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1. ObjectFinder: Open-Vocabulary Assistive System for Interactive Object Search by Blind People

Author

Liu, Ruiping, Zhang, Jiaming, Schön, Angela, Müller, Karin, Zheng, Junwei, Yang, Kailun, Gerling, Kathrin, and Stiefelhagen, Rainer

Subjects
Computer Science - Human-Computer Interaction, Computer Science - Computer Vision and Pattern Recognition
Abstract

Assistive technology can be leveraged by blind people when searching for objects in their daily lives. We created ObjectFinder, an open-vocabulary interactive object-search prototype, which combines object detection with scene description and navigation. It enables blind persons to detect and navigate to objects of their choice. Our approach used co-design for the development of the prototype. We further conducted need-finding interviews to better understand challenges in object search, followed by a study with the ObjectFinder prototype in a laboratory setting simulating a living room and an office, with eight blind users. Additionally, we compared the prototype with BeMyEyes and Lookout for object search. We found that most participants felt more independent with ObjectFinder and preferred it over the baselines when deployed on more efficient hardware, as it enhances mental mapping and allows for active target definition. Moreover, we identified factors for future directions for the development of object-search systems.

Published
2024

4. ACCSAMS: Automatic Conversion of Exam Documents to Accessible Learning Material for Blind and Visually Impaired

Author

Wilkening, David, Moured, Omar, Schwarz, Thorsten, Müller, Karin, Stiefelhagen, Rainer, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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5. ChartFormer: A Large Vision Language Model for Converting Chart Images into Tactile Accessible SVGs

Author

Moured, Omar, Alzalabny, Sara, Osman, Anas, Schwarz, Thorsten, Müller, Karin, Stiefelhagen, Rainer, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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6. Towards Establishing a Description Standard of Mathematical Function Graphs for People with Blindness

Author

Sobota, Zoé Esmeralda, Freese, Ann-Christin, Schwarz, Thorsten, Müller, Karin, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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7. STS New Methods for Creating Accessible Material in Higher Education : Introduction to the Special Thematic Session

Author

Hanousková, Michaela, Janča, Boris, Másilko, Lukáš, Müller, Karin, Ondra, Svatoslav, Pavlicek, Radek, Penaz, Petr, Petz, Andrea, Schwarz, Thorsten, Stiefelhagen, Rainer, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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8. Alt4Blind: A User Interface to Simplify Charts Alt-Text Creation

Author

Moured, Omar, Farooqui, Shahid Ali, Müller, Karin, Fadaeijouybari, Sharifeh, Schwarz, Thorsten, Javed, Mohammed, Stiefelhagen, Rainer, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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9. Testing Usability of Tools for Making PDFs Accessible: Pressing Issues and Pain Points

Author

Osthof, Linus Manuel, Schwarz, Thorsten, Müller, Karin, Hartmanis, Juris, Founding Editor, van Leeuwen, Jan, Series Editor, Hutchison, David, Editorial Board Member, Kanade, Takeo, Editorial Board Member, Kittler, Josef, Editorial Board Member, Kleinberg, Jon M., Editorial Board Member, Kobsa, Alfred, Series Editor, Mattern, Friedemann, Editorial Board Member, Mitchell, John C., Editorial Board Member, Naor, Moni, Editorial Board Member, Nierstrasz, Oscar, Series Editor, Pandu Rangan, C., Editorial Board Member, Sudan, Madhu, Series Editor, Terzopoulos, Demetri, Editorial Board Member, Tygar, Doug, Editorial Board Member, Weikum, Gerhard, Series Editor, Vardi, Moshe Y, Series Editor, Goos, Gerhard, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Miesenberger, Klaus, editor, Peňáz, Petr, editor, and Kobayashi, Makoto, editor

Published
2024
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10. Indoor Navigation Assistance for Visually Impaired People via Dynamic SLAM and Panoptic Segmentation with an RGB-D Sensor

Author

Ou, Wenyan, Zhang, Jiaming, Peng, Kunyu, Yang, Kailun, Jaworek, Gerhard, Müller, Karin, and Stiefelhagen, Rainer

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Human-Computer Interaction, Computer Science - Robotics, Electrical Engineering and Systems Science - Image and Video Processing
Abstract

