The non-coding RNA miR-17~92 is a central mediator of T cell activation

SummaryT cell activation is paramount for productive adaptive immune responses. CD28 is a key clinically targeted immunoregulatory receptor because it provides the prototypical costimulatory signal required for T cell activation. Therefore, a precise understanding of the molecular consequences of CD28 costimulation has direct therapeutic relevance. Here, we uncover that the microRNA cluster miR-17~92 is part of the molecular program triggered by CD28 costimulation and hence T cell activation. Combining genetics, transcriptomics, bioinformatics and biochemical miRNA:mRNA interaction maps we demonstrate that transgenic miR-17~92 can cell-intrinsically largely overcome defects caused by CD28-deficiency. miR-17~92 promotes transcription of a proinflammatory gene signature by enhancing the calcineurin/NFAT pathway. miR-17~92 binds to and represses a network of genes including several negative regulators of T cell activation. Finally, CD28-deficient T cells exhibit derepressed miR-17~92 target genes during activation, demonstrating that this non-coding RNA is required to shape the transcriptome. Thus, we propose that miR-17~92 constitutes a central mediator for T cell activation, integrating signals by the TCR and CD28 costimulation. In this model miR-17~92 facilitates T cell activation by dampening the breaks that prevent T cell activation.

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NFATc3 regulates the transcription of genes involved in T-cell activation and angiogenesis

Blood ◽

10.1182/blood-2010-12-322701 ◽

2011 ◽

Vol 118 (3) ◽

pp. 795-803 ◽

Cited By ~ 31

Author(s):

Katia Urso ◽

Arantzazu Alfranca ◽

Sara Martínez-Martínez ◽

Amelia Escolano ◽

Inmaculada Ortega ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Target Genes ◽

Gene Knockout ◽

Activated T Cells ◽

Knock Down ◽

And Function

Abstract The nuclear factor of activated T cells (NFAT) family of transcription factors plays important roles in many biologic processes, including the development and function of the immune and vascular systems. Cells usually express more than one NFAT member, raising the question of whether NFATs play overlapping roles or if each member has selective functions. Using mRNA knock-down, we show that NFATc3 is specifically required for IL2 and cyclooxygenase-2 (COX2) gene expression in transformed and primary T cells and for T-cell proliferation. We also show that NFATc3 regulates COX2 in endothelial cells, where it is required for COX2, dependent migration and angiogenesis in vivo. These results indicate that individual NFAT members mediate specific functions through the differential regulation of the transcription of target genes. These effects, observed on short-term suppression by mRNA knock-down, are likely to have been masked by compensatory effects in gene-knockout studies.

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Cooperative Interaction of Nck and Lck Orchestrates Optimal TCR Signaling

Cells ◽

10.3390/cells10040834 ◽

2021 ◽

Vol 10 (4) ◽

pp. 834

Author(s):

Frederike A. Hartl ◽

Jatuporn Ngoenkam ◽

Esmeralda Beck-Garcia ◽

Liz Cerqueira ◽

Piyamaporn Wipa ◽

...

Keyword(s):

T Cell ◽

Ligand Binding ◽

T Cell Activation ◽

Cell Activation ◽

Adaptor Protein ◽

Cooperative Interaction ◽

Tcr Signaling ◽

Binding Motifs ◽

Adaptive Immune

The T cell antigen receptor (TCR) is expressed on T cells, which orchestrate adaptive immune responses. It is composed of the ligand-binding clonotypic TCRαβ heterodimer and the non-covalently bound invariant signal-transducing CD3 complex. Among the CD3 subunits, the CD3ε cytoplasmic tail contains binding motifs for the Src family kinase, Lck, and the adaptor protein, Nck. Lck binds to a receptor kinase (RK) motif and Nck binds to a proline-rich sequence (PRS). Both motifs only become accessible upon ligand binding to the TCR and facilitate the recruitment of Lck and Nck independently of phosphorylation of the TCR. Mutations in each of these motifs cause defects in TCR signaling and T cell activation. Here, we investigated the role of Nck in proximal TCR signaling by silencing both Nck isoforms, Nck1 and Nck2. In the absence of Nck, TCR phosphorylation, ZAP70 recruitment, and ZAP70 phosphorylation was impaired. Mechanistically, this is explained by loss of Lck recruitment to the stimulated TCR in cells lacking Nck. Hence, our data uncover a previously unknown cooperative interaction between Lck and Nck to promote optimal TCR signaling.

