scholarly journals Distinct Structural Domains of Caveolin-1 Independently Regulate Ca2+Release-Activated Ca2+Channels and Ca2+Microdomain-Dependent Gene Expression

2015 ◽  
Vol 35 (8) ◽  
pp. 1341-1349 ◽  
Author(s):  
Yi-Chun Yeh ◽  
Anant B. Parekh
Keyword(s):  
Gene Expression ◽  
Immune Cell ◽  
Nuclear Gene ◽  
Calcium Entry ◽  
Scaffolding Protein ◽  
Activated T Cells ◽  
Caveolin 1 ◽  
Cell Functions ◽  
Crac Channels ◽  
Crac Channel

In eukaryotic cells, calcium entry across the cell surface activates nuclear gene expression, a process critically important for cell growth and differentiation, learning, and memory and immune cell functions. In immune cells, calcium entry occurs through store-operated Ca2+release-activated Ca2+(CRAC) channels, comprised of STIM1 and Orai1 proteins. Local calcium entry through CRAC channels activates expression of c-fos- and nuclear factor of activated T cells (NFAT)-dependent genes. Although c-fos and NFAT often interact to activate gene expression synergistically, they can be activated independently of one another to regulate distinct genes. This raises the question of how one transcription factor can be activated and not the other when both are stimulated by the same trigger. Here, we show that the lipid raft scaffolding protein caveolin-1 interacts with the STIM1-Orai1 complex to increase channel activity. Phosphorylation of tyrosine 14 on caveolin-1 regulates CRAC channel-evoked c-fos activation without impacting the NFAT pathway or Orai1 activity. Our results reveal that structurally distinct domains of caveolin-1 selectively regulate the ability of local calcium to activate distinct transcription factors. More generally, our findings reveal that modular regulation by a scaffolding protein provides a simple, yet effective, mechanism to tunnel a local signal down a specific pathway.

scholarly journals Comprehensive genomic and immunophenotypic analysis of CD4 T cell infiltrating human triple-negative breast cancer

2020 ◽  
Author(s):  
He Zhang ◽  
Guohui Qin ◽  
Hui Yu ◽  
Xu Han ◽  
Sha Zhu
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
T Cells ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Immune Cell ◽  
Differential Expression Analysis ◽  
Effector Memory ◽  
Activated T Cells ◽  
Cell Functions

AbstractThe aim of this study is to investigate the gene expression module of tumor-infiltrating CD4+T cells and its potential roles in modulating immune cell functions in triple-negative breast cancer. Differentially expressed genes were identified by comparison of the expression profile in CD4+T cells isolated from tumor tissues and peripheral blood of TNBC patients respectively. The differential expression analysis was conducted using R, and then the functional and pathway enrichment of the DEGs were analyzed using GSEA, followed by integrated regulatory network construction and genetic analysis of tumor-infiltrating immune cells based on a scientific deconvolution algorithm. As a result, abundant Treg and exhausted lymphocytes were detected, accompanied by largely decreased of effector/memory and cytotoxic T cells. Immune-related gene correlation analysis showed that the extent of follicular helper T cells gene expression signatures were inversely associated with those of CD4+ naive T cells and CD4+ memory resting T cells, but positively correlated with that of CD4+ memory activated T cells. In addition, we found five core genes including IFNG, CTLA4, FAS, CXCR6, and JUN were significantly over expressed in CD4+ TILs which may contribute to exhaustion of lymphocytes and participate in biological processes associated with regulation of chemotaxis. Study provides a comprehensive understanding of the roles of DEGs associated with the chemotactic and exhausted immunophenotypes of CD4+ TILs that are a valuable resource from which future investigation may be carried out to better understand the mechanisms that promote TNBC progression.

Association between cetuximab response and differential immunologic gene expression signatures in colorectal cancer metastases.

