| 1. |
- Agarkova, Irina, et al.
(författare)
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Assessing efficacy and immune-stimulatory effects of tumor-derived dendritic cell reprogramming using immuno-competent 3D tumor spheroid model
- 2023
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Ingår i: Cancer Research. - 1538-7445. ; 83:7 Supplement
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Konferensbidrag (refereegranskat)abstract
- Immunotherapy has brought hope for cancer treatment, but its clinical success remains limited. Recently, overexpression of the transcription factors PU.1, IRF8 and BATF3 (PIB) was shown to induce direct reprogramming of tumor cells into antigen-presenting type 1 conventional dendritic cells (cDC1s), a rare subset of immune cells with pivotal role in anti-cancer immunity. This strategy might open avenues to enhance cancer cell recognition and elimination by the immune system. However, currently existing in-vitro and in-vivo testing platforms do not qualify to reproduce all complex cell interactions essential for the approbation of this hypothesis. Here, we report the development of the InSphero 3D InSight™ Oncology Platform for in-vitro assessment of efficacy and immune-stimulatory effects of this novel cancer immunotherapy approach. The feasibility of 3D spheroid formation for several GFP-expressing tumor cell lines was evaluated by varying seeding conditions in AKURA 96 well plate. We have measured the growth (ATP content) and GFP signal overtime and analyzed the morphology of the spheroids by IHC. With this, we have established spheroid models of T98G (glioblastoma), PK59 (pancreatic cancer), and A375 (melanoma) cell lines that are growing and viable for at least 10 days. In parallel, using 2D cultures, we have identified the optimal multiplicity of infection of a lentiviral vector encoding for PIB and mCherry to enable high transduction (mCherry+ cells), reprogramming efficiency (mCherry+CD45+HLA-DR+ cells), and cell viability, quantified by flow cytometry and IHC. Then, we have demonstrated that cDC1 reprogramming progresses in the context of 3D cancer spheroids and tumor cells acquire expression of CD45+ and HLA-DR+ cells using IHC and confocal microscopy analysis. We developed an algorithm enabling automated analysis of confocal images and quantification of cDC1 reprogramming efficiency from individual image stacks calculated as a ratio of mCherry+, CD45+ and HLA-DR+ cells versus the number of DAPI+ nuclei. Using the new algorithm we have evaluated the reprogramming efficacy of the different virus dosages in all three types of 3D tumor spheroids. Lastly, we have cocultured tumor spheroids transduced with PIB with naïve or activated HLA-matched PBMCs and evaluated cytokine secretion as a readout of immune cell activation. We observed that reprogramming induces activation of T cells and correlated it to the number of reprogrammed cells in the tumor spheroid, evaluated by the HC imaging. In summary, we developed the InSphero 3D InSight™ Oncology Platform that allowed us to demonstrate the effects of direct reprogramming of tumor cells into immunogenic dendritic cells. Combined with high-content imaging analysis, this platform offers a powerful solution for preclinical translational research.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Ferreira, Alexandra G, et al.
(författare)
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Reprogramming Cancer Cells to Antigen-presenting Cells
- 2023
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Ingår i: Bio-protocol. - 2331-8325. ; 13:22, s. 1-25
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Tidskriftsartikel (refereegranskat)abstract
- Cancer cells evade the immune system by downregulating antigen presentation. Although immune checkpoint inhibitors (ICI) and adoptive T-cell therapies revolutionized cancer treatment, their efficacy relies on the intrinsic immunogenicity of tumor cells and antigen presentation by dendritic cells. Here, we describe a protocol to directly reprogram murine and human cancer cells into tumor-antigen-presenting cells (tumor-APCs), using the type 1 conventional dendritic cell (cDC1) transcription factors PU.1, IRF8, and BATF3 delivered by a lentiviral vector. Tumor-APCs acquire a cDC1 cell-like phenotype, transcriptional and epigenetic programs, and function within nine days (Zimmermannova et al., 2023). Tumor-APCs express the hematopoietic marker CD45 and acquire the antigen presentation complexes MHC class I and II as well as co-stimulatory molecules required for antigen presentation to T cells, but do not express high levels of negative immune checkpoint regulators. Enriched tumor-APCs present antigens to Naïve CD8 + and CD4 + T cells, are targeted by activated cytotoxic T lymphocytes, and elicit anti-tumor responses in vivo. The tumor-APC reprogramming protocol described here provides a simple and robust method to revert tumor evasion mechanisms by increasing antigen presentation in cancer cells. This platform has the potential to prime antigen-specific T-cell expansion, which can be leveraged for developing new cancer vaccines, neoantigen discovery, and expansion of tumor-infiltrating lymphocytes. Key features • This protocol describes the generation of antigen-presenting cells from cancer cells by direct reprogramming using lineage-instructive transcription factors of conventional dendritic cells type I. • Verification of reprogramming efficiency by flow cytometry and functional assessment of tumor-APCs by antigen presentation assays.