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

Molecular and Cellular Biology ◽

10.1128/mcb.14.12.7933-7942.1994 ◽

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.

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Williams-Beuren Syndrome Critical Region-5/Non-T Cell Activation Linker: A Novel Target Gene of AML1/ETO.

Blood ◽

10.1182/blood.v104.11.2898.2898 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2898-2898

Author(s):

Michael Lübbert ◽

Michael Stock ◽

Tobias Berg ◽

Manfred Fliegauf

Keyword(s):

Gene Expression ◽

T Cell ◽

T Cell Activation ◽

Critical Region ◽

Cell Activation ◽

Target Genes ◽

Chromosome 8 ◽

Chromosome 21 ◽

Acute Myeloid

Abstract The chromosomal translocation (8;21) fuses the AML1 gene on chromosome 21 and the ETO gene on chromosome 8 in human acute myeloid leukemias, resulting in expression of the chimeric transcription factor AML1/ETO. AML1/ETO-mediated dysregulation of target genes critical for hematopoietic differentiation and proliferation is thought to contribute to the leukemic phenotype. Several mechanisms, including recruitment of histone deacetylases (HDACs) to AML1 target genes, may be responsible for altered gene expression. We used an ecdysone-inducible expression system in the human monoblastic U-937 cell line to isolate genes that were differentially expressed upon induction of AML1/ETO expression. By representational difference analysis (cDNA-RDA), we identified 26 genes whose expression levels were significantly modulated following AML1/ETO induction for 48 hours. None of these genes has previously been described as a target of AML1, ETO or AML1/ETO. One gene down-regulated by AML1/ETO in vitro, Williams Beuren Syndrome critical region 5 (WBSCR5), was expressed in primary t(8;21) negative AML blasts but not in primary t(8;21) positive AML blasts, strongly implying a role of this gene in the phenotype of t(8;21) positive AML. WBSCR5 is part of the critical region located on chromosome 7q11.23 that is deleted in the Williams Beuren syndrome (OMIM 194050), an autosomal dominant disorder comprising vascular, neurological, behavioral and skeletal abnormalities. WBSCR5 has recently been shown to have a role in the activation and differentiation of B cells (Brdicka et al., J. Exp. Med. 196:1617, 2002) and thus was also termed Non-T cell activation linker.. WBSCR5 as well as seven other regulated genes were further studied using all-trans-retinoic acid (ATRA), an inducer of differentiation of U-937 cells, and Trichostatin A (TSA), an HDAC inhibitor. WBSCR5 and two other out of these eight genes were regulated during ATRA-induced monocytic differentiation of U-937 cells, however none of them antagonistically, upon both ATRA-treatment and AML1/ETO-induction. Since repression of WBSCR5 might be mediated by recruitment of HDACs through the fusion gene, cells were treated with TSA prior to transgene induction. However, the AML1/ETO-associated dysregulation of WBSCR5 gene expression (as well as that of the other seven genes studied) was not mediated by a TSA-sensitive mechanism. The identified genes provide a useful model to study the mechanism by which the AML1/ETO fusion protein exerts its function in transcriptional dysregulation in acute myeloid leukemia. The role of WBSCR5 in malignant hematopoietic cells warrants further study.

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In Vitro Platform Establishes Antigen-Specific CD8+ T Cell Cytotoxicity to Encapsulated Cells via Indirect Antigen Recognition

10.1101/2019.12.11.872978 ◽

2019 ◽

Author(s):

