scholarly journals Modulation of Kv Channel Expression and Function by TCR and Costimulatory Signals during Peripheral CD4+ Lymphocyte Differentiation

2002 ◽  
Vol 196 (7) ◽  
pp. 897-909 ◽  
Author(s):  
Qing-Hua Liu ◽  
Bernd K. Fleischmann ◽  
Brian Hondowicz ◽  
Curtis C. Maier ◽  
Laurence A. Turka ◽  
...  
Keyword(s):  
T Cells ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Cell Activation ◽  
Effector Cells ◽  
Kv Channel ◽  
Kv Channels ◽  
Costimulatory Signals ◽  
Cd4 Lymphocyte ◽  
Cd4 Lymphocytes

Ionic signaling pathways, including voltage-dependent potassium (Kv) channels, are instrumental in antigen-mediated responses of peripheral T cells. However, how Kv channels cooperate with other signaling pathways involved in T cell activation and differentiation is unknown. We report that multiple Kv channels are expressed by naive CD4+ lymphocytes, and that the current amplitude and kinetics are modulated by antigen receptor–mediated stimulation and costimulatory signals. Currents expressed in naive CD4+ lymphocytes are consistent with Kv1.1, Kv1.2, Kv1.3, and Kv1.6. Effector CD4+ cells generated by optimal TCR and costimulation exhibit only Kv1.3 current, but at approximately sixfold higher levels than naive cells. CD4+ lymphocytes anergized through partial stimulation exhibit similar Kv1.1, Kv1.2, and/or Kv1.6 currents, but approximately threefold more Kv1.3 current than naive cells. To determine if Kv channels contribute to the distinct functions of naive, effector, and anergized T cells, we tested their role in immunoregulatory cytokine production. Each Kv channel is required for maximal IL-2 production by naive CD4+ lymphocytes, whereas none appears to play a role in IL-2, IL-4, or IFN-γ production by effector cells. Interestingly, Kv channels in anergized lymphocytes actively suppress IL-4 production, and these functions are consistent with a role in regulating the membrane potential and calcium signaling.

scholarly journals 566 ATOR-1017, a second generation 4–1BB antibody with potential to enhance efficacy of PD-1 therapies

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A595-A595
Author(s):  
Karin Enell Smith ◽  
Anneli Nilsson ◽  
Peter Ellmark
Keyword(s):  
T Cells ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Effector Cells ◽  
Costimulatory Receptor ◽  
T Effector Cells ◽  
Murine Colon Carcinoma ◽  
Activation Profile

BackgroundATOR-1017 is a Fcγ-receptor (FcγR) crosslinking dependent agonistic IgG4 antibody targeting the costimulatory receptor 4 1BB, designed for improved tolerability and efficacy. 4-1BB is highly expressed on tumor infiltrating CD8+ T effector cells (T effs) in several cancer indications. By binding to 4-1BB, ATOR-1017 enhances the activity of tumor reactive T effs and NK cells within the tumor and induces a potent anti-tumor response. 4-1BB is a promising candidate for immunotherapy and holds great potential for combination with other immunomodulatory antibodies, targeting e.g. the PD-1 pathway.MethodsHuman 4-1BB knock-in transgenic mice with established murine colon carcinoma MC38 tumors were used to demonstrate anti-tumor efficacy after systemic treatment with ATOR-1017 in combination with anti-PD-1. Further, the effect of combining ATOR-1017 with anti-PD-1 on T cell activation (measured as production of IFNγ) was evaluated in a mixed lymphocyte reaction (MLR) assay with human primary CD4+ T cells and mature monocyte-derived DCs (mDC) expressing endogenous levels of both 4-1BB and PD-1.ResultsATOR-1017 in combination with anti-PD-1 improved survival and reduced tumor growth signifcantly in human 4-1BB knock-in transgenic mice with established tumors compared with each monotherapy alone. The potential for combining ATOR-1017 and PD-1 was further supported by data from a MLR assay demonstrating that the combination of ATOR-1017 with anti-PD-1 induced a more potent CD4+ T cells activation than each monotherapy alone.The functional activation profile of ATOR-1017 is expected to minimize the risk of systemic immune activation and toxicity, by directing a potent immune response to immune cells in tumor tissue and tumor draining lymph nodes. This is supported by early data from the ongoing first-in-human phase I study where ATOR-1017 has been shown to be safe and tolerable.ConclusionsIn summary, these results support further clinical development of ATOR-1017 in combination with PD-1 antibodies. By combining ATOR-1017 with anti-PD-1, tumor infiltrating T cells can be more effectively activated and potentially increase the response rate in multiple indications.Ethics ApprovalAll animal procedures were in accordance to IACUC guidance

