Presentation of proteins encapsulated in sterically stabilized liposomes by dendritic cells initiates CD8+ T-cell responses in vivo

Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3505-3513 ◽  
Author(s):  
Ralf Ignatius ◽  
Karsten Mahnke ◽  
Miguel Rivera ◽  
Keelung Hong ◽  
Frank Isdell ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Soluble Protein ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Sterically Stabilized Liposomes

Abstract Liposomes have been proposed as a vehicle to deliver proteins to antigen-presenting cells (APC), such as dendritic cells (DC), to stimulate strong T cell–mediated immune responses. Unfortunately, because of their instability in vivo and their rapid uptake by cells of the mononuclear phagocyte system on intravenous administration, most types of conventional liposomes lack clinical applicability. In contrast, sterically stabilized liposomes (SL) have increased in vivo stability. It is shown that both immature and mature DC take up SL into neutral or mildly acidic compartments distinct from endocytic vacuoles. These DC presented SL-encapsulated protein to both CD4+ and CD8+ T cells in vitro. Although CD4+ T-cell responses were comparable to those induced by soluble protein, CD8+ T-cell proliferation was up to 300-fold stronger when DC had been pulsed with SL-encapsulated ovalbumin. DC processed SL-encapsulated antigen through a TAP-dependent mechanism. Immunization of mice with SL-encapsulated ovalbumin led to antigen presentation by DC in vivo and stimulated greater CD8+ T-cell responses than immunization with soluble protein or with conventional or positively charged liposomes carrying ovalbumin. Therefore, the application of SL-encapsulated antigens offers a novel effective, safe vaccine approach if a combination of CD8+and CD4+ T-cell responses is desired (ie, in anti-viral or anti-tumor immunity).

Presentation of proteins encapsulated in sterically stabilized liposomes by dendritic cells initiates CD8+ T-cell responses in vivo

Blood ◽  
2000 ◽  
Vol 96 (10) ◽  
pp. 3505-3513 ◽  
Author(s):  
Ralf Ignatius ◽  
Karsten Mahnke ◽  
Miguel Rivera ◽  
Keelung Hong ◽  
Frank Isdell ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Soluble Protein ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Sterically Stabilized Liposomes

Liposomes have been proposed as a vehicle to deliver proteins to antigen-presenting cells (APC), such as dendritic cells (DC), to stimulate strong T cell–mediated immune responses. Unfortunately, because of their instability in vivo and their rapid uptake by cells of the mononuclear phagocyte system on intravenous administration, most types of conventional liposomes lack clinical applicability. In contrast, sterically stabilized liposomes (SL) have increased in vivo stability. It is shown that both immature and mature DC take up SL into neutral or mildly acidic compartments distinct from endocytic vacuoles. These DC presented SL-encapsulated protein to both CD4+ and CD8+ T cells in vitro. Although CD4+ T-cell responses were comparable to those induced by soluble protein, CD8+ T-cell proliferation was up to 300-fold stronger when DC had been pulsed with SL-encapsulated ovalbumin. DC processed SL-encapsulated antigen through a TAP-dependent mechanism. Immunization of mice with SL-encapsulated ovalbumin led to antigen presentation by DC in vivo and stimulated greater CD8+ T-cell responses than immunization with soluble protein or with conventional or positively charged liposomes carrying ovalbumin. Therefore, the application of SL-encapsulated antigens offers a novel effective, safe vaccine approach if a combination of CD8+and CD4+ T-cell responses is desired (ie, in anti-viral or anti-tumor immunity).

scholarly journals Plasmacytoid dendritic cells efficiently cross-prime naive T cells in vivo after TLR activation

Blood ◽  
2008 ◽  
Vol 112 (9) ◽  
pp. 3713-3722 ◽  
Author(s):  
Juliette Mouriès ◽  
Gabriel Moron ◽  
Géraldine Schlecht ◽  
Nicolas Escriou ◽  
Gilles Dadaglio ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Antigen Processing ◽  
Cytotoxic T Lymphocyte ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cross Presentation ◽  
Cell Responses

