Administration of cardiac mesenchymal cells modulates innate immunity in the acute phase of myocardial infarction in mice

Abstract Although cardiac mesenchymal cell (CMC) therapy mitigates post-infarct cardiac dysfunction, the underlying mechanisms remain unidentified. It is acknowledged that donor cells are neither appreciably retained nor meaningfully contribute to tissue regeneration—suggesting a paracrine-mediated mechanism of action. As the immune system is inextricably linked to wound healing/remodeling in the ischemically injured heart, the reparative actions of CMCs may be attributed to their immunoregulatory properties. The current study evaluated the consequences of CMC administration on post myocardial infarction (MI) immune responses in vivo and paracrine-mediated immune cell function in vitro. CMC administration preferentially elicited the recruitment of cell types associated with innate immunity (e.g., monocytes/macrophages and neutrophils). CMC paracrine signaling assays revealed enhancement in innate immune cell chemoattraction, survival, and phagocytosis, and diminished pro-inflammatory immune cell activation; data that identifies and catalogues fundamental immunomodulatory properties of CMCs, which have broad implications regarding the mechanism of action of CMCs in cardiac repair.

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IMMU-46. EXAMINATION OF THE EFFECTS OF DEXAMETHASONE ON THE EFFICACY OF IMMUNOTHERAPY IN GLIOMA USING GENE-MEDIATED CYTOTOXIC IMMUNOTHERAPY

Neuro-Oncology ◽

10.1093/neuonc/noz175.538 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi129-vi129

Author(s):

Marilin Koch ◽

Mykola Zdioruk ◽

M Oskar Nowicki ◽

Estuardo Aguilar ◽

Laura Aguilar ◽

...

Keyword(s):

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Symptomatic Treatment ◽

Tumor Cell Death ◽

The Impact

Abstract RATIONALE Dexamethasone is frequently used in symptomatic treatment of glioma patients, although it is known to cause immune suppression. Checkpoint inhibitor immunotherapies have not yet been successful in glioma treatments. Gene-mediated cytotoxic immunotherapy (GMCI) is an immunotherapeutic approach that uses aglatimagene besadenovec with an anti-herpetic prodrug to induce immunogenic tumor cell death and immune cell attraction to the tumor site with potent CD8 T cell activation. GMCI is currently in clinical trials for solid tumors including glioblastoma, where it showed encouraging survival results in a Phase 2 study that did not limit the use of dexamethasone. However, the effects of dexamethasone on its efficacy have not been explored. METHODS We investigated the effects of dexamethasone on GMCI in vitro using cytotoxicity and T-cell-killing assays in glioblastoma cell lines. The impact of dexamethasone in vivo was assessed in an orthotopic syngeneic murine glioblastoma model. RESULTS Cyotoxicity assays showed that Dexamethasone has a slight impact on GMCI in vitro. In contrast, we observed a highly significant effect in T-cell-functional assays in which killing was greatly impaired. Immune cell response assays revealed a reduced T-cell proliferation after co-culture with supernatant from dexamethasone or combination treated glioblastoma cells in contrast to GMCI alone. In a murine model, the combination of GMCI and dexamethasone resulted in a significant reduction in median symptom-free survival (29d) in comparison to GMCI alone (39.5d) (P = 0.0184). CONCLUSION Our data suggest that high doses of dexamethasone may negatively impact the efficacy of immunotherapy for glioma, which may be a consequence of impaired T cell function. These results support the idea that there is a need in identifying possible alternatives to dexamethasone to maximize the effectiveness of immunostimulatory therapies such as GMCI.

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TRPM2 Is Not Required for T-Cell Activation and Differentiation

Frontiers in Immunology ◽

10.3389/fimmu.2021.778916 ◽

2022 ◽

Vol 12 ◽

Author(s):

Niels C. Lory ◽

Mikolaj Nawrocki ◽

Martina Corazza ◽

Joanna Schmid ◽

Valéa Schumacher ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Transient Receptor Potential ◽

Cell Function ◽

Intestinal Inflammation ◽

Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

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Erratum: Bisphosphonate-induced differential modulation of immune cell function in gingiva and bone marrow in vivo: Role in osteoclast-mediated NK cell activation

Oncotarget ◽

10.18632/oncotarget.6431 ◽

2015 ◽

Vol 6 (38) ◽

pp. 41398-41398 ◽

Cited By ~ 1

Author(s):

Han-Ching Tseng ◽

Keiichi Kanayama ◽

Kawaljit Kaur ◽

So-Hyun Park ◽

Sil Park ◽

...

