scholarly journals NOD2 and TLR2 Signal via TBK1 and PI31 to Direct Cross-presentation and CD8 T Cell Responses

2019 ◽  
Author(s):  
Daniele Corridoni ◽  
Seiji Shiraishi ◽  
Thomas Chapman ◽  
Tessa Steevels ◽  
Daniele Muraro ◽  
...  
Keyword(s):  
T Cell ◽  
Mhc Class I ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Class I ◽  
Cross Presentation ◽  
Cell Responses ◽  
Direct Cross

AbstractNOD2 and TLR2 recognize components of bacterial cell wall peptidoglycan and direct defense against enteric pathogens. CD8+ T cells are important for immunity to such pathogens but how NOD2 and TLR2 induce antigen specific CD8+ T cell responses is unknown. Here, we define how these pattern recognition receptors (PRRs) signal in primary dendritic cells (DCs) to influence MHC class I antigen presentation. We show NOD2 and TLR2 phosphorylate PI31 via TBK1 following activation in DCs. PI31 interacts with TBK1 and Sec16A at endoplasmic reticulum exit sites (ERES), which positively regulates MHC class I peptide loading and immunoproteasome stability. Following NOD2 and TLR2 stimulation, depletion of PI31 or inhibition of TBK1 activity in vivo impairs DC cross-presentation and CD8+ T cell activation. DCs from Crohn’s patients expressing NOD2 polymorphisms show dysregulated cross-presentation and CD8+ T cell responses. Our findings reveal unidentified mechanisms that underlie CD8+ T cell responses to bacteria in health and in Crohn’s.

scholarly journals Stable Antigen Is Most Effective for Eliciting CD8+T-Cell Responses after DNA Vaccination and Infection with Recombinant Vaccinia VirusIn Vivo

2012 ◽  
Vol 86 (18) ◽  
pp. 9782-9793 ◽  
Author(s):  
Christopher Schliehe ◽  
Annegret Bitzer ◽  
Maries van den Broek ◽  
Marcus Groettrup
Keyword(s):  
T Cell ◽  
Mhc Class I ◽  
T Cell Responses ◽  
Dna Vaccination ◽  
Class I ◽  
Antigenic Peptides ◽  
Recombinant Vaccinia ◽  
Cross Presentation ◽  
Cell Responses

The induction of strong CD8+T-cell responses against infectious diseases and cancer has remained a major challenge. Depending on the source of antigen and the infectious agent, priming of CD8+T cells requires direct and/or cross-presentation of antigenic peptides on major histocompatibility complex (MHC) class I molecules by professional antigen-presenting cells (APCs). However, both pathways show distinct preferences concerning antigen stability. Whereas direct presentation was shown to efficiently present peptides derived from rapidly degraded proteins, cross-presentation is dependent on long-lived antigen species. In this report, we analyzed the role of antigen stability on DNA vaccination and recombinant vaccinia virus (VV) infection using altered versions of the same antigen. The long-lived nucleoprotein (NP) of lymphocytic choriomeningitis virus (LCMV) can be targeted for degradation by N-terminal fusion to ubiquitin or, as we show here, to the ubiquitin-like modifier FAT10. Direct presentation by cells either transfected with NP-encoding plasmids or infected with recombinant VVin vitrowas enhanced in the presence of short-lived antigens.In vivo, however, the highest induction of NP-specific CD8+T-cell responses was achieved in the presence of long-lived NP. Our experiments provide evidence that targeting antigens for proteasomal degradation does not improve the immunogenicity of DNA vaccines and recombinant VVs. Rather, it is the long-lived antigen that is superior for the efficient activation of MHC class I-restricted immune responsesin vivo. Hence, our results suggest a dominant role for antigen cross-priming in DNA vaccination and recombinant VV infection.

