The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Bjarne Bogen - One of the best experts on this subject based on the ideXlab platform.
-
Data_Sheet_1_Endocytosis Deficient Murine Xcl1-Fusion Vaccine Enhances Protective Antibody Responses in Mice.pdf
2019Co-Authors: Arnar Gudjonsson, Tor Kristian Andersen, Vibeke Sundvold-gjerstad, Bjarne Bogen, Even FossumAbstract:Targeting antigen to surface receptors on dendritic cells (DCs) can improve antibody response against subunit vaccines. We have previously observed that human XCL1-fusion vaccines target murine XCR1+ DCs without actively inducing endocytosis of the antigen, resulting in enhanced antibody responses in mice. However, the use of foreign chemokines for targeting is undesirable when translating this observation to human or veterinary medicine due to potential cross-reactive responses against the endogenous chemokine. Here we have identified a mutant version of murine Xcl1, labeled Xcl1(Δ1) owing to removal of a conserved valine in position 1 of the mature chemokine, that retains specific binding to XCR1+ DCs without inducing endocytosis of the receptor. DNA immunization with Xcl1(Δ1) conjugated to influenza hemagglutinin (HA) induced improved antibody responses, with higher end point titers of IgG compared to WT Xcl1-HA. The Xcl1(Δ1) fusion vaccine also resulted in an increased number of HA reactive germinal center B cells with higher avidity toward the antigen, and serum transfer experiments show that Xcl1(Δ1)-HA induced antibody responses provided better protection against influenza infection as compared to WT Xcl1-HA. In summary, our observations indicate that targeting antigen to XCR1+ DCs in an endocytosis deficient manner enhances antibody responses. This effect was obtained by introducing a single mutation to Xcl1, suggesting our strategy may easily be translated to human or veterinary vaccine settings.
-
Endocytosis Deficient Murine Xcl1-Fusion Vaccine Enhances Protective Antibody Responses in Mice
Frontiers Media S.A., 2019Co-Authors: Arnar Gudjonsson, Tor Kristian Andersen, Vibeke Sundvold-gjerstad, Bjarne Bogen, Even FossumAbstract:Targeting antigen to surface receptors on dendritic cells (DCs) can improve antibody response against subunit vaccines. We have previously observed that human XCL1-fusion vaccines target murine XCR1+ DCs without actively inducing endocytosis of the antigen, resulting in enhanced antibody responses in mice. However, the use of foreign chemokines for targeting is undesirable when translating this observation to human or veterinary medicine due to potential cross-reactive responses against the endogenous chemokine. Here we have identified a mutant version of murine Xcl1, labeled Xcl1(Δ1) owing to removal of a conserved valine in position 1 of the mature chemokine, that retains specific binding to XCR1+ DCs without inducing endocytosis of the receptor. DNA immunization with Xcl1(Δ1) conjugated to influenza hemagglutinin (HA) induced improved antibody responses, with higher end point titers of IgG compared to WT Xcl1-HA. The Xcl1(Δ1) fusion vaccine also resulted in an increased number of HA reactive germinal center B cells with higher avidity toward the antigen, and serum transfer experiments show that Xcl1(Δ1)-HA induced antibody responses provided better protection against influenza infection as compared to WT Xcl1-HA. In summary, our observations indicate that targeting antigen to XCR1+ DCs in an endocytosis deficient manner enhances antibody responses. This effect was obtained by introducing a single mutation to Xcl1, suggesting our strategy may easily be translated to human or veterinary vaccine settings
-
expanding the tools for identifying mononuclear phagocyte subsets in swine reagents to porcine cd11c and XCR1
Developmental and Comparative Immunology, 2016Co-Authors: Charlotte Deloizy, Even Fossum, Edwige Bouguyon, Peter Sebo, Radim Osicka, Angelique Bole, Michel Pierres, Stephane Biacchesi, Marc Dalod, Bjarne BogenAbstract:Pig is a domestic species of major importance in the agro-economy and in biomedical research. Mononuclear phagocytes (MNP) are organized in subsets with specialized roles in the orchestration of the immune response and new tools are awaited to improve MNP subset identification in the pig. We cloned pig CD11c cDNA and generated a monoclonal antibody to pig CD11c which showed a pattern of expression by blood and skin MNP subsets similar to humans. We also developed a porcine XCL1-mCherry dimer which specifically reacted with the XCR1-expressing dendritic cell subset of the type 1 lineage in blood and skin. These original reagents will allow the efficient identification of pig MNP subsets to study their role in physiological and pathological processes and also to target these cells in novel intervention and vaccine strategies for veterinary applications and preclinical evaluations.