2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 558-558 ◽  
Author(s):  
Michael Sangmin Lee ◽  
Benjamin Garrett Vincent ◽  
Autumn Jackson McRee ◽  
Hanna Kelly Sanoff
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Immune Cell ◽  
Expression Profiles ◽  
Gene Set Enrichment Analysis ◽  
Activated T Cells ◽  
Gene Sets

558 Background: Different immune cell infiltrates into colorectal cancer (CRC) tumors are associated with different prognoses. Tumor-associated macrophages contribute to immune evasion and accelerated tumor progression. Conversely, tumor infiltrating lymphocytes at the invasive margin of CRC liver metastases are associated with improved outcomes with chemotherapy. Cetuximab is an IgG1 monoclonal antibody against epidermal growth factor receptor (EGFR) and stimulates antibody-dependent cellular cytotoxicity (ADCC) in vitro. However, it is unclear in humans if response to cetuximab is modulated by the immune response. We hypothesized that different immune patterns detected in gene expression profiles of CRC metastases are associated with different responses to cetuximab. Methods: We retrieved gene expression data from biopsies of metastases from 80 refractory CRC patients treated with cetuximab monotherapy (GEO GSE5851). Samples were dichotomized by cetuximab response as having either disease control (DC) or progressive disease (PD). We performed gene set enrichment analysis (GSEA) with GenePattern 3.9.4 using gene sets of immunologic signatures obtained from the Molecular Signatures Database v5.0. Results: Among the 68 patients with response annotated, 25 had DC and 43 had PD. In the PD cohort, 59/1910 immunologic gene sets had false discovery rate (FDR) < 0.1. Notably, multiple gene sets upregulated in monocyte signatures were associated with PD. Also, gene sets consistent with PD1-ligated T cells compared to control activated T cells (FDR = 0.052) or IL4-treated CD4 T cells compared to controls (FDR = 0.087) were associated with PD. Conclusions: Cetuximab-resistant patients tended to have baseline increased expression of gene signatures reflective of monocytic infiltrates, consistent with also having increased expression of the IL4-treated T-cell signature. Cetuximab resistance was also associated with increased expression of the PD1-ligated T cell signature. These preliminary findings support further evaluation of the effect of differential immune infiltrates in prognosis of metastatic CRC treated with cetuximab.

scholarly journals Single Channel Properties and Regulated Expression of Ca2+ Release-Activated Ca2+ (Crac) Channels in Human T Cells

2000 ◽  
Vol 150 (6) ◽  
pp. 1435-1444 ◽  
Author(s):  
Alla F. Fomina ◽  
Christopher M. Fanger ◽  
J. Ashot Kozak ◽  
Michael D. Cahalan
Keyword(s):  
T Cells ◽  
Single Channel ◽  
Immunosuppressive Drug ◽  
Kinetic Properties ◽  
Activated T Cells ◽  
Expression Levels ◽  
Crac Channels ◽  
Human T Cells ◽  
Channel Expression ◽  
Crac Channel

Although the crucial role of Ca2+ influx in lymphocyte activation has been well documented, little is known about the properties or expression levels of Ca2+ channels in normal human T lymphocytes. The use of Na+ as the permeant ion in divalent-free solution permitted Ca2+ release-activated Ca2+ (CRAC) channel activation, kinetic properties, and functional expression levels to be investigated with single channel resolution in resting and phytohemagglutinin (PHA)-activated human T cells. Passive Ca2+ store depletion resulted in the opening of 41-pS CRAC channels characterized by high open probabilities, voltage-dependent block by extracellular Ca2+ in the micromolar range, selective Ca2+ permeation in the millimolar range, and inactivation that depended upon intracellular Mg2+ ions. The number of CRAC channels per cell increased greatly from ∼15 in resting T cells to ∼140 in activated T cells. Treatment with the phorbol ester PMA also increased CRAC channel expression to ∼60 channels per cell, whereas the immunosuppressive drug cyclosporin A (1 μM) suppressed the PHA-induced increase in functional channel expression. Capacitative Ca2+ influx induced by thapsigargin was also significantly enhanced in activated T cells. We conclude that a surprisingly low number of CRAC channels are sufficient to mediate Ca2+ influx in human resting T cells, and that the expression of CRAC channels increases ∼10-fold during activation, resulting in enhanced Ca2+ signaling.

scholarly journals Lipid-mediated insertion of Toll-like receptor (TLR) ligands for facile immune cell engineering

