Biology subjects

Brautigam, L.

Publications and source records attributed to Brautigam, L..

4 recordsLinked to original sources

bioRxiv2024

Advancing Adoptive Cell Therapy: Optimized Expansion of Adaptive NK Cells for Solid Tumors

BackgroundImmune therapies are emerging as a critical component of cancer treatment, capable of delivering durable and potentially curative responses. While CAR-T cell therapy has proven effective for hematological malignancies, it faces challenges in treating solid tumors due to tumor antigen heterogeneity, an immunosuppressive tumor microenvironment, and physical barriers hindering CAR-T cell infiltration. NK cells, particularly adaptive NK (aNK) cells, offer a promising alternative due to their ability to recognize and kill tumor cells without prior sensitization and their resistance to immunosuppressive environments. PurposeThe study investigates the role of cytokines, specifically IL-21 and IL-15, in enhancing aNK cell expansion and activation using peripheral blood mononuclear cells (PBMCs) from healthy donors and tumor-infiltrating lymphocytes (TILs) from glioblastoma (GBM) patients. MethodsBuffy coats and GBM TILs were collected from Karolinska Hospital. NK cells were isolated and expanded in vitro with IL-15 and IL-21 cytokines and feeder cells (K562 and K562E). Furthermore, tumor lysate was added in the cultures to boost memory responses in aNK cells. NK cell functionality, cytotoxicity, and phenotyping was assessed using flow cytometry and statistical analysis (t-test and two-way ANOVA) used to validate the results. Further animal model was used to validate the cytotoxicity capacities of these cells against GBM tumors using a zebrafish model. ResultsIL-21 drives the expansion of aNK better than IL-15 controls, data shown in PBMCs and TILs derived from GBM patients and IPLA OVCA patients. Additionally, the use of tumor lysate as a booster for restimulation further amplifies the cytotoxic capacity of aNK cells against autologous tumors. The zebrafish model validates this method, by decreasing the tumor size in zebrafish animals after 3 days of injection. ConclusionThe results demonstrate that IL-21 is essential for the specific expansion of aNK cells, enhancing their aggressiveness towards tumor cells. Additionally, tumor lysate significantly increases the cytotoxic efficacy of aNK cells upon restimulation with the same tumor cells. These findings suggest that IL-21 plays a crucial role in the specific expansion and activation of aNK cells, enhancing their aggressiveness towards tumor cells. By optimizing the expansion protocol, this method aims to advance the clinical application of aNK cells in immunotherapies for solid tumors, offering a potential solution to the limitations faced by current CAR-T therapies.

immunology↗

bioRxiv2024

Development of an orthotopic medulloblastoma zebrafish model for rapid drug testing.

Medulloblastoma (MB) is one of the most common malignant brain tumors in children. Current preclinical in vivo model systems for MB have increased our understanding of molecular mechanisms regulating MB development; however, they may not be suitable for high-throughput screening efforts. We demonstrate here that transplantation of seven different MB cell lines or patient-derived cells into the blastula stage of zebrafish embryos leads to orthotopic tumor cell growth that can be observed within 24 hours after transplantation. Importantly, the homing of transplanted cells to the hindbrain region and the aggressiveness of tumor growth are enhanced by pre-culturing cells in a neural stem cell-like medium. The change in culture conditions rewires the transcriptome towards a more migratory and neuronal progenitor phenotype, including the expression of guidance molecules SEMA3A and EFNB1, both of which correlate with lower overall survival in MB patients. Furthermore, we highlight that the orthotopic zebrafish MB xenograft model has the potential to be used for high-throughput drug screening. Key pointsO_LIMedulloblastoma cells home to the hindbrain region in developing zebrafish embryos. C_LIO_LINeural stem cell culture conditions improve the homing capacity of MB tumor cells. C_LIO_LIMedulloblastoma-transplanted zebrafish embryos can be used as a high-throughput in vivo model for drug screening. C_LI Importance of the StudyOne of the challenges of accurately modeling medulloblastoma is the large heterogeneity in tumor characteristics. To accurately model this heterogeneous disease, patient-derived xenograft mouse models are currently the standard. However, such mouse models are labor intensive, time-consuming, and not suitable for high-throughput studies. Here, we describe a quick and straightforward zebrafish xenograft model that provides a promising alternative to these existing mouse models. We demonstrate that this model can be utilized to study tumor cell growth of several major medulloblastoma subgroups. More importantly, our model facilitates high-throughput drug testing, providing a scalable opportunity for in vivo drug screenings that will support the discovery of novel therapeutic compounds against medulloblastoma.