-
abstract 2518 effective vaccination against melanoma in an animal study combination of laser assisted dermal skin delivery and cross presenting XCR1 dermal dcs targeting
Cancer Research, 2015Co-Authors: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Elmira Lechat, Reto Crameri, Roland Winteler, Bjarne BogenAbstract:Background/Aim/Method The induction of CD8+ cytotoxic T lymphocytes (CTL) is critical to eradicate tumor cells. In mouse skin, a subset of dendritic cell characterised by the expression of the chemokine receptor XCR1 is highly potent to activate CD8+ T cells. By combining PLEASE-assisted laser poration of the skin allowing dermal delivery and the use of dimeric vaccine molecule in which the XCR1 ligand, Xcl1, was fused to the antigen, we targeted specifically this XCR1+ dermal subset. Results Dermal delivery of this vaccine molecule after skin laser-poration induced specific strong T cell proliferation in an XCR1-dependent manner. A single immunization allowed protecting against melanoma in both therapeutic and prophylactic protocols. Discussion & Conclusion Thus, specific targeting of cross-presenting skin DCs represents a promising vaccine strategy for induction of CD8+ T cell responses and protection against cancers. Citation Format: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Elmira Lechat, Reto Crameri, Roland Winteler, Bjarne Bogen, Bernard Malissen, Sandrine Henri. Effective vaccination against melanoma in an animal study: Combination of laser-assisted dermal skin delivery and cross-presenting XCR1+ dermal DCs targeting. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2518. doi:10.1158/1538-7445.AM2015-2518
-
laser assisted intradermal delivery of adjuvant free vaccines targeting XCR1 dendritic cells induces potent antitumoral responses
Journal of Immunology, 2015Co-Authors: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Reinhard Braun, Elmira Lechat, Reto Crameri, Bjarne BogenAbstract:The development of vaccines inducing efficient CD8(+) T cell responses is the focus of intense research. Dendritic cells (DCs) expressing the XCR1 chemokine receptor, also known as CD103(+) or CD8α(+) DCs, excel in the presentation of extracellular Ags to CD8(+) T cells. Because of its high numbers of DCs, including XCR1(+) DCs, the skin dermis is an attractive site for vaccine administration. By creating laser-generated micropores through the epidermis, we targeted a model protein Ag fused to XCL1, the ligand of XCR1, to dermal XCR1(+) DCs and induced Ag-specific CD8(+) and CD4(+) T cell responses. Efficient immunization required the emigration of XCR1(+) dermal DCs to draining lymph nodes and occurred irrespective of TLR signaling. Moreover, a single intradermal immunization protected mice against melanoma tumor growth in prophylactic and therapeutic settings, in the absence of exogenous adjuvant. The mild inflammatory milieu created in the dermis by skin laser microporation itself most likely favored the development of potent T cell responses in the absence of exogenous adjuvants. The existence of functionally equivalent XCR1(+) dermal DCs in humans should permit the translation of laser-assisted intradermal delivery of a tumor-specific vaccine targeting XCR1(+) DCs to human cancer immunotherapy. Moreover, considering that the use of adjuvants in vaccines is often associated with safety issues, the possibility of inducing protective responses against melanoma tumor growth independently of the administration of exogenous adjuvants should facilitate the development of safer vaccines.
Even Fossum - One of the best experts on this subject based on the ideXlab platform.
-
Data_Sheet_1_Endocytosis Deficient Murine Xcl1-Fusion Vaccine Enhances Protective Antibody Responses in Mice.pdf
2019Co-Authors: Arnar Gudjonsson, Tor Kristian Andersen, Vibeke Sundvold-gjerstad, Bjarne Bogen, Even FossumAbstract:Targeting antigen to surface receptors on dendritic cells (DCs) can improve antibody response against subunit vaccines. We have previously observed that human XCL1-fusion vaccines target murine XCR1+ DCs without actively inducing endocytosis of the antigen, resulting in enhanced antibody responses in mice. However, the use of foreign chemokines for targeting is undesirable when translating this observation to human or veterinary medicine due to potential cross-reactive responses against the endogenous chemokine. Here we have identified a mutant version of murine Xcl1, labeled Xcl1(Δ1) owing to removal of a conserved valine in position 1 of the mature chemokine, that retains specific binding to XCR1+ DCs without inducing endocytosis of the receptor. DNA immunization with Xcl1(Δ1) conjugated to influenza hemagglutinin (HA) induced improved antibody responses, with higher end point titers of IgG compared to WT Xcl1-HA. The Xcl1(Δ1) fusion vaccine also resulted in an increased number of HA reactive germinal center B cells with higher avidity toward the antigen, and serum transfer experiments show that Xcl1(Δ1)-HA induced antibody responses provided better protection against influenza infection as compared to WT Xcl1-HA. In summary, our observations indicate that targeting antigen to XCR1+ DCs in an endocytosis deficient manner enhances antibody responses. This effect was obtained by introducing a single mutation to Xcl1, suggesting our strategy may easily be translated to human or veterinary vaccine settings.
