scholarly journals Tropomodulin1 Expression Increases Upon Maturation in Dendritic Cells and Promotes Their Maturation and Immune Functions

2021 ◽  
Vol 11 ◽  
Author(s):  
Xianmei Liu ◽  
Xue Xia ◽  
Xifu Wang ◽  
Jing Zhou ◽  
Lanping Amy Sung ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Actin Cytoskeleton ◽  
Costimulatory Molecules ◽  
Cell Stiffness ◽  
Actin Binding ◽  
Immune Functions ◽  
Dc Functions ◽  
Tlr4 Signaling ◽  
Functional Changes ◽  
Dc Maturation

Dendritic cells (DCs) are the most potent antigen-presenting cells. Upon maturation, DCs express costimulatory molecules and migrate to the lymph nodes to present antigens to T cells. The actin cytoskeleton plays key roles in multiple aspects of DC functions. However, little is known about the mechanisms and identities of actin-binding proteins that control DC maturation and maturation-associated functional changes. Tropomodulin1 (Tmod1), an actin-capping protein, controls actin depolymerization and nucleation. We found that Tmod1 was expressed in bone marrow-derived immature DCs and was significantly upregulated upon lipopolysaccharide (LPS)-induced DC maturation. By characterizing LPS-induced mature DCs (mDCs) from Tmod1 knockout mice, we found that compared with Tmod1+/+ mDCs, Tmod1-deficient mDCs exhibited lower surface expression of costimulatory molecules and chemokine receptors and reduced secretion of inflammatory cytokines, suggesting that Tmod1 deficiency retarded DC maturation. Tmod1-deficient mDCs also showed impaired random and chemotactic migration, deteriorated T-cell stimulatory ability, and reduced F-actin content and cell stiffness. Furthermore, Tmod1-deficient mDCs secreted high levels of IFN-β and IL-10 and induced immune tolerance in an experimental autoimmune encephalomyelitis (EAE) mouse model. Mechanistically, Tmod1 deficiency affected TLR4 signaling transduction, resulting in the decreased activity of MyD88-dependent NFκB and MAPK pathways but the increased activity of the TRIF/IRF3 pathway. Rescue with exogenous Tmod1 reversed the effect of Tmod1 deficiency on TLR4 signaling. Therefore, Tmod1 is critical in regulating DC maturation and immune functions by regulating TLR4 signaling and the actin cytoskeleton. Tmod1 may be a potential target for modulating DC functions, a strategy that would be beneficial for immunotherapy for several diseases.

NF-κB Blockade Induces Apoptosis and Decreases Costimulatory Molecules and IL-12 Secretion of Dendritic Cells, Altering DC Maturation: Role in Induction of Tolerance after Transplantation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2465-2465
Author(s):  
Luis I. Sanchez Abarca ◽  
Jose A. Perez-Simon ◽  
Belen Blanco ◽  
Norma Gutierrez ◽  
Juan Mateos ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Allogeneic Transplantation ◽  
Costimulatory Molecules ◽  
Cytokine Secretion ◽  
Gm Csf ◽  
Hla Dr ◽  
New Strategy ◽  
Th1 Cytokine ◽  
Dc Maturation

Abstract In steady state, dendritic cells (DC) are in an immature status and maintain tolerance to self antigens. By contrast, if DC maturation is stimulated, as it occurs in the proinflamatory milieu induced by allogeneic transplantation, they trigger effector and memory T cells and, for this reason, they play an essential role in the development of graft versus host disease (GVHD). DC maturation and survival is dependent on NF-kB. Thus, we explored the ability of the proteosome inhibitor bortezomib (B), which prevents Nuclear Factor kB (NF-kB) activation, to induce DC apoptosis and block maturation as a new strategy to prevent GVHD. DC were obtained from PBMN after culture with GM-CSF and IL-4 and were stimulated to maturate and express costimulatory molecules (CD80, CD83, CD86, CD40L) adding TNF and LPS. Even after this stimulation, B at doses ranging from 10 to 50 nM was able to decrease costimulatory molecules as well as HLA-DR expression, as assessed by flow cytometry. In addition, at 50 nM, B increased DC apoptosis (2650 vs 1404 anex/7AAD positive events among DC cultured with or w/o B, respectively; p=0.05). Moreover, B significantly decreased the production of IL-12, while IL10 secretion was unaffected (1,4% vs 6,2% DC cultured with or w/o B secreting IL-12, respectively; p=0.01). Cytokines and proinflamatory molecules genes expression profiling was also analysed by microarrays in DC cultured with or without B. Finally, after culture with bortezomib, DC were cocultured with T lymphocytes and, interestingly, allogeneic mixed lymphocyte reaction was markedly inhibited also inducing a decrease in Th1 cytokine secretion among T cells. In conclusion, bortezomib induces apoptosis and decreases DC maturation and cytokine secretion and favours tolerance to alloantigens. This new strategy based on DC therapy supports the use of proteosome inhibitors in the management of GVHD.