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.

scholarly journals HuR Plays a Positive Role to Strengthen the Signaling Pathways of CD4+ T Cell Activation and Th17 Cell Differentiation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiguang Yu ◽  
Morgan Tripod ◽  
Ulus Atasoy ◽  
Jing Chen
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Th17 Cell ◽  
Th17 Cells ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Th17 Cell Differentiation

After antigen and/or different cytokine stimulation, CD4+ T cells activated and differentiated into distinct T helper (Th) cells via differential T cell signaling pathways. Transcriptional regulation of the activation and differentiation of naïve CD4+ T cells into distinct lineage Th cells such as Th17 cells has been fully studied. However, the role of RNA-binding protein HuR in the signaling pathways of their activation and differentiation has not been well characterized. Here, we used HuR conditional knockout (HuR KO) CD4+ T cells to study mechanisms underlying HuR regulation of T cell activation and differentiation through distinct signaling pathways. Our work showed that, mechanistically, HuR positively promoted CD3g expression by binding its mRNA and enhanced the expression of downstream adaptor Zap70 and Malt1 in activated CD4+ T cells. Compared to WT Th0 cells, HuR KO Th0 cells with reduced Bcl-2 expression are much more susceptible to apoptosis than WT Th0 cells. We also found that HuR stabilized IL-6Rα mRNA and promoted IL-6Rα protein expression, thereby upregulating its downstream phosphorylation of Jak1 and Stat3 and increased level of phosphorylation of IκBα to facilitate Th17 cell differentiation. However, knockout of HuR increased IL-22 production in Th17 cells, which was due to HuR deficiency in reducing IL-22 transcription repressor c-Maf expression. These results highlight the importance of HuR in TCR signaling and IL-6/IL-6R axis driving naïve CD4+ T cell activation and differentiation into Th17 cells.

Shedded neuronal ICAM-5 suppresses T-cell activation

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3615-3625 ◽  
Author(s):  
Li Tian ◽  
Jani Lappalainen ◽  
Matti Autero ◽  
Satu Hänninen ◽  
Heikki Rauvala ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Receptor ◽  
Soluble Form ◽  
Mammalian Brain ◽  
Activated T Cells ◽  
Activation Markers ◽  
Costimulatory Signals

Abstract Intercellular adhesion molecules (ICAMs) bind to leukocyte β2 integrins, which, among other functions, provide costimulatory signals for T-cell activation. ICAM-5 (telencephalin) is expressed in the somadendritic region of neurons of the mammalian brain. The receptor for ICAM-5 is the integrin LFA-1, a major leukocyte integ-rin expressed in lymphocytes and microglia. In conditions of brain ischemia, epilepsy, and encephalitis, the soluble form of ICAM-5 (sICAM-5) has been detected in physiologic fluids. Here, we report that sICAM-5 attenuates the T-cell receptor-mediated activation of T cells as demonstrated by the decreased expression of the activation markers CD69, CD40L, and CD25 (IL-2R). This effect is most clearly seen in CD45ROLow (naive), and not in CD45ROHigh (memory) T cells, and is most effective early in priming, but not in the presence of strong costimulatory signals. Furthermore, sICAM-5 promotes the mRNA expression of the cytokines TGF-β1 and IFN-γ, but not TNF. The formation of sICAM-5 is promoted by activated T cells through the cleavage of ICAM-5 from neurons. This suggests that ICAM-5 is involved in immune privilege of the brain and acts as an anti-inflammatory agent.

scholarly journals Cellular Factors Targeting APCs to Modulate Adaptive T Cell Immunity

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Anabelle Visperas ◽  
Jeongsu Do ◽  
Booki Min
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Differentiation ◽  
T Cell Immunity ◽  
Immune Functions ◽  
Effector Cells ◽  
Cell Immunity

The fate of adaptive T cell immunity is determined by multiple cellular and molecular factors, among which the cytokine milieu plays the most important role in this process. Depending on the cytokines present during the initial T cell activation, T cells become effector cells that produce different effector molecules and execute adaptive immune functions. Studies thus far have primarily focused on defining how these factors control T cell differentiation by targeting T cells themselves. However, other non-T cells, particularly APCs, also express receptors for the factors and are capable of responding to them. In this review, we will discuss how APCs, by responding to those cytokines, influence T cell differentiation and adaptive immunity.

scholarly journals CD4-mediated enhancement or inhibition of T cell activation does not require the CD4:p56lck association.

