Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IL-2 and IFN-gamma gene expression was analyzed using an original method for in situ hybridization (ISH) with non-isotopic probes and flow cytometric analysis (FC). This method permits rapid detection of mRNA at a single cell level among in vitro activated human peripheral blood mononuclear cells (PBMC) and purified CD4 and CD8 T cell subsets. After stimulation with PMA and ionomycin (PMA+Io), cells were fixed at different times and hybridized with digoxigenin (DIG)-labelled RNA antisense or sense probes specific for IL-2 and IFN-gamma. The level of cytokine gene expression in individual cells was visualized using FITC-conjugated anti-DIG antibodies and the fluorescent signal was analyzed by flow cytometry. Specific hybridization with IL-2 and IFN-gamma antisense probes was detected among activated PBMC within lymphoid cells identified by their light scattering properties. Kinetic analysis of the frequency of mRNA producing cells exhibited a biphasic pattern with an early peak at 6-8 hrs. when percentages of IL-2 and IFN-gamma expressing cells reached 35 +/- 7% and 18 +/- 4%, respectively. Similar data were obtained by enzymatic detection on cell smears using AP-conjugated anti-DIG. Combination of ISH with FC was applied to the comparison of the pattern of cytokine gene expression between CD4 and CD8 T cell subsets isolated by negative selection using immunobeads and magnetic separation. IL-2 was expressed by activated CD8 T cells (25-35%), but CD4 T cells were the major producers of IL-2 as assessed by the high frequency of mRNA expressing cells (60%) and the large amount of mRNA per cell relative to the mean fluorescence intensity. In contrast, IFN-gamma mRNA was preferentially expressed by CD8 T cells (27-37%) and a minority of CD4 T cells (17-23%). Despite quantitative differences, kinetic analysis of IL-2 gene expression in CD4 and CD8 T cells showed similar profiles with an early peak at 6-8 hrs. Upregulation of IL-2 gene expression in CD4 T cells by CD28 co-stimulation increases the amount of IL-2 mRNA per cell as visualized by mean fluorescence intensity. In addition the effect of CD28 co-stimulation on IL-2 mRNA stabilisation was demonstrated by the maintenance of a high frequency of IL-2 expressing CD4 T cells and an elevated level of mRNA per cell for prolonged period after PMA+Io stimulation. By contrast CD28 co-stimulation had no obvious effect on IFN-gamma expression.
Cell Mol Biol (Noisy-le-grand) 1995 Nov
PMID:Distinct pattern of IL-2 and IFN-gamma gene expression in CD4 and CD8 T cells: cytofluorometric analysis at a single cell level using non-radioactive probes. 859 73

The ability of thymocytes to express cytokine genes changes during the different stages of thymic development. Although CD4- CD8- thymocytes are able to produce a wide spectrum of cytokines in response to a T-cell receptor (TcR)-independent stimulus, as they approach the double-positive (DP) CD4+ CD8+ stage, they lose the ability to produce cytokine. After the DP stage, thymocytes become single-positive CD4+ or CD8+ thymocytes which reacquire the ability to secrete cytokines. In an attempt to understand the molecular basis of this specific regulatin, we use AP-1-luciferase and newly generated NFAT-luciferase transgenic mice to analyze the transcriptional and DNA-binding activities of these two transcription factors that are involved in the regulation of cytokine gene expression. Here, we show that both AP-1 and NFAT transcriptional activities are not inducible in the majority of DP cells but that during the differentiation of DP cells to the mature single-positive stage, thymocytes regain this inducibility. Subpopulation analysis demonstrates that this inducibility is reacquired at the DP stage before the down-modulation of one of the coreceptors. Indeed AP-1 inducibility, just like the ability to express the interleukin-2 gene, is reacquired during the differentiation of DP TcRlow CD69low heat-stable antigen (HSA)high thymocytes to DP TcRhigh CD69high HSAhigh cells, which is considered to be the consequence of the first signal that initiates positive selection. We therefore propose that the inability of DP thymocytes to induce AP-1 and NFAT activities is one of the causes for the lack of cytokine gene expression at this stage and that this inducibility is reacquired at the latest stage of DP differentiation as a consequence of positive selection. This could be a mechanism to prevent the activation of DP thymocytes before selection has taken place.
Mol Cell Biol 1996 Mar
PMID:Regulation of AP-1 and NFAT transcription factors during thymic selection of T cells. 862 52

