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1.
Selective impairment of T lymphocyte activation through the T cell receptor/CD3 complex after cytomegalovirus infection. 下载免费PDF全文
M Timn A Arnaiz-Villena J Ruiz-Contreras J T Ramos-Amador A Pacheco J R Regueiro 《Clinical and experimental immunology》1993,94(1):38-42
Cytomegalovirus (CMV) infection is reported to cause transient immunosuppression in man. In this study we have analysed the effect of CMV on T lymphocyte function in 29 children diagnosed for acute CMV infection. Peripheral blood mononuclear cells (PBMC) obtained from the patients showed a significant specific impairment in their proliferative response to enterotoxins A and C1, to concanavalin A and to the anti-CD3 MoAb OKT3. The impaired responses were corrected with exogenous IL-2. In contrast, stimulation using phytohaemagglutinin, as well as activation signals delivered through the surface molecules CD26 or CD28, elicited normal proliferative responses in CMV PBMC. The results indicate that the T cell anergy associated with CMV infection is restricted to the T cell receptor/CD3 activation pathway. 相似文献
2.
Kristen A. Weigle Ciro Valent Sumaya Milka M. Montiel 《Journal of clinical immunology》1983,3(2):151-155
Lymphocyte subsets were measured using monoclonal antibodies in 11 children with Epstein-Barr virus-induced infectious mononucleosis and compared with those of 10 normal children. In acute infectious mononucleosis the percentage of T8+ lymphocytes was greater while the percentage of T4+ lymphocytes and the T4+ to T8+ ratio were less than those measured in normal children. The percentage and absolute number of T lymphocytes, as enumerated by E rosetting, did not differ from the values for normal children. The children with acute infectious mononucleosis had a somewhat lower T8+ response than that observed in four adult infectious mononucleosis patients. With clinical recovery, the T lymphocyte-subset values returned toward normal. T8+ lymphocytes, a phenotype subset with predominantly suppressor activity, presumably reduce normal cellular immune functions transiently and may limit the continued proliferation of Epstein-Barr virus-infected B lymphocytes. 相似文献
3.
L Wagner M Wiesholzer C P Worman G Lang W Base 《Clinical and experimental immunology》1995,100(2):223-226
Peripheral blood lymphocytes of three patients suffering from infectious mononucleosis due to Epstein-Barr virus (EBV) infection were analysed for BLT-esterase expression in peripheral blood lymphocytes by a well established cytochemical staining method. During the acute phase of disease with presence of clinical symptoms a very high level of up to 90% BLT-esterase-expressing lymphocytes were detected. The increased percentage of lymphocytes expressing BLT-esterase coincided with the time of greatest symptoms and the peak elevation of hepatocellular enzymes. The still moderately elevated level only gradually decreased to normal during the further recovery period of 2 months during which the patients described episodes of weakness. Peripheral blood lymphocyte phenotype analysis revealed a marked CD8 lymphocytosis, a CD4/CD8 ratio of about 0.2, low number of CD19+ B cells, and a high level of DR+ CD3+ lymphocytes. Reduction of BLT esterase expression during the recovery period coincided with reduction of CD8+ DR+ lymphocytes. By a combination of BLT-esterase staining with immunocytochemical phenotype analysis, 95% of CD8+ lymphocytes were found to be BLT-esterase-positive. BLT-esterase might be involved in the immunodefence against EBV in infectious mononucleosis by inducing apoptosis in EBV-transformed B cells. 相似文献
4.
Expression of CD45R0 (UCHL1) by CD4+ and CD8+ T cells as a sign of in vivo activation in infectious mononucleosis. 下载免费PDF全文
T Miyawaki Y Kasahara H Kanegane K Ohta T Yokoi A Yachie N Taniguchi 《Clinical and experimental immunology》1991,83(3):447-451
CD45R0 (UCHL1), a member of leucocyte common antigen family, is expressed largely on previously activated or memory T cells. We examined CD45R0 expression of T cell subpopulations in patients with Epstein-Barr virus (EBV) induced infectious mononucleosis (IMN) as a sign of in vivo activation. Consistent with the notion that activated CD8+ T cells expand in acute IMN; the majority of CD8+ T cells in patients with acute IMN expressed CD45R0 to the similar extent to HLA-DR expression. Most CD4+ T cells in these patients also demonstrated marked expression of CD45R0 as well as HLA-DR antigens, compared with age-matched controls. Expression of CD45R0 by CD4+ T cells in patients with acute IMN was more notable than their HLA-DR expression. While predominant CD8+ T cells resulted in decreased percentages of CD4+ T cells, CD4+ T cells expressing CD45R0 were shown to be significantly elevated in absolute number. The results suggest that both CD4+ and CD8+ T cells may be activated by stimulation with EBV infection. The appearance of two T cell subpopulations expressing CD45R0 in acute IMN implies their immunoregulatory roles in the control of EBV-infected cells. 相似文献
5.
