‐specific CD4+ T cell response targeting non‐structural proteins. However further research is needed in a larger group of patients to evaluate the role of HIV‐1 on HCV‐specific T cell responses in relation to outcome of acute HCV infection.     

The role of T cells in the development of cardiovascular disease in HIV-infected patients

Cardiovascular disease (CVD) is highly prevalent in HIV-infected patients. Besides the classical cardiovascular risk factors, HIV related factors play a role, such as immune activation and treatment with highly active antiretroviral therapy (HAART). The resulting T cell activation is regarded as one of the driving forces behind this accelerated atherogenesis. Interventions, such as early treatment and anti-inflammatory therapy, decreasing T cell activation might lead to a lower incidence of CVD in future HIV infected patients. This review specifically explores the role of T cells in the development of atherosclerosis in HIV-infected patients.     

Major role for CD8+ T cells in the protection against Toxoplasma gondii following dendritic cell vaccination

Toxoplasma gondii is the causative agent of toxoplasmosis, a worldwide zoonosis for which an effective vaccine is needed. Vaccination with pulsed dendritic cells is very efficient but their use in a vaccination protocol is unconceivable. Nevertheless, unravelling the induced effector mechanisms is crucial to design new vaccine strategies. We vaccinated CBA/J mice with parasite extract-pulsed dendritic cells, challenged them with T. gondii cysts and carried out in vivo depletion of CD4⁺ or CD8⁺ T lymphocytes to study the subsequent cellular immune response and protective mechanisms. CD4⁺ lymphocytes were poorly implicated either in spleen and mesenteric lymph node (MLN) cytokine secretion or in mice protection. By contrast, the increasing number of intracerebral cysts and depletion of CD8⁺ cells were strongly correlated, revealing a prominent role for CD8⁺ lymphocytes in the protection of mice. Splenic CD8⁺ lymphocytes induce a strong Th1 response controlled by a Th2 response whereas CD8⁺ cells from MLNs inhibit both Th1 and Th2 responses. CD8⁺ cells are the main effectors following dendritic cell vaccination and Toxoplasma infection while CD4⁺ T cells only play a minor role. This contrasts with T. gondii infection which elicits the generation of CD4⁺ and CD8⁺ T cells that provide protective immunity.     

Activated CD8+ T cells contribute to clearance of gastric Cryptosporidium muris infections

The role of CD4+ and CD8+ T lymphocytes in the development of a protective immune response against Cryptosporidium muris infection was studied by the reconstitution of severe combined immunodeficient (SCID) mice with well-defined populations of either naive or immune CD8+ or CD4+ T lymphocytes. Adoptive transfer of both naive and immune CD4+ T lymphocyte subpopulations protects SCID mice against cryptosporidiosis. Moreover, a significant biological impact of activated CD8+ T cells against gastric cryptosporidiosis was observed. The significant difference in the course and intensity of the infection in reconstituted SCID mice was found to be dependent on the protective function of both the CD4+ and CD8+ T-cell populations transferred. While SCID mice reconstituted with either immune or naive CD4+ or immune CD8+ T-cell subpopulations resolved the infection within 29, 37 and 51 days post-infection, respectively, those reconstituted with naive CD8+ T cells suffered from chronic infection similar to control SCID mice. Reconstitution with CD4+ T cells resulted in suppression of oocyst excretion and shortening of patent period in comparison with SCID mice reconstituted with CD8+ T cells. Thus, although CD4+ T cells are considered important in protective immunity, our results are the first to demonstrate the involvement of activated CD8+ T lymphocytes in the protection of mice against gastric cryptosporidiosis.     

CD4~+ CD25~+调节性T细胞与恶性腹水的相关研究进展

CD4+ CD25+调节性T细胞(CD4+ CD25+Treg细胞)是具有独特免疫调节功能的T细胞亚群,抑制免疫反应,在机体免疫稳态维持、肿瘤免疫及移植耐受等方面发挥重要的作用。近年来,调节性T细胞在肿瘤免疫及治疗的研究中受到越来越广泛的关注。现就调节性T细胞在恶性腹水方面的研究做一简要综述。     

外周血CD4+CD25+调节性T细胞在Graves病发病中的作用

测定不同阶段Graves病患者外周血中淋巴细胞亚群含量及CD4+ CD25+调节性T细胞功能.结果显示CD4+ CD25+调节性T细胞免疫功能减弱导致CD4+T细胞增殖失控可能是Graves病发病的重要原因,药物治愈患者其免疫功能难以完全恢复正常导致Grares病容易复发.     