Staphylococcal enterotoxins can cause toxic shock syndrome and autoimmune diseases. Circulating T cells from these diseases have a very wide range of expression in particular T cell receptor (TCR) beta chain variable regions (V beta). One possibility for this wide range of TCR V beta expression is that during acute infection with organisms secreting superantigens (SAg) these potent molecules might modulate TCR expression. To test this hypothesis, we investigated the potential effects of SAg on TCR V beta cell surface expression. Peripheral blood mononuclear cells (PBMC) from healthy donors were incubated with staphylococcal SAg. Toxic shock syndrome toxin-1 (TSST-1) induced downregulation of V beta 2 expression, whereas staphylococcal enterotoxin (SE) B induced V beta 3-and V beta 12-specific downregulation. TSST-1 did not interfere with anti-V beta 2 mAb binding. Therefore, this downregulation was not due to steric hindrance of Ab binding by TSST-1. TSST-1 induced V beta 2 downregulation was time-, dose- and temperature-dependent. CD3 expression decreased in parallel with reduction of V beta expression. CD4 and CD8 expression were only slightly decreased. CD2, CD25 and HLA-DR expression were upregulated following TSST-1 stimulation of T cell lines. To investigate the fate of TCR after toxin stimulation, V beta 8+ Jurkat T cells were incubated with SEE which is known to stimulate V beta 8+ T cells, and analysed with fluoresence microscopy, and immunoprecipitation and Western blotting. After SEE stimulation, there was an increase in V beta 8 molecules found in the cytoplasm which correlated with loss of cell surface V beta 8 molecules, suggesting internalization of cell surface V beta 8 molecules was induced by SEE stimulation. Shedding of V beta 8 molecules into the culture supernatant was not detected. These data demonstrate that SAg mediated downregulation of TCR expression occurs primarily as the result of TCR internalization. This downregulation phenomenon may have physiological and pathological consequences in patients infected with Staphylococcus aureus.
Mol Immunol 1996 Jul
PMID:Bacterial superantigens induce V beta-specific T cell receptor internalization. 884 21

Apoptosis in the immature thymus can be induced by both p53-dependent and -independent pathways, the former being activated by exposure to DNA-damaging agents and the latter being induced by glucocorticoids [Nature (Lond.) 362:847-849; Nature (Lond.) 362:849-852 (1993)]. We report that the DNA-damaging agents etoposide and gamma-radiation induced similar levels of apoptosis in both proliferatively enriched and quiescent immature rat thymocytes, as assessed by flow cytometry and the formation of both kilobase-pair and 180-bp integer fragments of DNA. However, a marked stabilization of p53 occurred exclusively in the proliferatively enriched population, which was also enriched for immature CD4- CD8- and mature CD4+ CD8-/CD4- CD8+ cells. In contrast, DNA damage-induced apoptosis in quiescent mature peripheral T cells was associated with an accumulation of p53. Our studies suggest that stabilization of p53 in thymocytes in response to DNA damage may be developmentally regulated. In immature thymocytes obtained from p53-null mice, DNA-damaging agents induced apoptosis at significantly lower levels and at later times than that seen in cells from p53 wild-type animals. These data support the hypothesis that DNA-damaging agents induce apoptosis primarily via a p53-dependent pathway in immature thymocytes as previously reported. We report here that DNA damage can also induce apoptosis by a p53-independent pathway in a particular subpopulation of immature thymocytes.
Mol Pharmacol 1996 Oct
PMID:DNA-damaging agents induce both p53-dependent and p53-independent apoptosis in immature thymocytes. 886 36

About 10 years ago, we implicated immune factors in the pathophysiology of Alzheimer disease (AD), the hypothesis being that AD may be an immunologically derived systemic disease, but clinical effects confined primarily to the brain. We originally hypothesized that an immune basis of the disease may involve faulty immune regulation and autoimmunity. As described here, the activation of immunoregulatory T-lymphocytes with CD8 phenotype may be important in the immunopathogenesis of the disease.
Mol Chem Neuropathol
PMID:Immune-activation model in Alzheimer disease. 887 48