Exploring an unfamiliar indoor environment and avoiding obstacles is challenging for visually impaired people. Currently, several approaches achieve the avoidance of static obstacles based on the mapping of indoor scenes. To solve the issue of distinguishing dynamic obstacles, we propose an assistive system with an RGB-D sensor to detect dynamic information of a scene. Once the system captures an image, panoptic segmentation is performed to obtain the prior dynamic object information. With sparse feature points extracted from images and the depth information, poses of the user can be estimated. After the ego-motion estimation, the dynamic object can be identified and tracked. Then, poses and speed of tracked dynamic objects can be estimated, which are passed to the users through acoustic feedback., Comment: Accepted to ICCHP 2022

Published
2022

13. Trans4Trans: Efficient Transformer for Transparent Object and Semantic Scene Segmentation in Real-World Navigation Assistance

Author

Zhang, Jiaming, Yang, Kailun, Constantinescu, Angela, Peng, Kunyu, Müller, Karin, and Stiefelhagen, Rainer

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Human-Computer Interaction, Computer Science - Robotics
Abstract

Transparent objects, such as glass walls and doors, constitute architectural obstacles hindering the mobility of people with low vision or blindness. For instance, the open space behind glass doors is inaccessible, unless it is correctly perceived and interacted with. However, traditional assistive technologies rarely cover the segmentation of these safety-critical transparent objects. In this paper, we build a wearable system with a novel dual-head Transformer for Transparency (Trans4Trans) perception model, which can segment general- and transparent objects. The two dense segmentation results are further combined with depth information in the system to help users navigate safely and assist them to negotiate transparent obstacles. We propose a lightweight Transformer Parsing Module (TPM) to perform multi-scale feature interpretation in the transformer-based decoder. Benefiting from TPM, the double decoders can perform joint learning from corresponding datasets to pursue robustness, meanwhile maintain efficiency on a portable GPU, with negligible calculation increase. The entire Trans4Trans model is constructed in a symmetrical encoder-decoder architecture, which outperforms state-of-the-art methods on the test sets of Stanford2D3D and Trans10K-v2 datasets, obtaining mIoU of 45.13% and 75.14%, respectively. Through a user study and various pre-tests conducted in indoor and outdoor scenes, the usability and reliability of our assistive system have been extensively verified. Meanwhile, the Tran4Trans model has outstanding performances on driving scene datasets. On Cityscapes, ACDC, and DADA-seg datasets corresponding to common environments, adverse weather, and traffic accident scenarios, mIoU scores of 81.5%, 76.3%, and 39.2% are obtained, demonstrating its high efficiency and robustness for real-world transportation applications., Comment: Extended version of arXiv:2107.03172

Published
2021

14. Trans4Trans: Efficient Transformer for Transparent Object Segmentation to Help Visually Impaired People Navigate in the Real World

Author

Zhang, Jiaming, Yang, Kailun, Constantinescu, Angela, Peng, Kunyu, Müller, Karin, and Stiefelhagen, Rainer

Subjects
Computer Science - Computer Vision and Pattern Recognition, Computer Science - Human-Computer Interaction, Computer Science - Robotics
Abstract

Common fully glazed facades and transparent objects present architectural barriers and impede the mobility of people with low vision or blindness, for instance, a path detected behind a glass door is inaccessible unless it is correctly perceived and reacted. However, segmenting these safety-critical objects is rarely covered by conventional assistive technologies. To tackle this issue, we construct a wearable system with a novel dual-head Transformer for Transparency (Trans4Trans) model, which is capable of segmenting general and transparent objects and performing real-time wayfinding to assist people walking alone more safely. Especially, both decoders created by our proposed Transformer Parsing Module (TPM) enable effective joint learning from different datasets. Besides, the efficient Trans4Trans model composed of symmetric transformer-based encoder and decoder, requires little computational expenses and is readily deployed on portable GPUs. Our Trans4Trans model outperforms state-of-the-art methods on the test sets of Stanford2D3D and Trans10K-v2 datasets and obtains mIoU of 45.13% and 75.14%, respectively. Through various pre-tests and a user study conducted in indoor and outdoor scenarios, the usability and reliability of our assistive system have been extensively verified., Comment: Accepted to ICCV 2021 ACVR Workshop. Code will be made publicly available at https://github.com/jamycheung/Trans4Trans

Published
2021

15. cGMP modulates hemin-mediated platelet death

Author

Rohlfing, Anne-Katrin, Kremser, Marcel, Schaale, David, Dicenta-Baunach, Valerie, Laspa, Zoi, Fu, Xiaoqing, Zizmare, Laimdota, Sigle, Manuel, Harm, Tobias, Münzer, Patrick, Pelzer, Andreas, Borst, Oliver, Trautwein, Christoph, Feil, Robert, Müller, Karin, Castor, Tatsiana, Lämmerhofer, Michael, and Gawaz, Meinrad P.