支气管哮喘大鼠CD4+CD25+T细胞的变化及地塞米松干预作用的研究

目的 研究支气管哮喘(简称哮喘)大鼠模型支气管肺泡灌洗液(BALF)、血液、脾脏CD4+CD25+T细胞的变化,及地塞米松对CD4+CD25+T细胞的影响.方法 50只SD大鼠随机分为5组,空白对照(A)组,哮喘(B)组,地塞米松1(C)组、地塞米松2(D)组,地塞米松3(E)组.A组第l天给予腹腔注射生理盐水l ml,第15～21天每天给予生理盐水雾化.B、C、D、E组用卵蛋白建立哮喘大鼠模型,第1天,每只大鼠腹腔注射抗原l ml(卵蛋白1 mg+灭活百日咳杆菌9×106个+氢氧化铝干粉100 mg)混悬液,第15～21天给予1%的卵蛋白雾化30 min,C、D、E组于雾化后分别给予腹腔注射地塞米松0.2 mg/kg、1 mg/kg、2 mg/kg.采用流式细胞仪检测的方法 ,观察大鼠体内BALF、外周血、脾脏CD4+CD25+T细胞的变化及使用不同剂量地塞米松后对其的影响.结果 B组BALF、外周血、脾脏CD4+CD25+T细胞表达占CD4+T细胞的百分比分别是(42.21±5.62)%、(12.69±2.70)%、(11.15±1.05)%,A组结果 分别是(18.76±5.85)%、(6.21±1.73)%、(7.85±2.13)%.B组与A组比较,差异均具有统计学意义(P＜0.01,P＜0.01,P＜0.05);C组、D组、E组BALF中CD4+CD25+T细胞占CD4+T细胞的百分比表达分别是(10.49±4.03)%、(13.28±5.12)%、(7.51±5.39)%,显著低于A组和B组,(P＜0.05,P＜0.01);外周血中,C组(6.03±1.43)%、D组(4.88±0.95)%与A组(6.21±1.73)%比较,差异无统计学意义,E组(3.49±0.62)%与C组、A组比较,差异有统计学意义(P＜0.05).脾脏中,C组(7.25±1.82)%、D组(8.63±3.18)%与A组(7.85±2.13)%比较,差异无统计学意义,E组(3.38±1.37)%与C组、D组、A组比较,差异有统计学意义(P＜0.05).结论 CD4+CD25+T细胞在哮喘大鼠体内有明显的优势表达,可能是哮喘发病的机制之一.地塞米松可以抑制CD4+CD25+T细胞的表达.BALF内CD4+CD25+T细胞的变化与外周血和脾脏的变化具有一致性,监测外周血或脾脏CD4+CD25+T细胞变化可了解肺部情况.     

Th17与CD8+T细胞在慢性阻塞性肺疾病中的作用

慢性阻塞性肺疾病(COPD)是由吸烟诱导的,影响肺实质及气道的慢性炎性疾病.Th17细胞能分泌多种细胞因子促进中性粒细胞聚集活化,并增加CD8+T细胞数量,在COPD发病机制中发挥重要作用.在不同炎性微环境中,Thl7细胞与CD8+T细胞共同参与COPD发病,连接COPD的先天免疫反应及后天免疫反应.     

Induction of CD4+CD8+ double positive T cells and increase in CD5+ B cells in efferent lymph in sheep infected with Trypanosoma evansi

The effects of Trypanosoma evansi on efferent lymphocyte phenotypes draining from a lymph node primed with Pasteurella haemolytica vaccine were studied in sheep. The prefemoral efferent lymphatic ducts of the infected sheep along with those of two uninfected sheep were surgically cannulated. Lymph was collected and lymphocytes recovered from it analysed by two-colour indirect immunofluorescence staining and cytofluoremetry in a fluorescence activated cell analyser (FACSCAN). The study showed the appearance and persistence of T. evansi in the efferent lymph for a long period of time and the appearance of CD4⁺CD8⁺ (double positive, DP) T lymphocytes in the efferent lymph of infected animals. The infection also resulted in increases in CD5⁺ B cells in the prefemoral efferent lymph. In addition, there were decreases in the output of conventional B cells, CD5⁺ and CD4⁺ T cell subsets but large increases in CD8⁺ cells followed by terminal depletion of all cell subsets. In contrast, inoculation of sheep with pasteurella vaccine antigen alone produced little alterations in the proportions, but large increases in the numbers of all T cell subsets except that of CD8⁺ cells which also showed little variation; and there was a concurrent increase in the numbers and proportions of efferent B cells. In addition, the abnormal expression of DP and CD5⁺ B cells did not occur in the uninfected vaccinated sheep. It is concluded that these abnormal changes in the kinetics of efferent lymphocyte phenotypes are likely to play a role in the genesis of the generalized immunosuppression seen in trypanosome-infected hosts.