Scherrenburg J Piriou ER Nanlohy NM van Baarle D 《Clinical and experimental immunology》2008,153(2):231-239
We studied simultaneously Epstein-Barr virus (EBV)-specific CD4(+) and CD8(+) T cell responses during and after infectious mononucleosis (IM), using a previously described 12-day stimulation protocol with EBNA1 or BZLF1 peptide pools. Effector function of EBV-specific T cells was determined after restimulation by measuring intracellular interferon-gamma production. During IM, BZLF1-specifc CD4(+) T cell responses were dominant compared with CD8(+) T cell responses. EBNA1-specific CD4(+) and CD8(+) T cell responses were low and remained similar for 6 months. However, 6 months after IM, BZLF1-specific CD4(+) T cell responses had declined, but CD8(+) T cell responses had increased. At diagnosis, EBV-specific CD8(+) T cells as studied by human leucocyte antigen class I tetramer staining comprised a tetramer(bright)CD8(bright) population consisting mainly of CD27(+) memory T cells and a tetramer(dim)CD8(dim) population consisting primarily of CD27(-) effector T cells. The remaining EBV-specific CD8(+) T cell population 6 months after the diagnosis of IM consisted mainly of tetramer(bright)CD8(bright) CD27(+) T cells, suggesting preferential preservation of memory T cells after contraction of the EBV-specific T cell pool. 相似文献
6.
Macallan DC Wallace DL Irvine AJ Asquith B Worth A Ghattas H Zhang Y Griffin GE Tough DF Beverley PC 《European journal of immunology》2003,33(10):2655-2665
During acute infectious mononucleosis (AIM), large clones of Epstein-Barr virus-specific T lymphocytes are produced. To investigate the dynamics of clonal expansion, we measured cell proliferation during AIM using deuterated glucose to label DNA of dividing cells in vivo, analyzing cells according to CD4, CD8 and CD45 phenotype. The proportion of labeled CD8(+)CD45R0(+) T lymphocytes was dramatically increased in AIM subjects compared to controls (mean 17.5 versus 2.8%/day; p<0.005), indicating very rapid proliferation. Labeling was also increased in CD4(+)CD45R0(+) cells (7.1 versus 2.1%/day; p<0.01), but less so in CD45RA(+) cells. Mathematical modeling, accounting for death of labeled cells and changing pool sizes, gave estimated proliferation rates in CD8(+)CD45R0(+) cells of 11-130% of cells proliferating per day (mean 47%/day), equivalent to a doubling time of 1.5 days and an appearance rate in blood of about 5 x 10(9) cells/day (versus 7 x 10(7) cells/day in controls). Very rapid death rates were also observed amongst labeled cells (range 28-124, mean 57%/day),indicating very short survival times in the circulation. Thus, we have shown direct evidence for massive proliferation of CD8(+)CD45R0(+) T lymphocytes in AIM and demonstrated that rapid cell division continues concurrently with greatly accelerated rates of cell disappearance. 相似文献
7.
