scholarly journals A Raf-1-related p110 polypeptide associates with the CD4-p56lck complex in T cells.

1992 ◽  
Vol 12 (11) ◽  
pp. 5260-5267 ◽  
Author(s):  
K V Prasad ◽  
C E Rudd
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Receptor Complexes ◽  
T Cell Lines ◽  
The Individual

The CD4 and CD8 antigens on T cells have been shown to associate with the Src family member p56lck and a GTP-binding protein, p32. The identification of receptor interactions with intracellular mediators is essential in the elucidation of downstream signals mediated by engagement of these receptor complexes. In this study, we report the detection of an additional 110-kDa polypeptide (p110) associated with the CD4-p56lck complex in human peripheral blood T lymphocytes and leukemic T-cell lines. p110 bound preferentially to CD4-p56lck as an assembled complex and poorly, if at all, to the individual components. p110 was recognized directly by an antiserum to the C-terminal region of the serine/threonine kinase Raf-1 and is related to a p110 polypeptide detected in anti-Raf-1 immunoprecipitates. Despite its association with the CD4-p56lck complex, p110 was found to be phosphorylated predominantly on serine residues. Furthermore, phorbol ester treatment of cells resulted in a transient increase in the detection of p110 associated with CD4-p56lck, concomitant with the modulation of CD4-p56lck from the cell surface. This Raf-1-related p110 is therefore likely to play a role in signals generated from the CD4-p56lck complex. p110 may serve as a bridge between the CD4-p56lck complex and the serine/threonine kinase pathways of T-cell activation.

A Raf-1-related p110 polypeptide associates with the CD4-p56lck complex in T cells

1992 ◽  
Vol 12 (11) ◽  
pp. 5260-5267
Author(s):  
K V Prasad ◽  
C E Rudd
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Receptor Complexes ◽  
T Cell Lines ◽  
The Individual

The CD4 and CD8 antigens on T cells have been shown to associate with the Src family member p56lck and a GTP-binding protein, p32. The identification of receptor interactions with intracellular mediators is essential in the elucidation of downstream signals mediated by engagement of these receptor complexes. In this study, we report the detection of an additional 110-kDa polypeptide (p110) associated with the CD4-p56lck complex in human peripheral blood T lymphocytes and leukemic T-cell lines. p110 bound preferentially to CD4-p56lck as an assembled complex and poorly, if at all, to the individual components. p110 was recognized directly by an antiserum to the C-terminal region of the serine/threonine kinase Raf-1 and is related to a p110 polypeptide detected in anti-Raf-1 immunoprecipitates. Despite its association with the CD4-p56lck complex, p110 was found to be phosphorylated predominantly on serine residues. Furthermore, phorbol ester treatment of cells resulted in a transient increase in the detection of p110 associated with CD4-p56lck, concomitant with the modulation of CD4-p56lck from the cell surface. This Raf-1-related p110 is therefore likely to play a role in signals generated from the CD4-p56lck complex. p110 may serve as a bridge between the CD4-p56lck complex and the serine/threonine kinase pathways of T-cell activation.

Effect of CD28 signal transduction on c-Rel in human peripheral blood T cells

1994 ◽  
Vol 14 (12) ◽  
pp. 7933-7942
Author(s):  
R G Bryan ◽  
Y Li ◽  
J H Lai ◽  
M Van ◽  
N R Rice ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Nuclear Translocation ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cell Receptor ◽  
Cd28 Costimulation

Optimal T-cell activation requires both an antigen-specific signal delivered through the T-cell receptor and a costimulatory signal which can be delivered through the CD28 molecule. CD28 costimulation induces the expression of multiple lymphokines, including interleukin 2 (IL-2). Because the c-Rel transcription factor bound to and activated the CD28 response element within the IL-2 promoter, we focused our study on the mechanism of CD28-mediated regulation of c-Rel in human peripheral blood T cells. We showed that CD28 costimulation accelerated the kinetics of nuclear translocation of c-Rel (and its phosphorylated form), p50 (NFKB1), and p65 (RelA). The enhanced nuclear translocation of c-Rel correlated with the stimulation of Il-2 production and T-cell proliferation by several distinct anti-CD28 monoclonal antibodies. This is explained at least in part by the long-term downregulation of I kappa B alpha following CD28 signalling as opposed to phorbol myristate acetate alone. Furthermore, we showed that the c-Rel-containing CD28-responsive complex is enhanced by, but not specific to, CD28 costimulation. Our results indicate that c-Rel is one of the transcription factors targeted by CD28 signalling.