CD4 T-lymphocytes, which orchestrate immune responses, receive a cognitive signal when clonally distributed receptors are occupied by MHC class II bound peptides on antigen-presenting cells. The latter provide costimulatory or accessory signals through macromolecules such as B7.1 and B7.2 which interact with coreceptors on T-cells to regulate outcomes in terms of T-cell activation or specific non-responsiveness. Complementary studies at the chemical level have implicated Schiff base formation between specialised carbonyls and amines, constitutively expressed on antigen-presenting cell and T-cell surfaces, as an essential element in specific T-cell activation. The small xenobiotic Schiff base forming molecule tucaresol, which substitutes for the physiological donor of carbonyl groups to provide a costimulatory signal to CD4 T-helper lymphocytes (Th-cells), has been developed for testing as an immunopotentiatory drug. Tucaresol, which is orally bioavailable and systemically active, enhances CD4 Th-cell and CD8 cytotoxic T-cell responses in vivo and selectively favours a Th1-type profile of cytokine production. In murine models of virus infection and syngeneic tumour growth it has substantial therapeutic activity. Schiff base formation by tucaresol on T-cell surface amines provides a costimulatory signal to the T-cell through a mechanism that activates clofilium-sensitive K+ and Na+ transport. The signalling pathway utilised by tucaresol converges with T-cell receptor signalling at the level of MAP kinase, promoting the tyrosyl phosphorylation of ERK2 by MEK (mitogen-activated protein kinase kinase). The Schiff base forming class of immunopotentiatory drug provides the first orally active, mechanism-based immunopotentiatory agents for therapeutic testing. Tucaresol is currently undergoing pilot phase I/II clinical trials as an immunopotentiator in chronic hepatitis B virus infection, HIV infection and malignant melanoma.
J Mol Med (Berl) 1996 Sep
PMID:Schiff base forming drugs: mechanisms of immune potentiation and therapeutic potential. 889 54

Masses of the complexes formed between the C-terminal region of CD8 alpha (CD8 alpha C) and the N-terminal region of p56lck (p56lckN) were measured by using Electrospray Ionization (ESI) and Matrix-Assisted Laser Desorption/Ionization (MALDI) Mass Spectrometry (MS). The two peptides were incubated with various metal ions, Zn++, Cd++, Co++, Fe++ and Ca++. The complex formed from the incubation did not contain any metal ions. Instead, its mass suggested that the complex was formed by two disulfide bonds. The fact that the incubation of the complex with Dithiothreitol broke the complex confirmed into monomers that the complex was formed through disulfide bonds. The only disulfide-mediated complex formed was hetero-dimer (CD8 alpha C-p56lckN) and none of homo-dimers (CD8 alpha C-CD8 alpha C or p56lckN-p56lckN) were observed from ESI and MALDI-TOF mass spectrometry.
Biochem Mol Biol Int 1996 Oct
PMID:Disulfide bond formation between the n-terminal region of p56LCK and the cytoplasmic domain of CD8 studied by electrospray ionization and matrix-assisted desorption/ionization time-of-flight mass spectrometry. 889 64

