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.

scholarly journals Plasmacytoid dendritic cells of melanoma patients present exogenous proteins to CD4+ T cells after FcγRII-mediated uptake

2006 ◽  
Vol 203 (7) ◽  
pp. 1629-1635 ◽  
Author(s):  
Daniel Benitez-Ribas ◽  
Gosse J. Adema ◽  
Gregor Winkels ◽  
Ina S. Klasen ◽  
Cornelis J.A. Punt ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
Secondary Phase ◽  
Plasmacytoid Dendritic Cells ◽  
Type I Interferons ◽  
Type I ◽  
Antigen Uptake ◽  
Melanoma Patients

Plasmacytoid dendritic cells (pDCs) contribute to innate antiviral immune responses by producing type I interferons. Although human pDCs can induce T cell responses upon viral infection, it remains unclear if pDCs can present exogenous antigens. Here, we show that human pDCs exploit FcγRII (CD32) to internalize antigen–antibody complexes, resulting in the presentation of exogenous antigen to T cells. pDCs isolated from melanoma patients vaccinated with autologous monocyte-derived peptide- and keyhold limpet hemocyanin (KLH)–loaded dendritic cells, but not from nonvaccinated patients or patients that lack a humoral response against KLH, were able to stimulate KLH-specific T cell proliferation. Interestingly, we observed that internalization of KLH by pDCs depended on the presence of serum from vaccinated patients that developed an anti-KLH antibody response. Anti-CD32 antibodies inhibited antigen uptake and presentation, demonstrating that circulating anti-KLH antibodies binding to CD32 mediate KLH internalization. We conclude that CD32 is an antigen uptake receptor on pDCs and that antigen presentation by pDCs is of particular relevance when circulating antibodies are present. Antigen presentation by pDCs may thus modulate the strength and quality of the secondary phase of an immune response.

scholarly journals Tr1 Cells, but Not Foxp3+ Regulatory T Cells, Suppress NLRP3 Inflammasome Activation via an IL-10–Dependent Mechanism

2015 ◽  
Vol 195 (2) ◽  
pp. 488-497 ◽  
Author(s):  
Yu Yao ◽  
Jens Vent-Schmidt ◽  
Matthew D. McGeough ◽  
May Wong ◽  
Hal M. Hoffman ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Tr1 Cells ◽  
Dependent Mechanism

scholarly journals CD40L+ CD4+ memory T cells migrate in a CD62P-dependent fashion into reactive lymph nodes and license dendritic cells for T cell priming

2008 ◽  
Vol 205 (11) ◽  
pp. 2561-2574 ◽  
Author(s):  
Alfonso Martín-Fontecha ◽  
Dirk Baumjohann ◽  
Greta Guarda ◽  
Andrea Reboldi ◽  
Miroslav Hons ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Memory T Cells ◽  
Effector Memory ◽  
High Endothelial Venules ◽  
T Cell Priming ◽  
Dc Maturation

There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4+ effector memory T (TEM) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4+ TEM cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4+ TEM cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4+ TEM cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that TEM cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.

scholarly journals PGE2 Dependent Inhibition of Macrophage Pyroptosis By MSCs Contributes to Alleviating aGVHD

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 15-15
Author(s):  
Xueyan Sun ◽  
Yan Su ◽  
Xiao Liu ◽  
Fengqi Liu ◽  
Gaochao Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
T Cells ◽  
Nlrp3 Inflammasome ◽  
Cd4 T Cells ◽  
Inflammasome Activation ◽  
Rt Pcr ◽  
Nlrp3 Inflammasome Activation ◽  
Therapeutic Mechanism ◽  
Scanning Electron

