scholarly journals Spinophilin and the immune synapse

2008 ◽  
Vol 181 (2) ◽  
pp. 181-183 ◽  
Author(s):  
Brian Seed ◽  
Ramnik Xavier
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Fusion Protein ◽  
Target Cells ◽  
Cellular Organization ◽  
Immune Synapse ◽  
Cellular Architecture ◽  
Gfp Fusion Protein ◽  
Cell Biol ◽  
In Cells

Extensive alterations in cellular organization are known to accompany the responses of sensitized T cells to target cells presenting an antigen of interest. Now, equally if not more dramatic changes are found to take place in cells presenting an antigen. With the help of a spinophilin-GFP fusion protein, Bloom et al. (Bloom, O., J.J. Unternaehrer, A. Jiang, J.-S. Shin, L. Delamarre, P. Allen, and I. Mellman. 2008. J. Cell Biol. 181:203–211) have captured a remarkable polarization of the cellular architecture of dendritic cells presenting an antigen to T cells.

scholarly journals Human anogenital monocyte-derived dendritic cells and langerin+cDC2 are major HIV target cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jake W. Rhodes ◽  
Rachel A. Botting ◽  
Kirstie M. Bertram ◽  
Erica E. Vine ◽  
Hafsa Rana ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd4 T Cells ◽  
Pathogen Detection ◽  
Hiv Transmission ◽  
Sexual Transmission ◽  
Mononuclear Phagocytes ◽  
Target Cells ◽  
Epithelial Surface ◽  
Transmission Studies

AbstractTissue mononuclear phagocytes (MNP) are specialised in pathogen detection and antigen presentation. As such they deliver HIV to its primary target cells; CD4 T cells. Most MNP HIV transmission studies have focused on epithelial MNPs. However, as mucosal trauma and inflammation are now known to be strongly associated with HIV transmission, here we examine the role of sub-epithelial MNPs which are present in a diverse array of subsets. We show that HIV can penetrate the epithelial surface to interact with sub-epithelial resident MNPs in anogenital explants and define the full array of subsets that are present in the human anogenital and colorectal tissues that HIV may encounter during sexual transmission. In doing so we identify two subsets that preferentially take up HIV, become infected and transmit the virus to CD4 T cells; CD14+CD1c+ monocyte-derived dendritic cells and langerin-expressing conventional dendritic cells 2 (cDC2).

scholarly journals 714 Selective expansion of antigen-specific CD8 T cells with engineered antigen presenting exosome

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A743-A743
Author(s):  
Tomoyoshi Yamano ◽  
Xiabing Lyu ◽  
Rikinari Hanayama
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cd8 T Cells ◽  
Costimulatory Molecule ◽  
Animal Experiments ◽  
Surface Proteins ◽  
Hek293 Cells ◽  
Target Cells ◽  
Single Chain ◽  
Antigen Presenting

BackgroundExosomes are vesicular granules of about 100 nm and are secreted by many types of cells. Exosomes contain various proteins, lipids, and RNAs that are transported to target cells which induce functional and physiological changes. Exosomes are promising nano-vesicles for clinical application, owing to their high biocompatibility, low immunogenicity, and high drug delivery efficacy. Recent studies have demonstrated that exosomes from tumor cells or antigen presenting cells (APCs) regulate immune responses. Tumor derived exosomes express PD-L1 on their surface and suppress tumor immunity systemically. On the other hand, mature dendritic cells derived exosomes exert immune activation, and tumor immunotherapy using DCs exosome has been developed. However, few studies have been found to exert a significant effect on cancer treatment, may be because of low expression of costimulatory molecules and lack of cytokines on DCs derived exosomes.MethodsIt has been demonstrated that GFP can be conveyed into exosomes by conjugating GFP with tetraspanins, exosome-specific surface proteins. First, we generated a tetraspanin fusion protein with a single-chain MHCI trimer (scMHCI). IL-2 is inserted on the second extracellular loop of CD81, allowing robust and functional expression of IL-2 on the exosome. We collected exosomes from HEK293 cells culture, which stably express scMHCI-CD81-IL2 and CD80-MFGE8, and used as Antigen-presenting exosome(AP-Exo).ResultsAP-Exo expresses high expression of MHCI-peptide complex, costimulatory molecule, and cytokine, activating cognate CD8 T cells as dendritic cells do. AP-Exo selectively delivered co-stimulation and IL-2 to antigen-specific CD8 T cells, resulting in a massive expansion of antigen-specific CD8 T cells without severe adverse effects in mice. AP-Exo can expand endogenous tumor-specific CD8 T cells and induce the potent anti-tumor effect.ConclusionsOur strategy for building engineered exosomes that work like APCs might develop novel methods for cancer immunotherapy.Ethics ApprovalAll mice were housed in a specific pathogen-free facility, and all animal experiments were performed according to a protocol approved by Kanazawa University, Kanazawa, Japan.