T lymphocytes expressing the alpha E beta 7 integrin are localized and selectively retained in mucosal tissues. To investigate a potential relationship between alpha E beta 7 expression and pulmonary inflammation, the distribution of alpha E beta 7-bearing CD4+ and CD8+ T cells in peripheral blood and bronchoalveolar lavage (BAL) fluids obtained from patients with allergic asthma, sarcoidosis, hypersensitivity pneumonitis, and idiopathic pulmonary fibrosis (IPF) was determined. In contrast to the distribution in peripheral blood, BAL fluid from these patients contained high number of cells expressing alpha E beta 7 with markedly different expression patterns on CD4 or CD8 cells as well as among the various diseases. Despite similar numbers of activated CD4 cells, alpha E beta 7+CD4+ T cells ranged from 15% in asthmatics to 70% in IPF. In contrast, even in normal individuals, 60% to 90% of BAL fluid CD8+ T cells express alpha E beta 7, suggesting differential induction mechanisms on CD4 and CD8 cells. In vitro experiments revealed that a substantial proportion of peripheral blood CD+ T cells express alpha E beta 7 after stimulation with anti-CD3 antibodies, and up to 80% positive cells were found after the addition of TGF-beta. In contrast, less than 10% of CD4 cells express this particular integrin after in vitro stimulation, and the presence of TGF-beta only increased the number to 30%. Supernatants from in vitro-activated BAL cells as well as concentrated BAL fluid from patients with high alpha E beta 7 expression had no further enhancing effect. However, crosslinking of alpha 4 beta 1-, but not beta 2-integrins, significantly increased the number of alpha E beta 7 expressing CD4+ and CD8+ T cells, even in the absence of TGF-beta. These data indicate that in addition to TGF-beta, the interaction of particular T-cell subsets with specific endothelial cell and extracellular matrix proteins may upregulate alpha E beta 7 integrin expression and thereby contribute to the selective accumulation of these cells in inflammatory lung diseases.
Am J Respir Cell Mol Biol 1996 Nov
PMID:Differential expression of alpha E beta 7 integrins on bronchoalveolar lavage T lymphocyte subsets: regulation by alpha 4 beta 1-integrin crosslinking and TGF-beta. 891 67

Two alloantisera and a monoclonal antibody (mAb 53-6.7) of proven specificities to the murine Lyt-2/3 macromolecule labeled, in indirect immunofluorescent assays, a distinct lymphocyte population in the toad, Bufo regularis. Lyt-2/3 antigenic activities expressed by B. regularis lymphocytes have been solubilized and purified by mAb 53-6.7 affinity chromatography and found to be associated with a single 67 kDa macromolecule in SDS-PAGE. Upon reduction, this macromolecule resolved into 38 kDa, 34 kDa and 28 kDa subunits corresponding to the alpha, alpha' and beta subunits of the murine Lyt-2/3 complex. Comparisons based on the S delta Q index of differences in amino acid compositions of HPLC-purified alpha- and alpha'-subunits of the amphibian Lyt-2/3 molecule indicated a significant structural relatedness to their murine counterpart as well as to the human CD8 polypeptide. Our observations point to an early phylogenetic emergence of Lyt-2/3 as an important component of the T cell cytolytic apparatus during vertebrate evolution.
Comp Biochem Physiol B Biochem Mol Biol 1996 Jan
PMID:Structural characterization of an Lyt-2/3 homolog expressed on Bufo regularis lymphocytes. 893 43

Late allergic airway responses can be transferred by CD4+ T cells in the rat. To investigate the role of T-cell cytokines in these responses, we examined the expression of mRNA for Th2 (interleukin [IL]-4 and IL-5) and Th1 (IL-2 and interferon gamma [INF-gamma])-type cytokines in Brown Norway rats that were administered either antigen-primed W3/25(CD4)+ or OX8(CD8)+ T cells. Donors were actively sensitized by subcutaneous injection of ovalbumin (OVA) in the neck and T cells were obtained from the cervical lymph nodes by immunomagnetic cell sorting for administration to unsensitized rats. Control rats received bovine serum albumin (BSA)-primed CD4+ and CD8+ T cells. Two days later, recipient rats were challenged with aerosolized OVA, and bronchoalveolar lavage (BAL) was performed 8 h after challenge. BAL cells expressing mRNA for IL-2, IL-4, IL-5, and INF-gamma were analyzed using the technique of in situ hybridization. Recipients of OVA-primed CD4+ T cells had an increase in the fraction of BAL cells expressing mRNA for IL-4 and IL-5 compared with BSA-primed CD4+ or OVA-primed CD8+ cells (P < 0.001). Recipients of CD8+ T cells had an increase in INF-gamma mRNA expression after OVA challenge compared with recipients of BSA-primed-CD8+ or OVA-primed CD4+ T cells (P < 0.001). In conclusion, T-cell-dependent allergen-induced late responses are associated with the expression of mRNA for IL-4 and IL-5, indicating Th2 cell activation. Furthermore, the increased expression of INF-gamma in allergen challenge recipients of antigen-primed CD8+ T cells suggests that CD8+ T cells may be important in modulating allergic responses.
Am J Respir Cell Mol Biol 1997 Jan
PMID:Adoptively transferred late allergic airway responses are associated with Th2-type cytokines in the rat. 899 81


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