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| 5. |
- Ferreira, Alexandra Gabriela, et al.
(författare)
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Restoring the immunogenicity of cancer cells with dendritic cell reprogramming
- 2021
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Ingår i: Experimental Hematology. - : Elsevier BV. - 1873-2399 .- 0301-472X. ; 100:Suppl, s. 72-72
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Konferensbidrag (refereegranskat)abstract
- An important hallmark of cancer is the ability to evade the immune system. Genetic mutations may result in the accumulation of tumor antigens, however, downregulation of antigen presentation in tumor cells results in decreased immunogenicity and immune surveillance evasion. Recently, we demonstrated that enforced expression of PU.1, IRF8 and BATF3 (PIB) imposes a conventional dendritic cell type 1 (cDC1) fate in fibroblasts by direct cell reprogramming. As such, we hypothesise that a similar combination of transcription factors can reprogram cancer cells into antigen presenting cells.Here, we show that expression of PIB factors is sufficient to induce hematopoietic and cDC1 markers in the mouse melanoma and lung cancer cell lines B16 and 3LL. We further show that reprogramming restores the expression of antigen presentation molecules (MHC-II, MHC-I and B2M) at cancer cell surface. This is accompanied by the activation of the co-stimulatory molecules CD80 and CD86. This reprogrammed tumor antigen presenting cell (tumor-APC) phenotype is specified gradually within the course of 9 days. PIB overwrites the cancer transcriptional program imposing global antigen presentation and cDC1 gene signatures. Functionally, tumor-APCs secrete inflammatory cytokines such as IL-12, IL-6, CXCL10 and type 1 interferons. After reprogramming they also acquire the capacity to uptake and process proteins as well as dead cells. Importantly, tumor-APCs directly prime antigen-specific naïve CD8+ T-cells after antigen loading. Finally, tumor-APCs are capable to show endogenous antigens to T cells and become prone to T cell mediated cell killing.Our approach combines cDC1’s antigen processing and presenting abilities with the endogenous generation of tumor antigens, and serves as a platform for the development of novel immunotherapies based on endowed antigen presentation in cancer cells.
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| 6. |
- Ferreira, Alexandra Gabriela, et al.
(författare)
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Restoring tumor immunogenicity with dendritic cell reprogramming
- 2022
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Ingår i: Cancer immunology research. - 2326-6074. ; 10:12 suppl
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Konferensbidrag (refereegranskat)abstract
- Immunotherapy is revolutionizing cancer treatment, but success is limited to a fraction of patients. Tumor immunosurveillance and immunotherapy relies on presentation of tumor-associated antigens by conventional dendritic cells type 1 (cDC1). However, tumors develop mechanisms to avoid immune recognition such as downregulation of antigen presentation and exclusion of cDC1. We have previously demonstrated that enforced expression of the transcription factors PU.1, IRF8 and BATF3 (PIB) imposes the lineage conversion of fibroblasts to cDC1 by direct cell reprogramming. Here, we hypothesize that PIB reprograms cancer cells directly into functional tumor-antigen presenting cells (tumor-APCs) with enhanced immunogenicity. First, we show that enforced expression of PIB in a wide range of murine and human cancer cells from different origins is sufficient to induce surface expression of hematopoietic and DC-lineage specific markers (CD45 and Clec9a). Moreover, reprogramming restored the expression of antigen presentation complexes (MHC-I and MHC-II) and activated the expression of the co-stimulatory molecules CD40, CD80 and CD86, required for productive T cell activation. Transcriptomic analysis using mRNA-sequencing showed that PIB imposes a global cDC1 gene signature and an antigen presentation program in tumor cells as early as day 3 of reprogramming, overriding the original cancer cell program. Furthermore, Assay for Transposase-Accessible Chromatin (ATAC) sequencing analysis revealed that PIB-mediated cDC1 reprogramming elicited rapid epigenetic remodeling followed by gradual rewiring of transcriptional program and stabilization of cDC1 identity. Functionally, tumor-APCs present endogenous antigens on MHC-I, prime naïve CD8+ T and become prone to CD8+ T cell mediated killing. Tumor-APCs secrete pro-inflammatory cytokines (IL-12) and chemoattractants (CXCL10), uptake and process exogenous antigens, phagocyte dead cells, and cross-present exogenous antigens to activate naïve T-cells. In addition, reprogrammed tumor cells harboring TP53, KRAS and PTEN mutations downregulated proliferation and showed impaired tumorigenicity in vitro and in vivo. Importantly, we show that intra-tumoral injection of reprogrammed tumor-APCs elicited tumour growth control in vivo alongside increasing infiltration of CD8+ T and NK cells in B16-OVA tumors. Finally, we showed that our approach can be employed to convert primary cancer cells derived from melanoma, lung, breast, pancreatic, urothelial, and head and neck carcinomas as well as cancer associated fibroblasts. In summary, we provide evidence for the direct reprogramming of tumor cells into immunogenic cDC1-like cells, with restored antigen presentation capacity and the ability to reinstate anti-tumor immunity. Our approach elicits the immune system against cancer and counteract major tumor evasion mechanisms including tumor heterogeneity and impaired antigen presentation, laying the foundation for developing immunotherapeutic strategies based on the cellular reprogramming of human cancer cells.
