scholarly journals Antitumor Effect of KML-B-Treated Dendritic Cells via Induction of Lymphocyte Activation

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Jong-Jin Kim ◽  
Yun-Ho Hwang ◽  
Kyung-Yun Kang ◽  
Sung-Ju Lee ◽  
Jong-Bae Kim ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Antitumor Effect ◽  
Biological Activities ◽  
Lymphocyte Activation ◽  
Carbohydrate Binding ◽  
Mistletoe Lectin

Lectins are carbohydrate-binding proteins with various biological activities, such as antitumor and immunomodulatory effects. Although lectins have various biological activities, they are still limited by cytotoxicity in normal cells. To overcome this problem, we used the noncytotoxic part of Korean mistletoe lectin B-chain (KML-B) to induce maturation of dendritic cells (DCs). A previous study reported that KML-B induces DC maturation by triggering TLR-4, including expression of costimulatory molecules (CD40, CD80, and CD86), MHC II, and secretion of cytokines in DCs. Additionally, matured DCs by KML-B induced T helper (Th) cell activation and differentiation toward Th1 cells. However, the interaction of KML-B-treated DCs with CD8+ T cells is still poorly understood. In this study, we confirmed the ability of matured DCs by KML-B to stimulate cytotoxic T cells using OT-1 mouse-derived CD8+ T cells. KML-B induced MHC I expression in DCs, stimulation of CD8+ T cell activation and proliferation, and IFN-γ secretion. Moreover, tumor sizes were reduced by KML-B treatment during vaccination of OVA257−264-pulsed DCs. Here, we confirmed induction of CD8+ T cell activation and the antitumor effect of KML-B treatment in DCs.

scholarly journals Immunomodulatory Effects of Polysaccharide from Marine FungusPhoma herbarumYS4108 on T Cells and Dendritic Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Song Chen ◽  
Ran Ding ◽  
Yan Zhou ◽  
Xian Zhang ◽  
Rui Zhu ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Interleukin 12 ◽  
Related Factors ◽  
Knock Out ◽  
Specific Immunity

YCP, as a kind of natural polysaccharides from the mycelium of marine filamentous fungusPhoma herbarumYS4108, has great antitumor potentialviaenhancement of host immune response, but little is known about the molecular mechanisms. In the present study, we mainly focused on the effects and mechanisms of YCP on the specific immunity mediated by dendritic cells (DCs) and T cells. T cell /DC activation-related factors including interferon- (IFN-)γ, interleukin-12 (IL-12), and IL-4 were examined with ELISA. Receptor knock-out mice and fluorescence-activated cell sorting are used to analyze the YCP-binding receptor of T cells and DCs. RT-PCR is utilized to measure MAGE-A3 for analyzing the tumor-specific killing effect. In our study, we demonstrated YCP can provide the second signal for T cell activation, proliferation, and IFN-γproduction through binding to toll-like receptor- (TLR-) 2 and TLR-4. YCP could effectively promote IL-12 secretion and expression of markers (CD80, CD86, and MHC II)viaTLR-4 on DCs. Antigen-specific immunity against mouse melanoma cells was strengthened through the activation of T cells and the enhancement of capacity of DCs by YCP. The data supported that YCP can exhibit specific immunomodulatory capacity mediated by T cells and DCs.

scholarly journals Combination Treatment of Topical Imiquimod Plus Anti-PD-1 Antibody Exerts Significantly Potent Antitumor Effect

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3948
Author(s):  
Kazumasa Oya ◽  
Yoshiyuki Nakamura ◽  
Zhu Zhenjie ◽  
Ryota Tanaka ◽  
Naoko Okiyama ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Combination Therapy ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Antitumor Effect ◽  
Skin Lesions ◽  
Ifn Γ ◽  
Deficient Mice

The exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody. Topical IMQ significantly suppressed the tumor growth of MC38 in wildtype mice. IMQ upregulated interferon γ (IFN-γ) expression in CD8+ T cells in both the lymph nodes and the tumor, and the antitumor effect was abolished in both Rag1-deficient mice and IFN-γ-deficient mice, indicating that IFN-γ produced by CD8+ T cells play a crucial role in the IMQ-induced antitumor effect. IMQ also upregulated PD-1 expression in T cells as well as PD-L1/PD-L2 expression in myeloid cells, suggesting that IMQ induces not only T-cell activation but also T-cell exhaustion by enhanced PD-1 inhibitory signaling. Combination therapy of topical IMQ plus anti-PD-1 antibody exerted a significantly potent antitumor effect when compared with each single therapy, indicating that the combination therapy is a promising therapy for the skin lesions of various cancers.

Regulation of Tim-3 function by binding to phosphatidylserine

2021 ◽  
Vol 478 (22) ◽  
pp. 3999-4004
Author(s):  
Lawrence P. Kane
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd8 T Cells ◽  
Cell Activation ◽  
Transmembrane Protein ◽  
Cytotoxic T Cells ◽  
Cross Presentation ◽  
First Time

Tim-3 is a transmembrane protein that is highly expressed on subsets of chronically stimulated CD4+ helper and CD8+ cytotoxic T cells, with more transient expression during acute activation and infection. Tim-3 is also constitutively expressed by multiple types of myeloid cells. Like other TIM family members, Tim-3 can bind to phosphatidylserine displayed by apoptotic cells, and this interaction has been shown to mediate uptake of such cells by dendritic cells and cross-presentation of antigens to CD8+ T cells. In contrast, how the recognition of PS by Tim-3 might regulate the function of Tim-3+ T cells is not known. In their recent paper, Lemmon and colleagues demonstrate for the first time that recognition of PS by Tim-3 leads to enhanced T 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.

scholarly journals Contact-dependent delivery of IL-2 by dendritic cells to CD4 T cells in the contraction phase promotes their long-term survival

2019 ◽  
Vol 11 (2) ◽  
pp. 108-123
Author(s):  
Dan Tong ◽  
Li Zhang ◽  
Fei Ning ◽  
Ying Xu ◽  
Xiaoyu Hu ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cd4 T Cells ◽  
Cell Activation ◽  
Cd4 T Cell ◽  
Immune Memory ◽  
Term Survival

Abstract Common γ chain cytokines are important for immune memory formation. Among them, the role of IL-2 remains to be fully explored. It has been suggested that this cytokine is critically needed in the late phase of primary CD4 T cell activation. Lack of IL-2 at this stage sets for a diminished recall response in subsequent challenges. However, as IL-2 peak production is over at this point, the source and the exact mechanism that promotes its production remain elusive. We report here that resting, previously antigen-stimulated CD4 T cells maintain a minimalist response to dendritic cells after their peak activation in vitro. This subtle activation event may be induced by DCs without overt presence of antigen and appears to be stronger if IL-2 comes from the same dendritic cells. This encounter reactivates a miniature IL-2 production and leads a gene expression profile change in these previously activated CD4 T cells. The CD4 T cells so experienced show enhanced reactivation intensity upon secondary challenges later on. Although mostly relying on in vitro evidence, our work may implicate a subtle programing for CD4 T cell survival after primary activation in vivo.

scholarly journals A novel form of immune signaling revealed by transmission of the inflammatory mediator serotonin between dendritic cells and T cells

Blood ◽  
2006 ◽  
Vol 107 (3) ◽  
pp. 1010-1017 ◽  
Author(s):  
Peta J. O'Connell ◽  
Xiangbin Wang ◽  
Matilde Leon-Ponte ◽  
Corrie Griffiths ◽  
Sandeep C. Pingle ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Activated T Cells ◽  
Immune Synapse ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
5 Ht Uptake