cancer biology↗

bioRxiv2023

The anti-leprosy drug clofazimine reduces polyQ toxicity through activation of PPARγ

PolyQ diseases are autosomal dominant neurodegenerative disorders caused by the expansion of CAG repeats. While of slow progression, these diseases are ultimately fatal and lack effective therapies. Here, we present our results from a High-Throughput chemical screen oriented to find drugs that lower the toxicity of a protein containing the first exon from the Huntingtons disease protein huntingtin (HTT) harboring 94 glutamines (Htt-Q94). Our screening identified the anti-leprosy drug clofazimine as a hit, which was subsequently validated in several in vitro models as well as in a zebrafish model of polyQ toxicity. Computational analyses of transcriptional signatures, together with molecular modeling and biochemical assays revealed that clofazimine is an agonist of the peroxisome proliferator activated receptor gamma (PPAR{gamma}), previously suggested as a potential therapy for HD by stimulating mitochondrial biogenesis. Accordingly, clofazimine rescued the mitochondrial dysfunction triggered by Htt-Q94 expression. Together, our results support the potential of clofazimine repurposing for the treatment of PolyQ diseases.

neuroscience↗

bioRxiv2019

MTH1 promotes mitotic progression to avoid oxidative DNA damage in cancer cells

BACKGROUNDWe developed MTH1 inhibitors (MTH1i) TH588 and TH1579 showing broad anti-cancer activity, while structurally distinct MTH1i fail to kill cancer cells. Here, we describe a new role of MTH1 in mitosis and the detailed mechanism of action of TH1579 (karonudib) and other structurally distinct MTH1i.\n\nMATERIALS AND METHODSCancer cell lines or zebrafish embryos were treated with MTH1i or siRNA targeting MTH1 and analysed primarily by live cell and immunofluorescence microscopy, survival assays, DNA fibre or COMET assays. MTH1 and tubulin interactions were analysed in vitro using co-immunoprecipitation and tubulin polymerisation assays.\n\nRESULTSHere, we describe a mitotic role for the MTH1 protein, which binds to tubulin, is required for microtubule polymerisation, correct spindle assembly, mitosis progression and suppression reactive oxygen species (ROS) generation in mitosis. Potent MTH1i display differential abilities to break the MTH1-tubulin interaction and cause mitotic arrest, demonstrating 8-oxodGTPase and mitotic function of MTH1 are mechanistically distinct. TH588 and TH1579 have more profound effect on mitotic arrest than other MTH1i explained by additional direct inhibition of tubulin polymerisation. MTH1i only inhibiting 8-oxodGTPase activity synergize with mitotic poisons.\n\nCONCLUSIONSEfficient MTH1 have a dual mechanism of action: inhibiting mitosis (to generate ROS) and promoting 8-oxodGTP incorporation into DNA during mitotic replication, dependent on ROS generation. Direct inhibition of tubulin polymerisation of TH588 and TH1579 increase their ability to arrest cells and generate ROS in mitosis. Furthermore, non-cytotoxic MTH1 can become effective and increase incorporation of oxidised nucleotides into DNA when combined with sub-therapeutic concentrations of mitotic inhibitors or challenged directly by 8-oxodGTP.

cancer biology↗