-
Endocytosis Deficient Murine Xcl1-Fusion Vaccine Enhances Protective Antibody Responses in Mice
Frontiers Media S.A., 2019Co-Authors: Arnar Gudjonsson, Tor Kristian Andersen, Vibeke Sundvold-gjerstad, Bjarne Bogen, Even FossumAbstract:Targeting antigen to surface receptors on dendritic cells (DCs) can improve antibody response against subunit vaccines. We have previously observed that human XCL1-fusion vaccines target murine XCR1+ DCs without actively inducing endocytosis of the antigen, resulting in enhanced antibody responses in mice. However, the use of foreign chemokines for targeting is undesirable when translating this observation to human or veterinary medicine due to potential cross-reactive responses against the endogenous chemokine. Here we have identified a mutant version of murine Xcl1, labeled Xcl1(Δ1) owing to removal of a conserved valine in position 1 of the mature chemokine, that retains specific binding to XCR1+ DCs without inducing endocytosis of the receptor. DNA immunization with Xcl1(Δ1) conjugated to influenza hemagglutinin (HA) induced improved antibody responses, with higher end point titers of IgG compared to WT Xcl1-HA. The Xcl1(Δ1) fusion vaccine also resulted in an increased number of HA reactive germinal center B cells with higher avidity toward the antigen, and serum transfer experiments show that Xcl1(Δ1)-HA induced antibody responses provided better protection against influenza infection as compared to WT Xcl1-HA. In summary, our observations indicate that targeting antigen to XCR1+ DCs in an endocytosis deficient manner enhances antibody responses. This effect was obtained by introducing a single mutation to Xcl1, suggesting our strategy may easily be translated to human or veterinary vaccine settings
-
The anti-influenza M2e antibody response is promoted by XCR1 targeting in pig skin
Scientific Reports, 2017Co-Authors: Charlotte Deloizy, Even Fossum, Christophe Barnier-quer, Celine Urien, Tiphany Chrun, Audrey Duval, Maëlle Codjovi, Edwige Bouguyon, Pauline Maisonnasse, Pierre Louis HerveAbstract:XCR1 is selectively expressed on a conventional dendritic cell subset, the cDC1 subset, through phylogenetically distant species. The outcome of antigen-targeting to XCR1 may therefore be similar across species, permitting the translation of results from experimental models to human and veterinary applications. Here we evaluated in pigs the immunogenicity of bivalent protein structures made of XCL1 fused to the external portion of the influenza virus M2 proton pump, which is conserved through strains and a candidate for universal influenza vaccines. Pigs represent a relevant target of such universal vaccines as pigs can be infected by swine, human and avian strains. We found that cDC1 were the only cell type labeled by XCR1-targeted mCherry upon intradermal injection in pig skin. XCR1-targeted M2e induced higher IgG responses in seronegative and seropositive pigs as compared to non-targeted M2e. The IgG response was less significantly enhanced by CpG than by XCR1 targeting, and CpG did not further increase the response elicited by XCR1 targeting. Monophosphoryl lipid A with neutral liposomes did not have significant effect. Thus altogether M2e-targeting to XCR1 shows promises for a trans-species universal influenza vaccine strategy, possibly avoiding the use of classical adjuvants.
-
expanding the tools for identifying mononuclear phagocyte subsets in swine reagents to porcine cd11c and XCR1
Developmental and Comparative Immunology, 2016Co-Authors: Charlotte Deloizy, Even Fossum, Edwige Bouguyon, Peter Sebo, Radim Osicka, Angelique Bole, Michel Pierres, Stephane Biacchesi, Marc Dalod, Bjarne BogenAbstract:Pig is a domestic species of major importance in the agro-economy and in biomedical research. Mononuclear phagocytes (MNP) are organized in subsets with specialized roles in the orchestration of the immune response and new tools are awaited to improve MNP subset identification in the pig. We cloned pig CD11c cDNA and generated a monoclonal antibody to pig CD11c which showed a pattern of expression by blood and skin MNP subsets similar to humans. We also developed a porcine XCL1-mCherry dimer which specifically reacted with the XCR1-expressing dendritic cell subset of the type 1 lineage in blood and skin. These original reagents will allow the efficient identification of pig MNP subsets to study their role in physiological and pathological processes and also to target these cells in novel intervention and vaccine strategies for veterinary applications and preclinical evaluations.
