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- Ascic, Ervin, et al.
(författare)
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Eliciting Anti-Tumor Immunity by Reprogramming Cancer Cells to Type 1 Conventional Dendritic Cells
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- IntroductionAn important hallmark of cancer is escaping the immune system. Despite advances in immunotherapy, only a subset of patients experiences clinical benefits. It was shown that adoptive T cell or checkpoint inhibition therapy rely on the presence of conventional dendritic cells type 1 (cDC1). cDC1 excel in recruiting and priming protective CD8+ T cells through cross-presentation. However, in tumors cDC1 are often impaired in function. Recently, we demonstrated that overexpression of PU.1, IRF8 and BATF3 (PIB) imposes a cDC1 fate in fibroblasts by direct cell reprogramming. As such, we hypothesise that a similar combination of transcription factors would reprogram cancer cells into tumor-antigen presenting cells (tumor-APCs) and set in motion antigen-specific immunity.Material and Methods30 mouse tumor lines were selected to evaluate reprogramming into tumor-APCs. Reprogramming was induced by overexpression of PIB via lentiviral transduction. The phenotype was profiled by flow cytometry for cDC1 markers CD45, MHC-II, CLEC9A, XCR1 and APC markers MHC-I, CD80/86. Population mRNA-seq was applied to assess transcriptional changes. To assess cDC1 functions, cytokine secretion, cross-presentation and T cell cytotoxicity assays were performed. In vivo, ovalbumin expressing tumors were established and treated by adoptive transfer of tumor-APCs. Tumor growth and animal survival were monitored.Results and DiscussionsUpon transduction with PIB, 26 solid tumor and 4 leukemia lines initiated expression of CD45, MHC-II, at efficiencies ranging from 0.5-57.7%. Reprogramming was accompanied by CLEC9A, XCR1 and MHC-I, CD80/86 upregulation. Transcriptomic analysis of low immunogenic lines B16 and LLC, reveals that PIB overwrites the cancer transcriptome and imposes antigen presentation and cDC1 gene signatures. Importantly, tumor-APCs present endogenous antigens on MHC-I and become prone to T cell mediated killing. Functionally, reprogrammed tumor-APCs secrete inflammatory cytokines such as IL12p70 and strikingly, acquire the ability to crosspresent antigens and prime naïve CD8+ T cells. In vivo, adoptive transfer of cross-presenting tumor-APCs delays tumor growth and extends survival of animals.ConclusionThis approach combines cDC1 antigen presentation abilities with endogenous generation of tumor antigens. The induction of a cDC1 identity in tumor cells sets in motion T cell responses and makes them target for T cell mediated killing. Our study represents a pioneering contribution merging cell reprogramming with immunotherapy.
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| 2. |
- Ascic, Ervin, et al.
(författare)
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Harnessing Dendritic Cell Reprogramming to Elucidate Mechanisms of Tumor Immunity
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The presence of conventional dendritic cells type 1 (cDC1) in the tumor correlates with positive treatment outcome. The ability to cross-present neoantigens and prime protective CD8+ T-cell responses, makes cDC1s central for tumor immunity. However, in tumors cDC1 are rare and often functionally impaired. Our group reported that overexpression of the transcription factors PU.1, IRF8 and BATF3 (PIB) converts mouse and human fibroblasts into cross-presenting cDC1-like cells. We employed the minimal gene regulatory network of highly immunogenic cDC1 and restored the immunogenicity of low immunogenic lung cancer and melanoma cell lines by reprogramming into professional tumor antigen presenting cells (tumor-APCs). Here, we report that upon transduction with PIB, 23 solid syngeneic cancer lines initiate reprogramming into cDC1-like cells expressing CD45 and MHC-II at efficiencies ranging from 0.5-57.7%. Functionally, PIB overexpression endows tumor cells with the capacity to cross-present exogenous antigen and prime naïve CD8+ T-cells. Adoptive transfer of ovalbumin cross-presenting B16 tumor-APCs into established ovalbumin expressing B16 tumors (B16-OVA) elicits tumor growth control and extends animal survival. Treated animals show a systemic antigen-specific T cell response against ovalbumin and endogenous tumor-associated antigen MuLV p15E. Intratumoral injection of reprogrammed B2905 and LLC into tumors shows differential response, correlating with their cross-presentation capacity. This approach combines cDC1 antigen cross-presentation abilities with the generation of tumor antigens. The induction of a cDC1 identity in tumor cells sets in motion T cell responses in vitro and in vivo. In the future of this project, dendritic cell reprogramming will be object in a 2-cell CRISPR/Cas9 screen using induced cDC1-like tumor cells and reporter T-cells to explore mechanistically cross-presentation regulators. The generation of cross-presenting tumor-APCs will be also used to map and characterize presented and cross-presented neoantigens. Finally, dendritic cell reprogramming of tumor cells will be explored in vivo by replenishing cDC1 within the tumor microenvironment through in vivo reprogramming. Ultimately, this project will provide insight into mechanisms of cross-presentation and pave the way for the development of novel cDC1-centric therapies.
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| 3. |
- Fernandes, Isabel, et al.
(författare)
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Salt Stress Tolerance in Casuarina glauca : Insights from the Branchlets Transcriptome
- 2022
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Ingår i: PLANTS. - : MDPI AG. - 2223-7747. ; 11:21
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Tidskriftsartikel (refereegranskat)abstract
- Climate change and the accelerated rate of population growth are imposing a progressive degradation of natural ecosystems worldwide. In this context, the use of pioneer trees represents a powerful approach to reverse the situation. Among others, N2-fixing actinorhizal trees constitute important elements of plant communities and have been successfully used in land reclamation at a global scale. In this study, we have analyzed the transcriptome of the photosynthetic organs of Casuarina glauca (branchlets) to unravel the molecular mechanisms underlying salt stress tolerance. For that, C. glauca plants supplied either with chemical nitrogen (KNO3+) or nodulated by Frankia (NOD+) were exposed to a gradient of salt concentrations (200, 400, and 600 mM NaCl) and RNA-Seq was performed. An average of ca. 25 million clean reads was obtained for each group of plants, corresponding to 86,202 unigenes. The patterns of differentially expressed genes (DEGs) clearly separate two groups: (i) control- and 200 mM NaCl-treated plants, and (ii) 400 and 600 mM NaCl-treated plants. Additionally, although the number of total transcripts was relatively high in both plant groups, the percentage of significant DEGs was very low, ranging from 6 (200 mM NaCl/NOD+) to 314 (600 mM NaCl/KNO3+), mostly involving down-regulation. The vast majority of up-regulated genes was related to regulatory processes, reinforcing the hypothesis that some ecotypes of C. glauca have a strong stress-responsive system with an extensive set of constitutive defense mechanisms, complemented by a tight mechanism of transcriptional and post-transcriptional regulation. The results suggest that the robustness of the stress response system in C. glauca is regulated by a limited number of genes that tightly regulate detoxification and protein/enzyme stability, highlighting the complexity of the molecular interactions leading to salinity tolerance in this species.
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