Neklasické MHC-II pozitívne typy buniek, funkcia a imunologický kontext

Major histocompatibility complex class II (MHC-II) is a group of glycoproteins responsible for the presentation of exogenous antigens to T-lymphocytes. Besides the "classical" antigen presenting cells (APCs), numerous cell types were proven to be able to express MHC-II molecules either constitutively or under specific conditions. Often, the stimulus for MHC-II expression is interferon g, a pro- inflammatory cytokine typically activating promoter IV of the Class II Transactivator. Many of the non- classical MHC-II-expressing cells can serve as APCs, activating or attenuating T-cell proliferation depending on the expression of costimulatory molecules. Additional research identified some unusual functions of MHC-II molecules on non-classical cell types, including a role in prenatal development or mating. Modulation of the MHC-II expression could potentially serve many promising therapeutic purposes and new research can lead to deeper understanding of the topic. Keywords: MHC-II, ILC, basophils, TEC, antigen presentation, CIITA, IFN-gammaHlavný histokompatibilný komplex II. triedy (MHC-II) je skupinou glykoproteínov zodpovedných za prezentáciu exogénnych antigénov T-lymfocytom. Okrem "klasických" antigén prezentujúcich buniek (APC) bolo potvrdených viacero typov buniek schopných exprimovať molekuly MHC-II buď konštitutívne, alebo za špecifických okolností. Častým stimulom expresie MHC-II je interferón g, cytokín podporujúci zápal, typicky aktivujúci promótor IV transaktivátora II. triedy. Mnoho neklasických buniek exprimujúcich MHC-II môže fungovať ako APC, teda aktivovať alebo tlmiť proliferáciu T-lymfocytov, pričom záleží na expresii kostimulačných molekúl. Ďalší výskum identifikoval aj neobvyklé funkcie MHC-II molekúl na neklasických typoch buniek, vrátane úlohy v prenatálnom vývoji či párení. Ovplyvnenie expresie MHC-II by mohlo potenciálne slúžiť mnohým sľubným terapeutickým účelom a nový výskum môže viesť k hlbšiemu porozumeniu danej témy. Kľúčové slová: MHC-II, ILC, bazofily, TEC, prezentácia antigénu, CIITA, IFN-gammaDepartment of Cell BiologyKatedra buněčné biologiePřírodovědecká fakultaFaculty of Scienc

MHC II-EGFP knock-in myší model jako vhodný nástroj pro kvantitativní střevní imunologii za běžných podmínek a podmínek bez bakterií

Bezmikróbne organizmy sú používané k štúdiu vplyvov mikrobioty po niekoľko desaťročí. Počas tohto času bolo hlásených mnoho odlišností od tzv. specific-pathogen-free (SPF) zvierat (neobsahujúcich špecifické patogény), vrátane absolútnych počtov alebo percent rôznych imunitných populácií, obrovsky zväčšeného céka takmer žiadnych germinálnych centier. Avšak mnoho kľúčových informácií o štruktúrnych a funkčných rozdieloch v ich druhotných lymfatických orgánoch je stale neobjavených. Pomocou nových mikroskopických prístupov, ako light sheet fluorescenčná mikroskopia, umožňujúca 3D vizualizáciu celých vzoriek bez nutnosti ich spracovávania na sériu rezových preparátov, a mnohofarebnou cytometriou, umožňujúca vysoko kvantitatívnu charakterizáciu množstva bunkových populácii za niekoľko sekúnd, odkrytie podstatných rozdielov vyzerá byť konečne na dosah. MHC II-EGFP knock-in myší model prináša výhodu fluorescenčného proteínu exprimovaného vo fyziologických historických kontextoch do oboch obstastí. Lymfatické a iné tkanivá môžu byť vizualizované mikroskopicky bez nutnosti farbenia (aj in vivo). Informácia o expresí MHC II na plazmatickej membráne i intracelulárne z rôznych tkanív môže byť okamžite získaná. Kombináciou MHC II-EGFP knock-in myšieho modelu s gnotobiologickým prístupom sa stáva vizualizácia...Germ-free animals have been used to study the effects of microbiota for several decades. In that time, numbers of differences from specific-pathogen-free (SPF) animals have been reported, including differences in absolute numbers or percentages of various immune populations, enormously enlarged coecum and lack of germinal centers. However, many of the crucial information about structural and functional differences in their secondary lymphoid organs still remains uncovered. With novel microscopical approaches, such as light sheet fluorescent microscopy, enabling 3D visualization of whole samples without processing them to a series of slides, and multicolor cytometry, allowing the characterization of numbers of cellular populations within a matter of seconds and in a highly quantitative manner, the uncovering of fundamental differences finally seems to be within reach. MHC II-EGFP knock-in mouse model brings the advantages of a fluorescent protein expressed in physiological histological contexts into both fields. Lymphoid and other tissues can be visualized microscopically without the need of staining (even in vivo). Information about the expression of both plasma membrane-localized and intracellular MHC II in various tissues could be acquired directly. Combining MHC II-EGFP knock-in mouse model with...Department of Cell BiologyKatedra buněčné biologiePřírodovědecká fakultaFaculty of Scienc