-
abstract 2518 effective vaccination against melanoma in an animal study combination of laser assisted dermal skin delivery and cross presenting XCR1 dermal dcs targeting
Cancer Research, 2015Co-Authors: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Elmira Lechat, Reto Crameri, Roland Winteler, Bjarne BogenAbstract:Background/Aim/Method The induction of CD8+ cytotoxic T lymphocytes (CTL) is critical to eradicate tumor cells. In mouse skin, a subset of dendritic cell characterised by the expression of the chemokine receptor XCR1 is highly potent to activate CD8+ T cells. By combining PLEASE-assisted laser poration of the skin allowing dermal delivery and the use of dimeric vaccine molecule in which the XCR1 ligand, Xcl1, was fused to the antigen, we targeted specifically this XCR1+ dermal subset. Results Dermal delivery of this vaccine molecule after skin laser-poration induced specific strong T cell proliferation in an XCR1-dependent manner. A single immunization allowed protecting against melanoma in both therapeutic and prophylactic protocols. Discussion & Conclusion Thus, specific targeting of cross-presenting skin DCs represents a promising vaccine strategy for induction of CD8+ T cell responses and protection against cancers. Citation Format: Dorothea Terhorst, Even Fossum, Anna Baranska, Samira Tamoutounour, Camille Malosse, Mattia Garbani, Elmira Lechat, Reto Crameri, Roland Winteler, Bjarne Bogen, Bernard Malissen, Sandrine Henri. Effective vaccination against melanoma in an animal study: Combination of laser-assisted dermal skin delivery and cross-presenting XCR1+ dermal DCs targeting. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2518. doi:10.1158/1538-7445.AM2015-2518
Richard A Kroczek - One of the best experts on this subject based on the ideXlab platform.
-
rat cytomegalovirus encoded γ chemokine vxcl1 is a highly adapted species specific agonist for rat XCR1 positive dendritic cells
Journal of Cell Science, 2019Co-Authors: Agnieszka Bauer, Hans W Mages, Julia Madela, Christian Berg, Viktorija Daugvilaite, Stephanie Gurka, Richard A Kroczek, Mette M Rosenkilde, Sebastian VoigtAbstract:Dendritic cells (DCs) expressing the chemokine receptor XCR1 are specialized in antigen cross-presentation to control infections with intracellular pathogens. XCR1-positive (XCR1+) DCs are attracted by XCL1, a γ-chemokine secreted by activated CD8+ T cells and natural killer cells. Rat cytomegalovirus (RCMV) is the only virus known to encode a viral XCL1 analog (vXCL1) that competes for XCR1 binding with the endogenous chemokine. Here we show that vXCL1 from two different RCMV strains, as well as endogenous rat XCL1 (rXCL1) bind to and induce chemotaxis exclusively in rat XCR1+ DCs. Whereas rXCL1 activates the XCR1 Gi signaling pathway in rats and humans, both of the vXCL1s function as species-specific agonists for rat XCR1. In addition, we demonstrate constitutive internalization of XCR1 in XCR1-transfected HEK293A cells and in splenic XCR1+ DCs. This internalization was independent of β-arrestin 1 and 2 and was enhanced after binding of vXCL1 and rXCL1; however, vXCL1 appeared to be a stronger agonist. These findings suggest a decreased surface expression of XCR1 during DC cultivation at 37°C, and subsequent impairment of chemotactic activity and XCR1+ DC function.