TREM-1 modulates dendritic cell maturation and dendritic cell–mediated T cell activation induced by ox-LDL

2020 ◽  
Author(s):  
Yunkai Wang ◽  
Jie Wang ◽  
Lu Han ◽  
Yun Li Shen ◽  
Jie Yun You ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Dendritic Cell Maturation ◽  
Cell Maturation ◽  
Blood Monocytes

Abstract Background: Triggering receptor expressed on myeloid cells (TREM)-1is identified as a major upstream proatherogenic receptor. However, the cellular processes modulated by TREM-1 in the development of atherosclerosis and plaque destabilization has not been fully elucidated. In this study, we investigated the effects of TREM-1 on dendritic cell maturation and dendritic cell–mediated T-cell activation induced by oxidized low-density lipoprotein (ox-LDL) in atherogenesis. Methods: Human peripheral blood monocytes were differentiated to dendritic cells and stimulated by ox-LDL. Naive autologous T cells were co-cultured with pretreated dendritic cells.The expressionof TREM-1 and the production of inflammatory cytokines were assessed by real-time PCR, western blot and ELISA.The expression of immune factors was determined with FACS to evaluate dendritic cell maturation and T-cell activation. Results: Stimulation with ox-LDL promoted dendritic cell maturation, TREM-1 expression and T-cell activation, and exposure of T cells to ox-LDL-treated dendritic cells induced production of interferon-γ and IL-17. Blocking TREM-1 suppressed dendritic cell maturation with low expression of CD1a, CD40, CD86 and HLA-DR, decreased production of TNF-α, IL-1β, IL-6 and MCP-1, and increased secretion of TGF-β and IL-10. In addition, stimulation of ox-LDL induced miR-155, miR-27, Let-7c and miR-185 expression, whereas inhibition of TREM-1 repressed miRNA-155. Silencing TREM-1 or miRNA-155 increased SOCS1 expression induced by ox-LDL. T cells derived from carotid atherosclerotic plaques or healthy individuals showed similar result patterns. Conclusion: These data suggest that TREM-1 modulates maturation of dendritic cells and activation of plaque T cells induced by ox-LDL, a pivotal player in atherogenesis.

Age-related increase of frequency of a new, phenotypically distinct subpopulation of human peripheral blood T cells expressing lowered levels of CD4

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 1100-1107 ◽  
Author(s):  
Ewa Bryl ◽  
Magdalena Gazda ◽  
Jerzy Foerster ◽  
Jacek M. Witkowski
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
The Elderly ◽  
Cell Subpopulation ◽  
Cell Phenotype ◽  
Receptor Complexes ◽  
Age Related

Aging is associated with modifications of T-cell phenotype and function, leading to impaired activation in response to both new and recall antigens. It is not known if T-cell activation results in elimination of a number of the CD4 molecules from the cell surface, as is the case with CD3/T-cell receptor complexes, or how aging influences the process. The T cells of young and elderly donors with reduced expression of CD4 were examined to see whether these cells exhibit other phenotypic features suggesting their active state. It was found that T lymphocytes expressing CD4 can be divided into 2 semidiscrete subpopulations: the major (CD4+) population, in which the level of expression of CD4 is constant and high, and a minor population (CD4lo), in which the expression of CD4 can be up to an order of magnitude lower than on the CD4+ cells. The proportion of CD4locells is age dependent and highly variable in the apparently healthy human population, with the expression of CD4 ranging from around 10% of all peripheral blood lymphocytes in the young to more than 30% in the elderly. Lowered expression of CD4 is correlated with a reduced expression of CD3, as well as with a decreased amount of CD28 and CD95Fas. Activation of CD4lo cells is suggested by their expression of CD25 and increased amounts of HLA-DR. Phenotypic characteristics of the CD4lo T-cell subpopulation suggest that it might be formed by (perhaps chronically) activated, temporarily apoptosis-resistant cells, possibly accumulating in the elderly.