Saccharomyces cerevisiae as delivery vehicle for a NY-ESO-1 protein vaccine

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 2578-2578
Author(s):  
C. Renner ◽  
G. Held ◽  
F. Neumann ◽  
S. Kleber ◽  
M. Thiel ◽  
...  
Keyword(s):  
T Cell ◽  
Mhc Class I ◽  
T Cell Responses ◽  
Full Length ◽  
Class I ◽  
Strong Positive Correlation ◽  
Cell Recognition ◽  
T Cell Recognition ◽  
Cross Presentation ◽  
Cell Responses

2578 Background: Vaccine strategies that target or activate dendritic cells in order to elicit potent cellular immunity are currently the subject of intense research. Here we report that genetically engineered yeast expressing the full-length tumor associated antigen NY-ESO-1 are a versatile host for protein production eliciting MHC class I and II T-cell responses. Methods: The pYD1 yeast display vector was chosen for full length NY-Eso-1 protein (pNY-ESO-1) expression. NY-ESO-1 and SSX-2 (as control) protein were affinity purified on. IFN-g ELISPOT assays were performed in triplicates on nitrocellulose-lined 96-well plates. MHC class I cross-presentation of peptide epitopes was demonstrated by blocking T-cell responses against DCs. For this purpose, antigen or peptide pulsed DCs were labeled with different doses (100, 10, 1 μg/ml) of antibodies specific for HLA-A2/peptide complexes (HLA-A2/ NY-Eso-1157–165; 3M4E5) or an irrelevant antibody (specific for HLA-A2/IMP58–66) as control. Results: Highest level of NY-ESO-1 expression was detected on the cell wall of wt EBY100 strain with lower expression levels on PMT deficient strains PMT-2 and PMT-4. After protein feeding of immature DCs, NY-ESO-1 157–165 peptide cross-presentation was detected by 3M4E5 and an antigen-specific CD8+ T cell clone. There was a strong positive correlation between the amount of Aga2p-NY-ESO-1 protein (0–15μg/ml) and peptide presentation. Specific T-cell recognition of NY-Eso-1 157–165/HLA-A2 complexes was validated by blocking experiments with Fab 3M4E5. Pre-incubation of protein fed DCs with the antibody at different concentrations (0–100 μg/ml) resulted in a significant reduction (p< 0.05) of spot numbers. Efficient presentation and T-cell recognition of epitope 157–165 was only adequately detectable when protein produced by EBY100 wt yeast strain was used (p < 0.05). MHC class II presentation was studied in an autologous setting using a T-cell line recognising the NY-ESO-1 157–170 in HLA-DP4 context revealing that NY-ESO-1 protein produced in yeast was efficiently taken up and presented. Conclusions: Together, these data add further evidence that yeast expressing recombinant proteins can be used for vaccine purposes and that antigen uptake in APC depends on glycoslation of yeast expressed antigens. No significant financial relationships to disclose.

scholarly journals Visualising the interaction of CD4 T cells and DCs in the evolution of inflammatory arthritis

2018 ◽  
Vol 77 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Catriona T Prendergast ◽  
Agapitos Patakas ◽  
Shaima Al-Khabouri ◽  
Claire L McIntyre ◽  
Iain B McInnes ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
T Cell Responses ◽  
Receptor Expression ◽  
Phenotypic Analysis ◽  
Necrosis Factor Alpha ◽  
Cell Responses

ObjectivesSuccessful early intervention in rheumatoid arthritis (RA) with the aim of resetting immunological tolerance requires a clearer understanding of how specificity, cellular kinetics and spatial behaviour shape the evolution of articular T cell responses. We aimed to define initial seeding of articular CD4+ T cell responses in early experimental arthritis, evaluating their dynamic behaviour and interactions with dendritic cells (DCs) in the inflamed articular environment.MethodsAntigen-induced arthritis was used to model articular inflammation. Flow cytometry and PCR of T cell receptor (TCR) diversity genes allowed phenotypic analysis of infiltrating T cells. The dynamic interactions of T cells with joint residing DCs were visualised using intravital multiphoton microscopy.ResultsInitial recruitment of antigen-specific T cells into the joint was paralleled by accumulation of CD4+ T cells with diverse antigen-receptor expression and ability to produce tumour necrosis factor alpha (TNFα) and interferon gamma (IFNγ) on mitogenic restimulation. A proportion of this infiltrate demonstrated slower motility speeds and engaged for longer periods with articular DCs in vivo. Abatacept treatment did not disrupt these interactions but did reduce T cell expression of inducible costimulatory (ICOS) molecule. We also demonstrated that non-specific CD4+ T cells could be recruited during these early articular events.ConclusionsWe demonstrate that CD4+ T cells engage with articular DCs supporting antigen specific T cell reactivation. This cellular dialogue can be targeted therapeutically to reduce local T cell activation.