Clathrin Hub Expression Dissociates the Actin-Binding Protein Hip1R from Coated Pits and Disrupts Their Alignment with the Actin Cytoskeleton

Traffic ◽  
2001 ◽  
Vol 2 (11) ◽  
pp. 851-858 ◽  
Author(s):  
Elizabeth M. Bennett ◽  
Chih-Ying Chen ◽  
Asa E. Y. Engqvist-Goldstein ◽  
David G. Drubin ◽  
Frances M. Brodsky
Keyword(s):  
Actin Cytoskeleton ◽  
Binding Protein ◽  
Actin Binding ◽  
Coated Pits ◽  
Actin Binding Protein

scholarly journals Thapsigargin-Stimulated LAD2 Human Mast Cell Line Is a Potent Cellular Adjuvant for the Maturation of Monocyte-Derived Dendritic Cells for Adoptive Cellular Immunotherapy

2021 ◽  
Vol 22 (8) ◽  
pp. 3978
Author(s):  
Pavla Taborska ◽  
Dmitry Stakheev ◽  
Jirina Bartunkova ◽  
Daniel Smrz
Keyword(s):  
Dendritic Cells ◽  
Mast Cell ◽  
Ex Vivo ◽  
Human Leukocyte ◽  
Poly I:C ◽  
Human Mast Cell ◽  
Cellular Immunotherapy ◽  
Adoptive Cellular Immunotherapy ◽  
Serum Free ◽  
Dc Maturation

The preparation of dendritic cells (DCs) for adoptive cellular immunotherapy (ACI) requires the maturation of ex vivo-produced immature(i) DCs. This maturation ensures that the antigen presentation triggers an immune response towards the antigen-expressing cells. Although there is a large number of maturation agents capable of inducing strong DC maturation, there is still only a very limited number of these agents approved for use in the production of DCs for ACI. In seeking novel DC maturation agents, we used differentially activated human mast cell (MC) line LAD2 as a cellular adjuvant to elicit or modulate the maturation of ex vivo-produced monocyte-derived iDCs. We found that co-culture of iDCs with differentially activated LAD2 MCs in serum-containing media significantly modulated polyinosinic:polycytidylic acid (poly I:C)-elicited DC maturation as determined through the surface expression of the maturation markers CD80, CD83, CD86, and human leukocyte antigen(HLA)-DR. Once iDCs were generated in serum-free conditions, they became refractory to the maturation with poly I:C, and the LAD2 MC modulatory potential was minimized. However, the maturation-refractory phenotype of the serum-free generated iDCs was largely overcome by co-culture with thapsigargin-stimulated LAD2 MCs. Our data suggest that differentially stimulated mast cells could be novel and highly potent cellular adjuvants for the maturation of DCs for ACI.

scholarly journals Actin cytoskeleton deregulation confers midostaurin resistance in FLT3-mutant acute myeloid leukemia

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Andoni Garitano-Trojaola ◽  
Ana Sancho ◽  
Ralph Götz ◽  
Patrick Eiring ◽  
Susanne Walz ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Actin Cytoskeleton ◽  
Myeloid Leukemia ◽  
Actin Polymerization ◽  
Cell Stiffness ◽  
Adhesion Forces ◽  
Frequent Mutations ◽  
New Perspective ◽  
The Impact ◽  
Acute Myeloid