Ying Li ◽

Anthony W. Frei ◽

Ethan Y. Yang ◽

Irayme Labrada-Miravet ◽

Chuqiao Sun ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

T Cell Activation ◽

Cell Activation ◽

Immune Recognition ◽

Adaptive Immune Responses ◽

Activated T Cells ◽

Encapsulated Cells ◽

Adaptive Immune

AbstractCell replacement therapy has the potential to cure diseases caused by the absence or malfunction of specialized cells. A substantial impediment to the success of any non-autologous cellular transplant is the need for systemic immunosuppressive drugs to prevent host-mediated rejection of the foreign cells. Cellular encapsulation, i.e., the entrapment of cells within stable polymeric hydrogels, has been clinically explored to prevent host immune recognition and attack, but the efficacy of these encapsulated grafts is poor. While several studies have explored improvements in innate immune acceptance of these encapsulated cells, little attention has been paid to the roles of adaptive immune responses, specifically graft-targeting T cell activation, in graft destabilization. Herein, we established an efficient, single-antigen in vitro platform capable of delineating direct and indirect host T cell recognition to microencapsulated cellular grafts and evaluating their consequential impacts. Using alginate as the model hydrogel, encapsulated membrane-bound ovalbumin (mOVA) stimulator cells were incubated with antigen-specific OTI lymphocytes and subsequent OVA-specific CD8+ T cell activation and effector function were quantified. We established that alginate microencapsulation abrogates direct T cell activation by interrupting donor-host interaction; however, indirect T cell activation mediated by host antigen presenting cells (APCs) primed with shed donor antigens still occurs. These activated T cells imparted cytotoxicity on the encapsulated cells, likely via diffusion of cytotoxic solutes. Overall, this platform delivers unique mechanistic insight into the impacts of hydrogel encapsulation on host adaptive immune responses, as well as a tool for the efficient immune screening on new encapsulation methods and/or synergistic immunomodulatory agents.

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CD28 Costimulation of Effector T Cells During An Anti-Tumor Attack Sustains Its Repression by Regulatory T Cells Which Can Be Overcome by Preventing Lck Activation.

Blood ◽

10.1182/blood.v114.22.3569.3569 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3569-3569

Author(s):

David M Kofler ◽

Markus Chmielewski ◽

Tobias Riet ◽

Andreas Hombach ◽

Michael Hallek ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Chimeric Antigen Receptor ◽

Cell Activation ◽

Antigen Receptor ◽

Treg Cells ◽

Effector T Cells ◽

Cd28 Costimulation ◽

Signaling Domain

Abstract Abstract 3569 Poster Board III-506 Background Massive infiltrations of the tumor tissue with CD4+CD25highFoxP3+ regulatory T (Treg) cells render a productive T cell anti-tumor response ineffective resulting in unrestricted tumor growth despite the presence of tumor-specific, cytolytic T cells. Methods Using a human/CD1-deficient mouse model we investigated the impact of human regulatory T cells on redirected effector T cells expressing a tumor-specific chimeric antigen receptor. The chimeric antigen receptor consists of an antibody derived binding domain for antigens in the extracellular part and of the TCR/CD3zeta or the combined CD3zeta-CD28 signaling domain in the intracellular part. Upon antigen binding the chimeric antigen receptor transmits an activation signal via the CD3zeta or CD3zeta-CD28 domain to drive T cell activation, resulting in cytokine secretion, T cell proliferation, and cytolytic activity. Results We revealed that effector T cells redirected by a tumor-specific chimeric antigen receptor are more effectively repressed by Treg cells when they are activated through a combined CD3zeta-CD28 signal compared to a CD3zeta signal without CD28 costimulation. Mutations in the CD28 signaling domain of the chimeric antigen receptors resulted in abolished IL-2 secretion by prevention of CD28 mediated lck activation. Abolished IL-2 induction in redirected effector T cells expressing the modified CD3zetaCD28delta antigen receptor increased their in vivo efficacy in an anti-tumor response by reduced sustaining of Treg cell suppression. Conclusions While data indicate the dichotomy of CD28 costimulation in inducing full effector T cell activation and sustaining Treg repression, our findings provide a strategy to improve the efficacy of the T cell anti-tumor attack in the presence of Treg cells for use in adoptive immunotherapy of cancer. Disclosures: No relevant conflicts of interest to declare.