Introduction Mesenchymal stem cells (MSCs) are being recognized as one of the treatment options for acute graft versus host disease (aGVHD), but their therapeutic mechanisms have not been fully elucidated. Pyroptosis, a novel form of inflammation related programmed cell death, often occurs in myeloid cells. Many studies have found that macrophage pyroptosis plays an important role in multiple inflammatory and autoimmune diseases (Journal of Autoimmunity, 2018). As an immune disease with involvement of various inflammatory factors, aGVHD exhibits macrophage dysfunction according to our previous study (Sci China Life Sci, 2020). However, whether macrophages undergo pyroptosis and their role in aGVHD remain unknown. MSCs have been reported to inhibit pyroptosis, and some cytokines that suppress pyroptosis can also be secreted by MSCs (Nature Immunology, 2016). Whether inhibition of macrophage pyroptosis represents a therapeutic mechanism for MSCs to alleviate aGVHD needs further exploration. Methods Twenty patients with aGVHD and 20 patients without aGVHD after hematopoietic stem cell transplantation were enrolled in our study. Macrophages were derived from CD14+ monocytes of patients and the THP-1 cell line. CD4+ T cells were isolated from peripheral blood mononuclear cells (PBMCs) of healthy volunteers. MSCs were obtained from fresh umbilical cord of healthy puerpera. Morphological analysis of macrophages was performed by scanning electron microscopy. Expression of GSDMD and NLRP3 inflammasome associated components was assessed by real-time transcription-polymerase chain reaction (RT-PCR), western blot and immunofluorescent staining. The subgroup of CD4+T cells was analyzed by flow cytometry. RT-PCR, ELISA and RNA interference were used to evaluate relevant immunomodulatory factors which were involved in the inhibitory effect of MSCs on macrophage pyroptosis. Additionally, an aGVHD mouse model was established to observe the therapeutic effect and mechanism of MSCs on macrophage pyroptosis. Results Scanning electron microscopy images showed the formation of membrane pores in macrophages of aGVHD patients. Meanwhile, expression of the pyroptosis executioner GSDMD, NLRP3 inflammasome associated components, IL-1β, IL-18, and LDH release were elevated in macrophages from aGVHD patients, indicating that macrophages in aGVHD underwent NLRP3 inflammasome activation and pyroptosis. Furthermore, NLRP3 inhibition reduced macrophages pyroptosis, suggesting that macrophages pyroptosis in aGVHD are mediated by NLRP3 inflammasome activation. Since CD4+T cells play a critical role in the pathogenesis of aGVHD, we investigated the effect of macrophage pyroptosis on CD4+T cells. In vitro, macrophage pyroptosis increased the proportion of CD69+, Th1 and Th17 cells among CD4+T cells, which was partially reversed by blocking IL-1β/IL-1R and IL-18/IL-18R signaling. We also observed that the proportion of macrophage pyroptosis was more increased in patients with III-IV aGVHD than in those with I-II aGVHD. In addition, administration of a pyroptosis inhibitor into aGVHD model mice greatly attenuated clinical and histopathological scores. Taken together, these results indicate that macrophage pyroptosis might be involved the development of aGVHD. Expression of GSDMD, NLRP3 inflammasome associated components, IL-1β, IL-18, and LDH release in aGVHD macrophages were reduced when cells were cocultured with MSCs, indicating that MSCs inhibit aGVHD macrophage pyroptosis by suppressing NLRP3 inflammasome activation. Furthermore, secretion of prostaglandin E2 (PGE2) was increased in MSCs cocultured with aGVHD macrophages, blocking which by small interfering RNA (siRNA) or inhibition of PGE2 induced CAMP-PKA signaling with antagonists both largely abrogated MSC effects. Consistently, the effect of MSCs on macrophage pyroptosis and the NLRP3 inflammasome in vivo was also dampened after transfection with prostaglandin E synthase (PTGES) siRNA, and the therapeutic effect in the aGVHD mouse model was impaired. Conclusions Our results demonstrate that macrophage pyroptosis plays a crucial role in the pathogenesis of aGVHD by promoting activation and differentiation of CD4+ T cells. MSCs suppress macrophage pyroptosis in aGVHD via PGE2/cAMP/PKA signaling, which might represent a therapeutic mechanism of MSCs for aGVHD. Disclosures No relevant conflicts of interest to declare.

scholarly journals Predominant Role for Directly Transfected Dendritic Cells in Antigen Presentation to CD8+ T Cells after Gene Gun Immunization

1998 ◽  
Vol 188 (6) ◽  
pp. 1075-1082 ◽  
Author(s):  
Angel Porgador ◽  
Kari R. Irvine ◽  
Akiko Iwasaki ◽  
Brian H. Barber ◽  
Nicholas P. Restifo ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Antigen Presentation ◽  
Cd8 T Cells ◽  
Cytotoxic T Cell ◽  
Gene Gun ◽  
Cross Presentation

Cutaneous gene (DNA) bombardment results in substantial expression of the encoded antigen in the epidermal layer as well as detectable expression in dendritic cells (DC) in draining lymph nodes (LNs). Under these conditions, two possible modes of DC antigen presentation to naive CD8+ T cells might exist: (a) presentation directly by gene-transfected DC trafficking to local lymph nodes, and (b) cross-presentation by untransfected DC of antigen released from or associated with transfected epidermal cells. The relative contributions of these distinct modes of antigen presentation to priming for cytotoxic T cell (CTL) responses have not been clearly established. Here we show that LN cells directly expressing the DNA-encoded antigen are rare; 24 h after five abdominal skin bombardments, the number of these cells does not exceed 50–100 cells in an individual draining LN. However, over this same time period, the total number of CD11c+ DC increases more than twofold, by an average of 20,000–30,000 DC per major draining node. This augmentation is due to gold bombardment and is independent of the presence of plasmid DNA. Most antigen-bearing cells in the LNs draining the site of DNA delivery appear to be DC and can be depleted by antibodies to an intact surface protein encoded by cotransfected DNA. This finding of predominant antigen presentation by directly transfected cells is also consistent with data from studies on cotransfection with antigen and CD86-encoding DNA, showing that priming of anti-mutant influenza nucleoprotein CTLs with a single immunization is dependent upon coexpression of the DNAs encoding nucleoprotein and B7.2 in the same cells. These observations provide insight into the relative roles of direct gene expression and cross-presentation in CD8+ T cell priming using gene gun immunization, and indicate that augmentation of direct DC gene expression may enhance such priming.