scholarly journals Generation of Human CD8 T Regulatory Cells by CD40 Ligand–activated Plasmacytoid Dendritic Cells

2002 ◽  
Vol 195 (6) ◽  
pp. 695-704 ◽  
Author(s):  
Michel Gilliet ◽  
Yong-Jun Liu
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Transforming Growth Factor ◽  
Cd8 T Cell ◽  
Cd40 Ligand ◽  
Plasmacytoid Dendritic Cells ◽  
Target Cells ◽  
Ifn Γ

Although CD8 T cell–mediated immunosuppression has been a well-known phenomenon during the last three decades, the nature of primary CD8 T suppressor cells and the mechanism underlying their generation remain enigmatic. We demonstrated that naive CD8 T cells primed with allogeneic CD40 ligand–activated plasmacytoid dendritic cells (DC)2 differentiated into CD8 T cells that displayed poor secondary proliferative and cytolytic responses. By contrast, naive CD8 T cells primed with allogeneic CD40 ligand–activated monocyte-derived DCs (DC1) differentiated into CD8 T cells, which proliferated to secondary stimulation and killed allogeneic target cells. Unlike DC1-primed CD8 T cells that produced large amounts of interferon (IFN)-γ upon restimulation, DC2-primed CD8 T cells produced significant amounts of interleukin (IL)-10, low IFN-γ, and no IL-4, IL-5, nor transforming growth factor (TGF)-β. The addition of anti–IL-10–neutralizing monoclonal antibodies during DC2 and CD8 T cell coculture, completely blocked the generation of IL-10–producing anergic CD8 T cells. IL-10–producing CD8 T cells strongly inhibit the allospecific proliferation of naive CD8 T cells to monocytes, and mature and immature DCs. This inhibition was mediated by IL-10, but not by TGF-β. IL-10–producing CD8 T cells could inhibit the bystander proliferation of naive CD8 T cells, provided that they were restimulated nearby to produce IL-10. IL-10–producing CD8 T cells could not inhibit the proliferation of DC1-preactivated effector T cells. This study demonstrates that IL-10–producing CD8 T cells are regulatory T cells, which provides a cellular basis for the phenomenon of CD8 T cell–mediated immunosuppression and suggests a role for plasmacytoid DC2 in immunological tolerance.

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.

Stimulation of cytotoxic T cells against idiotype immunoglobulin of malignant lymphoma with protein-pulsed or idiotype-transduced dendritic cells

Blood ◽  
2000 ◽  
Vol 95 (4) ◽  
pp. 1342-1349 ◽  
Author(s):  
Frank Osterroth ◽  
Annette Garbe ◽  
Paul Fisch ◽  
Hendrik Veelken
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Light Chain ◽  
Cytotoxic T Cells ◽  
Killer Cell ◽  
Cell Activity ◽  
Expression Vectors ◽  
Target Cells ◽  
Fab Fragment ◽  
Specific Lysis