scholarly journals Development of Acute Myeloid Leukemia Cell Membrane Coated Nanoparticles (AMCNPs) for Cancer Vaccination Immunotherapy

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4062-4062
Author(s):  
Daniel T Johnson ◽  
Ashley V Kroll ◽  
Ronnie H Fang ◽  
Justin Kline ◽  
Liangfang Zhang ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Membrane ◽  
Immune Responses ◽  
Mhc Class I ◽  
T Cell Activation ◽  
Cell Activation ◽  
Residual Disease ◽  
Surface Antigens ◽  
Class I

Abstract Acute Myeloid Leukemia (AML) is the most common acute leukemia in adults and has a five-year survival rate under 50%. Most patients will relapse even after complete remission is achieved through standard chemotherapy. Thus, one barrier in current AML therapy is how to target the minimal residual disease during remission. Recent developments in understanding cancer cell antigen presentation and immunosuppression have revealed the promise of cancer immunotherapy in activating immune responses to target residual disease. Each leukemia patient has a unique spectrum of cell surface antigens, which are mostly uncharacterized. If these antigens can be efficiently presented to the patient's immune system, immune responses to fight the leukemia can be significantly enhanced. We therefore sought to develop and characterize an AML cell membrane-coated nanoparticle (AMCNP) platform with nanoparticles (NPs) carrying the same surface antigens as the source leukemic cells for use as an anti-cancer vaccine. To demonstrate that our AMCNP vaccines enhance leukemia-specific antigen dendritic cell (DC) presentation and T-cell responses, we modified the C1498 murine AML cell line to express membrane-bound chicken ovalbumin (C1498-mOVA) as a model antigen. We confirmed that the C1498-mOVA line presents the OVA MHC class-I "SIINFEKL" antigen through flow-cytometry and LacZ B3Z T-cell activation assays. The C1498-mOVA line remained leukemogenic when injected into C57BL/6 mice, with survival times between 30 and 55 days. We generated both C1498 and C1498-mOVA membrane-coated nanoparticles, that were packaged with CpG oligo-deoxynucleotides (CpG) as an immune-stimulatory adjuvant. The final AMCNPs exhibit a core-shell structure with uniform coating as shown by transmission electron microscopy. The C1498-mOVA AMCNPs retained mOVA antigen. To confirm that the C1498-mOVA AMCNPs can effectively stimulate DC OVA MHC class I cross-presentation, we pulsed primary bone marrow derived DCs with C1498 AMCNPs or C1498-mOVA AMCNPs; only the C1498-mOVA AMCNP pulsed DCs specifically elicited OVA MHC class-I T-cell activation in lacZ B3Z T-cell activation assays. To verify that the AMCNPs can elicit antigen-specific immune responses in vivo, we vaccinated C57BL/6 mice with C1498 AMCNPs, C1498-mOVA AMCNPs, or equivalent amounts of whole cell lysates. When stimulated ex vivo with OVA peptide, immune-cell preparations from the C1498-mOVA AMCNP vaccinated mice showed significantly enhanced production of OVA-specific T-cells and IFN-γ, demonstrating increased immune responses. To assess if the enhanced cellular immunity afforded by the C1498-mOVA AMCNP formula can translate into functional rejection of leukemia cells, we performed a prophylactic study using the C1498-mOVA model. Mice vaccinated with the C1498-mOVA AMCNPs all survived beyond 120 days post C1498-mOVA cell challenge, compared to mock treated control mice which had a median survival of 60 days. Collectively, we developed an AMCNP platform that carries AML surface antigens and can be packaged with immunostimulatory adjuvants. These AMCNPs retained AML specific antigens, elicited enhanced antigen specific immune responses after in vivo vaccination, and improved immunity against AML challenge. Therefore, using AML cell membrane coated NPs to enhance anticancer immunity is a feasible strategy for AML vaccination immunotherapy. Disclosures Kline: iTeos: Research Funding; Merck: Honoraria, Research Funding.