-
structure function relationship of xcl1 used for in vivo targeting of antigen into XCR1 dendritic cells
Frontiers in Immunology, 2018Co-Authors: Arthur L Kroczek, Evelyn Hartung, Hans W Mages, Stephanie Gurka, Sebastian Voigt, Martina Becker, Nele Reeg, Christian Freund, Richard A KroczekAbstract:XCL1 is the ligand for XCR1, a chemokine receptor uniquely expressed on cross-presenting dendritic cells (DC) in mouse and man. We are interested in establishing therapeutic vaccines based on XCL1-mediated targeting of peptides or proteins into these DC. Therefore, we have functionally analyzed various XCL1 domains in highly relevant settings in vitro and in vivo. Murine XCL1 fused to ovalbumin (XCL1-OVA) was compared to an N-terminal deletion variant lacking the first seven N-terminal amino acids and to several C-terminal (deletion) variants. Binding studies with primary XCR1+ DC revealed that the N-terminal region stabilizes the binding of XCL1 to its receptor, as is known for other chemokines. Deviating from the established paradigm for chemokines, the N-terminus does not contain critical elements for inducing chemotaxis. On the contrary, this region appears to limit the chemotactic action of XCL1 at higher concentrations. A participation of the XCL1 C-terminus in receptor binding or chemotaxis could be excluded in a series of experiments. Binding studies with apoptotic and necrotic XCR1-negative cells suggested a second function for XCL1: marking of stressed cells for uptake into cross-presenting DC. In vivo studies using CD8+ T cell proliferation and cytotoxicity as readouts confirmed the critical role of the N-terminus for antigen targeting, and excluded any involvement of the C-terminus in the uptake, processing, and presentation of the fused OVA antigen. Together, these studies provide basic data on the function of the various XCL1 domains as well as relevant information on XCL1 as an antigen carrier in therapeutic vaccines.
-
cd8 t cells orchestrate pdc XCR1 dendritic cell spatial and functional cooperativity to optimize priming
Immunity, 2017Co-Authors: Anna Brewitz, Richard A Kroczek, Sarah Eickhoff, Sabrina Dahling, Thomas Quast, Sammy Bedoui, Christian Kurts, Natalio Garbi, Winfried Barchet, Matteo IannaconeAbstract:Adaptive cellular immunity is initiated by antigen-specific interactions between T lymphocytes and dendritic cells (DCs). Plasmacytoid DCs (pDCs) support antiviral immunity by linking innate and adaptive immune responses. Here we examined pDC spatiotemporal dynamics during viral infection to uncover when, where, and how they exert their functions. We found that pDCs accumulated at sites of CD8+ T cell antigen-driven activation in a CCR5-dependent fashion. Furthermore, activated CD8+ T cells orchestrated the local recruitment of lymph node-resident XCR1 chemokine receptor-expressing DCs via secretion of the XCL1 chemokine. Functionally, this CD8+ T cell-mediated reorganization of the local DC network allowed for the interaction and cooperation of pDCs and XCR1+ DCs, thereby optimizing XCR1+ DC maturation and cross-presentation. These data support a model in which CD8+ T cells upon activation create their own optimal priming microenvironment by recruiting additional DC subsets to the site of initial antigen recognition.
-
cross presentation of cutaneous melanoma antigen by migratory XCR1 cd103 and XCR1 cd103 dendritic cells
OncoImmunology, 2015Co-Authors: Ben Wylie, Richard A Kroczek, Elke Seppanen, Kun Xiao, Rachael M Zemek, Damien Zanker, Sandro Prato, Bree Foley, Prue H Hart, Weisan ChenAbstract:The question of which dendritic cells (DCs) cross-present peripheral tumor antigens remains unanswered. We assessed the ability of multiple skin-derived and lymphoid resident DCs to perform this function in a novel orthotopic murine melanoma model where tumor establishment and expansion is within the skin. Two migratory populations defined as CD103−XCR1+ and CD103+XCR1+ efficiently cross-presented melanoma-derived antigen, with the CD103−XCR1+ DCs surprisingly dominating this process. These results are critical for understanding how antitumor CD8+ T cell immunity is coordinated to tumor antigens present within the skin.
-
cytomegalovirus expresses the chemokine homologue vxcl1 capable of attracting XCR1 cd4 dendritic cells
Journal of Virology, 2014Co-Authors: Henriette Geyer, Evelyn Hartung, Hans W Mages, Richard A Kroczek, Christoph Weise, Robert Belužic, Oliver Vugrek, Stipan Jonjic, Sebastian VoigtAbstract:Cytomegaloviruses (CMV) have developed various strategies to escape the immune system of the host. One strategy involves the expression of virus-encoded chemokines to modulate the host chemokine network. We have identified in the English isolate of rat CMV (murid herpesvirus 8 [MuHV8]) an open reading frame encoding a protein homologous to the chemokine XCL1, the only known C chemokine. Viral XCL1 (vXCL1), a glycosylated protein of 96 amino acids, can be detected 13 h postinfection in the supernatant of MuHV8-infected rat embryo fibroblasts. vXCL1 exclusively binds to CD4(-) rat dendritic cells (DC), a subset of DC that express the corresponding chemokine receptor XCR1. Like endogenous rat XCL1, vXCL1 selectively chemoattracts XCR1(+) CD4(-) DC. Since XCR1(+) DC in mice and humans have been shown to excel in antigen cross-presentation and thus in the induction of cytotoxic CD8(+) T lymphocytes, the virus has apparently hijacked this gene to subvert cytotoxic immune responses. The biology of vXCL1 offers an interesting opportunity to study the role of XCL1 and XCR1(+) DC in the cross-presentation of viral antigens.