GITR, a member of the TNF receptor superfamily, is costimulatory to mouse T lymphocyte subpopulations 总被引:13,自引:0,他引:13
Ronchetti S Zollo O Bruscoli S Agostini M Bianchini R Nocentini G Ayroldi E Riccardi C 《European journal of immunology》2004,34(3):613-622
GITR (glucocorticoid-induced TNFR family related gene) is a member of the TNFR superfamily (TNFRSF) that is expressed in different cell types, including T lymphocytes. Because of a high homology in its cytoplasmic region with other known costimulatory members of the TNFRSF, we investigated whether GITR played a costimulatory role in T lymphocyte subpopulations. Our results show that the proliferation response of CD8+ and CD4+ peripheral T cell subpopulations was potentiated when a GITR costimulus was added to an anti-CD3 stimulus. Furthermore, expression of the main activation-induced receptor (IL-2Ralpha) and production of IL-2 and IFN-gamma were increased more with a GITR costimulus than with anti-CD3 alone. GITR stimulation also enhanced anti-CD3-induced ERK phosphorylation, suggesting that GITR is involved in MAPK-pathway activation. Interestingly, CD4+CD25+ regulatory T cell (Treg cell) proliferation was triggered by the GITR costimulus; Treg cell proliferation was paralleled by the loss of the anergic phenotype and suppressor activity. Nevertheless, unstimulated GITR(-/-) CD4+CD25+ and GITR(+/+) CD4+CD25+ cells were equally able to exert suppressor activity on CD4+CD25- responder cells. These results indicate a novel function for GITR as costimulatory molecule of T cell subsets. 相似文献
8.
Immunosuppression follows systemic T lymphocyte activation in the burn patient. 总被引:1,自引:0,他引:1 下载免费PDF全文
J A Teodorczyk-Injeyan B G Sparkes G B Mills W J Peters 《Clinical and experimental immunology》1991,85(3):515-518
A general consensus that thermal injury affects T lymphocyte function adversely is supported particularly by the observation that burned patients' lymphocytes secrete reduced levels of biologically active IL-2 in vitro. In the same patients, however, high serum concentrations of the low-affinity IL-2 receptor (IL2R alpha), a product of an IL-2-activated gene, have been observed. In this study a significant proportion of patients also demonstrated over-physiological levels (from 2 to 500 U/ml) of serum IL-2 ascertained by immunoassay. Increases in serum IL-2 content correlated significantly (P less than 0.02) with those of serum IL-2R alpha during the first week post-burn. Later, serum IL-2R alpha levels continued to increase up to 30 days while IL-2 eventually declined. Thus, augmented secretion of IL-2R alpha appears related to the high serum IL-2 content. Therefore refractoriness to further immune stimulation may be due to early activation of the lymphoid system, rather than to an intrinsic incapacity of T lymphocytes for generating sequential responses. 相似文献
9.
We have investigated the effects of the protein synthesis inhibitor,cycloheximide (CHX), on the induction of post-thymic T celltolerance in mice primed with the bacterial superantigen, Staphylococcusaureus enterotoxin B (SEB). A single injection of 1 mg CHX preventedprotein synthesis in splenic cells for <6 h in vivo. Theconcomitant administration of SEB and CHX prevented inductionof SEB-specific anergy, but did not interfere with the deletionof SEB-speclfic Vß8+ T cells by activation-induced,programmed cell death. When CHX was given 24 h after SEB administrationthe expression of anergy was not affected. These findings suggestthat anergy and deletion represent independent processes. Furthermore,these observations, together with the fact that SEB retainsthe potential to induce anergy in specific T cells 8 h afterpriming in vivo, imply that the determination of alternate fates(anergy or death) occurs at early time points after SEB injection 相似文献
10.
11.
Cytotoxic T lymphocytes (CTL) with the CD4+ phenotype that recognize major histocompatibility complex (MHC) class II antigens are detectable very frequently in cultures of human alloreactive or virus-specific T cells. The significance of these CD4+ CTL for an immune reaction in vivo is not clear. Since Epstein-Barr virus (EBV) transformed B cells express HLA-class I and class II antigens equally well both CD8+ and CD4+ CTL should be stimulated during an acute EBV infection. We analysed the MHC specificity and the phenotype of EBV-specific CTL from patients with infectious mononucleosis (IM). When tested directly without any previous culture, T cells from patients in the acute phase of IM showed specific MHC-restricted cytotoxicity against the autologous B cell line. Addition of a HLA class I specific monoclonal antibody (MoAb) but not of a HLA class II specific MoAb resulted in a complete blocking of the lytic activity. Cell sorting revealed that the entire cytotoxic activity was present in the CD8+ fraction whereas no specific CTL were detectable in the CD4+ fraction. The absence of cytotoxicity in CD4+ cells was not due to a lack of activation of these cells since both CD8+ and CD4+ cells were activated in situ, showing spontaneous growth in interleukin-2 (IL-2) and expressing the activation marker TP103. Frequency estimation revealed that 1/300-1/600 CD8+ but only 1/2000-1/4000 CD4+ T cells gave rise to a specific CTL colony after 10 days. If CD4+ colonies were tested repeatedly for cytotoxicity we found that CD4+ CTL acquired their cytotoxicity during in vitro culture. In addition, we isolated EBV-specific CD4+ T cell clones able to lyse their stimulator cells in the presence but not in the absence of lectin, even after a long period of culture. Taken together our results show that cytotoxicity mediated by CD4+ T cells does not play a role in an anti-viral immune response. 相似文献
12.
