Giese, MadleenTuriello, NadineMolenda, NicolePalesch, DavidMeid, AnnikaSchroeder, RomanBasilico, PaolaBenarafa, CharafHalatsch, Marc-EricZimecki, MichalWesthoff, Mike-AndrewRainer Wirtz, ChristianBurster, Timo2018-08-202018-08-202016-10-28Madleen Giese, Nadine Turiello, Nicole Molenda, David Palesch, Annika Meid, Roman Schroeder, Paola Basilico, Charaf Benarafa, Marc-Eric Halatsch, Michal Zimecki, Mike-Andrew Westhoff, Christian Rainer Wirtz and Timo Burste. 2016. Exogenous cathepsin G upregulates cell surface MHC class I molecules on immune and glioblastoma cells. Oncotarget.http://nur.nu.edu.kz/handle/123456789/3387Major histocompatibility complex (MHC) class I molecules present antigenic peptides to cytotoxic T cells. During an adaptive immune response, MHC molecules are regulated by several mechanisms including lipopolysaccharide (LPS) and interferon gamma (IFN-g). However, it is unclear whether the serine protease cathepsin G (CatG), which is generally secreted by neutrophils at the site of inflammation, might regulate MHC I molecules. We identified CatG, and to a higher extend CatG and lactoferrin (LF), as an exogenous regulator of cell surface MHC I expression of immune cells and glioblastoma stem cells. In addition, levels of MHC I molecules are reduced on dendritic cells from CatG deficient mice compared to their wild type counterparts. Furthermore, cell surface CatG on immune cells, including T cells, B cells, and NK cells triggers MHC I on THP-1 monocytes suggesting a novel mechanism for CatG to facilitate intercellular communication between infiltrating cells and the respective target cell. Subsequently, our findings highlight the pivotal role of CatG as a checkpoint protease which might force target cells to display their intracellular MHC I:antigen repertoireenAttribution-NonCommercial-ShareAlike 3.0 United Statescathepsin GMHC class Iglioblastoma stem cellslactoferrinCatG deficient miceImmunology and Microbiology SectionImmune responseImmunityArticle