Glycan-Modified Melanoma-Derived Apoptotic Extracellular Vesicles as Antigen Source for Anti-Tumor Vaccination

Tumors that lack T cell infiltration are less likely to respond to immune checkpoint inhibition and could benefit from cancer vaccination for the initiation of anti-tumor T cell responses. An attractive vaccine strategy is in vivo targeting of dendritic cells (DCs), key initiators of antigen-specific T cell responses. In this study we generated tumor-derived apoptotic extracellular vesicles (ApoEVs), which are potentially an abundant source of tumor-specific neo-antigens and other tumor-associated antigens (TAAs), and which can be manipulated to express DC-targeting ligands for efficient antigen delivery. Our data demonstrates that by specifically modifying the glycocalyx of tumor cells, high-mannose glycans can be expressed on their cell surface and on extracellular vesicles derived after the induction of apoptosis. High-mannose glycans are the natural ligands of dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN), a dendritic cell associated C-type lectin receptor (CLR), which has the ability to efficiently internalize its cargo and direct it to both major histocompatibility complex (MHC)-I and MHC-II pathways for the induction of CD8+ and CD4+ T cell responses, respectively. Compared to unmodified ApoEVs, ApoEVs carrying DC-SIGN ligands are internalized to a higher extent, resulting in enhanced priming of tumor-specific CD8+ T cells. This approach thus presents a promising vaccination strategy in support of T cell-based immunotherapy of cancer.

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CD63-Mediated Antigen Delivery into Extracellular Vesicles via DNA Vaccination Results in Robust CD8+ T Cell Responses

The Journal of Immunology ◽

10.4049/jimmunol.1600731 ◽

2017 ◽

Vol 198 (12) ◽

pp. 4707-4715 ◽

Cited By ~ 9

Author(s):

Tomohiro Kanuma ◽

Takuya Yamamoto ◽

Kouji Kobiyama ◽

Eiko Moriishi ◽

Yuji Masuta ◽

...

Keyword(s):

T Cell ◽

Extracellular Vesicles ◽

T Cell Responses ◽

Cd8 T Cell ◽

Dna Vaccination ◽

Antigen Delivery ◽

Cell Responses

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Deciphering the Mechanisms of Improved Immunogenicity of Hypochlorous Acid-Treated Antigens in Anti-Cancer Dendritic Cell-Based Vaccines

Vaccines ◽

10.3390/vaccines8020271 ◽

2020 ◽

Vol 8 (2) ◽

pp. 271

Author(s):

Michele Graciotti ◽

Fabio Marino ◽

HuiSong Pak ◽

Petra Baumgaertner ◽

Anne-Christine Thierry ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

Hypochlorous Acid ◽

T Cell Responses ◽

Cd4 T Cell ◽

Tumor Lysate ◽

Cell Responses ◽

Significant Difference

Hypochlorous acid (HOCl)-treated whole tumor cell lysates (Ox-L) have been shown to be more immunogenic when used as an antigen source for therapeutic dendritic cell (DC)-based vaccines, improving downstream immune responses both in vitro and in vivo. However, the mechanisms behind the improved immunogenicity are still elusive. To address this question, we conducted a proteomic and immunopeptidomics analyses to map modifications and alterations introduced by HOCl treatment using a human melanoma cell line as a model system. First, we show that one-hour HOCl incubation readily induces extensive protein oxidation, mitochondrial biogenesis, and increased expression of chaperones and antioxidant proteins, all features indicative of an activation of oxidative stress-response pathways. Characterization of the DC proteome after loading with HOCl treated tumor lysate (Ox-L) showed no significant difference compared to loading with untreated whole tumor lysate (FT-L). On the other hand, detailed immunopeptidomic analyses on monocyte-derived DCs (mo-DCs) revealed a great increase in human leukocyte antigen class II (HLA-II) presentation in mo-DCs loaded with Ox-L compared to the FT-L control. Further, 2026 HLA-II ligands uniquely presented on Ox-L-loaded mo-DCs were identified. In comparison, identities and intensities of HLA class I (HLA-I) ligands were overall comparable. We found that HLA-II ligands uniquely presented by DCs loaded with Ox-L were more solvent exposed in the structures of their source proteins, contrary to what has been hypothesized so far. Analyses from a phase I clinical trial showed that vaccinating patients using autologous Ox-L as an antigen source efficiently induces polyfunctional vaccine-specific CD4+ T cell responses. Hence, these results suggest that the increased immunogenicity of Ox-L is, at least in part, due to qualitative and quantitative changes in the HLA-II ligandome, potentially leading to an increased HLA-II dependent stimulation of the T cell compartment (i.e., CD4+ T cell responses). These results further contribute to the development of more effective and immunogenic DC-based vaccines and to the molecular understanding of the mechanism behind HOCl adjuvant properties.