A hereditary immunodeficiency characterized by CD8+ T lymphocyte deficiency and impaired lymphocyte activation. 下载免费PDF全文
W J Monafo S H Polmar S Neudorf A Mather A H Filipovich 《Clinical and experimental immunology》1992,90(3):390-393
An unusual form of severe combined immunodeficiency in children from two different families was associated with absence of CD8+ T lymphocytes and normal numbers of CD4+ T lymphocytes that did not respond to stimulation by non-specific mitogens, specific antibodies against T cell receptor or specific antigens. The defect in the CD4+ cells was bypassed by activating agents which are independent of the T cell receptor. The combination of an activation defect and selective depletion of CD8+ T lymphocytes suggests that the defective pathway is important in the differentiation of immature thymocytes as well as the proliferation of mature lymphocytes. 相似文献
13.
CpG-ODN是人工合成的含有CpG基序的ODNs,能够模拟细菌DNA的免疫刺激活性,通过细胞内定位的Toll样受体9活化抗原递呈细胞(APC),如树突状细胞(DC)和B细胞,分泌大量Th1型细胞因子诱导产生Th1型免疫应答。CpG—ODN不仅增强T淋巴细胞的活化,在特定条件下还可以抑制T淋巴细胞功能。在抗感染、抗肿瘤疾病中,CpG—ODN作为新型的免疫佐剂得到了广泛的应用,但其安全性问题应引起足够的重视。 相似文献
14.
Mariolina Salio Salvatore Valitutti Antonio Lanzavecchia 《European journal of immunology》1997,27(7):1769-1773
T cell receptor (TCR) down-regulation is a consequence of specific receptor engagement and plays an important role in modulating the T cell response. We have investigated the role of protein kinase C (PKC) and protein tyrosine kinases (PTK) in the induction of TCR down-regulation. We report that the mutation of S126 in the CD3-γ chain that is known to inhibit phorbol-12-myristate 13-acetate-induced TCR down-regulation does not affect down-regulation induced by a specific agonist. In addition, agonist-induced TCR down-regulation is not affected by blockade or depletion of PKC, neither by blockade or lack of PTK, while the same treatments efficiently interfere with T cell activation. These results demonstrate that TCR down-regulation is induced by early events which follow specific engagement by an agonist and can be dissociated from those required for full T cell activation. 相似文献
15.
目的 探讨儿童传染性单核细胞增多症(IM)T细胞亚群的变化及免疫干预的有效性.方法 入选的48例患儿分为2组,治疗组患儿28例,用丙种球蛋白(IVIG)治疗,IVIG 400 mg/(kg·d),连用5 d;或IVIG 1g/(kg·d),连用2 d.对照组患儿20例,予更昔洛韦(GCV)5~10 mg/(kg·d)连用5 d.并予对症支持治疗.选择20例正常儿童作为健康对照.结果 健康儿童CD4(%)、CD8(%)及CD4/CD8比值分别为(34.12±3.53)%、(26.22±4.43)%及(1.41±0.3);IVIG组分别为(24.2±4.3)%、(36.4±6.8)%及(0.72±0.12);GCV组(23.7±5.1)%、(37.3±7.8)%及(0.67±0.13),健康对照组与两组IM患儿比较,差异有统计学意义(P<0.05);与治疗前比较,IVIG组患儿治疗后CD4(%)升高、CD8(%)下降及CD4/CD8比值升高(P<0.05);而GCV组患儿治疗前后上述指标无显著性变化(P>0.05);IVIG治疗组患儿临床症状及体征较GCV治疗组消失快(P<0.05),IVIG组患儿治疗有效率88.7%,GCV组患儿治疗有效率59.2%(χ2=3.97,P<0.05);IVIG组患儿平均住院日为(9.2±4.3)d,较GCV组(13.8±5.1)d明显缩短(t=-4.24,P<0.05);结论IM患儿除了病毒感染导致的直接影响外,存在明显的免疫功能紊乱;IVIG免疫干预治疗优于单纯抗病毒治疗. 相似文献
16.