Evelyn Hartung - One of the best experts on this subject based on the ideXlab platform.
-
structure function relationship of xcl1 used for in vivo targeting of antigen into XCR1 dendritic cells
Frontiers in Immunology, 2018Co-Authors: Arthur L Kroczek, Evelyn Hartung, Hans W Mages, Stephanie Gurka, Sebastian Voigt, Martina Becker, Nele Reeg, Christian Freund, Richard A KroczekAbstract:XCL1 is the ligand for XCR1, a chemokine receptor uniquely expressed on cross-presenting dendritic cells (DC) in mouse and man. We are interested in establishing therapeutic vaccines based on XCL1-mediated targeting of peptides or proteins into these DC. Therefore, we have functionally analyzed various XCL1 domains in highly relevant settings in vitro and in vivo. Murine XCL1 fused to ovalbumin (XCL1-OVA) was compared to an N-terminal deletion variant lacking the first seven N-terminal amino acids and to several C-terminal (deletion) variants. Binding studies with primary XCR1+ DC revealed that the N-terminal region stabilizes the binding of XCL1 to its receptor, as is known for other chemokines. Deviating from the established paradigm for chemokines, the N-terminus does not contain critical elements for inducing chemotaxis. On the contrary, this region appears to limit the chemotactic action of XCL1 at higher concentrations. A participation of the XCL1 C-terminus in receptor binding or chemotaxis could be excluded in a series of experiments. Binding studies with apoptotic and necrotic XCR1-negative cells suggested a second function for XCL1: marking of stressed cells for uptake into cross-presenting DC. In vivo studies using CD8+ T cell proliferation and cytotoxicity as readouts confirmed the critical role of the N-terminus for antigen targeting, and excluded any involvement of the C-terminus in the uptake, processing, and presentation of the fused OVA antigen. Together, these studies provide basic data on the function of the various XCL1 domains as well as relevant information on XCL1 as an antigen carrier in therapeutic vaccines.
-
induction of potent cd8 t cell cytotoxicity by specific targeting of antigen to cross presenting dendritic cells in vivo via murine or human XCR1
Journal of Immunology, 2015Co-Authors: Evelyn Hartung, Annabell Bachem, Christoph Weise, Martina Becker, Nele Reeg, Anika Jakel, Andreas Hutloff, Harald Weber, Claudia Giesecke, Volker HennAbstract:Current subunit vaccines are incapable of inducing Ag-specific CD8(+) T cell cytotoxicity needed for the defense of certain infections and for therapy of neoplastic diseases. In experimental vaccines, cytotoxic responses can be elicited by targeting of Ag into cross-presenting dendritic cells (DC), but almost all available systems use target molecules also expressed on other cells and thus lack the desired specificity. In the present work, we induced CD8(+) T cell cytotoxicity by targeting of Ag to XCR1, a chemokine receptor exclusively expressed on murine and human cross-presenting DC. Targeting of Ag with a mAb or the chemokine ligand XCL1 was highly specific, as determined with XCR1-deficient mice. When applied together with an adjuvant, both vector systems induced a potent cytotoxic response preventing the outgrowth of an inoculated aggressive tumor. By generating a transgenic mouse only expressing the human XCR1 on its cross-presenting DC, we could demonstrate that targeting of Ag using human XCL1 as vector is fully effective in vivo. The specificity and efficiency of XCR1-mediated Ag targeting to cross-presenting DC, combined with its lack of adverse effects, make this system a prime candidate for the development of therapeutic cytotoxic vaccines in humans.
-
ontogenic phenotypic and functional characterization of XCR1 dendritic cells leads to a consistent classification of intestinal dendritic cells based on the expression of XCR1 and sirpα
bioRxiv, 2014Co-Authors: Martina Becker, Annabell Bachem, Steffen Guttler, Evelyn Hartung, Hans W Mages, Volker Henn, Anika Jakel, Andreas Hutloff, Ahmed Mora, Stephanie GurkaAbstract:In the past, lack of lineage markers confounded the classification of dendritic cells (DC) in the intestine and impeded a full understanding of their location and function. We have recently shown that the chemokine receptor XCR1 is a lineage marker for cross-presenting DC in the spleen. Now we provide evidence that intestinal XCR1+ DC largely, but not fully, overlap with CD103+ CD11b- DC, the hypothesized correlate of cross-presenting DC in the intestine, and are selectively dependent in their development on the transcription factor Batf3. XCR1+ DC are located in the villi and epithelial crypts of the lamina propria of the small intestine, the T cell zones of Peyers Patches, and in the T cell zones and sinuses of the draining mesenteric lymph node. Functionally, we could demonstrate for the first time that XCR1+ / CD103+ CD11b- DC excel in the cross-presentation of orally applied antigen. Together, our data show that XCR1 is a lineage marker for cross-presenting DC also in the intestinal immune system. Further, extensive phenotypic analyses reveal that expression of the integrin SIRPα consistently demarcates the XCR1- DC population. We propose a simplified and consistent classification system for intestinal DC based on the expression of XCR1 and SIRPα.