1994 ◽  
Vol 179 (6) ◽  
pp. 1973-1983 ◽  
Author(s):  
A C Zerbib ◽  
A B Reske-Kunz ◽  
P Lock ◽  
R P Sékaly
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mhc Class Ii ◽  
T Cell Activation ◽  
Cell Activation ◽  
Positive Function ◽  
Cell Receptor ◽  
Class Ii ◽  
Specific Response ◽  
Effector Cells

CD4 is the coreceptor molecule expressed on the surface of T cells specific for or restricted by class II molecules of the major histocompatibility complex (MHC). Its expression on T cells is required for an optimal response to antigen (Ag). Three mechanisms have been invoked for the involvement of CD4 in T cell activation. First, it was shown that CD4 binds to MHC class II molecules on antigen presenting cells (APCs) thereby favoring an adhesion between effector cells and APCs. Association of CD4 to the T cell receptor and to the tyrosine kinase p56lck have also been shown to be critically involved in the positive function of CD4. Here, we demonstrate that the interaction of CD4 with p56lck is not required to enhance the response of two CD4-dependent, Ag-specific T cell hybridomas. Mutant forms of CD4 (TCD4), which lose association to p56lck, were expressed in these T cells and were shown to enhance the Ag-specific response as efficiently as the wild-type CD4. Moreover both CD4-dependent and independent T cell responses were inhibited by CD4-specific mAbs even when CD4 was not associated with p56lck. These results indicate that mechanisms distinct from sequestration of p56lck and/or negative signaling operate in these inhibitions. Results demonstrating enhancement of TCR-mediated signaling by the coaggregation of TCD4 mutant to the TCR further confirm that the association of p56lck to CD4 is not absolutely required for the regulatory functions of CD4. Our results suggest that the mechanisms implicated in the enhancement of T cell stimulation via CD4 depend solely on the extracellular and transmembrane domains of CD4.

scholarly journals The circadian clock of CD8 T cells modulates their early response to vaccination and the rhythmicity of related signaling pathways

2019 ◽  
Vol 116 (40) ◽  
pp. 20077-20086 ◽  
Author(s):  
Chloé C. Nobis ◽  
Geneviève Dubeau Laramée ◽  
Laura Kervezee ◽  
Dave Maurice De Sousa ◽  
Nathalie Labrecque ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Signaling Pathways ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Response ◽  
Cell Activation ◽  
Cd8 T Cell ◽  
Time Of Day ◽  
T Cell Response

Circadian variations of various aspects of the immune system have been described. However, the circadian control of T cells has been relatively unexplored. Here, we investigated the role of circadian clocks in regulating CD8 T cell response to antigen presentation by dendritic cells (DCs). The in vivo CD8 T cell response following vaccination with DCs loaded with the OVA257–264 peptide antigen (DC-OVA) leads to a higher expansion of OVA-specific T cells in response to vaccination done in the middle of the day, compared to other time points. This rhythm was dampened when DCs deficient for the essential clock gene Bmal1 were used and abolished in mice with a CD8 T cell-specific Bmal1 deletion. Thus, we assessed the circadian transcriptome of CD8 T cells and found an enrichment in the daytime of genes and pathways involved in T cell activation. Based on this, we investigated early T cell activation events. Three days postvaccination, we found higher T cell activation markers and related signaling pathways (including IRF4, mTOR, and AKT) after a vaccination done during the middle of the day compared to the middle of the night. Finally, the functional impact of the stronger daytime response was shown by a more efficient response to a bacterial challenge at this time of day. Altogether, these results suggest that the clock of CD8 T cells modulates the response to vaccination by shaping the transcriptional program of these cells and making them more prone to strong and efficient activation and proliferation according to the time of day.

scholarly journals Interferon regulatory factor 4 controls effector functions of CD8+ memory T cells

2021 ◽  
Vol 118 (16) ◽  
pp. e2014553118
Author(s):  
Aenne Harberts ◽  
Constantin Schmidt ◽  
Joanna Schmid ◽  
Daniel Reimers ◽  
Friedrich Koch-Nolte ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Population ◽  
T Cell Activation ◽  
Cell Activation ◽  
Memory T Cells ◽  
Memory Cell ◽  
Effector Memory ◽  
Effector Cells ◽  
Effector Functions