The role of T3 in the activation of human T cells 总被引:13,自引:0,他引:13
Arthur Weiss John Imboden Robert Wiskocil John Stobo 《Journal of clinical immunology》1984,4(3):165-173
17.
Francesco Novelli Mirella Giovarelli Reiner Gentz Mario Zucca Francesco Di Pierro Gianni Garotta Guido Forni 《European journal of immunology》1993,23(6):1226-1231
Previous work has shown that neutralization of physiologically secreted interferon(IFN)-γ or blockade of its receptor during T lymphocyte activation inhibits both proliferation and cytotoxic T lymphocyte generation, suggesting that IFN-γ plays a crucial role in T lymphocyte induction and differentiation. In this study, the kinetics of the surface expression of the 90-kDa IFN-γ receptor (IFN-γR) was followed during human mixed lymphocyte reaction (MLR) to alloantigens. IFN-γR mRNA is constitutively expressed on resting peripheral blood lymphocytes emerging from nylon wood column (NW-PBL) and its expression increases two- to threefold on alloactivated NW-PBL. IFN-γR protein is poorly expressed on the membrane of resting CD3+ cells, but up-modulates after 3-day MLR and sharply down-modulates at day 6. Both the p55 and the p75 chains of interleukin-2 receptor (IL-2R) were shown to up-modulate in parallel with IFN-γR, whereas they were still highly expressed at day 6. After alloactivation, IFN-γ and IL-2 secretion starts at 24 h, peaks at day 3 and decreases just when IFN-γR and IL-2R begin to up-modulate. Proliferation peaks at day 6. Lastly, stimulation with distinct cell populations showed that the intensity of lymphocyte proliferation, IFN-γR membrane up-modulation, and IFN-γ and IL-2 secretion are regulated in a parallel manner, thus suggesting that they are interrelated. Taken as whole these results demonstrate that increased expression of IFN-γR on T lymphocytes can be a critical event during their activation, and strongly support the hypothesis that IFN-γ/IFN-γR interaction provides a signal for its progression. 相似文献
18.
19.
Clements James L.; Winslow Genine; Donahue Christopher; Cooper Sheldon M.; Allison James P.; Budd Ralph C. 《International immunology》1993,5(11):1451-1460
Peripheral lymphoid tissues of Ipr mice contain a large proportionof TCRß/CD3+CD4–CD8– T cells that lacksurface CD2 and express the B cell isoform of CD45, B220. Thissubset of T cells does not proliferate or produce IL-2 in responseto mitogenic signals or TCR–CD3 ligation. At the sametime, these abnormal T cells display several characteristicsof an activated phenotype. Collectively, these properties ofIpr CD4–CD8– T cells have functional parallels withanergic T cells. A critical co-stimulatory molecule implicatedin the prevention of or recovery from anergy is CD28, whichbinds the ligand BB1/B7 on certain accessory cells. Ipr CD4–CD8–T cells express normal levels of CD28 which is capable of transducinga strong proliferative signal to these cells in co-stimulationwith mitogens. However, proliferation of Ipr CD4–CD8–T cells in response to CD28 co-stimulation does not reach thelevels observed in normal T cells stimulated under similar conditions.Stimulation with anti-CD28 mAb in conjunction with phorbol myristateacetate and lonomycin promotes cell cycling in the CD2–subset of CD4–CD8– T cells, and results in a slightinduction of CD2 levels during the course of the culture period.However, the majority of cells obtained at the end of the cultureperiod remain TCRß+ CD4–CD8–, CD2low/–and B220high, similar to freshly isolated CD4–CD8–Ipr T cells. In contrast, if IL-2 is included in the cultures,a strong shift toward a CD2+ phenotype is observed by a majorityof the Ipr T cells. Upon repeat stimulation, these Ipr CD4–CD8–T cells can now proliferate in an IL-2-dependent manner whenstimulated with only anti-CD3 mAb or mitogens, in the absenceof exogenous IL-2 or anti-CD28 mAb. These data show that thehyporesponsiveness of Ipr CD4–CD8– T cells doesnot result from a lack of CD28 expression, that it is not afixed state, and that it can be reversed by the induction ofcell cycling in the presence of IL-2. These observations extendthe parallels between Ipr CD4–CD8– T cells and anergicT cells. 相似文献