AbstractAdaptive immunity is triggered at the immune synapse, where peptide-major histocompatibility complexes and costimulatory molecules expressed by dendritic cells (DCs) are physically presented to T cells. Here we describe transmission of the inflammatory monoamine serotonin (5-hydroxytryptamine [5-HT]) between these cells. DCs take up 5-HT from the microenvironment and from activated T cells (that synthesize 5-HT) and this uptake is inhibited by the antidepressant, fluoxetine. Expression of 5-HT transporters (SERTs) is regulated by DC maturation, exposure to microbial stimuli, and physical interactions with T cells. Significantly, 5-HT sequestered by DCs is stored within LAMP-1+ vesicles and subsequently released via Ca2+-dependent exocytosis, which was confirmed by amperometric recordings. In turn, extracellular 5-HT can reduce T-cell levels of cAMP, a modulator of T-cell activation. Thus, through the uptake of 5-HT at sites of inflammation, and from activated T cells, DCs may shuttle 5-HT to naive T cells and thereby modulate T-cell proliferation and differentiation. These data constitute the first direct measurement of triggered exocytosis by DCs and reveal a new and rapid type of signaling that may be optimized by the intimate synaptic environment between DCs and T cells. Moreover, these results highlight an important role for 5-HT signaling in immune function and the potential consequences of commonly used drugs that target 5-HT uptake and release.

scholarly journals Role of Ly-6 in lymphocyte activation. II. Induction of T cell activation by monoclonal anti-Ly-6 antibodies.

1986 ◽  
Vol 164 (3) ◽  
pp. 709-722 ◽  
Author(s):  
T R Malek ◽  
G Ortega ◽  
C Chan ◽  
R A Kroczek ◽  
E M Shevach
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Proliferative Response ◽  
Cell Activation ◽  
Critical Role ◽  
Lymphocyte Activation ◽  
Accessory Cells ◽  
Peripheral T Cells ◽  
Activation Cascade

The Ly-6 locus controls the expression and/or encodes for alloantigenic specificities found primarily on subpopulations of murine T and B lymphocytes. We have recently identified and characterized a new rat mAb, D7, that recognizes a nonpolymorphic Ly-6 specificity. After crosslinking by anti-Ig reagents or by Fc receptor-bearing accessory cells, mAb D7 could induce IL-2 production from T cell hybridomas, and in the presence of PMA could trigger a vigorous proliferative response in resting peripheral T cells. The addition of mAb D7 to cultures of antigen- and alloantigen-, but not mitogen-stimulated T cells resulted in a marked augmentation of the proliferative response. A number of other well-characterized mAbs to Ly-6 locus products could also stimulate a T cell proliferative response after crosslinking by anti-Ig and in the presence of PMA. These results strongly suggest that Ly-6 molecules may play a critical role in the T cell activation cascade, either as receptors for an unidentified soluble or cell-associated ligand or as transducing molecules that modulate signals initiated by antigen stimulation of the T3-Ti complex.

scholarly journals Both Maturation and Survival of Human Dendritic Cells are Impaired in the Presence of Anergic/Suppressor T Cells

2003 ◽  
Vol 10 (1) ◽  
pp. 61-65 ◽  
Author(s):  
L. Frasca ◽  
C. Scottà ◽  
G. Lombardi ◽  
E. Piccolella
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Costimulatory Molecule ◽  
T Cell Suppression ◽  
Cell Suppression ◽  
Anergic T Cells ◽  
Human Dendritic Cells

T cell suppression is a well established phenomenon, but the mechanisms involved are still a matter of debate. Mouse anergic T cells were shown to suppress responder T cell activation by inhibiting the antigen presenting function of DC. In the present work we studied the effects of co-culturing human anergic CD4+T cells with autologous dendritic cells (DC) at different stages of maturation. Either DC maturation or survival, depending on whether immature or mature DC where used as APC, was impaired in the presence of anergic cells. Indeed, MHC and costimulatory molecule up-regulation was inhibited in immature DC, whereas apoptotic phenomena were favored in mature DC and consequently in responder T cells. Defective ligation of CD40 by CD40L (CD154) was responsible for CD95-mediated and spontaneous apoptosis of DC as well as for a failure of their maturation process. These findings indicate that lack of activation of CD40 on DC by CD40L-defective anergic cells might be the primary event involved in T cell suppression and support the role of CD40 signaling in regulating both activation and survival of DC.