Abstract Cross-presentation is a crucial mechanism in tumoral and microbial immunity because it allows internalized cell associated or exogenous antigens (Ags) to be delivered into the major histocompatibility complex I pathway. This pathway is important for the development of CD8+ T-cell responses and for the induction of tolerance. In mice, cross-presentation is considered to be a unique property of CD8α+ conventional dendritic cells (DCs). Here we show that splenic plasmacytoid DCs (pDCs) efficiently capture exogenous Ags in vivo but are not able to cross-present these Ags at steady state. However, in vitro and in vivo stimulation by Toll-like receptor-7, or -9 or viruses licenses pDCs to cross-present soluble or particulate Ags by a transporter associated with antigen processing-dependent mechanism. Induction of cross-presentation confers to pDCs the ability to generate efficient effector CD8+ T-cell responses against exogenous Ags in vivo, showing that pDCs may play a crucial role in induction of adaptive immune responses against pathogens that do not infect tissues of hemopoietic origin. This study provides the first evidence for an in vivo role of splenic pDCs in Ag cross-presentation and T-cell cross-priming and suggests that pDCs may constitute an attractive target to boost the efficacy of vaccines based on cytotoxic T lymphocyte induction.

scholarly journals Increasing the Survival of Dendritic Cells In Vivo Does Not Replace the Requirement for CD4+T Cell Help during Primary CD8+T Cell Responses

2007 ◽  
Vol 179 (9) ◽  
pp. 5738-5747 ◽  
Author(s):  
Kate E. Matthews ◽  
Jim S. Qin ◽  
Jianping Yang ◽  
Ian F. Hermans ◽  
Michael J. Palmowski ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cd4 T Cell ◽  
Cell Responses ◽  
Cd4 T Cell Help ◽  
T Cell Help

scholarly journals Neutrophil subtypes shape HIV-specific CD8 T-cell responses after vaccinia virus infection

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mauro Di Pilato ◽  
Miguel Palomino-Segura ◽  
Ernesto Mejías-Pérez ◽  
Carmen E. Gómez ◽  
Andrea Rubio-Ponce ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Vaccinia Virus ◽  
Adaptive Immune System ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Adaptive Immune

AbstractNeutrophils are innate immune cells involved in the elimination of pathogens and can also induce adaptive immune responses. Nα and Nβ neutrophils have been described with distinct in vitro capacity to generate antigen-specific CD8 T-cell responses. However, how these cell types exert their role in vivo and how manipulation of Nβ/Nα ratio influences vaccine-mediated immune responses are not known. In this study, we find that these neutrophil subtypes show distinct migratory and motility patterns and different ability to interact with CD8 T cells in the spleen following vaccinia virus (VACV) infection. Moreover, after analysis of adhesion, inflammatory, and migration markers, we observe that Nβ neutrophils overexpress the α4β1 integrin compared to Nα. Finally, by inhibiting α4β1 integrin, we increase the Nβ/Nα ratio and enhance CD8 T-cell responses to HIV VACV-delivered antigens. These findings provide significant advancements in the comprehension of neutrophil-based control of adaptive immune system and their relevance in vaccine design.

scholarly journals The GM-CSF–IRF5 signaling axis in eosinophils promotes antitumor immunity through activation of type 1 T cell responses

2020 ◽  
Vol 217 (12) ◽  
Author(s):  
Isabelle C. Arnold ◽  
Mariela Artola-Boran ◽  
Alessandra Gurtner ◽  
Katrin Bertram ◽  
Michael Bauer ◽  
...  
Keyword(s):  
T Cell ◽  
Antitumor Immunity ◽  
Critical Role ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Tumor Control ◽  
Gm Csf ◽  
Cell Responses

The depletion of eosinophils represents an efficient strategy to alleviate allergic asthma, but the consequences of prolonged eosinophil deficiency for human health remain poorly understood. We show here that the ablation of eosinophils severely compromises antitumor immunity in syngeneic and genetic models of colorectal cancer (CRC), which can be attributed to defective Th1 and CD8+ T cell responses. The specific loss of GM-CSF signaling or IRF5 expression in the eosinophil compartment phenocopies the loss of the entire lineage. GM-CSF activates IRF5 in vitro and in vivo and can be administered recombinantly to improve tumor immunity. IL-10 counterregulates IRF5 activation by GM-CSF. CRC patients whose tumors are infiltrated by large numbers of eosinophils also exhibit robust CD8 T cell infiltrates and have a better prognosis than patients with eosinophillow tumors. The combined results demonstrate a critical role of eosinophils in tumor control in CRC and introduce the GM-CSF–IRF5 axis as a critical driver of the antitumor activities of this versatile cell type.