2019 ◽  
Author(s):  
Michael H. Zhang ◽  
Emily M. Slaby ◽  
Georgina Stephanie ◽  
Chunsong Yu ◽  
Darcy M. Watts ◽  
...  
Keyword(s):  
Immune Cells ◽  
Plasma Membranes ◽  
Cell Activation ◽  
Immune Cell ◽  
Cell Lineage ◽  
Genetic System ◽  
Cell Engineering ◽  
Toll Like Receptor ◽  
Activated T Cells ◽  
Cell Functions

AbstractCell-based immunotherapies have tremendous potential to treat many diseases, such as activating immunity in cancer or suppressing it in autoimmune diseases. Most cell-based cancer immunotherapies in the clinic provide adjuvant signals through genetic engineering to enhance T cell functions. However, genetically encoded signals have minimal control over dosing and persist for the life of a cell lineage. These properties make it difficult to balance increasing therapeutic efficacy with reducing toxicities. Here, we demonstrated the potential of phospholipid-coupled ligands as a non-genetic system for immune cell engineering. This system provides simple, controlled, non-genetic adjuvant delivery to immune cells via lipid-mediated insertion into plasma membranes. Lipid-mediated insertion (depoting) successfully delivered Toll-like receptor (TLR) ligands intracellularly and onto cell surfaces of diverse immune cells. These ligands depoted into immune cells in a dose-controlled fashion and did not compete during multiplex pairwise loading. Immune cell activation could be enhanced by autocrine and paracrine mechanisms depending on the biology of the TLR ligand tested. We determined that depoted ligands can functionally persist on plasma membranes for up to four days in naïve and activated T cells, enhancing their activation, proliferation, and skewing cytokine secretion. Depoted ligands provide a persistent yet non-permanent adjuvant signal to immune cells that may minimize the intensity and duration of toxicities compared to permanent genetic delivery. Altogether, these findings demonstrate potential for lipid-mediated insertion (depoting) as a universal cell engineering approach with unique, complementary advantages to other cell engineering methods.

scholarly journals An essential and NSF independent role for α-SNAP in store-operated calcium entry

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Yong Miao ◽  
Cathrine Miner ◽  
Lei Zhang ◽  
Phyllis I Hanson ◽  
Adish Dani ◽  
...  
Keyword(s):  
Essential Role ◽  
Calcium Release ◽  
Calcium Entry ◽  
Snare Complex ◽  
Functional Coupling ◽  
Crac Channels ◽  
Store Depletion ◽  
Store Operated Calcium Entry ◽  
Crac Channel

Store-operated calcium entry (SOCE) by calcium release activated calcium (CRAC) channels constitutes a primary route of calcium entry in most cells. Orai1 forms the pore subunit of CRAC channels and Stim1 is the endoplasmic reticulum (ER) resident Ca2+ sensor. Upon store-depletion, Stim1 translocates to domains of ER adjacent to the plasma membrane where it interacts with and clusters Orai1 hexamers to form the CRAC channel complex. Molecular steps enabling activation of SOCE via CRAC channel clusters remain incompletely defined. Here we identify an essential role of α-SNAP in mediating functional coupling of Stim1 and Orai1 molecules to activate SOCE. This role for α-SNAP is direct and independent of its known activity in NSF dependent SNARE complex disassembly. Importantly, Stim1-Orai1 clustering still occurs in the absence of α-SNAP but its inability to support SOCE reveals that a previously unsuspected molecular re-arrangement within CRAC channel clusters is necessary for SOCE.