MHC II-EGFP Knock-in Mouse Model

The MHC II–EGFP knock-in mouse model enables us to visualize and track MHC-II-expressing cells in vivo by expressing enhanced green fluorescent protein (EGFP) fused to the MHC class II molecule under the MHC II beta chain promoter. Using this model, we can easily identify MHC-II-expressing cells, including dendritic cells, B cells, macrophages, and ILC3s, which play a key role as antigen-presenting cells (APCs) for CD4+ T cells. In addition, we can also precisely identify and analyze APC-containing tissues and organs. Even after fixation, EGFP retains its fluorescence, so this model is suitable for immunofluorescence studies, facilitating an unbiased characterization of the histological context, especially with techniques such as light-sheet fluorescence microscopy. Furthermore, the MHC II–EGFP knock-in mouse model is valuable for studying the molecular mechanisms of MHC II gene regulation and expression by making it possible to correlate MHC II expression (MHC II–EGFP) with surface fraction through antibody detection, thereby shedding light on the intricate regulation of MHC II expression

Non-classical MHC class II positive cell types, function and immunological context

Major histocompatibility complex class II (MHC-II) is a group of glycoproteins responsible for the presentation of exogenous antigens to T-lymphocytes. Besides the "classical" antigen presenting cells (APCs), numerous cell types were proven to be able to express MHC-II molecules either constitutively or under specific conditions. Often, the stimulus for MHC-II expression is interferon g, a pro- inflammatory cytokine typically activating promoter IV of the Class II Transactivator. Many of the non- classical MHC-II-expressing cells can serve as APCs, activating or attenuating T-cell proliferation depending on the expression of costimulatory molecules. Additional research identified some unusual functions of MHC-II molecules on non-classical cell types, including a role in prenatal development or mating. Modulation of the MHC-II expression could potentially serve many promising therapeutic purposes and new research can lead to deeper understanding of the topic. Keywords: MHC-II, ILC, basophils, TEC, antigen presentation, CIITA, IFN-gamm

MHC II-EGFP knock-in mouse model as a suitable tool for quantitative gut immunology under conventional and germ-free conditions

Germ-free animals have been used to study the effects of microbiota for several decades. In that time, numbers of differences from specific-pathogen-free (SPF) animals have been reported, including differences in absolute numbers or percentages of various immune populations, enormously enlarged coecum and lack of germinal centers. However, many of the crucial information about structural and functional differences in their secondary lymphoid organs still remains uncovered. With novel microscopical approaches, such as light sheet fluorescent microscopy, enabling 3D visualization of whole samples without processing them to a series of slides, and multicolor cytometry, allowing the characterization of numbers of cellular populations within a matter of seconds and in a highly quantitative manner, the uncovering of fundamental differences finally seems to be within reach. MHC II-EGFP knock-in mouse model brings the advantages of a fluorescent protein expressed in physiological histological contexts into both fields. Lymphoid and other tissues can be visualized microscopically without the need of staining (even in vivo). Information about the expression of both plasma membrane-localized and intracellular MHC II in various tissues could be acquired directly. Combining MHC II-EGFP knock-in mouse model with..

MHC II - EGFP knock-in mouse model is a suitable tool for systems and quantitative immunology

Immunology is a rapidly evolving field of research with sophisticated models and methods. However, detailed data on total immune cell counts and population distributions remain surprisingly scarce. Nevertheless, recently established quantitative approaches could help us understand the overall complexity of the immune system. Here, we studied a major histocompatibility complexclass II - enhanced green fluorescent protein knock-in mouse model to precisely identify and manipulate lymphoid structures. By combining flow cytometry with light sheet microscopy, we quantified MHC II + populations of the small intestine and associated individual mesenteric lymph nodes, with 36.7 × 10 6 cells in lamina propria, 3.0 × 10 5 cells in scattered lymphoid tissue and 1.1 × 10 6 cells in Peyer's patches. In addition to these whole-organ cell counts, we assessed approximately 1 × 10 6 total villi in the small intestine and 450 scattered lymphoid tissue follicles. By direct noninvasive microscopic observation of a naturally fully translucent mouse organ, the cornea, we quantified 12 ± 4 and 35 ± 7 cells/mm 2 Langerhans- and macrophage-like populations, respectively. Ultimately, our findings show that flow cytometry with quantitative imaging data analysis enables us to avoid methodological discrepancies while gaining new insights into the relevance of organ-specific quantitative approaches for immunology