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| 7. |
- Rosa, Fábio F, et al.
(författare)
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Direct Reprogramming of Mouse Embryonic Fibroblasts to Conventional Type 1 Dendritic Cells by Enforced Expression of Transcription Factors
- 2020
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Ingår i: Bio-protocol. - 2331-8325. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- Ectopic expression of transcription factor combinations has been recently demonstrated to reprogram differentiated somatic cells towards the dendritic cell (DC) lineage without reversion to a multipotent state. DCs have the ability to induce potent and long-lasting adaptive immune responses. In particular, conventional type 1 DCs (cDC1s) excel on antigen cross-presentation, a critical step for inducing CD8+ T cell cytotoxic responses. The rarity of naturally occurring cDC1s and lack of in vitro methodologies for the generation of pure cDC1 populations strongly hinders the study of cDC1 lineage specification and function. Here, we describe a protocol for the generation of induced DCs (iDCs) by lentiviral-mediated expression of the transcription factors PU.1, IRF8 and BATF3 in mouse embryonic fibroblasts. iDCs acquire DC morphology, cDC1 phenotype and transcriptional signatures within 9 days. iDCs generated with this protocol acquire functional ability to respond to inflammatory stimuli, engulf dead cells, process and cross-present antigens to CD8+ T cells. DC reprogramming provides a simple and tractable system to generate high numbers of cDC1-like cells for high content screening, opening new avenues to better understand cDC1 specification and function. In the future, faithful induction of cDC1 fate in fibroblasts may lead to the generation of patient-specific DCs for vaccination.
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| 8. |
- Rosa, Fábio F, et al.
(författare)
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Single-cell transcriptional profiling informs efficient reprogramming of human somatic cells to cross-presenting dendritic cells
- 2022
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Ingår i: Science Immunology. - : American Association for the Advancement of Science (AAAS). - 2470-9468. ; 7:69, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Type 1 conventional dendritic cells (cDC1s) are rare immune cells critical for the induction of antigen-specific cytotoxic CD8+ T cells, although the genetic program driving human cDC1 specification remains largely unexplored. We previously identified PU.1, IRF8, and BATF3 transcription factors as sufficient to induce cDC1 fate in mouse fibroblasts, but reprogramming of human somatic cells was limited by low efficiency. Here, we investigated single-cell transcriptional dynamics during human cDC1 reprogramming. Human induced cDC1s (hiDC1s) generated from embryonic fibroblasts gradually acquired a global cDC1 transcriptional profile and expressed antigen presentation signatures, whereas other DC subsets were not induced at the single-cell level during the reprogramming process. We extracted gene modules associated with successful reprogramming and identified inflammatory signaling and the cDC1-inducing transcription factor network as key drivers of the process. Combining IFN-γ, IFN-β, and TNF-α with constitutive expression of cDC1-inducing transcription factors led to improvement of reprogramming efficiency by 190-fold. hiDC1s engulfed dead cells, secreted inflammatory cytokines, and performed antigen cross-presentation, key cDC1 functions. This approach allowed efficient hiDC1 generation from adult fibroblasts and mesenchymal stromal cells. Mechanistically, PU.1 showed dominant and independent chromatin targeting at early phases of reprogramming, recruiting IRF8 and BATF3 to shared binding sites. The cooperative binding at open enhancers and promoters led to silencing of fibroblast genes and activation of a cDC1 program. These findings provide mechanistic insights into human cDC1 specification and reprogramming and represent a platform for generating patient-tailored cDC1s, a long-sought DC subset for vaccination strategies in cancer immunotherapy.
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| 9. |
- Velasco Santiago, Marta, et al.
