| 1. |
- Albrekt, Ann-Sofie, et al.
(författare)
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Skin sensitizers differentially regulate signaling pathways in MUTZ-3 cells in relation to their individual potency
- 2014
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Ingår i: Bmc Pharmacology & Toxicology. - : Springer Science and Business Media LLC. - 1471-2210 .- 2050-6511. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Due to the recent European legislations posing a ban of animal tests for safety assessment within the cosmetic industry, development of in vitro alternatives for assessment of skin sensitization is highly prioritized. To date, proposed in vitro assays are mainly based on single biomarkers, which so far have not been able to classify and stratify chemicals into subgroups, related to risk or potency. Methods: Recently, we presented the Genomic Allergen Rapid Detection (GARD) assay for assessment of chemical sensitizers. In this paper, we show how the genome wide readout of GARD can be expanded and used to identify differentially regulated pathways relating to individual chemical sensitizers. In this study, we investigated the mechanisms of action of a range of skin sensitizers through pathway identification, pathway classification and transcription factor analysis and related this to the reactive mechanisms and potency of the sensitizing agents. Results: By transcriptional profiling of chemically stimulated MUTZ-3 cells, 33 canonical pathways intimately involved in sensitization to chemical substances were identified. The results showed that metabolic processes, cell cycling and oxidative stress responses are the key events activated during skin sensitization, and that these functions are engaged differently depending on the reactivity mechanisms of the sensitizing agent. Furthermore, the results indicate that the chemical reactivity groups seem to gradually engage more pathways and more molecules in each pathway with increasing sensitizing potency of the chemical used for stimulation. Also, a switch in gene regulation from up to down regulation, with increasing potency, was seen both in genes involved in metabolic functions and cell cycling. These observed pathway patterns were clearly reflected in the regulatory elements identified to drive these processes, where 33 regulatory elements have been proposed for further analysis. Conclusions: This study demonstrates that functional analysis of biomarkers identified from our genomics study of human MUTZ-3 cells can be used to assess sensitizing potency of chemicals in vitro, by the identification of key cellular events, such as metabolic and cell cycling pathways.
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| 2. |
- Lindberg, Tim, et al.
(författare)
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An integrated transcriptomic- and proteomic-based approach to evaluate the human skin sensitization potential of glyphosate and its commercial agrochemical formulations
- 2020
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 217
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the skin sensitization hazard of glyphosate, the surfactant polyethylated tallow amine (POEA) and two commercial glyphosate-containing formulations using different omics-technologies based on a human dendritic cell (DC)-like cell line. First, the GARD™skin assay, investigating changes in the expression of 200 transcripts upon cell exposure to xenobiotics, was used for skin sensitization prediction. POEA and the formulations were classified as skin sensitizers while glyphosate alone was classified as a non-sensitizer. Interestingly, the mixture of POEA together with glyphosate displayed a similar sensitizing prediction as POEA alone, indicating that glyphosate likely does not increase the sensitizing capacity when associated with POEA. Moreover, mass spectrometry analysis identified differentially regulated protein groups and predicted molecular pathways based on a proteomic approach in response to cell exposures with glyphosate, POEA and the glyphosate-containing formulations. Based on the protein expression data, predicted pathways were linked to immunologically relevant events and regulated proteins further to cholesterol biosynthesis and homeostasis as well as to autophagy, identifying novel aspects of DC responses after exposure to xenobiotics. In summary, we here present an integrative analysis involving advanced technologies to elucidate the molecular mechanisms behind DC activation in the skin sensitization process triggered by the investigated agrochemical materials. Significance: The use of glyphosate has increased worldwide, and much effort has been made to improve risk assessments and to further elucidate the mechanisms behind any potential human health hazard of this chemical and its agrochemical formulations. In this context, omics-based techniques can provide a multiparametric approach, including several biomarkers, to expand the mechanistic knowledge of xenobiotics-induced toxicity. Based on this, we performed the integration of GARD™skin and proteomic data to elucidate the skin sensitization hazard of POEA, glyphosate and its two commercial mixtures, and to investigate cellular responses more in detail on protein level. The proteomic data indicate the regulation of immune response-related pathways and proteins associated with cholesterol biosynthesis and homeostasis as well as to autophagy, identifying novel aspects of DC responses after exposure to xenobiotics. Therefore, our data show the applicability of a multiparametric integrated approach for the mechanism-based hazard evaluation of xenobiotics, eventually complementing decision making in the holistic risk assessment of chemicals regarding their allergenic potential in humans.