scholarly journals Targeting of antigens to B cells augments antigen-specific T-cell responses and breaks immune tolerance to tumor-associated antigen MUC1

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2817-2825 ◽  
Author(s):  
Chuanlin Ding ◽  
Li Wang ◽  
Jose Marroquin ◽  
Jun Yan
Keyword(s):  
T Cell ◽  
B Cells ◽  
T Cell Activation ◽  
Cell Activation ◽  
Vaccine Development ◽  
High Titer ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses

Abstract B cells are antibody (Ab)–secreting cells as well as potent antigen (Ag)–presenting cells that prime T-cell activation, which evokes great interest in their use for vaccine development. Here, we targeted ovalbumin (OVA) to B cells via CD19 and found that a single low dose of anti–CD19-OVA conjugates, but not isotype mAb-OVA, stimulated augmented CD4 and CD8 T-cell proliferation and expansion. Administration of TLR9 agonist CpG could significantly enhance long-term T-cell survival. Similar results were obtained when the tumor-associated Ag MUC1 was delivered to B cells. MUC1 transgenic (Tg) mice were previously found to lack effective T-cell help and produce low-titer of anti-MUC1 Abs after vaccination. Targeting MUC1 to B cells elicited high titer of anti-MUC1 Abs with different isotypes, predominantly IgG2a and IgG2b, in MUC1 Tg mice. The isotype switching of anti-MUC1 Ab was CD4 dependent. In addition, IFN-γ–producing CD8 T cells and in vivo cytolytic activity were significantly increased in these mice. The mice also showed significant resistance to MUC1+ lymphoma cell challenge both in the prophylactic and therapeutic settings. We conclude that Ags targeting to B cells stimulate CD4 and CD8 T-cell responses as well as Th-dependent humoral immune responses.

scholarly journals Pathogen-reduced PRP blocks T-cell activation, induces Treg cells, and promotes TGF-β expression by cDCs and monocytes in mice

2020 ◽  
Vol 4 (21) ◽  
pp. 5547-5561
Author(s):  
Johnson Q. Tran ◽  
Marcus O. Muench ◽  
Rachael P. Jackman
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
T Cell Responses ◽  
Treg Cells ◽  
Cell Responses ◽  
Pathogen Reduction ◽  
Specific Tolerance

Abstract Alloimmunization against platelet-rich plasma (PRP) transfusions can lead to complications such as platelet refractoriness or rejection of subsequent transfusions and transplants. In mice, pathogen reduction treatment of PRP with UVB light and riboflavin (UV+R) prevents alloimmunization and appears to induce partial antigen-specific tolerance to subsequent transfusions. Herein, the in vivo responses of antigen-presenting cells and T cells to transfusion with UV+R-treated allogeneic PRP were evaluated to understand the cellular immune responses leading to antigen-specific tolerance. Mice that received UV+R-treated PRP had significantly increased transforming growth factor β (TGF-β) expression by CD11b+ CD4+ CD11cHi conventional dendritic cells (cDCs) and CD11bHi monocytes (P &lt; .05). While robust T-cell responses to transfusions with untreated allogeneic PRP were observed (P &lt; .05), these were blocked by UV+R treatment. Mice given UV+R-treated PRP followed by untreated PRP showed an early significant (P &lt; .01) enrichment in regulatory T (Treg) cells and associated TGF-β production as well as diminished effector T-cell responses. Adoptive transfer of T-cell–enriched splenocytes from mice given UV+R-treated PRP into naive recipients led to a small but significant reduction of CD8+ T-cell responses to subsequent allogeneic transfusion. These data demonstrate that pathogen reduction with UV+R induces a tolerogenic profile by way of CD11b+ CD4+ cDCs, monocytes, and induction of Treg cells, blocking T-cell activation and reducing secondary T-cell responses to untreated platelets in vivo.