scholarly journals Uptake of HLA Alloantigens via CD89 and CD206 Does Not Enhance Antigen Presentation by Indirect Allorecognition

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Eytan Breman ◽  
Jurjen M. Ruben ◽  
Kees L. Franken ◽  
Mirjam H. M. Heemskerk ◽  
Dave L. Roelen ◽  
...  
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
Antigen Presenting Cells ◽  
Mannose Receptor ◽  
Class Ii ◽  
Hla Class Ii ◽  
Indirect Allorecognition ◽  
Antigen Presenting

In organ transplantation, alloantigens are taken up by antigen presenting cells and presented via the indirect pathway to T-cells which in turn can induce allograft rejection. Monitoring of these T-cells is of major importance; however no reliable assay is available to routinely monitor indirect allorecognition. Recently we showed that HLA monomers can be successfully used to monitor indirect allorecognition. Targeting antigens to endocytic receptors on antigen presenting cells may further enhance the presentation of antigens via HLA class II and improve the efficiency of this assay. In the current study we explored targeting of HLA monomers to either CD89 expressing monocytes or mannose receptor expressing dendritic cells. Monomer-antibody complexes were generated using biotin-labeled monomers and avidin labeling of the antibodies. We demonstrate that targeting the complexes to these receptors resulted in a dose-dependent HLA class II mediated presentation to a T-cell clone. The immune-complexes were efficiently taken up and presented to T-cells. However, the level of T-cell reactivity was similar to that when only exogenous antigen was added. We conclude that HLA-A2 monomers targeted for presentation through CD89 on monocytes or mannose receptor on dendritic cells lead to proper antigen presentation but do not enhance indirect allorecognition via HLA-DR.

scholarly journals Withaferin A InhibitsHelicobacter pylori-induced Production of IL-1β in Dendritic Cells by Regulating NF-κB and NLRP3 Inflammasome Activation

2015 ◽  
Vol 15 (6) ◽  
pp. 269 ◽  
Author(s):  
Jae-Eun Kim ◽  
Jun-Young Lee ◽  
Min-Jung Kang ◽  
Yu-Jin Jeong ◽  
Jin-A Choi ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Nlrp3 Inflammasome ◽  
Withaferin A ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation

scholarly journals MHC Class II Expression Restricted to CD8α+ and CD11b+ Dendritic Cells Is Sufficient for Control of Leishmania major

2004 ◽  
Vol 199 (5) ◽  
pp. 725-730 ◽  
Author(s):  
Maria P. Lemos ◽  
Fatima Esquivel ◽  
Phillip Scott ◽  
Terri M. Laufer
Keyword(s):  
T Cells ◽  
Dendritic Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
Cd4 T Cells ◽  
Leishmania Major ◽  
Cd4 T Cell ◽  
Major Infection ◽  
Mhc Ii ◽  
Antigen Presenting

Control of the intracellular protozoan, Leishmania major, requires major histocompatibility complex class II (MHC II)–dependent antigen presentation and CD4+ T cell T helper cell 1 (Th1) differentiation. MHC II–positive macrophages are a primary target of infection and a crucial effector cell controlling parasite growth, yet their function as antigen-presenting cells remains controversial. Similarly, infected Langerhans cells (LCs) can prime interferon (IFN)γ–producing Th1 CD4+ T cells, but whether they are required for Th1 responses is unknown. We explored the antigen-presenting cell requirement during primary L. major infection using a mouse model in which MHC II, I-Aβb, expression is restricted to CD11b+ and CD8α+ dendritic cells (DCs). Importantly, B cells, macrophages, and LCs are all MHC II–negative in these mice. We demonstrate that antigen presentation by these DC subsets is sufficient to control a subcutaneous L. major infection. CD4+ T cells undergo complete Th1 differentiation with parasite-specific secretion of IFNγ. Macrophages produce inducible nitric oxide synthase, accumulate at infected sites, and control parasite numbers in the absence of MHC II expression. Therefore, CD11b+ and CD8α+ DCs are not only key initiators of the primary response but also provide all the necessary cognate interactions for CD4+ T cell Th1 effectors to control this protozoan infection.

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