-
cytomegalovirus expresses the chemokine homologue vxcl1 capable of attracting XCR1 cd4 dendritic cells
Journal of Virology, 2014Co-Authors: Henriette Geyer, Evelyn Hartung, Hans W Mages, Richard A Kroczek, Christoph Weise, Robert Belužic, Oliver Vugrek, Stipan Jonjic, Sebastian VoigtAbstract:Cytomegaloviruses (CMV) have developed various strategies to escape the immune system of the host. One strategy involves the expression of virus-encoded chemokines to modulate the host chemokine network. We have identified in the English isolate of rat CMV (murid herpesvirus 8 [MuHV8]) an open reading frame encoding a protein homologous to the chemokine XCL1, the only known C chemokine. Viral XCL1 (vXCL1), a glycosylated protein of 96 amino acids, can be detected 13 h postinfection in the supernatant of MuHV8-infected rat embryo fibroblasts. vXCL1 exclusively binds to CD4(-) rat dendritic cells (DC), a subset of DC that express the corresponding chemokine receptor XCR1. Like endogenous rat XCL1, vXCL1 selectively chemoattracts XCR1(+) CD4(-) DC. Since XCR1(+) DC in mice and humans have been shown to excel in antigen cross-presentation and thus in the induction of cytotoxic CD8(+) T lymphocytes, the virus has apparently hijacked this gene to subvert cytotoxic immune responses. The biology of vXCL1 offers an interesting opportunity to study the role of XCL1 and XCR1(+) DC in the cross-presentation of viral antigens.
-
expression of XCR1 characterizes the batf3 dependent lineage of dendritic cells capable of antigen cross presentation
Frontiers in Immunology, 2012Co-Authors: Annabell Bachem, Steffen Guttler, Evelyn Hartung, Ahmed Mora, Xuefei Zhou, Anika Hegemann, Maud Plantinga, Elisa Mazzini, Patrizia Stoitzner, Stephanie GurkaAbstract:Cross-presentation of antigen by dendritic cells (DCs) to CD8 C T cells is a fundamen- tally important mechanism in the defense against pathogens and tumors. Due to the lack of an appropriate lineage marker, cross-presenting DCs in the mouse are provision- ally classified as "Batf3-IRF-8-Id2-dependent DCs" or as "CD8 C DCs" in the spleen, and as "CD103 C CD11b DCs" in the periphery. We have now generated a mAb to XCR1, a chemokine receptor which is specifically expressed on CD8 C DCs and a subpopula- tion of double negative DCs in the spleen. Using this antibody, we have determined that only XCR1 C CD8 C (around 80% of CD8 C DCs) and their probable precursors, XCR1 C CD8 DCs, efficiently take up cellular material and excel in antigen cross-presentation. In lymph nodes (LNs) and peripheral tissues, XCR1 C DCs largely, but not fully, correspond to CD103 C CD11b DCs. Most importantly, we demonstrate that XCR1 C DCs in the spleen, LNs, and peripheral tissues are dependent on the growth factor Flt3 ligand and are selec- tively absent in Batf3-deficient animals. These results provide evidence that expression of XCR1 throughout the body defines the Batf3-dependent lineage of DCs with a spe- cial capacity to cross-present antigen. XCR1 thus emerges as the first surface marker characterizing a DC lineage in the mouse and potentially also in the human.
Sebastian Voigt - One of the best experts on this subject based on the ideXlab platform.