Lysophosphatidic acid enhances interleukin-13 gene expression and promoter activity in T cells

2006 ◽  
Vol 290 (1) ◽  
pp. L66-L74 ◽  
Author(s):  
Joshua Rubenfeld ◽  
Jia Guo ◽  
Nitat Sookrung ◽  
Rongbing Chen ◽  
Wanpen Chaicumpa ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Lysophosphatidic Acid ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Regulatory Elements ◽  
Jurkat Cells

Lysophosphatidic acid (LPA) is a membrane-derived lysophospholipid with wide-ranging effects on multiple lung cells including airway epithelial and smooth muscle cells. LPA can augment migration and cytokine synthesis in lymphocytes, but its potential effects on Th2 cytokines have not been well studied. We examined the effects of physiological concentrations of LPA on IL-13 gene expression in human T cells. The Jurkat T cell line and human peripheral blood CD4+ T cells were incubated with LPA alone or with 1) pharmacological agonists of different signaling pathways, or 2) antibodies directed against the T cell receptor complex and costimulatory molecules. Luciferase-based reporter constructs driven by different lengths of the human IL-13 promoter were transfected by electroporation in Jurkat cells treated with and without LPA. The effects of LPA on IL-13 mRNA stability were examined using actinomycin D to halt ongoing transcription. Expression of mRNA encoding LPA2and LPP-1 increased with T cell activation. LPA augmented IL-13 secretion under conditions of submaximal T cell activation. This was observed using pharmacological agonists activating intracellular calcium-, PKC-, and cAMP-dependent signaling pathways, as well as antibodies directed against CD3 and CD28. LPA only slightly prolonged IL-13 mRNA half-life in submaximally stimulated Jurkat cells. In contrast, LPA significantly enhanced transcriptional activation of the IL-13 promoter via regulatory elements contained within proximal 312 bp. The effects of LPA on IL-13 promoter activation appeared to be distinct from those mediated by GATA-3. LPA can augment IL-13 gene expression in T cells, especially under conditions of submaximal activation.

DAP10 Costimulates Chimeric Receptor-Mediated T Cell Responses to Tumor Antigen.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3052-3052
Author(s):  
Bianca Altvater ◽  
Sibylle Pscherer ◽  
Heribert Juergens ◽  
Claudia Rossig
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
T Cell Activation ◽  
Adoptive Immunotherapy ◽  
Peripheral Blood ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Cytokine Secretion ◽  
Immunotherapy Of Cancer

Abstract Chimeric receptors (chRecs) combining extracellular recognition domains with the T cell receptor ζ an redirect the cellular immune response of primary T-cells to tumor cells. T cell activation by chRec induces efficient cytokine release and cytotoxicity, however, it fails to mediate proliferative responses, limiting the usefulness of chRec-gene-modified T cells for adoptive immunotherapy of cancer. Inclusion of a CD28 costimulatory signaling component in the chRec endodomain enhances antigen-specific proliferation. Whereas the signal mediated by ligation of CD28 is of crucial importance for the activation of resting CD4+ T cells, further molecules with costimulatory functions have contributory roles. NKG2D is a stimulatory receptor that was first identified in NK cells, but is also expressed in cytotoxic T cells and positively modulates CD8+ T cell immune responses. We hypothesized that inclusion of the NKG2D-associated signaling domain DAP10 would enhance the capacity of chRecs to induce tumor-specific activation and proliferation of in vitro expanded effector T cells. Based on a GD2-specific scFv, we generated chRecs containing either the DAP10 signaling chain alone (14.G2a-DAP10) or combined with TCRζ 14.G2a-DAP10ζ), and expressed them in nonspecifically activated human peripheral blood T cells of three individual donors by retroviral gene transfer. As controls, T cells were transduced with 14.G2a-ζ and -CD28ζ chRec. High chRec surface expression was obtained with all four constructs (55±11%, ζ; 85±3, CD28ζ; 68±5%, DAP10; 78±1%; DAP10ζ). Immunophenotypes were dominated by a CD3+CD8+ population in all cell cultures. Whereas DAP10 alone failed to mediate specific tumor cell lysis, 51Cr release assays revealed efficient and comparable lysis of GD2+ tumor targets by T cells transduced with all ζ-containing constructs, with 49±8% (ζ), 52±7% (CD28ζ), and 52±18% (DAP10ζ) cytolysis at an effector-to-target ratio of 40:1. Intracellular cytokine secretion by chRec+ T cells was induced in response to tumor targets by 14.G2a-ζ (up to 37% IFN-γ secreting cells), CD28ζ, and DAPζ (both up to 22%), but not by DAP10 alone (0,2%). Weekly stimulation with tumor cells for 6 weeks induced only limited expansion of T cells transduced with 14.G2a-ζ (7–45fold) or with 14.G2a-DAP10 (14–26-fold). Adding CD28 or DAP10 domains significantly enhanced expansion by a comparable degree (270–483-fold and 126–436-fold, respectively). Thus, while neither CD28 nor DAP10 enhances antigen-specific cytokine secretion and cytolysis, DAP10 signaling can completely replace CD28 signaling in costimulating antigen-specific proliferation of peripheral blood T cells. DAP10-containing chRec may be a powerful new tool for adoptive immunotherapy of cancer.