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DIgR2, dendritic cell-derived immunoglobulin receptor 2, is one representative of a family of IgSF inhibitory receptors and mediates negative regulation of dendritic cell-initiated antigen-specific T-cell responses

Blood ◽

10.1182/blood-2006-04-015404 ◽

2006 ◽

Vol 108 (8) ◽

pp. 2678-2686 ◽

Cited By ~ 38

Author(s):

Liyun Shi ◽

Kun Luo ◽

Dajing Xia ◽

Taoyong Chen ◽

Guoyou Chen ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

Protein Tyrosine Phosphatases ◽

T Cell Responses ◽

Immunoglobulin Superfamily ◽

Inhibitory Receptors ◽

Immunoglobulin Receptor ◽

Cell Responses

AbstractDendritic cells (DCs) are specialized antigen-presenting cells that play crucial roles in the initiation and regulation of immune responses. Maturation and activation of DCs are controlled by a balance of the inhibitory and activating signals transduced through distinct surface receptors. Many inhibitory receptors expressed by DCs have been identified, whereas the new members and their functions need further investigation. In this study, we functionally characterized DC-derived immunoglobulin receptor 2 (DIgR2) as a novel representative of a family of inhibitory receptors belonging to the immunoglobulin superfamily. We show that DIgR2 contains 2 immunoreceptor tyrosine-based inhibitory motifs (ITIMs) within its cytoplasmic region and that DIgR2 associates with Src homology-2 domain-containing protein tyrosine phosphatases-1 (SHP-1). Blockade of DIgR2 on DCs by pretreatment with DIgR2-Ig fusion protein or by silencing with specific small interfering RNA enhances DC-initiated T-cell proliferation and antigen-specific T-cell responses both in vitro and in vivo. Furthermore, immunization of mice with antigen-pulsed, DIgR2-silenced DCs elicits more potent antigen-specific CD4+ and CD8+ T-cell responses, thus protecting the vaccinated mice from tumor challenge more effectively. Our data suggest that DIgR2 is a functionally inhibitory receptor and can mediate negative signaling to regulate DC-initiated antigen-specific T-cell responses.

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Polymicrobial Sepsis Diminishes Dendritic Cell Numbers and Function Directly Contributing to Impaired Primary CD8 T Cell Responses In Vivo

The Journal of Immunology ◽

10.4049/jimmunol.1601463 ◽

2016 ◽

Vol 197 (11) ◽

pp. 4301-4311 ◽

Cited By ~ 23

Author(s):

Robert K. Strother ◽

Derek B. Danahy ◽

Dmitri I. Kotov ◽

Tamara A. Kucaba ◽

Zeb R. Zacharias ◽

...

Keyword(s):

T Cell ◽

Dendritic Cell ◽

T Cell Responses ◽

Cd8 T Cell ◽

Polymicrobial Sepsis ◽

Cell Numbers ◽

Cell Responses ◽

And Function

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

Blood ◽

10.1182/blood-2008-12-192252 ◽

2009 ◽

Vol 113 (23) ◽

pp. 5793-5800 ◽

Cited By ~ 27

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.

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Effective induction of naive and recall T-cell responses by targeting antigen to human dendritic cells via a humanized anti–DC-SIGN antibody

Blood ◽

10.1182/blood-2005-01-0318 ◽

2005 ◽

Vol 106 (4) ◽

pp. 1278-1285 ◽

Cited By ~ 205

Author(s):

Paul J. Tacken ◽

I. Jolanda M. de Vries ◽

Karlijn Gijzen ◽

Ben Joosten ◽

Dayang Wu ◽

...

Keyword(s):

T Cell ◽

Ex Vivo ◽

T Cell Responses ◽

Keyhole Limpet Hemocyanin ◽

Peripheral Blood Lymphocytes ◽

Intercellular Adhesion Molecule ◽

Chimeric Antibody ◽

Surface Receptors ◽

Cell Responses

AbstractCurrent dendritic cell (DC)–based vaccines are based on ex vivo–generated autologous DCs loaded with antigen prior to readministration into patients. A more direct and less laborious strategy is to target antigens to DCs in vivo via specific surface receptors. Therefore, we developed a humanized antibody, hD1V1G2/G4 (hD1), directed against the C-type lectin DC-specific intercellular adhesion molecule 3–grabbing nonintegrin (DC-SIGN) to explore its capacity to serve as a target receptor for vaccination purposes. hD1 was cross-linked to a model antigen, keyhole limpet hemocyanin (KLH). We observed that the chimeric antibody-protein complex (hD1-KLH) bound specifically to DC-SIGN and was rapidly internalized and translocated to the lysosomal compartment. To determine the targeting efficiency of hD1-KLH, monocyte-derived DCs and peripheral blood lymphocytes (PBLs) were obtained from patients who had previously been vaccinated with KLH-pulsed DCs. Autologous DCs pulsed with hD1-KLH induced proliferation of patient PBLs at a 100-fold lower concentration than KLH-pulsed DCs. In addition, hD1-KLH–targeted DCs induced proliferation of naive T cells recognizing KLH epitopes in the context of major histocompatibility complex (MHC) classes I and II. We conclude that antibody-mediated targeting of antigen to DCs via DC-SIGN effectively induces antigen-specific naive as well as recall T-cell responses. This identifies DC-SIGN as a promising target molecule for DC-based vaccination strategies.

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