scholarly journals Bystander T-Cells Support Clonal T-Cell Activation by Controlling the Release of Dendritic Cell-Derived Immune-Stimulatory Extracellular Vesicles

2019 ◽  
Vol 10 ◽  
Author(s):  
Marthe F. S. Lindenbergh ◽  
Daniëlle G. J. Koerhuis ◽  
Ellen G. F. Borg ◽  
Esther M. van ‘t Veld ◽  
Tom A. P. Driedonks ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
Extracellular Vesicles ◽  
T Cell Activation ◽  
Cell Activation

TREM-1 modulates dendritic cell maturation and dendritic cell–mediated T cell activation induced by ox-LDL

2020 ◽  
Author(s):  
Yunkai Wang ◽  
Jie Wang ◽  
Lu Han ◽  
Yun Li Shen ◽  
Jie Yun You ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Human Peripheral Blood ◽  
Dendritic Cell Maturation ◽  
Cell Maturation ◽  
Blood Monocytes

Abstract Background: Triggering receptor expressed on myeloid cells (TREM)-1is identified as a major upstream proatherogenic receptor. However, the cellular processes modulated by TREM-1 in the development of atherosclerosis and plaque destabilization has not been fully elucidated. In this study, we investigated the effects of TREM-1 on dendritic cell maturation and dendritic cell–mediated T-cell activation induced by oxidized low-density lipoprotein (ox-LDL) in atherogenesis. Methods: Human peripheral blood monocytes were differentiated to dendritic cells and stimulated by ox-LDL. Naive autologous T cells were co-cultured with pretreated dendritic cells.The expressionof TREM-1 and the production of inflammatory cytokines were assessed by real-time PCR, western blot and ELISA.The expression of immune factors was determined with FACS to evaluate dendritic cell maturation and T-cell activation. Results: Stimulation with ox-LDL promoted dendritic cell maturation, TREM-1 expression and T-cell activation, and exposure of T cells to ox-LDL-treated dendritic cells induced production of interferon-γ and IL-17. Blocking TREM-1 suppressed dendritic cell maturation with low expression of CD1a, CD40, CD86 and HLA-DR, decreased production of TNF-α, IL-1β, IL-6 and MCP-1, and increased secretion of TGF-β and IL-10. In addition, stimulation of ox-LDL induced miR-155, miR-27, Let-7c and miR-185 expression, whereas inhibition of TREM-1 repressed miRNA-155. Silencing TREM-1 or miRNA-155 increased SOCS1 expression induced by ox-LDL. T cells derived from carotid atherosclerotic plaques or healthy individuals showed similar result patterns. Conclusion: These data suggest that TREM-1 modulates maturation of dendritic cells and activation of plaque T cells induced by ox-LDL, a pivotal player in atherogenesis.

DOCK8-Deficient Mice Reveal a Crucial Role for Dendritic Cell Activity in the Initiation of the Allogeneic Response to Transfused Red Blood Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 658-658
Author(s):  
Stephanie C. Eisenbarth ◽  
Jeanne E. Hendrickson ◽  
Samuele Calabro ◽  
Antonia Gallman
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Innate Immune ◽  
Allogeneic Response ◽  
Deficient Mice