scholarly journals CTLA-4 controls follicular helper T-cell differentiation by regulating the strength of CD28 engagement

2014 ◽  
Vol 112 (2) ◽  
pp. 524-529 ◽  
Author(s):  
Chun Jing Wang ◽  
Frank Heuts ◽  
Vitalijs Ovcinnikovs ◽  
Lukasz Wardzinski ◽  
Chantelle Bowers ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cytotoxic T Lymphocyte ◽  
T Cell Responses ◽  
Dependent Manner ◽  
Cell Responses ◽  
Follicular Helper ◽  
Follicular Helper T Cell

Cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is an essential regulator of T-cell responses, and its absence precipitates lethal T-cell hyperactivity. However, whether CTLA-4 acts simply to veto the activation of certain clones or plays a more nuanced role in shaping the quality of T-cell responses is not clear. Here we report that T cells in CTLA-4–deficient mice show spontaneous T-follicular helper (TFH) differentiation in vivo, and this is accompanied by the appearance of large germinal centers (GCs). Remarkably, short-term blockade with anti–CTLA-4 antibody in wild-type mice is sufficient to elicit TFH generation and GC development. The latter occurs in a CD28-dependent manner, consistent with the known role of CTLA-4 in regulating the CD28 pathway. CTLA-4 can act by down-regulating CD80 and CD86 on antigen presenting cells (APCs), thereby altering the level of CD28 engagement. To mimic reduced CD28 ligation, we used mice heterozygous for CD28, revealing that the magnitude of CD28 engagement is tightly linked to the propensity for TFH differentiation. In contrast, other parameters of T-cell activation, including CD62L down-regulation and Ki67 expression, were relatively insensitive to altered CD28 level. Altered TFH generation as a result of graded reduction in CD28 was associated with decreased numbers of GC B cells and a reduction in overall GC size. These data support a model in which CTLA-4 control of immunity goes beyond vetoing T-cell priming and encompasses the regulation of TFH differentiation by graded control of CD28 engagement.

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 HLA class I genotypes customize vaccination strategies in immune simulation to combat COVID-19

2020 ◽  
Author(s):  
Shouxiong Huang ◽  
Ming Tan
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Vaccination Strategy ◽  
T Cell Responses ◽  
Hla Class I ◽  
Class I ◽  
Human Populations ◽  
Anchor Residue ◽  
Cell Responses

AbstractMemory CD8+ T cells are associated with a better outcome in Coronavirus Disease 2019 (COVID-19) and recognized as promising vaccine targets against viral infections. This study determined the efficacy of population-dominant and infection-relevant human leukocyte antigens (HLA) class I proteins to present severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) peptides through calculating binding affinities and simulating CD8+ T cell responses. As a result, HLA class I proteins distinguished or shared various viral peptides derived from viruses. HLA class I supertypes clustered viral peptides through recognizing anchor and preferred residues. SARS-CoV-2 peptides overlapped significantly with SARS but minimally with common human coronaviruses. Immune simulation of CD8+ T cell activation using predicted SARS-CoV-2 peptide antigens depended on high-affinity peptide binding, anchor residue interaction, and synergistic presentation of HLA class I proteins in individuals. Results demonstrated that multi-epitope vaccination, employing a strong binding affinity, viral adjuvants, and heterozygous HLA class I genes, induced potent immune responses. Therefore, optimal CD8+ T cell responses can be achieved and customized contingent on HLA class I genotypes in human populations, supporting a precise vaccination strategy to combat COVID-19.

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