| 11. |
- Edin, Sofia, et al.
(author)
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Macrophages : Good guys in colorectal cancer
- 2013
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In: Oncoimmunology. - : Informa UK Limited. - 2162-4011 .- 2162-402X. ; 2:2, s. e23038-
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Journal article (peer-reviewed)abstract
- Macrophages play a complex role in tumor progression since they can exert both tumor-preventing (M1 macrophages) and tumor-promoting (M2 macrophages) activities. In colorectal carcinoma (CRC), at odds to many other cancers, macrophage infiltration has been correlated with an improved patient survival. In a recent study, we have evaluated the distribution of M1 and M2 macrophage subtypes in CRC and their impact on patient prognosis.
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| 12. |
- Eissler, Nina, et al.
(author)
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Regulation of myeloid cells by activated T cells determines the efficacy of PD-1 blockade
- 2016
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In: Oncoimmunology. - : Taylor & Francis. - 2162-4011 .- 2162-402X. ; 5:12
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Journal article (peer-reviewed)abstract
- Removal of immuno-suppression has been reported to enhance antitumor immunity primed by checkpoint inhibitors. Although PD-1 blockade failed to control tumor growth in a transgenic murine neuroblastoma model, concurrent inhibition of colony stimulating factor 1 receptor (CSF-1R) by BLZ945 reprogrammed suppressive myeloid cells and significantly enhanced therapeutic effects. Microarray analysis of tumor tissues identified a significant increase of T-cell infiltration guided by myeloid cell-derived chemokines CXCL9, 10, and 11. Blocking the responsible chemokine receptor CXCR3 hampered T-cell infiltration and reduced antitumor efficacy of the combination therapy. Multivariate analysis of 59 immune-cell parameters in tumors and spleens detected the correlation between PD-L1-expressing myeloid cells and tumor burden. In vitro, anti-PD-1 antibody Nivolumab in combination with BLZ945 increased the activation of primary human T and NK cells. Importantly, we revealed a previously uncharacterized pathway, in which T cells secreted M-CSF upon PD-1 blockade, leading to enhanced suppressive capacity of monocytes by upregulation of PD-L1 and purinergic enzymes. In multiple datasets of neuroblastoma patients, gene expression of CD73 correlated strongly with myeloid cell markers CD163 and CSF-1R in neuroblastoma tumors, and associated with worse survival in high-risk patients. Altogether, our data reveal the dual role of activated T cells on myeloid cell functions and provide a rationale for the combination therapy of anti-PD-1 antibody with CSF-1R inhibitor.
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| 13. |
- Ellmark, Peter, et al.
(author)
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Kick-starting the cancer-immunity cycle by targeting CD40
- 2015
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In: Oncoimmunology. - 2162-4011 .- 2162-402X. ; 4:7
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Journal article (other academic/artistic)abstract
- Stimulation of CD40 on dendritic cells to expand and activate tumor-specific T cells and generate anticancer immunity is an attractive therapeutic approach. Since CD40 agonists exert their effects upstream of checkpoint inhibitors, including PD-1 or PD-L1 antagonists, they are ideal candidates for combination regimens.
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| 14. |
- Fotaki, Grammatiki, et al.
(author)
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Cancer vaccine based on a combination of an infection-enhanced adenoviral vector and pro-inflammatory allogeneic DCs leads to sustained antigen-specific immune responses in three melanoma models
- 2018
-
In: Oncoimmunology. - 2162-4011 .- 2162-402X. ; 7:3
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Journal article (peer-reviewed)abstract
- Autologous patient-derived dendritic cells (DCs) modified ex vivo to present tumor-associated antigens (TAAs) are frequently used as cancer vaccines. However, apart from the stringent logistics in producing DCs on a patient basis, accumulating evidence indicate that ex vivo engineered DCs are poor in migration and in fact do not directly present TAA epitopes to naïve T cells in vivo. Instead, it is proposed that bystander host DCs take up material from vaccine-DCs, migrate and subsequently initiate antitumor T-cell responses. We used mouse models to examine the possibility of using pro-inflammatory allogeneic DCs (alloDCs) to activate host DCs and enable them to promote antigen-specific T-cell immunity. We found that alloDCs were able to initiate host DC activation and migration to draining lymph node leading to T-cell activation. The pro-inflammatory milieu created by alloDCs also led to recruitment of NK cells and neutrophils at the site of injection. Vaccination with alloDCs combined with Ad5M(gp100), an infection-enhanced adenovirus encoding the human melanoma-associated antigen gp100 resulted in generation of CD8+ T cells with a T-cell receptor (TCR) specific for the gp10025-33 epitope (gp100-TCR+). Ad5M(gp100)-alloDC vaccination in combination with transfer of gp100-specific pmel-1 T cells resulted in prolonged survival of B16-F10 melanoma-bearing mice and altered the composition of the tumor microenvironment (TME). We hereby propose that alloDCs together with TAA- or neoepitope-encoding Ad5M can become an “off-the-shelf” cancer vaccine, which can reverse the TME-induced immunosuppression and induce host cellular anti-tumor immune responses in patients without the need of a time-consuming preparation step of autologous DCs.