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Antibody Response to Achromobacter xylosoxidans during HIV Infection Is Associated with Lower CD4 Levels and Increased Lymphocyte Activation

Clinical and Vaccine Immunology ◽

10.1128/cvi.00553-13 ◽

2013 ◽

Vol 21 (1) ◽

pp. 46-50 ◽

Cited By ~ 1

Author(s):

Erick T. Tatro ◽

Intan Purnajo ◽

Douglas D. Richman ◽

Davey M. Smith ◽

Sara Gianella

Keyword(s):

T Cell ◽

Hiv Infection ◽

T Cell Activation ◽

Cell Activation ◽

Bacterial Species ◽

Microbial Translocation ◽

Achromobacter Xylosoxidans ◽

Content Type ◽

Adaptive Immune ◽

Cell Counts

ABSTRACTInflammation during HIV infection is associated with worse disease outcomes and progression. Many mechanisms have been indicted, including HIV itself, coinfections, and gut microbial translocation. Concerning microbial translocation, we hypothesized that adaptive immune responses to a specific bacterial species known to be present in gut-associated lymphoid tissue are higher among HIV-infected individuals than among HIV-uninfected controls and are associated with T cell activation and lower CD4 T cell counts. By characterizing the IgG response toAchromobacter xylosoxidans, we found that HIV-infected participants who were immunoresponsive (n= 48) had significantly lower CD4 percentages (P= 0.01), greater CD4 activation (percentages of RA−CD38+) (P= 0.03), and higher soluble CD14 (P= 0.01). HIV-positive individuals had higher anti-A. xylosoxidansIgG titers than HIV-uninfected individuals (P= 0.04). The results suggest an abnormal adaptive immune activation to gut microflora during HIV infection.

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

Molecular and Cellular Biology ◽

10.1128/mcb.14.12.7933 ◽

1994 ◽

Vol 14 (12) ◽

pp. 7933-7942 ◽

Cited By ~ 55

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

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Enhanced NFATc1 Nuclear Occupancy Causes T Cell Activation Independent of CD28 Costimulation

The Journal of Immunology ◽

10.4049/jimmunol.178.7.4315 ◽

2007 ◽

Vol 178 (7) ◽

pp. 4315-4321 ◽

Cited By ~ 23

Author(s):

Minggui Pan ◽

Monte M. Winslow ◽

Lei Chen ◽

Ann Kuo ◽

Dean Felsher ◽

...

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Cd28 Costimulation

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Transcriptomic Profiles of CD47 in Breast Tumors Predict Outcome and Are Associated with Immune Activation

International Journal of Molecular Sciences ◽

10.3390/ijms22083836 ◽

2021 ◽

Vol 22 (8) ◽

pp. 3836

Author(s):

María del Mar Noblejas-López ◽

Mariona Baliu-Piqué ◽

Cristina Nieto-Jiménez ◽

Francisco J. Cimas ◽

Esther C. Morafraile ◽

...

Keyword(s):

Breast Cancer ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Breast Tumors ◽

Gene Signature ◽

Immune Gene ◽

Cancer Subtypes ◽

Immune Signature ◽

Her2 Breast Cancer

Targeting the innate immune system has attracted attention with the development of anti- CD47 antibodies. Anti-CD47 antibodies block the inhibition of the phagocytic activity of macrophages caused by the up-regulation of CD47 on tumor cells. In this study, public genomic data was used to identify genes highly expressed in breast tumors with elevated CD47 expression and analyzed the association between the presence of tumor immune infiltrates and the expression of the selected genes. We found that 142 genes positively correlated with CD47, of which 83 predicted favorable and 32 detrimental relapse-free survival (RFS). From those associated with favorable RFS, we selected the genes with immunologic biological functions and defined a CD47-immune signature composed of PTPRC, HLA-E, TGFBR2, PTGER4, ETS1, and OPTN. In the basal-like and HER2+ breast cancer subtypes, the expression of the CD47-immune signature predicted favorable outcome, correlated with the presence of tumor immune infiltrates, and with gene expression signatures of T cell activation. Moreover, CD47 up-regulated genes associated with favorable survival correlated with pro-tumoral macrophages. In summary, we described a CD47-immune gene signature composed of 6 genes associated with favorable prognosis, T cell activation, and pro-tumoral macrophages in breast cancer tumors expressing high levels of CD47.

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