Keyword(s):

Bone Marrow ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Nk Cell ◽

Differential Modulation ◽

Immune Cell Function

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Revisiting the role of IRF3 in inflammation and immunity by conditional and specifically targeted gene ablation in mice

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1803936115 ◽

2018 ◽

Vol 115 (20) ◽

pp. 5253-5258 ◽

Cited By ~ 19

Author(s):

Hideyuki Yanai ◽

Shiho Chiba ◽

Sho Hangai ◽

Kohei Kometani ◽

Asuka Inoue ◽

...

Keyword(s):

Immune Cell ◽

Cell Types ◽

Type I ◽

Type I Ifn ◽

Cell Type ◽

Gene Ablation ◽

Cell Type Specific

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.

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Signaling function of PRC2 is essential for TCR-driven T cell responses

Journal of Experimental Medicine ◽

10.1084/jem.20170084 ◽

2018 ◽

Vol 215 (4) ◽

pp. 1101-1113 ◽

Cited By ~ 16

Author(s):

Marc-Werner Dobenecker ◽

Joon Seok Park ◽

Jonas Marcello ◽

Michael T. McCabe ◽

Richard Gregory ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

T Cell Activation ◽

Cell Activation ◽

Therapeutic Potential ◽

Cell Types ◽

Polycomb Repressive Complex 2 ◽

Histone Lysine Methyltransferases

Differentiation and activation of T cells require the activity of numerous histone lysine methyltransferases (HMT) that control the transcriptional T cell output. One of the most potent regulators of T cell differentiation is the HMT Ezh2. Ezh2 is a key enzymatic component of polycomb repressive complex 2 (PRC2), which silences gene expression by histone H3 di/tri-methylation at lysine 27. Surprisingly, in many cell types, including T cells, Ezh2 is localized in both the nucleus and the cytosol. Here we show the presence of a nuclear-like PRC2 complex in T cell cytosol and demonstrate a role of cytosolic PRC2 in T cell antigen receptor (TCR)–mediated signaling. We show that short-term suppression of PRC2 precludes TCR-driven T cell activation in vitro. We also demonstrate that pharmacological inhibition of PRC2 in vivo greatly attenuates the severe T cell–driven autoimmunity caused by regulatory T cell depletion. Our data reveal cytoplasmic PRC2 is one of the most potent regulators of T cell activation and point toward the therapeutic potential of PRC2 inhibitors for the treatment of T cell–driven autoimmune diseases.

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GABAA receptor α4-subunit knockout enhances lung inflammation and airway reactivity in a murine asthma model

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00107.2017 ◽

2017 ◽

Vol 313 (2) ◽

pp. L406-L415 ◽

Cited By ~ 14

Author(s):

Gene T. Yocum ◽

Damian L. Turner ◽

Jennifer Danielsson ◽

Matthew B. Barajas ◽

Yi Zhang ◽

...

Keyword(s):

T Cell ◽

T Cell Activation ◽

Immune Cells ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Therapeutic Potential ◽

Ex Vivo ◽

Asthma Model

Emerging evidence indicates that hypnotic anesthetics affect immune function. Many anesthetics potentiate γ-aminobutyric acid A receptor (GABAAR) activation, and these receptors are expressed on multiple subtypes of immune cells, providing a potential mechanistic link. Like immune cells, airway smooth muscle (ASM) cells also express GABAARs, particularly isoforms containing α4-subunits, and activation of these receptors leads to ASM relaxation. We sought to determine if GABAAR signaling modulates the ASM contractile and inflammatory phenotype of a murine allergic asthma model utilizing GABAAR α4-subunit global knockout (KO; Gabra40/0) mice. Wild-type (WT) and Gabra4 KO mice were sensitized with house dust mite (HDM) antigen or exposed to PBS intranasally 5 days/wk for 3 wk. Ex vivo tracheal rings from HDM-sensitized WT and Gabra4 KO mice exhibited similar magnitudes of acetylcholine-induced contractile force and isoproterenol-induced relaxation ( P = not significant; n = 4). In contrast, in vivo airway resistance (flexiVent) was significantly increased in Gabra4 KO mice ( P < 0.05, n = 8). Moreover, the Gabra4 KO mice demonstrated increased eosinophilic lung infiltration ( P < 0.05; n = 4) and increased markers of lung T-cell activation/memory (CD62L low, CD44 high; P < 0.01, n = 4). In vitro, Gabra4 KO CD4+ cells produced increased cytokines and exhibited increased proliferation after stimulation of the T-cell receptor as compared with WT CD4+ cells. These data suggest that the GABAAR α4-subunit plays a role in immune cell function during allergic lung sensitization. Thus GABAAR α4-subunit-specific agonists have the therapeutic potential to treat asthma via two mechanisms: direct ASM relaxation and inhibition of airway inflammation.

