| | Concentrating on AAV Impurities With Ultrasensitive Total Protein Detection on Simple Western | [概要表示] |
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Purity is a critical quality attribute (CQA) that must be monitored during AAV manufacturing. Impurities in protein products can be dangerous and impact efficacy. For example, protein impurities in final drug products may lead to undesirable immune responses in patients, so detecting total protein is critical for revealing impurities in preparative protein production. Traditional methods for total protein detection rely on SDS-PAGE with dyes like Coomassie Blue, or more sensitive stains like SYPRO Ruby and silver stain. However, SDS-PAGE requires large sample volumes, a lot of hands-on time, and it is poorly reproducible. Also, the use of staining dyes often comes with a lot of waste and can require specialized imaging equipment to which not every researcher has access.
Here, we present a new workflow that enables total protein detection of AAVs on the Simple Western capillary electrophoresis-based immunoassay platform with a sensitivity that exceeds SYPRO Ruby. While SYPRO Ruby requires at least 1 ng of protein for reliable detection, Simple Western can reliably detect as little as 150 pg. These findings should enable researchers who are currently using SDS-PAGE to monitor purity to apply the automated platform and sensitivity improvements enabled by this workflow to assess AAV purity using smaller AAV sample sizes. |
| | Precision Cut Cancer Tissue slices as human model for the testing of immune-modulatory compounds | [概要表示] |
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The goal of personalized medicine is to stratify individual patients to the appropriate treatment. This approach depends on extensive characterization of individual tumors and their sensitivity to therapeutics. In the context of the immunotherapy of cancer, information on the localization, abundance and activation of immune cells within individual tumors gained in importance. Here we present a preclinical drug testing model to monitor individual drug responses of patients to targeted immunotherapy with the checkpoint inhibitor Nivolumab (anti- PD-1) and subsequent applications. In this study, we were able to determine different populations of infiltrating immune cells within viable tumors from colorectal cancer patients using our drug testing platform and a variety of subsequent applications.
Analysis of immune cells was conducted on disaggregated cells from viable tumor slices. Disaggregation of precision cut cancer tissue slices was performed using the GentleMACS from Miltenyi. Immune cell subsets were analyzed by flow cytometric multiplexing of CD3, CD4, CD8 and CD45. Furthermore, we identified PD-1 positive cells among the CD45+/CD3+ lymphocyte population, indicating relevance for anti-PD-1 targeted therapy in colorectal cancer. Presence and localization of immune cells (CD45+) was confirmed by immunohistochemistry of tumor tissue slices. In addition, protein expression of CD8 and PD-1 was analyzed by Simple Western Size analyses. Cytokine secretion affected by Nivolumab treatment was analyzed in supernatants of tissue cultures using the proinflammatory panel from Meso Scale Discovery. The results demonstrated that immune cell compositions were stable and uniform within our precision cut cancer tissue slices both pre- and post-cultivation, and pre- and post-treatment with Nivolumab. |
| | Analysis of minute amounts of clinical biospecimen for the AXL receptor expression using real-time PCR and Simple Western Size technology. | [概要表示] |
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AXL, a tyrosine kinase receptor, is expressed in a variety of cancers and has been revealed as the most highly expressed gene in preclinical models with acquired resistance, and second most common alteration in EGFR (epidermal growth factor receptor) inhibitor-resistant tumors, behind the T790M mutation. It has become obvious that targeted therapy of patients has to be monitored by taking and analyzing biopsies on a regular basis. Therefore, laboratory methods have to be adapted. |
| | Predicting response to Mcl-1 targeting agents in Non-Small Cell Lung Cancer (NSCLC) and Multiple Myeloma (MM) cell lines. | [概要表示] |
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Mcl-1 is an anti-apoptotic member of the Bcl-2 family of proteins and is frequently amplified or over-expressed in both solid tumors and hematological malignancies, suggesting that its activity may be important for the survival of cancer cells. CDK9 inhibition results in the down regulation of Mcl-1 mRNA and subsequent protein levels by inhibiting transcription and represents an indirect approach to targeting Mcl-1. Mcl-1 can also be targeted directly using an inhibitor that disrupts the Mcl-1 complexes to induce apoptosis. |
| | Toxic events of beta-amyloid oligomers on cortical neurons and protective effect of beta-Estradiol: A mechanistic study (Neuro-Sys, SfN 2014) | [概要表示] |
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Alzheimer disease (AD) affects mainly people over the age of 65 years, suffering from different clinical symptoms such as progressive decline in memory, thinking, language, and learning capacity. The toxic role of beta amyloid peptide (Ab) has now shifted from insoluble Ab fibrils to smaller, soluble oligomeric Ab aggregates (AβO). Many evidences suggest that the neurodegenerative process would be due to the interaction of AβO with binding targets, activation of stress kinases, hyperphosphorylation of tau protein, caspase activation, loss of synapse, neuronal death, loss of cholinergic function, generation of reactive intermediates of oxygen (oxidative stress), or glutamate excitotoxicity. Urgent need for efficient new therapies is high, but could only be successful with an extensively comprehension of AβO degeneration process. In the present work, based on an in vitro primary cell culture treated with AβO preparation, we have carefully studied the cytopathological effects of AβO on neuronal death and then we have investigated the effect of 17-beta Estradiol (β-estr) on the degeneration process induced by AβO. Briefly we used rat cortical neurons (from E15). The cells were seeded in 96-well plates and intoxicated with AβO solution after 11 days of culture for 24 hours. β-estr was used at 100 nM (final concentration) and was added as pretreatment (1h before injuries). A co-incubation with selective inhibitors was performed for the mechanistic study. In parallel, western blotting (WB) analysis was done to quantify protein levels and their activation. We showed that β-estr was able to significantly protect neurons as well as glial cells from degeneration decreasing the caspase 3 activation and the massive mitochondrial stress (induced by AβO). Preservation of neurite network and synapsis integrity was also observed. Moreover, the large hyperphosphorylation of tau protein induced by AβO was significantly reduced with β-Estr. A mechanistic study was also performed co-incubating inhibitors of main survival pathways to try to better understand the mode of action of β-estr and the pathway involved in the AβO toxicity. We showed that the effects of -Estr were fully abolished blocking the MEK pathway as well as the DNA repair pathway (PARP-g) or the mitochondrial anti-apoptotic pathway (Bcl2). Interestingly the effect was inexisting coincubating β-estr with TrK receptor or Ras/Raf inhibitors showing the predominant role of growth factors paythway in its neuroprotective effect. Finally, we showed a large inactivation of AKT protein in presence of AβO that was reversed even over activated in presence of β-Estr. |
| | Eliminating Western Blot Variability for High Molecular Proteins with Sally Sue (HUPO 2014) | |
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