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| 3. |
- Lindstedt, Malin
(författare)
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Human Dendritic Cells and the Regulation of Allergic Immune Responses
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dendritic cells (DC) are a heterogeneous lineage of bone-marrow-derived leukocytes that serve as the link between innate and adaptive immunity. They are professional antigen-presenting cells that play an important protective and regulatory role in both health and disease. This thesis is based upon six original papers that deal with the function and transcription of human DCs, with focus on their role in the inflammatory immune responses, such as allergic rhinitis. Transcriptional profiling of DCs with microarrays has been an extensively utilized technique in the projects presented in this thesis. We have evaluated the gene expression profiles and functions of two in vitro models of human DCs, namely the monocyte-derived DCs and the differentiated cell line MUTZ-3, and the transcriptional regulation induced in these models by pro-inflammatory signals. We have also studied the effect of allergenic stimulation on the transcription and function of DCs derived from healthy and allergic individuals. Two allergens were used, the detergent enzyme lipase and grass pollen, to evaluate the direct effect on phenotype and gene expression of DCs in addition to the subsequent ability of allergen-challenged DCs to amplify and modify the autologous effector T cell response. We demonstrate that the transcriptional responses of DCs and effector T cells to allergenic stimulation are different between allergic and healthy individuals. These transcriptional profiles involved in the immune recognition of allergens will be further evaluated in order to understand the interplay between DCs and T cells in allergic rhinitis. Furthermore, in addition to the in vitro models studied, we have performed phenotypical and transcriptional characterizations of in vivo DCs isolated from peripheral blood and tonsillar tissue. We suggest that follicular DCs in tonsils may have previously unacknowledged costimulatory functions in the germinal center reaction, as they express CD137. An extensive transcriptional profiling of freshly sorted DC subsets from blood and tonsils identified DC-subset selective gene expression and pinpoint their relationships. We demonstrate innate specialization of these subsets and show that the environment in tonsils determines the transcriptional activity of myeloid DCs. In conclusion, these studies have provided insight in the transcription and phenotype of in vivo immature/mature DC populations as well as in the immune response induced by allergens or inflammatory signals.
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| 4. |
- Lundberg, Kristina, et al.
(författare)
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Allergen-Specific Immunotherapy Alters the Frequency, as well as the FcR and CLR Expression Profiles of Human Dendritic Cell Subsets.
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:2
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Tidskriftsartikel (refereegranskat)abstract
- Allergen-specific immunotherapy (AIT) induces tolerance and shifts the Th2 response towards a regulatory T-cell profile. The underlying mechanisms are not fully understood, but dendritic cells (DC) play a vital role as key regulators of T-cell responses. DCs interact with allergens via Fc receptors (FcRs) and via certain C-type lectin receptors (CLRs), including CD209/DC-SIGN, CD206/MR and Dectin-2/CLEC6A. In this study, the effect of AIT on the frequencies as well as the FcR and CLR expression profiles of human DC subsets was assessed. PBMC was isolated from peripheral blood from seven allergic donors before and after 8 weeks and 1 year of subcutaneous AIT, as well as from six non-allergic individuals. Cells were stained with antibodies against DC subset-specific markers and a panel of FcRs and CLRs and analyzed by flow cytometry. After 1 year of AIT, the frequency of CD123+ DCs was increased and a larger proportion expressed FcεRI. Furthermore, the expression of CD206 and Dectin-2 was reduced on CD141+ DCs after 1 year of treatment and CD206 as well as Dectin-1 was additionally down regulated in CD1c+ DCs. Interestingly, levels of DNGR1/CLEC9A on CD141+ DCs were increased by AIT, reaching levels similar to cells isolated from non-allergic controls. The modifications in phenotype and occurrence of specific DC subsets observed during AIT suggest an altered capacity of DC subsets to interact with allergens, which can be part of the mechanisms by which AIT induces allergen tolerance.
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| 5. |
- Schiött, Åsa, et al.