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| 15. |
- Fotaki, Grammatiki, et al.
(author)
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Pro-inflammatory allogeneic DCs promote activation of bystander immune cells and thereby license antigen-specific T-cell responses
- 2018
-
In: Oncoimmunology. - 2162-4011 .- 2162-402X. ; 7:3
-
Journal article (peer-reviewed)abstract
- Accumulating evidence support an important role for endogenous bystander dendritic cells (DCs) in the efficiency of autologous patient-derived DC-vaccines, as bystander DCs take up material from vaccine-DCs, migrate to draining lymph node and initiate antitumor T-cell responses. We examined the possibility of using allogeneic DCs as vaccine-DCs to activate bystander immune cells and promote antigen-specific T-cell responses. We demonstrate that human DCs matured with polyI:C, R848 and IFN-γ (denoted COMBIG) in combination with an infection-enhanced adenovirus vector (denoted Ad5M) exhibit a pro-inflammatory state. COMBIG/Ad5M-matured allogeneic DCs (alloDCs) efficiently activated T-cells and NK-cells in allogeneic co-culture experiments. The secretion of immunostimulatory factors during the co-culture promoted the maturation of bystander-DCs, which efficiently cross-presented a model-antigen to activate antigen-specific CD8+ T-cells in vitro. We propose that alloDCs, in combination with Ad5M as loading vehicle, may be a cost-effective and logistically simplified DC vaccination strategy to induce anti-tumor immune responses in cancer patients.
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| 16. |
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| 17. |
- Georganaki, Maria, et al.
(author)
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Tumor endothelial cell up-regulation of IDO1 is an immunosuppressive feed-back mechanism that reduces the response to CD40-stimulating immunotherapy
- 2020
-
In: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 9:1
-
Journal article (peer-reviewed)abstract
- CD40-stimulating immunotherapy can elicit potent anti-tumor responses by activating dendritic cells and enhancing T-cell priming. Tumor vessels orchestrate T-cell recruitment during immune response, but the effect of CD40-stimulating immunotherapy on tumor endothelial cells has not been evaluated. Here, we have investigated how tumor endothelial cells transcriptionally respond to CD40-stimulating immunotherapy by isolating tumor endothelial cells from agonistic CD40 mAb- or isotype-treated mice bearing B16-F10 melanoma, and performing RNA-sequencing. Gene set enrichment analysis revealed that agonistic CD40 mAb therapy increased interferon (IFN)-related responses in tumor endothelial cells, including up-regulation of the immunosuppressive enzyme Indoleamine 2, 3-Dioxygenase 1 (IDO1). IDO1 was predominantly expressed in endothelial cells within the tumor microenvironment, and its expression in tumor endothelium was positively correlated to T-cell infiltration and to increased intratumoral expression of IFN gamma. In vitro, endothelial cells up-regulated IDO1 in response to T-cell-derived IFN gamma, but not in response to CD40-stimulation. Combining agonistic CD40 mAb therapy with the IDO1 inhibitor epacadostat delayed tumor growth in B16-F10 melanoma, associated with increased activation of tumor-infiltrating T-cells. Hereby, we show that the tumor endothelial cells up-regulate IDO1 upon CD40-stimulating immunotherapy in response to increased IFN gamma-secretion by T-cells, revealing a novel immunosuppressive feedback mechanism whereby tumor vessels limit T-cell activation.
