No abstract

Chinese hamster ovary (CHO) cells are the number one production system for therapeutic proteins. A pre-requirement for their use in industrial production of biopharmaceuticals is to be clonal, thus originating from a single cell in order to be phenotypically and genomically identical. In the present study it was evaluated whether standard procedures, such as the generation of a recombinant cell line in combination with selection for a specific and stable phenotype (expression of the recombinant product) or subcloning have any impact on karyotype stability or homogeneity in CHO cells. Analyses used were the distribution of chromosome counts per cell as well as chromosome painting to identify specific karyotype patterns within a population. Results indicate that subclones both of the host and the recombinant cell line are of comparable heterogeneity and (in)stability as the original pool. In contrast, the rigorous selection for a stably expressing phenotype generated cell lines with fewer variation and more stable karyotypes, both at the level of the sorted pool and derivative subclones. We conclude that the process of subcloning itself does not contribute to an improved karyotypic homogeneity of a population, while the selection for a specific cell property inherently can provide evolutionary pressure that may lead to improved chromosomal stability as well as to a more homogenous population.

No abstract

Multicolor image analysis finds its applications in a broad range of biological studies. Specifically, multiplex fluorescence in situ hybridization (M‐FISH) for chromosome painting facilitates the analysis of individual chromosomes in complex metaphase spreads and is widely used to detect both numerical and structural aberrations. While this is well established for human and mouse karyotypes, for which species sophisticated software and analysis tools are available, other organisms and species are less well served. Commercially available software is proprietary and not easily adaptable to other karyotypes. Therefore, a publically available open source software that combines flexibility and customizable functionalities is needed. Here we present such a tool called “ChromaWizard” which is based on popular scientific image analysis libraries (OpenCV, scikit‐image, and NumPy). We demonstrate its functionality on the example of primary Chinese hamster (Cricetulus griseus) fibroblasts metaphase spreads and on Chinese Hamster Ovary cell lines known for the large number of chromosomal rearrangements. The application can be easily adapted to any kind of available labeling kits and is https://dict.leo.org/englisch-deutsch/independent of the used organism and instrumentation. It allows direct inspection of the original hybridization signals and enables either manual or automatic assignment of colors, making it a functional and versatile tool that can be used also for other multicolor applications.

3052 Background: Prognosis of ovarian cancer remains poor after initial responsiveness to surgery and chemotherapy followed by high recurrence and mortality rates and new experimental approaches are warranted. Our goal was to evaluate a novel DC-based vaccine, which exploits a unique dual loading strategy to amplify specific anti-tumor short- and long-term immune responses to delay or even prevent recurrent and metastatic disease. Methods: Monocytes were collected via apheresis, matured into DCs and pulsed with two universal tumor associated antigens (uTAA) in our GMP facility. DCs were loaded with TERT and Survivin via two different pathways (mRNA and peptide) to elicit CD8+ and CD4+T cells directly. Endpoints of the study were tolerability and safety, immunological and clinical responses. T cell responses against the IMP and loaded antigens were evaluated by cytokine bead array (CBA) and intracellular staining assays. Results: 15 non HLA-restricted patients with advanced ovarian cancer were enrolled 8 weeks after standard treatment (surgery and chemotherapy). Each patient was vaccinated intradermally on a weekly or fortnightly basis with a maximum of 8 doses of 13*106 double loaded DCs. The majority of treatment related side effects were grade 1 fever and erythema. Overall the therapy was well tolerated. Immune response data is available for 14/15 patients, 1 was withdrawn after the first administration. The IMP leads to strong immune responses with high frequency (>90%), which is proven for both uTAAs in CD8+ as well as CD4+ T cells. A clear positive trend in progression free survival is demonstrated compared to matched historical control. Conclusions: Therapy with our unique double loaded DC vaccine was feasible, safe and well-tolerated by patients. The vaccine was highly immune stimulatory and elicited both, long-term and short-term anti-tumor immune responses, establishing a promising platform for immune therapy for ovarian cancer and all solid tumors in general. The first two authors contributed equally. Clinical trial information: NCT01456065.