(författare)
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CD27- CD4+ memory T cells define a differentiated memory population at both the functional and transcriptional levels
- 2004
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 113:3, s. 363-370
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Tidskriftsartikel (refereegranskat)abstract
- The memory T-cell population is a heterogeneous population, including both effector cells, which exert a direct secondary immune response, and resting or intermediate cells, which serve as a reservoir and exert a possible regulatory role. To further dissect the T-cell memory population residing in the CD4 +CD45RO+ T-cell pool, we studied the functional properties of memory populations identified by the CD27 marker. This marker clearly divides the memory population into two groups. One group consists of effector cells lacking CD27 and displaying a high antigen recall response. The other group consists of an intermediate memory population, displaying CD27. This latter group lacks an antigen recall response and requires costimulation for T-cell receptor triggering. To evaluate the function of the CD27+ memory pool, we analysed the transcriptional profile, using high-density microarray technology. These gene data strongly support the different functional profiles of CD27+ and CD27+ memory populations, in terms of protein expression and the capacity to respond to antigen.
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| 6. |
- Ascic, Ervin, et al.
(författare)
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In vivo dendritic cell reprogramming for cancer immunotherapy
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Ingår i: Science (New York, N.Y.). - 1095-9203.
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Tidskriftsartikel (refereegranskat)abstract
- Immunotherapy can lead to long-term survival for some cancer patients, yet generalized success has been hampered by insufficient antigen presentation and exclusion of immunogenic cells from the tumor microenvironment. Here, we developed an approach to reprogram tumor cells in vivo by adenoviral delivery of the transcription factors PU.1, IRF8, and BATF3, which enabled them to present antigens as type 1 conventional dendritic cells. Reprogrammed tumor cells remodeled their tumor microenvironment, recruited, and expanded polyclonal cytotoxic T cells, induced tumor regressions, and established long-term systemic immunity in multiple mouse melanoma models. In human tumor spheroids and xenografts, reprogramming to immunogenic dendritic-like cells progressed independently of immunosuppression, which usually limits immunotherapy. Our study paves the way for human clinical trials of in vivo immune cell reprogramming for cancer immunotherapy.
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| 7. |
- Weltzien, Hans Ulrich, et al.
(författare)
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Safe cosmetics without animal testing? Contributions of the EU Project Sens-it-iv
- 2009
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Ingår i: Journal für Verbraucherschütz und Lebensmittelsicherheit. - : Springer Science and Business Media LLC. - 1661-5867 .- 1661-5751. ; 4:suppl. 2, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- The 7th Ammendment to the Cosmetics Directive of the European Commission (Directive 76/768/EEC2) bans the marketing of cosmetics containing animal-tested ingredients since March 2009. Excepted are only tests for repeated dose toxicity, for which the animal ban will come into effect by 2013. One major concern for cosmetics, i.e. the risk of containing skin (contact) sensitizers, has in the past been addressed almost exclusively by animal testing. It is this problem attracting the central interest of the integrated research project Sens-it-iv (Novel Testing Strategies for in vitro Assessment of Allergens, http://www.sens-it-iv.eu ), funded by the EC within framework 6 since October 2005. Here, the 28 Sens-it-iv partners from 10 European States present the 5 most promising types of in vitro assays selected for further refinement. These are: (1) a human epidermal equivalent (EE) model to rank contact allergens according to their sensitizing potency, (2) identification of contact sensitizers, including pro-haptens, through intracellular production of IL-18 by the human keratinocyte cell line NCTC 2544, (3) determination of activation markers such as CD86, CD54 and most prominently CXCL8 (IL-8) on/in dendritic cell lines, (4) contact sensitizer-specific migration of MUTZ Langerhans cells towards the chemokine CXCL12, and (5) the allergen-specific activation and proliferation of na < ve human T cells. Ongoing genomic and proteomic experiments are in the process of identifying larger sensitizer-specific biological marker signatures to be integrated into the above assays. We hope to supply the European control agencies with a basis for further validation of in vitro assays by the end of 2010.
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| 8. |
- Andersson, Hampus, et al.