Because of their hypervariable regions and somatic mutations, the antigen receptor molecules of lymphomas (idiotypes) are tumor-specific antigens and attractive targets for antilymphoma immunotherapy. For the optimal induction of human idiotype-specific cytotoxic T cells (CTL), idiotype was presented to CD8+ peripheral blood mononuclear cells by monocyte-derived autologous dendritic cells (DC) after the endocytosis of idiotype protein or by idiotype-expressing DC. Recombinant idiotype was obtained as a functionally folded Fab fragment by periplasmic expression in Escherichia coli. Idiotype-expressing DC were generated by transduction with recombinant Semliki forest virus vectors encompassing heavy- or light-chain idiotype genes. Autologous lymphoblastoid cell lines stably transfected with Epstein-Barr virus-based idiotype expression vectors were used as target cells to detect idiotype-specific lysis. CTL stimulated with idiotype-loaded DC showed strong specific, CD8-mediated, and major histocompatibility complex (MHC) class I-restricted cytotoxicity against autologous heavy- and light-chain idiotype. In contrast, stimulation with idiotype-transduced DC resulted in only moderate natural killer cell activity. These data confirm the existence of idiotype-specific CTL in patients with lymphoma, define a “good manufacturing practice”-compatible protocol for the generation of these cells without the requirement of viable lymphoma cells, and favor the processing of exogenous antigen over DC transduction for the induction of MHC I-restricted CTL against idiotypes with unknown antigenicity.

scholarly journals A Superantigen-Antibody Fusion Protein for T-Cell Immunotherapy of Human B-Lineage Malignancies

Blood ◽  
1997 ◽  
Vol 89 (6) ◽  
pp. 2089-2097 ◽  
Author(s):  
Cecilia Gidlöf ◽  
Mikael Dohlsten ◽  
Peter Lando ◽  
Terje Kalland ◽  
Christer Sundström ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Fusion Protein ◽  
B Cell ◽  
Binding Affinity ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Target Cells ◽  
Cell Based Therapy ◽  
B Lineage

Abstract The bacterial superantigen staphylococcal enterotoxin A (SEA) is an efficient activator of cytotoxic T cells when presented on major histocompatibility complex (MHC) class II molecules of target cells. Our previous studies showed that such SEA-directed T cells efficiently lysed chronic B-lymphocytic leukemia (B-CLL) cells. Next, we made a mutated SEA–protein A (SEAm-PA) fusion protein with more than 1,000-fold reduced binding affinity for MHC class II compared with native SEA. The fusion protein was successfully used to direct T cells to B-CLL cells coated with different B lineage–directed monoclonal antibodies (MoAbs). In this communication, we constructed a recombinant anti-CD19-Fab-SEAm fusion protein. The MHC class II binding capacity of the SEA part was drastically reduced by a D227A point mutation, whereas the T-cell activation properties were retained. The Fab part of the fusion protein displayed a binding affinity for CD19+ cells in the nanomolar range. The anti-CD19-Fab-SEAm molecule mediated effective, specific, rapid, and perforin-like T-cell lysis of B-CLL cells at low effector to target cell ratios. Normal CD19+ B cells were sensitive to lysis, whereas CD34+ progenitor cells and monocytes/macrophages were resistant. A panel of CD19+ B-cell lines representing different B-cell developmental stages were efficiently lysed, and the sensitivity correlated with surface ICAM-1 expression. The anti-CD19-Fab-SEAm fusion protein mediated highly effective killing of tumor biopsy cells representing several types of B-cell non-Hodgkin's lymphoma (B-NHL). Humanized severe combined immune deficiency (SCID) mice carrying Daudi lymphoma cells were used as an in vivo therapy model for evaluation of the anti-CD19-Fab-SEAm fusion protein. Greater than 90% reduction in tumor weight was recorded in anti-CD19-Fab-SEAm–treated animals compared with control animals receiving an irrelevant Fab-SEAm fusion protein. The present results indicate that MoAb-targeted superantigens (SAgs) may represent a promising approach for T-cell–based therapy of CD19+ B-cell malignancies.