AbstractThe presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD + AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD + AML.

scholarly journals Methotrexate enhances antigen presentation and maturation of tumour antigen-loaded dendritic cells through NLRP3 inflammasome activation: a strategy for dendritic cell-based cancer vaccine

2021 ◽  
Vol 13 ◽  
pp. 175883592098705
Author(s):  
Gao-Na Shi ◽  
Min Hu ◽  
Chengjuan Chen ◽  
Junmin Fu ◽  
Shuai Shao ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
Nlrp3 Inflammasome ◽  
Tumour Antigen ◽  
Inflammasome Activation ◽  
Antigen Uptake ◽  
Nlrp3 Inflammasome Activation ◽  
Dc Maturation

Background: Dendritic cells (DCs) are antigen-presenting cells that play a pivotal role in adaptive cell-mediated immunity by priming and activating T cells against specific tumour and pathogenic antigens. Methotrexate (MTX), a folate derivative, functions as an immunoregulatory agent. However, the possible effect of MTX on tumour antigen-loaded DCs has not yet been investigated. Methods: We analysed the effect of MTX on the maturation and function of DCs along with tumour cell lysates (TCLs). Using bone marrow-derived DCs, we investigated the effect of MTX combined TCL-loaded DCs on T cells priming and proliferation. We also tested the anti-tumour immune effect on DCs when treated with MTX and/or TCL in vivo. Results: MTX combined with TCL not only enhanced DC maturation and stimulated cytokine release but also promoted CD8+ T cell activation and proliferation. The latter was associated with increased tumour antigen uptake and cross-presentation to T cells. Mechanistically, DC maturation and antigen presentation were partly modulated by NLRP3 inflammasome activation. Furthermore, immunisation of mice with MTX and TCL-pulsed DCs before a tumour challenge significantly delayed tumour onset and retarded its growth. This protective effect was due to priming of IFN-γ releasing CD8+ T cells and enhanced killing of tumour cells by cytotoxic T lymphocytes isolated from these immunised mice. Conclusion: MTX can function as a potent adjuvant in DC vaccines by increasing antigen presentation and T cell priming. Our findings provide a new strategy for the application of DC-based anti-tumour immunotherapy.

Monocyte-derived dendritic cells of patients with coronary artery disease show an increased expression of costimulatory molecules CD40, CD80 and CD86 in vitro

2007 ◽  
Vol 18 (7) ◽  
pp. 523-531 ◽  
Author(s):  
Jörn F. Dopheide ◽  
Urban Sester ◽  
Axel Schlitt ◽  
Georg Horstick ◽  
Hans J. Rupprecht ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Dendritic Cells ◽  
Coronary Artery ◽  
Costimulatory Molecules ◽  
Artery Disease

Expression of Tyk2 in dendritic cells is required for IL-12, IL-23, and IFN-γ production and the induction of Th1 cell differentiation

Blood ◽  
2007 ◽  
Vol 110 (2) ◽  
pp. 553-560 ◽  
Author(s):  
Naoki Tokumasa ◽  
Akira Suto ◽  
Shin-ichiro Kagami ◽  
Shunsuke Furuta ◽  
Koichi Hirose ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Cell Differentiation ◽  
Cpg Odn ◽  
T Helper ◽  
Dc Functions ◽  
Th1 Cell ◽  
Th2 Cell ◽  
Ifn Γ ◽  
Antigen Presenting

Abstract It is well documented that dendritic cells (DCs), representative antigen-presenting cells, are important sources of Th1-promoting cytokines and are actively involved in the regulation of T-helper–cell differentiation. However, the intracellular event that regulates this process is still largely unknown. In this study, we examined the role of Tyk2, a JAK kinase that is involved in the signaling pathway under IL-12 and IL-23, in DC functions. While the differentiation and maturation of DCs was normal in Tyk2-deficient (Tyk2−/−) mice, IL-12–induced Stat4 phosphorylation was diminished in Tyk2−/− DCs. IL-12–induced IFN-γ production was also significantly diminished in Tyk2−/− DCs to levels similar to those in Stat4−/− DCs. Interestingly, Tyk2−/− DCs were defective in IL-12 and IL-23 production upon stimulation with CpG ODN. Furthermore, Tyk2−/− DCs were impaired in their ability to induce Th1-cell differentiation but not Th2-cell differentiation. Taken together, these results indicate that the expression of Tyk2 in DCs is crucial for the production of Th1-promoting cytokines such as IL-12 and IFN-γ from DCs and thereby for the induction of antigen-specific Th1-cell differentiation.

scholarly journals Ultrastructure of the yeast actin cytoskeleton and its association with the plasma membrane.