Effect of rapamycin on the cyclosporin A–resistant CD28-mediated costimulatory pathway

Blood ◽  
2002 ◽  
Vol 99 (12) ◽  
pp. 4517-4524 ◽  
Author(s):  
Paritosh Ghosh ◽  
Meredith A. Buchholz ◽  
Shingo Yano ◽  
Dennis Taub ◽  
Dan L. Longo
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cyclosporin A ◽  
T Cell Activation ◽  
Messenger Rna ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Immunosuppressive Drug ◽  
Receptor Interaction

The consequences of T-cell activation depend exclusively on costimulation during antigen–T-cell receptor interaction. Interaction between the T-cell coreceptor CD28 and its ligand B7 during antigen-antigen receptor engagement results in full activation of T cells, the outcomes of which are proliferation and effector functions. The ability of CD28 to costimulate the production of interleukin-2 (IL-2) explains the importance of this costimulation. The signaling event mediated by CD28 engagement has been proposed to have 2 components: one is sensitive to the immunosuppressive drug cyclosporin A (CsA), and the other one is CsA-resistant. In this report, we demonstrate that the CsA-resistant pathway is sensitive to the immunosuppressive drug rapamycin. Treatment with rapamycin blocked IL-2 production after activation of human peripheral blood T cells with phorbol ester (PMA) and anti-CD28 (CsA-resistant pathway), whereas this drug did not have any effect on PMA plus ionomycin stimulation (CsA-sensitive pathway). The inhibitory effect of rapamycin was on messenger RNA stability and translation, rather than on IL-2 transcription or protein turnover.

scholarly journals NSOM/QD-Based Visualization of GM1 Serving as Platforms for TCR/CD3 Mediated T-Cell Activation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Liyun Zhong ◽  
Zhun Zhang ◽  
Xiaoxu Lu ◽  
Shengde Liu ◽  
Crystal Y. Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Imaging System ◽  
Near Field ◽  
Cell Receptor ◽  
Dependent Manner ◽  
Receptor Complexes ◽  
Before And After

Direct molecular imaging of nanoscale relationship between T-cell receptor complexes (TCR/CD3) and gangliosidosis GM1 before and after T-cell activation has not been reported. In this study, we made use of our expertise of near-field scanning optical microscopy(NSOM)/immune-labeling quantum dots- (QD-)based dual-color imaging system to visualize nanoscale profiles for distribution and organization of TCR/CD3, GM1, as well as their nanospatial relationship and their correlation with PKCθsignaling cascade during T-cell activation. Interestingly, after anti-CD3/anti-CD28 Ab co-stimulation, both TCR/CD3 and GM1 were clustered to form nanodomains; moreover, all of TCR/CD3 nanodomains were colocalized with GM1 nanodomains, indicating that the formation of GM1 nanodomains was greatly correlated with TCR/CD3 mediated signaling. Specially, while T-cells were pretreated with PKCθsignaling inhibitor rottlerin to suppress IL-2 cytokine production, no visible TCR/CD3 nanodomains appeared while a lot of GM1 nanodomains were still observed. However, while T-cells are pretreated with PKCαβsignaling inhibitor GÖ6976 to suppress calcium-dependent manner, all of TCR/CD3 nanodomains were still colocalized with GM1 nanodomains. These findings possibly support the notion that the formation of GM1 nanodomains indeed serves as platforms for the recruitment of TCR/CD3 nanodomains, and TCR/CD3 nanodomains are required for PKCθsignaling cascades and T-cell activation

scholarly journals In Vitro Monitoring of Human T Cell Responses to Skin Sensitizing Chemicals—A Systematic Review