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.

Presence of Vasoactive Intestinal Polypeptide Signaling in Plasmacytoid Dendritic Cells Improves Survival in a Murine Allo-BMT Model

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2154-2154
Author(s):  
Jing-Xia Li ◽  
Jian-Ming Li ◽  
Edmund K Waller
Keyword(s):  
Bone Marrow ◽  
Weight Loss ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Expansion ◽  
Cell Activation ◽  
Post Transplant ◽  
Cytokine Analysis

Abstract Introduction: Pre-clinical murine experiments and clinical data from allogeneic bone marrow transplantation (allo-BMT) have shown that increased numbers of plasmacytoid dendritic cells (pDC) in the bone marrow graft results in better clinical outcomes with less severe graft-versus-host disease (GvHD) and improved survival. The mechanism by which donor pDC modulate GvHD is unknown. Knowing that vasoactive intestinal polypeptide (VIP) is an immunosuppressive peptide , we reasoned that VIP signaling might play a role in regulating T-cell activation and expansion, and the VIP pathway may be a potential therapeutic target for regulating GvHD in allo-BMT. We have tested the hypothesis that VIP synthesis by donor pDCs can modulate T cell alloreactivity. Methods: To explore the mechanisms by which pDC and VIP signaling regulate T cell activation in murine allo-BMT, we prepared B6-background donor cell grafts and transplanted them into lethally irradiated B10.BR recipients. In experiment 1, recipients were transplanted with grafts containing the combination of 5 x 103 VIP-GFP hematopoietic stem cells (HSC) and 3 x 106 VIP-wild type (VIP-WT) or VIP-knock out (VIP-KO) splenocytes. At day 7, splenocytes were isolated for flow cytometric analysis looking for GFP signal, which represents VIP-promotor activity. Experiment 2 used combinations of 5 x 103 VIP-WT HSC, 1 x 106 luciferase+ T cells, and 50 x 103 VIP-WT or VIP-KO pDC from B6 as donor grafts. Recipients were monitored for survival and GvHD based on fur texture, posture, activity, skin integrity and weight loss. T cell expansion was measured by bioluminescent imaging (BLI). Serum cytokines from bleeds at day 3 and day 8 post-transplant were analyzed using a Luminex 38 plex panel. Some recipients were euthanized on day 3 for intracellular cytokine analysis of splenic T cells. Results: In experiment 1, 7 days post-transplant, analysis of splenocytes from all mice showed increased activity of the VIP gene promoter in donor pDC that were derived from HSC, compared to other cell types. The VIP promoter signal was also stronger in donor HSC-derived pDCs, if originally transplanted with VIP-KO splenocytes. In experiment 2 over 70% of mice receiving HSC+T+VIP-WT pDC in the BM graft survived to day 100 post-transplant, while those getting VIP-KO pDC instead only had 30% survival (Fig 1A). All surviving recipients were fully engrafted by day 30. BLI revealed greater total T-cell proliferation (measured as radiance) in recipients of VIP-KO pDC (Fig 1B). Furthermore, recipients of VIP-KO pDC had more severe acute GvHD, with increased weight loss and GvHD clinical scores (Fig 1C, 1D). Some recipients were euthanized and their serum were collected for cytokine analysis on day 8 post-transplant, which showed up-regulation of pro-inflammatory or chemotactic cytokines MCP1, IL-1, IL-12, IL-17 in T cells co-transplanted with VIP-KO pDC compared to WT pDC. Conclusion: The present findings show that: 1) VIP is produced by donor pDC early after allo-BMT; 2) absence of VIP production by donor pDC leads to increased T-cell expansion in a murine allo-BMT model. Thus the pDC-T cell VIP signaling pathway is a critical element in controlling donor T cell alloreactivity after allo-BMT. Future studies will include VIP qPCR to confirm VIP production in donor pDC post-transplant, and determine the mechanism by which VIP production by pDC regulates T cell activity and modulates GvHD. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

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