Concomitant Induction of CMVpp65-Specific CD4+ and CD8+ T Cells Using Dendritic Cells Transfected with mRNA Encoding an Invariant Chain-pp65 Fusion Protein.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3243-3243
Author(s):  
Ngocdiep Le ◽  
Jens Dannull ◽  
Nelson Chao ◽  
Johannes Vieweg
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Fusion Protein ◽  
Mhc Class Ii ◽  
Cellular Immunity ◽  
Invariant Chain ◽  
Cell Transplant ◽  
Presentation Pathway ◽  
Cmv Disease ◽  
Ctl Responses

Abstract Human cytomegalovirus (CMV) disease is increasingly recognized as a major cause of morbidity and mortality in post-stem cell transplant (SCT) recipients due to a lack of cellular immunity. Thus, novel therapies that offer the restoration of cellular immunity in SCT patients are highly desirable for clinical use. Cytotoxic T lymphocyte (CTL) responses against CMV represent a major effector arm of the immune system to control viremia. However, it is well established that the efficient induction and persistence of CTL responses in vivo requires the concomitant induction of antigen-specific CD4+ T helper cells. In this study, we sought to determine whether human dendritic cells (DC) transfected with mRNA encoding an invariant chain-CMVpp65 fusion protein (Ii-pp65) were capable of inducing concomitant CMV-specific CTL and CD4+ responses, thereby constituting a useful strategy for immunotherapy of CMV disease. We show that transfection of DC with Ii-pp65 mRNA leads to enhanced stimulation of CMV-specific CTL in vitro (Figure 1). Furthermore, DC expressing Ii-pp65 are potent inducers of primary CMV-specific CD4+ T cell responses as evidenced by ELISPOT analyses of primed CD4+CD45RA+ T cells (Figure 2). Lastly, efficient routing of Ii-pp65 into the MHC class II presentation pathway is demonstrated by confocal microscopy (data not shown). Based on these preclinical findings, we propose a clinical trial to administer DC, transfected with mRNA encoding a chimeric Ii-pp65, to post-SCT patients. Our primary goal will be to prevent CMV infection and reactivation by inducing strong immune reactivities against CMV. Figure Figure

Monosodium Urate Crystals Bind with Idiotype Protein and Promote Dendritic Cells to Induce Cytotoxic T Cells in Vitro

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4904-4904
Author(s):  
Ippei Sakamaki ◽  
Kunihiro Inai ◽  
Takanori Ueda ◽  
Hiroshi Tsutani
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
Cytotoxic T Cells ◽  
Target Cells ◽  
Monosodium Urate ◽  
Cd4 Cells ◽  
Antigenic Protein ◽  
Positively Charged ◽  
Msu Crystals

Abstract Monosodium urate (MSU) crystals have been studied to act as a key substance in local immunoreactions. MSU released from damaged cells works as an endogenous danger signal to antigen-presenting cells. MSU crystals evoke specific cell immunity and work as an adjuvant in a mouse model. The crystals also have another unique characteristic to bind with positively charged proteins, which could help to deliver some antigens into human dendritic cells (DCs). We focused on the application of MSU crystals as a not only an adjuvant but also as a carrier of positively charged antigenic protein to induce human cytotoxic T cells (CTLs) efficiently in vitro. We confirmed that MSU crystals facilitated human DCs to express the maturation marker, CD83, deliver (Fab′)2 attaching to the crystals. In order to determine whether MSU crystals facilitate the T-cell proliferation activity of DCs, the proliferative effects of DCs on allogeneic CD4+ cells were investigated. DCs pulsed with MSU crystals significantly facilitated the proliferation of allogeneic CD4+ cells when compared to DCs alone. The stimulation index (SI) was 2.5 ± 0.1 and 1.7 ± 0.1, respectively. When using DCs pulsed with the Fab attached to MSU crystals, the proliferation of CD4+ cells was significantly greater than when using DCs pulsed with Fab alone. The SI was 2.6 ± 0.2 and 1.9 ± 0.1, respectively. No significant differences were seen in the proliferation of allogeneic CD4+ cells between DCs pulsed with the Fab attached to MSU and DCs pulsed with MSU alone. We selected the multiple myeloma IM-9 cell line and its product idiotype (Id) protein as an ideal pair of target cells and positively charged tumor-specific antigen, respectively. After sensitizing DCs derived from HLA-A matched volunteers pulsed with tumor-specific monoclonal IgG-Fab fragments (IM-9 Fab) attached to MSU crystals, the CD8+ T cells stimulated by the DCs killed significantly more target cells (38.5 ± 3.5%, n=4) than those stimulated by DCs pulsed with IM-9 Fab alone (3.5 ± 7.5%). These cytotoxic effects of CD8+ cells stimulated by the DCs pulsed with IM-9 Fab attached to MSU crystals were reduced (3.6 ± 1.7%) when MSU crystals were pre-coated with fetal bovine serum to block to bind with IM-9 Fab. For efficient induction of CTLs, it is necessary for Id proteins to attach to MSU crystals. MSU crystals have some advantages of a protein carrier binding with positively charged proteins and delivering antigenic protein into DCs, as well as an adjuvant promoting DC maturation and inducing CTLs.