Published
2024
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22. Traveling to Unknown Buildings: Accessibility Features for Indoor Maps

Author

Constantinescu, Angela, Müller, Karin, Loitsch, Claudia, Zappe, Sebastian, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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23. Listening First: Egocentric Textual Descriptions of Indoor Spaces for People with Blindness

Author

Constantinescu, Angela, Neumann, Eva-Maria, Müller, Karin, Jaworek, Gerhard, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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24. The Accessible Tactile Indoor Maps (ATIM) Symbol Set: A Common Symbol Set for Different Printing Methods

Author

Melfi, Giuseppe, Müller, Karin, Jaworek, Gerhard, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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25. An Audio-Tactile System for Visually Impaired People to Explore Indoor Maps

Author

Melfi, Giuseppe, Baumgarten, Jean, Müller, Karin, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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26. Split it Up: Allocentric Descriptions of Indoor Maps for People with Visual Impairments

Author

Anken, Julia, Rosenthal, Danilo, Müller, Karin, Jaworek, Gerhard, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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27. Digital Solutions for Inclusive Mobility: Solutions and Accessible Maps for Indoor and Outdoor Mobility : Introduction to the Special Thematic Session

Author

Loitsch, Claudia, Müller, Karin, Weber, Gerhard, Petrie, Helen, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Kouroupetroglou, Georgios, editor, Mavrou, Katerina, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Penáz, Petr, editor

Published
2022
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33. Immune signature of patients with cardiovascular disease predicts increased risk for a severe course of COVID‐19.

Author

Günter, Manina, Mueller, Karin Anne Lydia, Salazar, Mathew J., Gekeler, Sarah, Prang, Carolin, Harm, Tobias, Gawaz, Meinrad Paul, and Autenrieth, Stella E.

Subjects
SARS-CoV-2, INNATE lymphoid cells, KILLER cells, IMMUNOLOGIC memory, CELL populations
Abstract

Severe acute respiratory syndrome coronavirus type 2 (SARS‐CoV‐2) infection can lead to life‐threatening clinical manifestations. Patients with cardiovascular disease (CVD) are at higher risk for severe courses of COVID‐19. So far, however, there are hardly any strategies for predicting the course of SARS‐CoV‐2 infection in CVD patients at hospital admission. Thus, we investigated whether this prediction is achievable by prospectively analysing the blood immunophenotype of 94 nonvaccinated participants, including uninfected and acutely SARS‐CoV‐2‐infected CVD patients and healthy donors, using a 36‐colour spectral flow cytometry panel. Unsupervised data analysis revealed little differences between healthy donors and CVD patients, whereas the distribution of the cell populations changed dramatically in SARS‐CoV‐2‐infected CVD patients. The latter had more mature NK cells, activated monocyte subsets, central memory CD4+ T cells, and plasmablasts but fewer dendritic cells, CD16+ monocytes, innate lymphoid cells, and CD8+ T‐cell subsets. Moreover, we identified an immune signature characterised by CD161+ T cells, intermediate effector CD8+ T cells, and natural killer T (NKT) cells that is predictive for CVD patients with a severe course of COVID‐19. Thus, intensified immunophenotype analyses can help identify patients at risk of severe COVID‐19 at hospital admission, improving clinical outcomes through specific treatment. [ABSTRACT FROM AUTHOR]

Published
2024
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35. Hemin-induced platelet activation is regulated via ACKR3 chemokine surface receptor - implications for passivation of vulnerable atherosclerotic plaque

Author

Laspa, Zoi, primary, Dicenta-Baunach, Valerie, additional, Schaale, David, additional, Sigle, Manuel, additional, Hochuli, Ravi, additional, Castor, Tatsiana, additional, Bayrak, Alp, additional, Harm, Tobias, additional, Mueller, Karin Anne Lydia, additional, Pillaiyar, Thanigaimalai, additional, Laufer, Stefan, additional, Rohfling, Anne-Katrin, additional, and Gawaz, Meinrad, additional

Published
2024
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37. AccessibleMaps: Addressing Gaps in Maps for People with Visual and Mobility Impairments

Author

Loitsch, Claudia, Müller, Karin, Engel, Christin, Weber, Gerhard, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Peňáz, Petr, editor

