% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Hazin:126676, author = {J. Hazin$^*$ and G. Moldenhauer$^*$ and P. Altevogt$^*$ and N. R. Brady$^*$}, title = {{A} novel method for measuring cellular antibody uptake using imaging flow cytometry reveals distinct uptake rates for two different monoclonal antibodies targeting {L}1.}, journal = {Journal of immunological methods}, volume = {423}, issn = {0022-1759}, address = {Amsterdam [u.a.]}, publisher = {Elsevier Science}, reportid = {DKFZ-2017-02704}, pages = {70 - 77}, year = {2015}, abstract = {Monoclonal antibodies (mAbs) have emerged as a promising tool for cancer therapy. Differing approaches utilize mAbs to either deliver a drug to the tumor cells or to modulate the host's immune system to mediate tumor kill. The rate by which a therapeutic antibody is being internalized by tumor cells is a decisive feature for choosing the appropriate treatment strategy. We herein present a novel method to effectively quantitate antibody uptake of tumor cells by using image-based flow cytometry, which combines image analysis with high throughput of sample numbers and sample size. The use of this method is established by determining uptake rate of an anti-EpCAM antibody (HEA125), from single cell measurements of plasma membrane versus internalized antibody, in conjunction with inhibitors of endocytosis. The method is then applied to two mAbs (L1-9.3, L1-OV52.24) targeting the neural cell adhesion molecule L1 (L1CAM) at two different epitopes. Based on median cell population responses, we find that mAb L1-OV52.24 is rapidly internalized by the ovarian carcinoma cell line SKOV3ip while L1 mAb 9.3 is mainly retained at the cell surface. These findings suggest the L1 mAb OV52.24 as a candidate to be further developed for drug-delivery to cancer cells, while L1-9.3 may be optimized to tag the tumor cells and stimulate immunogenic cancer cell killing. Furthermore, when analyzing cell-to-cell variability, we observed L1 mAb OV52.24 rapidly transition into a subpopulation with high-internalization capacity. In summary, this novel high-content method for measuring antibody internalization rate provides a high level of accuracy and sensitivity for cell population measurements and reveals further biologically relevant information when taking into account cellular heterogeneity.}, keywords = {Antibodies, Monoclonal (NLM Chemicals) / Antigens, Neoplasm (NLM Chemicals) / CADM1 protein, human (NLM Chemicals) / Cell Adhesion Molecules (NLM Chemicals) / EPCAM protein, human (NLM Chemicals) / Epithelial Cell Adhesion Molecule (NLM Chemicals) / Immunoglobulins (NLM Chemicals)}, cin = {D015 / B170}, ddc = {610}, cid = {I:(DE-He78)D015-20160331 / I:(DE-He78)B170-20160331}, pnm = {312 - Functional and structural genomics (POF3-312)}, pid = {G:(DE-HGF)POF3-312}, typ = {PUB:(DE-HGF)16}, pubmed = {pmid:25967950}, doi = {10.1016/j.jim.2015.04.024}, url = {https://inrepo02.dkfz.de/record/126676}, }