-
rat cytomegalovirus encoded γ chemokine vxcl1 is a highly adapted species specific agonist for rat XCR1 positive dendritic cells
Journal of Cell Science, 2019Co-Authors: Agnieszka Bauer, Hans W Mages, Julia Madela, Christian Berg, Viktorija Daugvilaite, Stephanie Gurka, Richard A Kroczek, Mette M Rosenkilde, Sebastian VoigtAbstract:Dendritic cells (DCs) expressing the chemokine receptor XCR1 are specialized in antigen cross-presentation to control infections with intracellular pathogens. XCR1-positive (XCR1+) DCs are attracted by XCL1, a γ-chemokine secreted by activated CD8+ T cells and natural killer cells. Rat cytomegalovirus (RCMV) is the only virus known to encode a viral XCL1 analog (vXCL1) that competes for XCR1 binding with the endogenous chemokine. Here we show that vXCL1 from two different RCMV strains, as well as endogenous rat XCL1 (rXCL1) bind to and induce chemotaxis exclusively in rat XCR1+ DCs. Whereas rXCL1 activates the XCR1 Gi signaling pathway in rats and humans, both of the vXCL1s function as species-specific agonists for rat XCR1. In addition, we demonstrate constitutive internalization of XCR1 in XCR1-transfected HEK293A cells and in splenic XCR1+ DCs. This internalization was independent of β-arrestin 1 and 2 and was enhanced after binding of vXCL1 and rXCL1; however, vXCL1 appeared to be a stronger agonist. These findings suggest a decreased surface expression of XCR1 during DC cultivation at 37°C, and subsequent impairment of chemotactic activity and XCR1+ DC function.
-
structure function relationship of xcl1 used for in vivo targeting of antigen into XCR1 dendritic cells
Frontiers in Immunology, 2018Co-Authors: Arthur L Kroczek, Evelyn Hartung, Hans W Mages, Stephanie Gurka, Sebastian Voigt, Martina Becker, Nele Reeg, Christian Freund, Richard A KroczekAbstract:XCL1 is the ligand for XCR1, a chemokine receptor uniquely expressed on cross-presenting dendritic cells (DC) in mouse and man. We are interested in establishing therapeutic vaccines based on XCL1-mediated targeting of peptides or proteins into these DC. Therefore, we have functionally analyzed various XCL1 domains in highly relevant settings in vitro and in vivo. Murine XCL1 fused to ovalbumin (XCL1-OVA) was compared to an N-terminal deletion variant lacking the first seven N-terminal amino acids and to several C-terminal (deletion) variants. Binding studies with primary XCR1+ DC revealed that the N-terminal region stabilizes the binding of XCL1 to its receptor, as is known for other chemokines. Deviating from the established paradigm for chemokines, the N-terminus does not contain critical elements for inducing chemotaxis. On the contrary, this region appears to limit the chemotactic action of XCL1 at higher concentrations. A participation of the XCL1 C-terminus in receptor binding or chemotaxis could be excluded in a series of experiments. Binding studies with apoptotic and necrotic XCR1-negative cells suggested a second function for XCL1: marking of stressed cells for uptake into cross-presenting DC. In vivo studies using CD8+ T cell proliferation and cytotoxicity as readouts confirmed the critical role of the N-terminus for antigen targeting, and excluded any involvement of the C-terminus in the uptake, processing, and presentation of the fused OVA antigen. Together, these studies provide basic data on the function of the various XCL1 domains as well as relevant information on XCL1 as an antigen carrier in therapeutic vaccines.
-
cytomegalovirus expresses the chemokine homologue vxcl1 capable of attracting XCR1 cd4 dendritic cells
Journal of Virology, 2014Co-Authors: Henriette Geyer, Evelyn Hartung, Hans W Mages, Richard A Kroczek, Christoph Weise, Robert Belužic, Oliver Vugrek, Stipan Jonjic, Sebastian VoigtAbstract:Cytomegaloviruses (CMV) have developed various strategies to escape the immune system of the host. One strategy involves the expression of virus-encoded chemokines to modulate the host chemokine network. We have identified in the English isolate of rat CMV (murid herpesvirus 8 [MuHV8]) an open reading frame encoding a protein homologous to the chemokine XCL1, the only known C chemokine. Viral XCL1 (vXCL1), a glycosylated protein of 96 amino acids, can be detected 13 h postinfection in the supernatant of MuHV8-infected rat embryo fibroblasts. vXCL1 exclusively binds to CD4(-) rat dendritic cells (DC), a subset of DC that express the corresponding chemokine receptor XCR1. Like endogenous rat XCL1, vXCL1 selectively chemoattracts XCR1(+) CD4(-) DC. Since XCR1(+) DC in mice and humans have been shown to excel in antigen cross-presentation and thus in the induction of cytotoxic CD8(+) T lymphocytes, the virus has apparently hijacked this gene to subvert cytotoxic immune responses. The biology of vXCL1 offers an interesting opportunity to study the role of XCL1 and XCR1(+) DC in the cross-presentation of viral antigens.