Bidirectional regulation of calcium release–activated calcium (CRAC) channel by SARAF

2021 ◽  
Vol 220 (12) ◽  
Author(s):  
Elia Zomot ◽  
Hadas Achildiev Cohen ◽  
Inbal Dagan ◽  
Ruslana Militsin ◽  
Raz Palty
Keyword(s):  
Gene Expression ◽  
Calcium Release ◽  
Cell Receptor ◽  
Crac Channels ◽  
Bidirectional Regulation ◽  
Dependent Inactivation ◽  
Store Operated Calcium Entry ◽  
Crac Channel ◽  
Initial Activation ◽  
Downstream Gene Expression

Store-operated calcium entry (SOCE) through the Ca2+ release–activated Ca2+ (CRAC) channel is a central mechanism by which cells generate Ca2+ signals and mediate Ca2+-dependent gene expression. The molecular basis for CRAC channel regulation by the SOCE-associated regulatory factor (SARAF) remained insufficiently understood. Here we found that following ER Ca2+ depletion, SARAF facilitates a conformational change in the ER Ca2+ sensor STIM1 that relieves an activation constraint enforced by the STIM1 inactivation domain (ID; aa 475–483) and promotes initial activation of STIM1, its translocation to ER–plasma membrane junctions, and coupling to Orai1 channels. Following intracellular Ca2+ rise, cooperation between SARAF and the STIM1 ID controls CRAC channel slow Ca2+-dependent inactivation. We further show that in T lymphocytes, SARAF is required for proper T cell receptor evoked transcription. Taking all these data together, we uncover a dual regulatory role for SARAF during both activation and inactivation of CRAC channels and show that SARAF fine-tunes intracellular Ca2+ responses and downstream gene expression in cells.

Calcium oscillations in T-cells: mechanisms and consequences for gene expression

2003 ◽  
Vol 31 (5) ◽  
pp. 925-929 ◽  
Author(s):  
R.S. Lewis
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Nuclear Factor Κb ◽  
Cellular Mechanism ◽  
Calcium Oscillations ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Crac Channels ◽  
Kinetics Of ◽  
Ca2 Channels

[Ca2+]i (intracellular Ca2+ concentration) oscillations play a central role in the activation of T-lymphocytes by antigen. Oscillations in T-cells are absolutely dependent on Ca2+ influx through store-operated CRAC channels (Ca2+-release-activated Ca2+ channels), and evidence suggests that they arise from delayed interactions between these channels and Ca2+ stores. Their potential functions have been explored by creating controlled [Ca2+]i oscillations with pulses of Ca2+ entry or pulses of Ins(1,4,5)P3. Oscillations enhance both the efficiency and specificity of signalling through the Ca2+-dependent transcription factors nuclear factor of activated T-cells (NFAT), Oct/Oap and nuclear factor κB (NFκB) in ways that are consistent with each factor's Ca2+ dependence and kinetics of activation and deactivation. These studies show how [Ca2+]i oscillations may enhance signalling to the nucleus, and suggest a possible cellular mechanism for extracting information encoded in oscillation frequency.

scholarly journals Caveolin-1 in Kidney Chronic Antibody-Mediated Rejection: An Integrated Immunohistochemical and Transcriptomic Analysis Based on the Banff Human Organ Transplant (B-HOT) Gene Panel

Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1318
Author(s):  
Alessandro Gambella ◽  
Antonella Barreca ◽  
Simona Osella-Abate ◽  
Emanuel Bottasso ◽  
Manuela Maria Giarin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mhc Class Ii ◽  
Immune Cell ◽  
Nk Cell ◽  
Organ Transplant ◽  
Surrogate Marker ◽  
Conclusive Evidence ◽  
Human Organ ◽  
Caveolin 1 ◽  
Antibody Mediated Rejection

Caveolin-1 overexpression has previously been reported as a marker of endothelial injury in kidney chronic antibody-mediated rejection (c-ABMR), but conclusive evidence supporting its use for daily diagnostic practice is missing. This study aims to evaluate if Caveolin-1 can be considered an immunohistochemical surrogate marker of c-ABMR. Caveolin-1 expression was analyzed in a selected series of 22 c-ABMR samples and 11 controls. Caveolin-1 immunohistochemistry proved positive in peritubular and glomerular capillaries of c-ABMR specimens, irrespective of C4d status whereas all controls were negative. Multiplex gene expression profiling in c-ABMR cases confirmed Caveolin-1 overexpression and identified additional genes (n = 220) and pathways, including MHC Class II antigen presentation and Type II interferon signaling. No differences in terms of gene expression (including Caveolin-1 gene) were observed according to C4d status. Conversely, immune cell signatures showed a NK-cell prevalence in C4d-negative samples compared with a B-cell predominance in C4d-positive cases, a finding confirmed by immunohistochemical assessment. Finally, differentially expressed genes were observed between c-ABMR and controls in pathways associated with Caveolin-1 functions (angiogenesis, cell metabolism and cell–ECM interaction). Based on our findings, Caveolin-1 resulted as a key player in c-ABMR, supporting its role as a marker of this condition irrespective of C4d status.