Abstract The generation of antibodies against transfused red blood cells (RBCs) can pose a serious health risk, especially in chronically transfused patients requiring life-long transfusion support; yet our understanding of what immune signals or cells dictate when someone will become alloimmunized is lacking. The relative role of dendritic cells, B cells and macrophages in the induction of RBC alloimmunization remain unclear. Given the now well established role of innate immune signals in regulating adaptive immunity, understanding if and how innate immunity is triggered during transfusion may allow development of therapies to prevent alloimmunization in chronically transfused subjects such as those with myelodysplasia or hemoglobinopathies. We have established a murine model system in which we can evaluate both the role of particular innate immune stimuli as well as particular cells of the immune system in regulating the allogeneic response to transfused RBCs. A particularly useful transgenic "HOD mouse" has been engineered, which encodes a triple fusion protein and provides a unique tool to directly assess both RBC-specific T and B cell responses. This RBC-specific antigen contains the model protein antigen hen egg lysozyme (HEL) fused to chicken ovalbumin (OVA) fused to the human Duffyb blood group antigen (HEL-OVA-Duffy) as an integral membrane protein under control of the beta globin promoter. Transfusion of genetically targeted mice lacking various innate immune cells or receptors allows us to screen for important immune pathways regulating the response to allogeneic RBCs. Using these models, we recently discovered that mice lacking the GEF (guanine nucleotide exchange factor) DOCK8 fail to develop alloimmunity to transfused RBCs. Dendritic cells in these knockout mice fail to migrate to T cells due to lack of coordinated actin rearrangement governed by this GEF. Both B cell and T cell activation in the spleen to the transgenic transfused RBCs is abrogated. Inclusion of OVA in the alloantigen of the HOD mice allows us to readily study naïve CD4+ T cell activation following transfusion by using the OTII T cell receptor (TCR) transgenic mice in which essentially all T cells express one antigen receptor specific for a peptide of OVA. By tracking rounds of cell division we found that adoptively transferred OTII undergo more than 5-8 rounds of division in the spleen three days following transfusion of HOD RBCs in WT recipients. In contrast, no OTII proliferation was observed in DOCK8-deficient mice following OTII adoptive transfer and HOD RBC transfusion, suggesting that T cells are failing to receive activation signals by splenic antigen presenting cells. Our preliminary data now suggest that DOCK8-deficient dendritic cells are able to process and present RBC-derived antigens, but do not migrate to T cell zones in the spleen to prime naïve RBC-specific T cells. The need for dendritic cell migration within the spleen in the induction of alloimmunity to transfused RBCs has not been addressed; these mice allow us for the first time to answer these fundamental immunologic questions during transfusion. Future work will aim to determine how dendritic cell movement within the spleen is regulated during transfusion and the specific role of splenic dendritic cell subsets in CD4+ T cell priming to allogeneic RBCs. Disclosures No relevant conflicts of interest to declare.

Modeling HIV transfer between dendritic cells and T cells: importance of HIV phenotype, dendritic cell– T cell contact and T-cell activation

AIDS ◽  
2000 ◽  
Vol 14 (15) ◽  
pp. 2299-2311 ◽  
Author(s):  
Guido Vanham ◽  
Lieve Penne ◽  
Heidi Allemeersch ◽  
Luc Kestens ◽  
Betty Willems ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Contact

scholarly journals HIV-1 Nef Enhances Dendritic Cell-Mediated Viral Transmission to CD4+ T Cells and Promotes T-Cell Activation

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e34521 ◽  
Author(s):  
Corine St. Gelais ◽  
Christopher M. Coleman ◽  
Jian-Hua Wang ◽  
Li Wu
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Viral Transmission ◽  
Hiv 1

scholarly journals Dendritic Cell Autophagy Contributes to Herpes Simplex Virus-Driven Stromal Keratitis and Immunopathology

mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Yike Jiang ◽  
Xiaotang Yin ◽  
Patrick M. Stuart ◽  
David A. Leib
Keyword(s):  
T Cells ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Herpetic Stromal Keratitis ◽  
Stromal Keratitis ◽  
Simplex Virus

ABSTRACTHerpetic stromal keratitis (HSK) is a blinding ocular disease that is initiated by HSV-1 and characterized by chronic inflammation in the cornea. Although HSK immunopathology of the cornea is well documented in animal models, events preceding this abnormal inflammatory cascade are poorly understood. In this study, we have examined the activation of pathological CD4+T cells in the development of HSK. Dendritic cell autophagy (DC-autophagy) is an important pathway regulating major histocompatibility complex class II (MHCII)-dependent antigen presentation and proper CD4+T cell activation during infectious diseases. Using DC-autophagy-deficient mice, we found that DC-autophagy significantly and specifically contributes to HSK disease without impacting early innate immune infiltration, viral clearance, or host survival. Instead, the observed phenotype was attributable to the abrogated activation of CD4+T cells and reduced inflammation in HSK lesions. We conclude that DC-autophagy is an important contributor to primary HSK immunopathology upstream of CD4+T cell activation.IMPORTANCEHerpetic stromal keratitis (HSK) is the leading cause of infectious blindness in the United States and a rising cause worldwide. HSK is induced by herpes simplex virus 1 but is considered a disease of inappropriately sustained inflammation driven by CD4+T cells. In this study, we investigated whether pathways preceding CD4+T cell activation affect disease outcome. We found that autophagy in dendritic cells significantly contributed to the incidence of HSK. Dendritic cell autophagy did not alter immune control of the virus or neurological disease but specifically augmented CD4+T cell activation and pathological corneal inflammation. This study broadens our understanding of the immunopathology that drives HSK and implicates the autophagy pathway as a new target for therapeutic intervention against this incurable form of infectious blindness.

scholarly journals Expansion of effector and memory T cells is associated with increased survival in recurrent glioblastomas treated with dendritic cell immunotherapy