In Vitro Generation of Cytotoxic T Lymphocytes against MAGE A1 and MAGE A3 Derived From Healthy Donors.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4079-4079
Author(s):  
Lei Bao ◽  
Mindy M Stamer ◽  
Kimberly Dunham ◽  
Deepa Kolaseri Krishnadas ◽  
Kenneth G Lucas
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Lymphocytes ◽  
Cell Therapy ◽  
Cytotoxic T Lymphocytes ◽  
Cd8 T Cells ◽  
Target Cells ◽  
Ifn Gamma ◽  
Healthy Donors

Abstract Abstract 4079 Poster Board III-1014 MAGE A1 and MAGE A3 are cancer testis antigens that are expressed on a number of malignant tumor cells, but not by normal cells, except for male germ cells which lack HLA expression. Therefore, MAGE cytotoxic T lymphocytes are strictly tumor-specific. Adoptive transfer of antigen specific cytotoxic T lymphocytes (CTL) provides immediate graft-versus tumor effects while minimizing risk for graft-versus-host disease. The aim of the current study was to find ideal conditions for expansion of CTL targeting tumor-associated antigens from peripheral blood mononuclear cells (PBMCs) of healthy donors to be used in allogenic cell therapy. In this study we investigated the ability to generate MAGE A1 and MAGE A3 specific cytotoxic T cells using autologous dendritic cells (DC) loaded with MAGE A1 and MAGE A3 overlapping peptides. CTL lines specific for MAGE A1 and MAGE A3 were established by stimulating CD8 T cells from healthy donors with autologous dendritic cells loaded with MAGE A1 or MAGE A3 overlapping pooled peptides in round-bottomed, 96-well plates. CD8+ T cells were restimulated with the same ratio of peptide pulsed DC on days 7 and 14 in the presence of IL-2 (50 U/ml), IL-7 and IL-15 (5 ng/ml). These microcultures were screened 10 days after the third stimulation for their capacity to produce interferon-gamma (IFN-gamma) when stimulated with autologous EBV-transformed B lymphocytes (BLCL) transduced with lentivirus(LV) encoding MAGE A1 or MAGE A3 and autologous BLCL transduced with LV encoding GFP. MAGE A1 and MAGE-A3 specific IFN-gamma producing cells were rapidly expanded in OKT3 and IL2. The specificity of the rapidly expanded MAGE A1 and MAGE A3 specific T cells was confirmed by IFN-gamma production as measured by intracellular cytokine staining and ELISA as well as antigen specific cytotoxicity by a standard 51chromium (51Cr) release assay. We successfully generated MAGE A1 and MAGE A3 specific CTL lines from healthy donors using this method. Specific CTL lines showed cytotoxicity in vitro not only to target cells pulsed with MAGE A1 or MAGE A3 peptides but also to target cells transduced with LV-MAGE A1 or LV-MAGE A3. Specific cytolytic activity was accompanied by IFN-gamma secretion. These data indicate that tumor antigen specific CTL can be expanded using overlapping peptides regardless of an individual's HLA specificity. The ability to generate tumor specific CTL from donors of various HLA backgrounds provide a rationale for utilizing MAGE A1 and MAGE A3 overlapping peptides for expansion of antigen specific T cells for adoptive T-cell therapy against MAGE A1 or MAGE A3 expressing tumors. Disclosures: No relevant conflicts of interest to declare.

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