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Stimulation of Innate Immunity byIn VivoCyclic di-GMP Synthesis Using Adenovirus

Clinical and Vaccine Immunology ◽

10.1128/cvi.00471-14 ◽

2014 ◽

Vol 21 (11) ◽

pp. 1550-1559 ◽

Cited By ~ 4

Author(s):

Benjamin J. Koestler ◽

Sergey S. Seregin ◽

David P. W. Rastall ◽

Yasser A. Aldhamen ◽

Sarah Godbehere ◽

...

Keyword(s):

Innate Immunity ◽

Mammalian Cells ◽

Immune Cell ◽

Innate Immune ◽

Host Cells ◽

Content Type ◽

Cytokines And Chemokines ◽

Novel Approach

ABSTRACTThe bacterial second messenger cyclic di-GMP (c-di-GMP) stimulates inflammation by initiating innate immune cell recruitment and triggering the release of proinflammatory cytokines and chemokines. These properties make c-di-GMP a promising candidate for use as a vaccine adjuvant, and numerous studies have demonstrated that administration of purified c-di-GMP with different antigens increases protection against infection in animal models. Here, we have developed a novel approach to produce c-di-GMP inside host cells as an adjuvant to exploit a host-pathogen interaction and initiate an innate immune response. We have demonstrated that c-di-GMP can be synthesizedin vivoby transducing a diguanylate cyclase (DGC) gene into mammalian cells using an adenovirus serotype 5 (Ad5) vector. Expression of DGC led to the production of c-di-GMPin vitroandin vivo, and this was able to alter proinflammatory gene expression in murine tissues and increase the secretion of numerous cytokines and chemokines when administered to animals. Furthermore, coexpression of DGC modestly increased T-cell responses to aClostridium difficileantigen expressed from an adenovirus vaccine, although no significant differences in antibody titers were observed. This adenovirus c-di-GMP delivery system offers a novel method to administer c-di-GMP as an adjuvant to stimulate innate immunity during vaccination.

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Bisphosphonate-induced differential modulation of immune cell function in gingiva and bone marrow in vivo: Role in osteoclast-mediated NK cell activation

Oncotarget ◽

10.18632/oncotarget.4755 ◽

2015 ◽

Vol 6 (24) ◽

pp. 20002-20025 ◽

Cited By ~ 26

Author(s):

Han-Ching Tseng ◽

Keiichi Kanayama ◽

Kawaljit Kaur ◽

So-Hyun Park ◽

Sil Park ◽

...

Keyword(s):

Bone Marrow ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Nk Cell ◽

Differential Modulation ◽

Immune Cell Function

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Cell-specific and targeted delivery of RNA moieties

10.1101/2020.01.03.893818 ◽

2020 ◽

Author(s):

Aditi Bhargava ◽

Peter Ohara ◽

Luc Jasmin

Keyword(s):