(författare)
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Reprogramming primary melanoma cells to dendritic cell fate enhances tumor immunogenicity
- 2022
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Konferensbidrag (refereegranskat)abstract
- Background Direct cell reprogramming is characterized by the use of defined factors to rewire the transcriptional and epigenetic network of one cell-type into one of a different lineage. We have recently identified the transcription factors PU.1, IRF8, and BAFT3 (PIB) as sufficient to induce a type 1 conventional dendritic cell (cDC1) fate in both somatic and cancer cells.1,2 cDC1 is a rare dendritic cell subset with unique ability to initiate de novo T cell responses after migrating to the tumor site. Several studies have shown that higher levels of cDC1s within the tumor microenvironment strongly correlate with good prognosis and responsiveness to immunotherapy for patients with melanoma.3 Therefore, we hypothesized that PIB factors could reprogram primary melanoma cells into functional antigen presenting cDC1s capable of presenting tumor antigens and restoring anti-tumor immunity.Methods Primary melanoma cells from eight patients were reprogrammed into cDC1-like cells through transduction with lentivirus constitutively expressing PIB. Reprogrammed cells were profiled at multiple time-points to characterize reprogramming efficiency, phenotype, and functional properties including cytokine secretion and the capacity to prime T cells.Results All eight PIB-transduced melanoma cells progressively acquired a cDC1 surface phenotype characterized by the expression of CD45 and HLA-DR, marking the acquisition of hematopoietic and antigen presentation phenotype. The cell reprogramming process was consistent across all cell lines. Induced cDC1s also expressed CD11c, the cDC1-specific markers CLEC9A and CD141 as well as the costimulatory molecules CD40, CD80 and CD86. Functionally, cDC1-like melanoma cells at day 9 secreted the human cDC1-specific cytokines IL12p70 and IL-29 upon stimulation with Poly(I:C). After pulsing with a 9mer MART-1 peptide restricted to HLA-A2, cDC1-like melanoma cells were able to prime allogeneic HLA-A2 matched naïve CD8+ T cells and resulted in expansion of MART-1-specific T-cells after an eight-day co-culture with IL-2 and IL-7. Moreover, autologous tumor-infiltrating lymphocytes (TILs) were more reactive (higher expression of CD107a, CD137, IFN-gamma, and TNF-alpha) and cytotoxic towards cDC1-like melanoma cells compared to the original tumor cells.Conclusions Here, we demonstrated that melanoma cells from multiple patients can be efficiently reprogrammed into cDC1-like cells and present tumor-associated antigens. These results lay the groundwork for the development of cDC1 reprogramming as an innovative cancer immunotherapy to counteract immune escape and reactivating anti-tumor immunity.
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| 10. |
- Zimmermannova, Olga, et al.
(författare)
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Cell Fate Reprogramming in the Era of Cancer Immunotherapy
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 12
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Forskningsöversikt (refereegranskat)abstract
- Advances in understanding how cancer cells interact with the immune system allowed the development of immunotherapeutic strategies, harnessing patients’ immune system to fight cancer. Dendritic cell-based vaccines are being explored to reactivate anti-tumor adaptive immunity. Immune checkpoint inhibitors and chimeric antigen receptor T-cells (CAR T) were however the main approaches that catapulted the therapeutic success of immunotherapy. Despite their success across a broad range of human cancers, many challenges remain for basic understanding and clinical progress as only a minority of patients benefit from immunotherapy. In addition, cellular immunotherapies face important limitations imposed by the availability and quality of immune cells isolated from donors. Cell fate reprogramming is offering interesting alternatives to meet these challenges. Induced pluripotent stem cell (iPSC) technology not only enables studying immune cell specification but also serves as a platform for the differentiation of a myriad of clinically useful immune cells including T-cells, NK cells, or monocytes at scale. Moreover, the utilization of iPSCs allows introduction of genetic modifications and generation of T/NK cells with enhanced anti-tumor properties. Immune cells, such as macrophages and dendritic cells, can also be generated by direct cellular reprogramming employing lineage-specific master regulators bypassing the pluripotent stage. Thus, the cellular reprogramming toolbox is now providing the means to address the potential of patient-tailored immune cell types for cancer immunotherapy. In parallel, development of viral vectors for gene delivery has opened the door for in vivo reprogramming in regenerative medicine, an elegant strategy circumventing the current limitations of in vitro cell manipulation. An analogous paradigm has been recently developed in cancer immunotherapy by the generation of CAR T-cells in vivo. These new ideas on endogenous reprogramming, cross-fertilized from the fields of regenerative medicine and gene therapy, are opening exciting avenues for direct modulation of immune or tumor cells in situ, widening our strategies to remove cancer immunotherapy roadblocks. Here, we review current strategies for cancer immunotherapy, summarize technologies for generation of immune cells by cell fate reprogramming as well as highlight the future potential of inducing these unique cell identities in vivo, providing new and exciting tools for the fast-paced field of cancer immunotherapy.
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