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| 18. |
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| 19. |
- Jin, Chuan, 1986-, et al.
(author)
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Intratumoral administration of pro-inflammatory allogeneic dendritic cells improved the anti-turnor response of systemic anti-CTLA-4 treatment via unleashing a T cell-dependent response
- 2022
-
In: Oncoimmunology. - : Informa UK Limited. - 2162-4011 .- 2162-402X. ; 11:1
-
Journal article (peer-reviewed)abstract
- Immune checkpoint inhibitors (ICIs) have revolutionized the oncology field. However, a significant number of patients do not respond, at least partly due to the lack of preexisting anti-tumor T-cell immunity. Therefore, it is emergent to add an immune-priming step to improve efficacy. Here, we report a combined approach consisting of intratumoral administration of pro-inflammatory allogeneic dendritic cells (AlloDCs) and systemic treatment with alpha CTLA-4 that can drastically improve the anti-tumor efficacy compared to alpha CTLA-4 monotherapy. When evaluated in mice with large established CT-26 tumors, monotherapy with alpha CTLA-4 neither delayed tumor progression nor improved mice survival. However, combination treatment of AlloDCs and alpha CTLA-4 drastically improved the effectiveness, with 70% of mice being cured. This effect was T cell-dependent, and all survived mice rejected a subsequent tumor re-challenge. Further investigation revealed an immune-inflamed tumor microenvironment (TME) in the combination treatment group characterized by enhanced infiltration of activated antigen-presenting endogenous DCs and CD8(+) T cells with a tissue-resident memory (T-RM) phenotype (CD49a(+)CD103(+)). This correlated with elevated levels of tumor-specific CD39(+)CD103(+)CD8(+) T cells in the tumor and "tumor-matching" NKG2D(+)CD39(+)CX3CR1(+)CD8(+) T cells in peripheral blood. Moreover, splenocytes from mice in the combination treatment group secreted significantly higher IFN-gamma upon stimulation with the peptide from the endogenous CT-26 retroviral gp70 (model neoantigen), confirming the induction of a tumor-specific CD8(+) T-cell response. Taken together, these data indicate a strong anti-tumor synergy between AlloDCs and alpha CTLA-4 that warrant further clinical investigation with the corresponding human AlloDC product (ilixadencel) for patients receiving alpha CTLA-4 therapy.
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| 20. |
- Kaffes, Ioannis, et al.
(author)
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Human Mesenchymal glioblastomas are characterized by an increased immune cell presence compared to Proneural and Classical tumors
- 2019
-
In: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 8:11
-
Journal article (peer-reviewed)abstract
- Glioblastoma (GBM) is the most aggressive malignant primary brain tumor in adults, with a median survival of 14.6 months. Recent efforts have focused on identifying clinically relevant subgroups to improve our understanding of pathogenetic mechanisms and patient stratification. Concurrently, the role of immune cells in the tumor microenvironment has received increasing attention, especially T cells and tumor-associated macrophages (TAM). The latter are a mixed population of activated brain-resident microglia and infiltrating monocytes/monocyte-derived macrophages, both of which express ionized calcium-binding adapter molecule 1 (IBA1). This study investigated differences in immune cell subpopulations among distinct transcriptional subtypes of GBM. Human GBM samples were molecularly characterized and assigned to Proneural, Mesenchymal or Classical subtypes as defined by NanoString nCounter Technology. Subsequently, we performed and analyzed automated immunohistochemical stainings for TAM as well as specific T cell populations. The Mesenchymal subtype of GBM showed the highest presence of TAM, CD8(+), CD3(+) and FOXP3(+) T cells, as compared to Proneural and Classical subtypes. High expression levels of the TAM-related gene AIF1, which encodes the TAM-specific protein IBA1, correlated with a worse prognosis in Proneural GBM, but conferred a survival benefit in Mesenchymal tumors. We used our data to construct a mathematical model that could reliably identify Mesenchymal GBM with high sensitivity using a combination of the aforementioned cell-specific IHC markers. In conclusion, we demonstrated that molecularly distinct GBM subtypes are characterized by profound differences in the composition of their immune microenvironment, which could potentially help to identify tumors amenable to immunotherapy.
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