Nucleic Acids ◽

Targeted Delivery ◽

Immune Cell ◽

Neuronal Cell ◽

Cell Types ◽

Specific Cell ◽

Chemically Modified ◽

Covalently Linked

AbstractDelivery of therapeutic moieties to specific cell types, such as neurons remains a challenge. Genes present in neurons are also expressed in non-neuronal cell types such as glia where they mediate non-targeted related functions. Thus, non-specific targeting of these proteins/channels has numerous unwanted side effects, as is the case with current small molecules or drug therapies. Current methodologies that use nanoparticles, lipid-mediated uptake, or mannitol in conjunction with lipids to deliver double-stranded RNA (dsRNA) have yielded mixed and unreliable results. We used a neuroanatomical tracer (B subunit of Cholera Toxin (CTB)) that binds to the ganglioside receptors (GM1) expressed on cells, including primary sensory neurons to deliver encapsulated dsRNA. This approach greatly improved delivery of dsRNA to the desired cells by enhancing uptake, reducing vehicle-mediated toxicity and protecting nucleotides from degradation by endonucleases. The delivery complex is internalized, and once inside the cell, the dsRNA naturally dissociates itself from the carrier complex and is very effective in knocking down cognate targets, both in vivo and in vitro. Past methods have used CTB-fusion proteins or chemically modified oligos or DNA moieties that have been covalently conjugated to CTB. Furthermore, CTB conjugated to an antigen, protein, or chemically modified nucleic acid is a potent activator of immune cell (T and B cells, macrophages) response, whereas CTB admixed with antigens or unmodified nucleic acids does not evoke this immune response. Importantly, in our method, the nucleic acids are not covalently linked to the carrier molecules. Thus, our method holds strong potential for targeted delivery of therapeutic moieties for cell types expressing GM1 receptors, including neuronal cell types.

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587 Tumor-activated Fc-engineered anti-CTLA-4 monoclonal antibody, XTX101, demonstrates tumor-selective PD and efficacy in preclinical models

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2020-sitc2020.0587 ◽

2020 ◽

Vol 8 (Suppl 3) ◽

pp. A622-A622

Author(s):

Kurt Jenkins ◽

Parker Johnson ◽

Minjie Zhang ◽

Wilson Guzman ◽

Ugur Eskiocak ◽

...

Keyword(s):

T Cell ◽

Cell Activation ◽

Cell Function ◽

Immune Cell ◽

Tumor Regression ◽

Dependent Manner ◽

Human Solid Tumor ◽

Covalently Linked ◽

Tumor Selective

BackgroundThe clinical benefit of CTLA-4 blockade to cancer patients has been well established. However, the promising antitumor activity shown by anti-CTLA-4 monoclonal antibodies (mAb) has been limited by the occurrence of immune-mediated adverse reactions, especially when CTLA-4 inhibition is used in combination with anti-PD-1 therapy. These dose-limiting toxicities restrict the therapeutic use of CTLA-4 blockade. To overcome these limitations, we have developed a potent anti-CTLA-4 antibody that is selectively active in the tumor microenvironment (TME). This antibody is engineered with an Fc region for enhanced FcγR binding and peptides that mask antigen-binding regions. The masking peptides are designed to be selectively cleaved and released by proteases that are more active in the TME, resulting in restoration of full activity of the antibody in the TME.MethodsA novel, fully-humanized anti-huCTLA-4 mAb was shown to bind human CTLA-4 with improved affinity compared to ipilimumab, as measured by SPR. Engineering of the Fc region enhanced FcγR binding and ADCC function. In addition, CDR-binding peptides identified by phage display were covalently linked to the antibody using a protease-sensitive polypeptide linker. This engineered anti-CTLA-4 antibody (XTX101) showed protease-dependent binding to CTLA-4 both with recombinant and tumor tissue derived proteases.ResultsXTX101 demonstrated a 100-fold reduction in binding to human CTLA-4 by ELISA, compared to the non-masked antibody. Incubation with recombinant protease led to cleavage and release of the masking peptides and restored full binding to CTLA-4. Similarly, in vitro ADCC activity was impaired by masking and restored in a protease-dependent manner. SEB-stimulated human PMBCs were minimally responsive in vitro to XTX101, whereas PBMCs treated with proteolytically-activated XTX101 exhibited robust activation of T cell function. In human CTLA-4 knock-in mice with syngeneic MB49 tumors, XTX101 treatment led to complete tumor regression, enhanced CD8+ T cell proliferation, and depletion of tumor Tregs in the TME. By contrast, XTX101 had minimal pharmacodynamic effects in the periphery. In addition, XTX101 is effectively activated in culture supernatants from human solid tumor explants obtained from a broad range of tumor types.ConclusionsXTX101 is a tumor-selective anti-CTLA-4 mAb capable of: 1) effective CTLA-4 blockade, 2) depletion of intratumoral Tregs through enhanced antibody-dependent cellular cytotoxicity (ADCC) function, 3) minimization of systemic immune cell activation, and 4) potent anti-tumor activity. These pre-clinical data support the further evaluation of XTX101 in clinical studies.

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