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 83
Author(s):  
Marina Aparicio-Soto ◽  
Caterina Curato ◽  
Franziska Riedel ◽  
Hermann-Josef Thierse ◽  
Andreas Luch ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cross Reactivity ◽  
T Cell Epitopes ◽  
Cell Responses ◽  
Human T Cell ◽  
The Individual

Background: Chemical allergies are T cell-mediated diseases that often manifest in the skin as allergic contact dermatitis (ACD). To prevent ACD on a public health scale and avoid elicitation reactions at the individual patient level, predictive and diagnostic tests, respectively, are indispensable. Currently, there is no validated in vitro T cell assay available. The main bottlenecks concern the inefficient generation of T cell epitopes and the detection of rare antigen-specific T cells. Methods: Here, we systematically review original experimental research papers describing T cell activation to chemical skin sensitizers. We focus our search on studies published in the PubMed and Scopus databases on non-metallic allergens in the last 20 years. Results: We identified 37 papers, among them 32 (86%) describing antigen-specific human T cell activation to 31 different chemical allergens. The remaining studies measured the general effects of chemical allergens on T cell function (five studies, 14%). Most antigen-specific studies used peripheral blood mononuclear cells (PBMC) as antigen-presenting cells (APC, 75%) and interrogated the blood T cell pool (91%). Depending on the individual chemical properties, T cell epitopes were generated either by direct administration into the culture medium (72%), separate modification of autologous APC (29%) or by use of hapten-modified model proteins (13%). Read-outs were mainly based on proliferation (91%), often combined with cytokine secretion (53%). The analysis of T cell clones offers additional opportunities to elucidate the mechanisms of epitope formation and cross-reactivity (13%). The best researched allergen was p-phenylenediamine (PPD, 12 studies, 38%). For this and some other allergens, stronger immune responses were observed in some allergic patients (15/31 chemicals, 48%), illustrating the in vivo relevance of the identified T cells while detection limits remain challenging in many cases. Interpretation: Our results illustrate current hardships and possible solutions to monitoring T cell responses to individual chemical skin sensitizers. The provided data can guide the further development of T cell assays to unfold their full predictive and diagnostic potential, including cross-reactivity assessments.

scholarly journals Costimulation of T-cell activation and virus production by B7 antigen on activated CD4+ T cells from human immunodeficiency virus type 1-infected donors

1993 ◽  
Vol 90 (23) ◽  
pp. 11094-11098 ◽  
Author(s):  
O K Haffar ◽  
M D Smithgall ◽  
J Bradshaw ◽  
B Brady ◽  
N K Damle ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Immunodeficiency Virus ◽  
T Cell Lines ◽  
Antigen Presenting ◽  
Hiv 1

Infection with the human immunodeficiency virus type 1 (HIV-1) requires T-cell activation. Recent studies have shown that interactions of the T-lymphocyte receptors CD28 and CTLA-4 with their counter receptor, B7, on antigen-presenting cells are required for optimal T-cell activation. Here we show that HIV-1 infection is associated with decreased expression of CD28 and increased expression of B7 on CD4+ T-cell lines generated from seropositive donors by alloantigen stimulation. Loss of CD28 expression was not seen on CD4+ T-cell lines from seronegative donors, but up-regulation of B7 expression was observed upon more prolonged culture. Both T-cell proliferation and interleukin 2 mRNA accumulation in HIV-1-infected cultures required costimulation with exogenous B7 because these events were blocked by CTLA4Ig, a soluble form of CTLA-4 that binds B7 with high avidity. In contrast, levels of HIV-1 RNA were not affected by CTLA4Ig, indicating that regulation of virus transcription in these cultures did not depend upon CD28-B7 engagement. Infected T cells could present alloantigen to fresh, uninfected CD4+ T cells, leading to increased proliferation and virus spread to the activated cells. Both of these events were blocked by CTLA4Ig. Thus, chronic activation of HIV-1-infected CD4+ T cells reduces expression of CD28 and increases expression of B7, thereby enabling these T cells to become antigen-presenting cells for uninfected CD4+ T cells; this might be another mechanism for HIV-1 transmission via T-cell-T-cell contact.

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