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Marica Eoli ◽  
Cristina Corbetta ◽  
Elena Anghileri ◽  
Natalia Di Ianni ◽  
Micaela Milani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Memory T Cells ◽  
Therapeutic Modality ◽  
Effector Memory ◽  
Autologous Tumor ◽  
Vaccine Site

Abstract Background The efficacy of dendritic cell (DC) immunotherapy as a single therapeutic modality for the treatment of glioblastoma (GBM) patients remains limited. In this study, we evaluated in patients with GBM recurrence the immune-mediated effects of DC loaded with autologous tumor lysate combined with temozolomide (TMZ) or tetanus toxoid (TT). Methods In the phase I-II clinical study DENDR2, 12 patients were treated with 5 DC vaccinations combined with dose-dense TMZ. Subsequently, in eight patients, here defined as Variant (V)-DENDR2, the vaccine site was preconditioned with TT 24 hours before DC vaccination and TMZ was avoided. As a survival endpoint for these studies, we considered overall survival 9 months (OS9) after second surgery. Patients were analyzed for the generation of effector, memory, and T helper immune response. Results Four of 12 DENDR2 patients reached OS9, but all failed to show an immunological response. Five of eight V-DENDR2 patients (62%) reached OS9, and one patient is still alive (OS >30 months). A robust CD8+ T-cell activation and memory T-cell formation were observed in V-DENDR2 OS>9. Only in these patients, the vaccine-specific CD4+ T-cell activation (CD38+/HLA-DR+) was paralleled by an increase in TT-induced CD4+/CD38low/CD127high memory T cells. Only V-DENDR2 patients showed the formation of a nodule at the DC injection site infiltrated by CCL3-expressing CD4+ T cells. Conclusions TT preconditioning of the vaccine site and lack of TMZ could contribute to the efficacy of DC immunotherapy by inducing an effector response, memory, and helper T-cell generation.

scholarly journals Regulation of T cell-dendritic cell interactions by IL-7 governs T-cell activation and homeostasis

Blood ◽  
2009 ◽  
Vol 113 (23) ◽  
pp. 5793-5800 ◽  
Author(s):  
Manoj Saini ◽  
Claire Pearson ◽  
Benedict Seddon
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Tcr Signaling ◽  
Cell Responses

Abstract Interleukin-7 (IL-7) plays a central role in the homeostasis of the T-cell compartment by regulating T-cell survival and proliferation. Whether IL-7 can influence T-cell receptor (TCR) signaling in T cells remains controversial. Here, using IL-7–deficient hosts and TCR-transgenic T cells that conditionally express IL-7R, we examined antigen-specific T-cell responses in vitro and in vivo to viral infection and lymphopenia to determine whether IL-7 signaling influences TCR-triggered cell division events. In vitro, we could find no evidence that IL-7 signaling could costimulate T-cell activation over a broad range of conditions, suggesting that IL-7 does not directly tune TCR signaling. In vivo, however, we found an acute requirement for IL-7 signaling for efficiently triggering T-cell responses to influenza A virus challenge. Furthermore, we found that IL-7 was required for the enhanced homeostatic TCR signaling that drives lymphopenia-induced proliferation by a mechanism involving efficient contacts of T cells with dendritic cells. Consistent with this, saturating antigen-presenting capacity in vivo overcame the triggering defect in response to cognate peptide. Thus, we demonstrate a novel role for IL-7 in regulating T cell–dendritic cell interactions that is essential for both T-cell homeostasis and activation in vivo.

scholarly journals Soluble CD83 Regulates Dendritic Cell–T Cell Immunological Synapse Formation by Disrupting Rab1a-Mediated F-Actin Rearrangement

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Lin ◽  
Shuping Zhou ◽  
Meng Feng ◽  
Yong Yu ◽  
Qinghong Su ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Synapse Formation ◽  
Immunological Synapse ◽  
Binding Activity ◽  
Soluble Form ◽  
Mhc Ii

Dendritic cell–T cell (DC-T) contacts play an important role in T cell activation, clone generation, and development. Regulating the cytoskeletal protein rearrangement of DCs can modulate DC-T contact and affect T cell activation. However, inhibitory factors on cytoskeletal regulation in DCs remain poorly known. We showed that a soluble form of CD83 (sCD83) inhibited T cell activation by decreasing DC-T contact and synapse formation between DC and T cells. This negative effect of sCD83 on DCs was mediated by disruption of F-actin rearrangements, leading to alter expression and localization of major histocompatibility complex class II (MHC-II) and immunological synapse formation between DC and T cells. Furthermore, sCD83 was found to decrease GTP-binding activity of Rab1a, which further decreased colocalization and expression of LRRK2 and F-actin rearrangements in DCs, leading to the loss of MHC-II at DC-T synapses and reduced DC-T synapse formation. Further, sCD83-treated DCs alleviated symptoms of experimental autoimmune uveitis in mice and decreased the number of T cells in the eyes and lymph nodes of these animals. Our findings demonstrate a novel signaling pathway of sCD83 on regulating DC-T contact, which may be harnessed to develop new immunosuppressive therapeutics for autoimmune disease.