scholarly journals Caveolin-1: a critical regulator of lung injury

2011 ◽  
Vol 300 (2) ◽  
pp. L151-L160 ◽  
Author(s):  
Yang Jin ◽  
Seon-Jin Lee ◽  
Richard D. Minshall ◽  
Augustine M. K. Choi
Keyword(s):  
Lung Injury ◽  
Severe Form ◽  
Therapeutic Interventions ◽  
Scaffolding Protein ◽  
Type I ◽  
Cellular Functions ◽  
Cellular Mechanisms ◽  
Caveolin 1 ◽  
Cell Functions ◽  
And Function

Caveolin-1 (cav-1), a 22-kDa transmembrane scaffolding protein, is the principal structural component of caveolae. Cav-1 regulates critical cell functions including proliferation, apoptosis, cell differentiation, and transcytosis via diverse signaling pathways. Abundant in almost every cell type in the lung, including type I epithelial cells, endothelial cells, smooth muscle cells, fibroblasts, macrophages, and neutrophils, cav-1 plays a crucial role in the pathogenesis of acute lung injury (ALI). ALI and its severe form, acute respiratory distress syndrome (ARDS), are responsible for significant morbidity and mortality in intensive care units, despite improvement in ventilation strategies. The pathogenesis of ARDS is still poorly understood, and therapeutic options remain limited. In this article, we summarize recent data regarding the regulation and function of cav-1 in lung biology and pathology, in particular as it relates to ALI. We further discuss the potential molecular and cellular mechanisms by which cav-1 expression contributes to ALI. Investigating the cellular functions of cav-1 may provide new insights for understanding the pathogenesis of ALI and provide novel targets for therapeutic interventions in the future.

scholarly journals ORAI1 and ORAI2 modulate murine neutrophil calcium signaling, cellular activation, and host defense

2020 ◽  
Vol 117 (39) ◽  
pp. 24403-24414
Author(s):  
Derayvia Grimes ◽  
Ryan Johnson ◽  
Madeline Pashos ◽  
Celeste Cummings ◽  
Chen Kang ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Calcium Release ◽  
Immune Cell ◽  
Calcium Influx ◽  
Cell Types ◽  
Receptor Activation ◽  
Neutrophil Function ◽  
Staphylococcal Infection ◽  
Crac Channels ◽  
Crac Channel

Calcium signals are initiated in immune cells by the process of store-operated calcium entry (SOCE), where receptor activation triggers transient calcium release from the endoplasmic reticulum, followed by opening of plasma-membrane calcium-release activated calcium (CRAC) channels. ORAI1, ORAI2, and ORAI3 are known to comprise the CRAC channel; however, the contributions of individual isoforms to neutrophil function are not well understood. Here, we show that loss of ORAI1 partially decreases calcium influx, while loss of both ORAI1 and ORAI2 completely abolishes SOCE. In other immune-cell types, loss of ORAI2 enhances SOCE. In contrast, we find that ORAI2-deficient neutrophils display decreased calcium influx, which is correlated with measurable differences in the regulation of neutrophil membrane potential via KCa3.1. Decreased SOCE in ORAI1-, ORAI2-, and ORAI1/2-deficient neutrophils impairs multiple neutrophil functions, including phagocytosis, degranulation, leukotriene, and reactive oxygen species (ROS) production, rendering ORAI1/2-deficient mice highly susceptible to staphylococcal infection. This study demonstrates that ORAI1 and ORAI2 are the primary components of the neutrophil CRAC channel and identifies subpopulations of neutrophils where cell-membrane potential functions as a rheostat to modulate the SOCE response. These findings have implications for mechanisms that modulate neutrophil function during infection, acute and chronic inflammatory conditions, and cancer.

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