1994 ◽  
Vol 125 (2) ◽  
pp. 381-391 ◽  
Author(s):  
J Mulholland ◽  
D Preuss ◽  
A Moon ◽  
A Wong ◽  
D Drubin ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Actin Cytoskeleton ◽  
Binding Proteins ◽  
Ultrastructural Level ◽  
Actin Binding ◽  
Cortical Actin ◽  
Actin Binding Proteins ◽  
Double Labeling ◽  
Wall Growth ◽  
Cortical Cytoskeleton

We characterized the yeast actin cytoskeleton at the ultrastructural level using immunoelectron microscopy. Anti-actin antibodies primarily labeled dense, patchlike cortical structures and cytoplasmic cables. This localization recapitulates results obtained with immunofluorescence light microscopy, but at much higher resolution. Immuno-EM double-labeling experiments were conducted with antibodies to actin together with antibodies to the actin binding proteins Abp1p and cofilin. As expected from immunofluorescence experiments, Abp1p, cofilin, and actin colocalized in immuno-EM to the dense patchlike structures but not to the cables. In this way, we can unambiguously identify the patches as the cortical actin cytoskeleton. The cortical actin patches were observed to be associated with the cell surface via an invagination of plasma membrane. This novel cortical cytoskeleton-plasma membrane interface appears to consist of a fingerlike invagination of plasma membrane around which actin filaments and actin binding proteins are organized. We propose a possible role for this unique cortical structure in wall growth and osmotic regulation.

scholarly journals Synthetic lethality screen identifies a novel yeast myosin I gene (MYO5): myosin I proteins are required for polarization of the actin cytoskeleton.

1996 ◽  
Vol 133 (6) ◽  
pp. 1277-1291 ◽  
Author(s):  
H V Goodson ◽  
B L Anderson ◽  
H M Warrick ◽  
L A Pon ◽  
J A Spudich
Keyword(s):  
Actin Cytoskeleton ◽  
Synthetic Lethality ◽  
Critical Role ◽  
Neck Region ◽  
Actin Binding ◽  
Cell Physiology ◽  
Deletion Mutants ◽  
Tail Domain ◽  
Amino Terminal ◽  
Myosin I

The organization of the actin cytoskeleton plays a critical role in cell physiology in motile and nonmotile organisms. Nonetheless, the function of the actin based motor molecules, members of the myosin superfamily, is not well understood. Deletion of MYO3, a yeast gene encoding a "classic" myosin I, has no detectable phenotype. We used a synthetic lethality screen to uncover genes whose functions might overlap with those of MYO3 and identified a second yeast myosin 1 gene, MYO5. MYO5 shows 86 and 62% identity to MYO3 across the motor and non-motor regions. Both genes contain an amino terminal motor domain, a neck region containing two IQ motifs, and a tail domain consisting of a positively charged region, a proline-rich region containing sequences implicated in ATP-insensitive actin binding, and an SH3 domain. Although myo5 deletion mutants have no detectable phenotype, yeast strains deleted for both MYO3 and MYO5 have severe defects in growth and actin cytoskeletal organization. Double deletion mutants also display phenotypes associated with actin disorganization including accumulation of intracellular membranes and vesicles, cell rounding, random bud site selection, sensitivity to high osmotic strength, and low pH as well as defects in chitin and cell wall deposition, invertase secretion, and fluid phase endocytosis. Indirect immunofluorescence studies using epitope-tagged Myo5p indicate that Myo5p is localized at actin patches. These results indicate that MYO3 and MYO5 encode classical myosin I proteins with overlapping functions and suggest a role for Myo3p and Myo5p in organization of the actin cytoskeleton of Saccharomyces cerevisiae.

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