Published
2020
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38. Can We Unify Perception and Localization in Assisted Navigation? An Indoor Semantic Visual Positioning System for Visually Impaired People

Author

Chen, Haoye, Zhang, Yingzhi, Yang, Kailun, Martinez, Manuel, Müller, Karin, Stiefelhagen, Rainer, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Miesenberger, Klaus, editor, Manduchi, Roberto, editor, Covarrubias Rodriguez, Mario, editor, and Peňáz, Petr, editor

Published
2020
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44. Anti–platelet factor 4 antibodies causing VITT do not cross-react with SARS-CoV-2 spike protein

Author

Greinacher, Andreas, Selleng, Kathleen, Mayerle, Julia, Palankar, Raghavendra, Wesche, Jan, Reiche, Sven, Aebischer, Andrea, Warkentin, Theodore E., Muenchhoff, Maximilian, Hellmuth, Johannes C., Keppler, Oliver T., Duerschmied, Daniel, Lother, Achim, Rieg, Siegbert, Gawaz, Meinrad Paul, Mueller, Karin Anne Lydia, Scheer, Christian S., Napp, Matthias, Hahnenkamp, Klaus, Lucchese, Guglielmo, Vogelgesang, Antje, Flöel, Agnes, Lovreglio, Piero, Stufano, Angela, Marschalek, Rolf, and Thiele, Thomas

Published
2021
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48. Scavenger Receptor CD36 Directs Nonclassical Monocyte Patrolling Along the Endothelium During Early Atherogenesis

Author

Marcovecchio, Paola M, Thomas, Graham D, Mikulski, Zbigniew, Ehinger, Erik, Mueller, Karin AL, Blatchley, Amy, Wu, Runpei, Miller, Yury I, Nguyen, Anh Tram, Taylor, Angela M, McNamara, Coleen A, Ley, Klaus, and Hedrick, Catherine C

Subjects
Biomedical and Clinical Sciences, Cardiovascular Medicine and Haematology, Clinical Sciences, Cardiovascular, Atherosclerosis, Aetiology, 2.1 Biological and endogenous factors, Actin Cytoskeleton, Adaptor Proteins, Signal Transducing, Animals, Apolipoproteins E, CD36 Antigens, Diet, Western, Disease Models, Animal, Endothelial Cells, Endothelium, Vascular, Femoral Artery, Genetic Predisposition to Disease, Humans, Intravital Microscopy, Leukocyte Rolling, Lipoproteins, LDL, Mice, Inbred C57BL, Mice, Knockout, Monocytes, Phenotype, Signal Transduction, Time Factors, src-Family Kinases, atherosclerosis, humans, mice, monocytes, phosphorylation, Cardiorespiratory Medicine and Haematology, Cardiovascular System & Hematology, Cardiovascular medicine and haematology, Clinical sciences
Abstract

ObjectiveNonclassical monocytes (NCM) function to maintain vascular homeostasis by crawling or patrolling along the vessel wall. This subset of monocytes responds to viruses, tumor cells, and other pathogens to aid in protection of the host. In this study, we wished to determine how early atherogenesis impacts NCM patrolling in the vasculature.Approach and resultsTo study the role of NCM in early atherogenesis, we quantified the patrolling behaviors of NCM in ApoE-/- (apolipoprotein E) and C57BL/6J mice fed a Western diet. Using intravital imaging, we found that NCM from Western diet-fed mice display a 4-fold increase in patrolling activity within large peripheral blood vessels. Both human and mouse NCM preferentially engulfed OxLDL (oxidized low-density lipoprotein) in the vasculature, and we observed that OxLDL selectively induced NCM patrolling in vivo. Induction of patrolling during early atherogenesis required scavenger receptor CD36, as CD36-/- mice revealed a significant reduction in patrolling activity along the femoral vasculature. Mechanistically, we found that CD36-regulated patrolling was mediated by a SFK (src family kinase) through DAP12 (DNAX activating protein of 12KDa) adaptor protein.ConclusionsOur studies show a novel pathway for induction of NCM patrolling along the vascular wall during early atherogenesis. Mice fed a Western diet showed increased NCM patrolling activity with a concurrent increase in SFK phosphorylation. This patrolling activity was lost in the absence of either CD36 or DAP12. These data suggest that NCM function in an atheroprotective manner through sensing and responding to oxidized lipoprotein moieties via scavenger receptor engagement during early atherogenesis.

Published
2017

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