The transcription factor IRF4 is required for CD8+ T cell activation, proliferation, and differentiation to effector cells and thus is essential for robust CD8+ T cell responses. The function of IRF4 in memory CD8+ T cells yet needs to be explored. To investigate the role of IRF4 for maintaining differentiation state and survival of CD8+ memory T cells, we used a mouse model with tamoxifen-inducible Irf4 knockout to preclude effects due to inefficient memory cell differentiation in absence of IRF4. We infected mice with ovalbumin-recombinant listeria and induced Irf4 knockout after clearance of the pathogen. Loss of IRF4 resulted in phenotypical changes of CD8+ memory T cells but did not cause a reduction of the total memory T cell population. However, upon reencounter of the pathogen, CD8+ memory T cells showed impaired expansion and acquisition of effector functions. When compared to CD8+ effector memory T cells, CD8+ tissue-resident memory T cells (TRM cells) expressed higher IRF4 levels. Mice with constitutive Irf4 knockout had diminished CD8+ TRM-cell populations, and tamoxifen-induced Irf4 deletion caused a reduction of this cell population. In conclusion, our results demonstrate that IRF4 is required for effective reactivation but not for general survival of CD8+ memory T cells. Formation and maintenance of CD8+ TRM cells, in contrast, appear to depend on IRF4.

scholarly journals The STAT5-IRF4-BATF pathway drives heightened epigenetic remodeling in naïve CD4+ T cell responses of older adults

2021 ◽  
Author(s):  
Huimin Zhang ◽  
Rohit R Jadhav ◽  
Wenqiang Cao ◽  
Isabel N Goronzy ◽  
Jun Jin ◽  
...  
Keyword(s):  
Older Adults ◽  
T Cells ◽  
T Cell ◽  
Cell Fate ◽  
T Cell Activation ◽  
Cell Activation ◽  
Memory Cell ◽  
Cell Aging ◽  
Effector Cells ◽  
Cell Fate Decisions

T cell aging is a complex process combining the emergence of cellular defects with the activation of adaptive mechanisms. Generation of T cell memory is impaired, while a low-inflammatory state is induced, in part due to activity of effector cells. To determine whether age-associated changes in T cell fate decisions occur early after T cell activation, we profiled the longitudinal transcriptional and epigenetic landscape induced by TCR stimulation comparing naïve CD4+ T cells from young and older adults. In spite of attenuated TCR signaling, activation-induced remodeling of the epigenome increased with age, culminating in increased BATF and BLIMP1 activity. Single cell studies, integrating ATAC-seq and RNA-seq data, identified an increase in dysfunctional and effector T cells and a decrease in BACH2-expressing memory cell precursors with age. pSTAT5, in part due to aberrant IL-2 receptor and reduced HELIOS expression, accounted for the induction of transcription factor networks favoring effector cell differentiation.

scholarly journals De novo DNA methylation by DNA methyltransferase 3a controls early effector CD8+ T-cell fate decisions following activation

2016 ◽  
Vol 113 (38) ◽  
pp. 10631-10636 ◽  
Author(s):  
Brian H. Ladle ◽  
Kun-Po Li ◽  
Maggie J. Phillips ◽  
Alexandra B. Pucsek ◽  
Azeb Haile ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Fate ◽  
T Cell Activation ◽  
Dna Methyltransferase ◽  
Cell Activation ◽  
De Novo ◽  
Effector Cells ◽  
Cell Fate Decisions ◽  
Terminal Effector

DNMT3a is a de novo DNA methyltransferase expressed robustly after T-cell activation that regulates plasticity of CD4+ T-cell cytokine expression. Here we show that DNMT3a is critical for directing early CD8+ T-cell effector and memory fate decisions. Whereas effector function of DNMT3a knockout T cells is normal, they develop more memory precursor and fewer terminal effector cells in a T-cell intrinsic manner compared with wild-type animals. Rather than increasing plasticity of differentiated effector CD8+ T cells, loss of DNMT3a biases differentiation of early effector cells into memory precursor cells. This is attributed in part to ineffective repression of Tcf1 expression in knockout T cells, as DNMT3a localizes to the Tcf7 promoter and catalyzes its de novo methylation in early effector WT CD8+ T cells. These data identify DNMT3a as a crucial regulator of CD8+ early effector cell differentiation and effector versus memory fate decisions.

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