Dendritic cells overexpressing CD95 (Fas) ligand elicit vigorous allospecific T-cell responses in vivo

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1469-1476 ◽  
Author(s):  
Sofia Buonocore ◽  
Frédéric Paulart ◽  
Alain Le Moine ◽  
Michel Braun ◽  
Isabelle Salmon ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Fas Ligand ◽  
T Cell Responses ◽  
Genetically Engineered ◽  
Peripheral Tolerance ◽  
Cytotoxic T Cell ◽  
Cell Responses

Dendritic cells (DCs) genetically engineered to overexpress CD95 (Fas) ligand (CD95L-DC) were proposed as tools to induce peripheral tolerance to alloantigens. Herein, we observed that CD95L-DC obtained after retroviral gene transfer in bone marrow (BM) precursors derived from CD95-deficient (lpr/lpr) mice elicit much stronger allospecific type 1 helper T-cell and cytotoxic T-cell activities than control DCs upon injection in vivo, although they induce lower T-cell responses in vitro. Indeed, a single injection of CD95L-DC prepared from C57BL/6 mice was sufficient to prime bm13 recipients for acute rejection of C57BL/6 skin allografts that were otherwise tolerated in the context of this single weak major histocompatibility complex (MHC) class I incompatibility. Massive neutrophil infiltrates depending on interleukin (IL)–1 signaling were observed at sites of CD95L-DC injection. Experiments in IL-1 receptor–deficient mice or in animals injected with depleting anti-Gr1 monoclonal antibody (mAb) established that neutrophil recruitment is required for the development of vigorous T-cell responses after injection of CD95L-DC in vivo.

Dasatinib inhibits recombinant viral antigen-specific murine CD4+ and CD8+ T-cell responses and NK-cell cytolytic activity in vitro and in vivo

2009 ◽  
Vol 37 (2) ◽  
pp. 256-265 ◽  
Author(s):  
Cara K. Fraser ◽  
Stephen J. Blake ◽  
Kerrilyn R. Diener ◽  
A. Bruce Lyons ◽  
Michael P. Brown ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Antigen ◽  
Nk Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cytolytic Activity ◽  
Cell Responses

scholarly journals Increasing the potency of dendritic cell based vaccines for the treatment of cancer

2021 ◽  
Author(s):  
◽  
Dianne Sika-Paotonu
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Responses ◽  
Cd8 T Cell ◽  
Cell Responses ◽  
Vaccination Strategies ◽  
Monophosphoryl Lipid A ◽  
Tlr Agonist

<p>Tumours can be eradicated by T cells that recognise unique tumour-associated antigens. These T cells are initially stimulated by dendritic cells (DCs) that have acquired antigens from tumour tissue. Vaccination strategies that increase the frequencies of tumour-specific T cells by enhancing the activity of DCs are being evaluated in the clinic as novel cancer therapies. Our hypothesis is that existing DC-based vaccination strategies can be improved by stimulating toll-like receptor (TLR) signalling in the DCs, and also by encouraging interactions with iNKT cells, as these two activities are known to enhance DC function. It was also hypothesised that superior T cell responses could be induced by combining these two activities together. We used the TLR 4 agonist monophosphoryl lipid A (MPL) alone and in combination with other TLR agonists to achieve effective activation of bone marrow-derived DCs (BM-DCs) cultured in-vitro, which was characterised by upregulated expression of maturation markers on the cell surface, and enhanced release of pro-inflammatory cytokines. Some TLR agonist combinations provided significantly enhanced activities in this regard, notably the combination of MPL with either the TLR 2 agonist Pam3Cys, or the TLR 7/8 agonist Resiquimod. Although in-vitro activated BM-DCs were unable to induce stronger antigen-specific CD8+ T cell responses after intravenous injection when compared to BMDCs without TLR stimulation, enhanced CD8+ T cell responses were achieved in-vivo with the co-administration of TLR ligands, implying that TLR stimulation needed to act on cells of the host. Further studies identified the langerin-expressing CD8ɑ+ splenic DC subset in the spleen as recipients of antigen that was transferred from injected cells, and that these recipients were participants in the cross-presentation and T cell priming activities driving the CD8+ T cell response after vaccination. Antigen-loaded BM-DCs carrying the NKT cell ligand ɑ-galactosylceramide (ɑ-GalCer) were found to consistently increase antigen-specific CD8+ T cell responses in-vivo, and also cytotoxic responses as seen in cytotoxic killing assays. Again, langerin-expressing CD8ɑ+ splenic DCs were shown to be involved in this response by acquiring antigen and ɑ-GalCer from the injected vaccine BM-DCs. Finally, it was possible to achieve even greater CD8+ T cell responses in-vivo by injecting BM-DCs carrying antigen and ɑ-GalCer, together with timely co-administration of the TLR agonist. These results suggest a reassessment of the activities of DC-based vaccines to include the important role of “courier” to DCs already resident in the host that can be exploited to improve vaccination outcomes.</p>

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