scholarly journals The role of extracellular vesicles and PD-L1 in glioblastoma-mediated immunosuppressive monocyte induction

2020 ◽  
Vol 22 (7) ◽  
pp. 967-978 ◽  
Author(s):  
Benjamin T Himes ◽  
Timothy E Peterson ◽  
Tristan de Mooij ◽  
Luz M Cumba Garcia ◽  
Mi-Yeon Jung ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Extracellular Vesicles ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Proliferation ◽  
Cell Inhibition

Abstract Background Immunosuppression in glioblastoma (GBM) is an obstacle to effective immunotherapy. GBM-derived immunosuppressive monocytes are central to this. Programmed cell death ligand 1 (PD-L1) is an immune checkpoint molecule, expressed by GBM cells and GBM extracellular vesicles (EVs). We sought to determine the role of EV-associated PD-L1 in the formation of immunosuppressive monocytes. Methods Monocytes collected from healthy donors were conditioned with GBM-derived EVs to induce the formation of immunosuppressive monocytes, which were quantified via flow cytometry. Donor-matched T cells were subsequently co-cultured with EV-conditioned monocytes in order to assess effects on T-cell proliferation. PD-L1 constitutive overexpression or short hairpin RNA–mediated knockdown was used to determined the role of altered PD-L1 expression. Results GBM EVs interact with both T cells and monocytes but do not directly inhibit T-cell activation. However, GBM EVs induce immunosuppressive monocytes, including myeloid-derived suppressor cells (MDSCs) and nonclassical monocytes (NCMs). MDSCs and NCMs inhibit T-cell proliferation in vitro and are found within GBM in situ. EV PD-L1 expression induces NCMs but not MDSCs, and does not affect EV-conditioned monocytes T-cell inhibition. Conclusion These findings indicate that GBM EV-mediated immunosuppression occurs through induction of immunosuppressive monocytes rather than direct T-cell inhibition and that, while PD-L1 expression is important for the induction of specific immunosuppressive monocyte populations, immunosuppressive signaling mechanisms through EVs are complex and not limited to PD-L1.

Abstract 60: Renal Denervation Prevents Dendritic Cell Activation and Renal T Cell Activation in Mice During Angiotensin Ii-induced Hypertension

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Liang Xiao ◽  
Annet Kirabo ◽  
David G Harrison
Keyword(s):  
Blood Pressure ◽  
T Cells ◽  
T Cell ◽  
Angiotensin Ii ◽  
Dendritic Cell ◽  
T Cell Activation ◽  
Renal Denervation ◽  
Cell Activation ◽  
Sympathetic Nerves ◽  
Dendritic Cell Activation

Increased sympathetic outflow has been implicated in the pathogenesis of hypertension. Recent evidence has also suggested a role of T lymphocytes in hypertension. Renal sympathectomy is an effective approach to lower blood pressure in hypertensive patients and animal models. We hypothesized that renal sympathetics link the central nervous system to immune activation in hypertension. To test this hypothesis, we performed either unilateral or bilateral renal denervation (DNX) in C57BL/6 mice by applying phenol to the renal artery and cutting large visible nerves. On the same day mice received an osmotic minipump for angiotensin II (ANG) infusion (490 ng/kg/min, for 14 days). DNX decreased renal norepinephrine content from 162±13 to 42±11 ng/g (p=0.005) as measured by HPLC. Bilateral DNX lowered systolic blood pressure in mice with ANG infusion (137±4 vs. 159±5 mmHg, p=0.003) measured with tail-cuff. Analysis of T cells was performed using flow cytometry in single cell suspensions from kidneys. Angiotensin II significantly increased total leukocyte (CD45+) and T cell (CD3+) infiltration in the kidney, and this was prevented by DNX. Dendritic cells (DCs), which are the major antigen presenting cells that activate T cells, were isolated from the spleen and cultured in RPMI medium for 24 hours for cytokine measurements via Luminex100 system. Angiotensin II infusion increased DC production in IL-1α, IL-1β, and IL-6 production by 4 to 6-fold, and these increases were prevented by DNX. These results suggest that renal sympathetic nerves participate in T cell activation, and this is associated with dendritic cell activation in the spleen.

Sign in / Sign up

Export Citation Format

Share Document