(författare)
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Early Pharmacodynamic Changes Measured Using RNA Sequencing of Peripheral Blood from Patients in a Phase I Study with Mitazalimab, a Potent CD40 Agonistic Monoclonal Antibody
- 2023
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Ingår i: Cells. - 2073-4409. ; 12:19
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Tidskriftsartikel (refereegranskat)abstract
- CD40-targeting therapies can enhance the dendritic cell priming of tumor-specific T cells and repolarize intratumoral macrophages to alleviate the tumoral immunosuppressive environment and remodel the extracellular matrix. Mitazalimab is a potent agonistic CD40 monoclonal IgG1 antibody currently under clinical development. This study used RNA sequencing of blood samples from a subset of patients from a Phase I trial with mitazalimab (NCT02829099) to assess peripheral pharmacodynamic activity. We found that mitazalimab induced transient peripheral transcriptomic alterations (at 600 µg/kg and 900 µg/kg dose administered intravenously), which mainly were attributed to immune activation. In particular, the transcriptomic alterations showed a reduction in effector cells (e.g., CD8+ T cells and natural killer cells) and B cells peripherally with the remaining cells (e.g., dendritic cells, monocytes, B cells, and natural killer cells) showing transcription profiles consistent with activation. Lastly, distinct patient subgroups based on the pattern of transcriptomic alterations could be identified. In summary, the data presented herein reinforce the anticipated mode of action of mitazalimab and support its ongoing clinical development.
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| 9. |
- Andersson, Hampus, et al.
(författare)
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Next-generation CD40 agonists for cancer immunotherapy
- 2024
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Ingår i: Expert Opinion on Biological Therapy. - : TAYLOR & FRANCIS LTD. - 1471-2598 .- 1744-7682. ; 24:5, s. 351-363
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Forskningsöversikt (refereegranskat)abstract
- Introduction: There is a need for new therapies that can enhance response rates and broaden the number of cancer indications where immunotherapies provide clinical benefit. CD40 targeting therapies provide an opportunity to meet this need by promoting priming of tumor-specific T cells and reverting the suppressive tumor microenvironment. This is supported by emerging clinical evidence demonstrating the benefits of immunotherapy with CD40 antibodies in combination with standard of care chemotherapy. Areas covered: This review is focused on the coming wave of next-generation CD40 agonists aiming to improve efficacy and safety, using new approaches and formats beyond monospecific antibodies. Further, the current understanding of the role of different CD40 expressing immune cell populations in the tumor microenvironment is reviewed. Expert opinion: There are multiple promising next-generation approaches beyond monospecific antibodies targeting CD40 in immuno-oncology. Enhancing efficacy is the most important driver for this development, and approaches that maximize the ability of CD40 to both remodel the tumor microenvironment and boost the anti-tumor T cell response provide great opportunities to benefit cancer patients. Enhanced understanding of the role of different CD40 expressing immune cells in the tumor microenvironment may facilitate more efficient clinical development of these compounds.
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| 10. |
- Askmyr, David, et al.
(författare)
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Pattern recognition receptor expression and maturation profile of dendritic cell subtypes in human tonsils and lymph nodes
- 2021
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Ingår i: Human Immunology. - : Elsevier BV. - 0198-8859. ; 82:12, s. 976-981
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic cells (DCs) with capacity of antigen cross-presentation are of key interest for immunotherapy against cancer as they can induce antigen-specific cytotoxic T lymphocyte (CTL) responses. This study describes frequencies of DC subtypes in human tonsils and lymph nodes, and phenotypic aspects that may be targeted by adjuvant measures. From human tonsils and neck lymph nodes, DCs were identified through flow cytometry, and subsets of plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) were investigated. Maturity status was assessed and surface receptors with CTL-promoting potentials were studied. CD123+ pDCs as well as CD1c+, CD141+, and CD1c-CD141- mDCs were detected in tonsils and lymph nodes. Both sites featured a similar presence of DC subsets, with CD123+ pDC being dominant and CD141+ mDCs least frequent. Based on CD80/CD86 expression, all DC subtypes featured a low degree of maturation. Expression of pattern recognition receptors (PRRs) CD206, CD207, DC-SIGN, TLR2, and TLR4, as well as the chemokine receptor XCR1, indicated DC subset-specific receptor profiles. We conclude that tonsils and lymph nodes share common features in terms of DC subset frequency and maturation as well as PRR and XCR1 expression pattern. Our work suggests that both sites may be considered for vaccine deposition in DC-mediated immunotherapy.
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