Cross-presentation Dotaz Zobrazit nápovědu
Vaccines currently in the clinical use contain adjuvants stimulating preferably Th2 type of immune response associated with the production of specific antibodies, mostly of neutralizing isotypes. This kind of immune response is effective only against some types of pathogens and has limited effect against tumors and many viruses where parallel activation of antigen-specific humoral and cell-mediated immunity is required. One of the main objectives of the current vaccine research is the development of approaches leading to the induction of antigen-specific CD8(+) T cell response including cytotoxic T lymphocyte (CTL). Induction of antigen-specific CD8(+) T cell response to exogenously delivered antigen requires their cross-presentation by antigen presenting cells, especially dendritic cells. The cross-presentation principles seem to be crucial for effective activation of CTL. In this paper, we discuss some approaches to employing heat shock proteins for induction of antigen-specific CD8(+) T cells in the context of cross-presentation and cross-priming principles.
- MeSH
- aktivace lymfocytů MeSH
- CD8-pozitivní T-lymfocyty imunologie MeSH
- cytotoxicita imunologická MeSH
- dendritické buňky imunologie transplantace MeSH
- lidé MeSH
- nádory imunologie terapie MeSH
- nepřímá aktivace * MeSH
- proteiny teplotního šoku imunologie MeSH
- protinádorové vakcíny * MeSH
- virové nemoci imunologie terapie MeSH
- virové vakcíny * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Zkřížená prezentace antigenů je proces, kdy dendritické buňky předkládají antigeny zvenčí CD8+ T lymfocytům na MHC I glykoproteinech. Jako zkřížená se označuje proto, že oproti cestám klasické prezentace vede vskutku křížem, protože vnější antigeny jsou zpravidla prezentovány na MHC II a vnitřní na MHC I glykoproteinech. Molekulární mechanismus zkřížené prezentace doposud není uspokojivě objasněn. Uvažují se dvě hlavní cesty – vakuolární a cytosolická. Vakuolární cesta předpokládá, že pohlcené antigeny jsou naštěpeny v endosomu pomocí proteas a následně navázány na MHC I. Cytosolická cesta předpokládá, že pohlcený antigen proniká z váčku do cytosolu, kde je naštěpen v proteazomu. Odtud putuje buď do endoplasmatického retikula (ER), kde dochází k vazbě peptidu na MHC I i při klasické prezentaci antigenu, nebo zpět do endosomu, kam se mašinérie vázající peptid na MHC I přesouvá. Procesu se účastní proteiny z ER, včetně těch, které spolupracují na mechanismu ERAD, Rab GTPasy regulující váčkový transport a struktury podílející se na maturaci endosomů. Zkřížená prezentace má svůj význam z medicínského hlediska, jelikož aktivuje CD8+ T lymfocyty proti intracelulárním patogenům a rakovinným buňkám a také navozuje toleranci na periferii.
Antigen cross‑presentation is a process, when dendritic cells present exogenous antigens in context of MHC I to CD8+ T lymphocytes. Unlike classical antigen presentation, this one goes crosswise, because exogenous antigens are otherwise usually presented on MHC‑II and endogenous antigens on MHC‑I glycoproteins. Molecular mechanism of cross‑presentation has not been well established yet. Two major pathways are considered – vacuolar and cytosolic. In the vacuolar pathway, the internalised antigens are cleaved in the endosome by proteases and then loaded onto MHC I. In the cytosolic pathway, the internalised antigens leave the endosome to be cleaved by the proteasome in the cytosol. They are then imported into the endoplasmic reticulum (ER) to by loaded onto MHC I as in classical antigen presentation, or they go back into the endosome where the MHC‑I loading machinery is trafficked. This process is mediated by ER proteins including those participating in ERAD, by Rab GTPases regulating vesicular transport, and by structures important for endosome maturation. Cross presentation is important in medicine, because it ensures activation of CD8+ T lymphocytes against intracellular pathogens and cancer cells, and induction of tolerance at the periphery.
- Klíčová slova
- zkřížená prezentace, retrotranslokony, vnitrobuněčný transport,
- MeSH
- antigen prezentující buňky MeSH
- antigeny MeSH
- bakteriální infekce imunologie MeSH
- CD8-pozitivní T-lymfocyty MeSH
- cytosol MeSH
- degradace proteinů v endoplasmatickém retikulu MeSH
- dendritické buňky imunologie MeSH
- geny MHC třídy I MeSH
- geny MHC třídy II MeSH
- HLA antigeny MeSH
- hlavní histokompatibilní komplex MeSH
- imunitní systém - jevy MeSH
- nádory imunologie MeSH
- prezentace antigenu * imunologie MeSH
- rab proteiny vázající GTP MeSH
- translokační kanály SEC MeSH
- ubikvitinligasy MeSH
- vakuoly MeSH
- virové nemoci imunologie MeSH
- Publikační typ
- práce podpořená grantem MeSH
The source of peptides that enter the major histocompatibility class I (MHCI) pathway has been intensively debated over the last two decades. The initial assumption that peptides are derived from degradation of full length proteins was challenged by a model in which alternative translation products are a source of peptides. This model has been tested and supported by scientific data. We now need new hypotheses on the physiological implications of different sources of peptides for the MHCI pathway. The aim of this overview is to give an up-to-date account of the source of antigenic peptide material for the MHCI pathway and to incorporate the more recent observations of alternative mRNA translation products into existing models of the direct and cross-presentation pathways.
It has been demonstrated that pterostilbene inhibits reactive oxygen species production in neutrophils in vitro. However, little is known about its effects on neutrophils during inflammation in vivo. In this study, the effect of pterostilbene on neutrophil activity was investigated in experimental arthritis model. Lewis rats were injected by a single intradermal injection of heat-killed Mycobacterium butyricum in Freund's adjuvant to develop arthritis. Another group of arthritic animals received pterostilbene 30 mg/kg, daily, p.o. The number and activity of neutrophils in blood were measured on a weekly basis during the whole experiment. Moreover, the total radical trapping potential in plasma was measured at the end of the experiment. In the pterostilbene treated arthritic group, the treatment significantly lowered the number of neutrophils in blood on days 14 and 21 without significant downregulation of neutrophil oxidative burst. Pterostilbene nonsignificantly increased total radical trapping potential in arthritic animals. These results indicate that the promising effects of pterostilbene on reactive oxygen species operate by different mechanisms in vitro and in the animal model of inflammation. In conclusion, the positive effects of pterostilbene in the model of arthritis may be attributed to regulation of neutrophil number.
- MeSH
- artritida experimentální farmakoterapie patologie MeSH
- down regulace účinky léků MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech MeSH
- nepřímá aktivace účinky léků imunologie MeSH
- neutrofily cytologie účinky léků patologie MeSH
- peroxidy metabolismus MeSH
- počet leukocytů MeSH
- potkani inbrední LEW MeSH
- reaktivní formy kyslíku metabolismus MeSH
- stilbeny chemie farmakologie terapeutické užití MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Heat shock proteins hsp70 and gp96 have been confirmed as adjuvants enabling induction of cell- and antibody-mediated immunity specific to associated protein or peptide antigens due to the activation of naive dendritic cells and supporting cross-presentation of associated antigen. An efficacious vaccine preventing HIV-1 infection should induce (1) antibodies neutralizing HIV-1 Env protein, preventing virus spreading and (2) CD4(+) Th1 and CD8(+) T cells specific to viral proteins, especially gag p24, important for elimination of HIV-1 infected cells. As p24 is relatively poorly recognized by dendritic cells, its targeting to DC is important for enhancement of vaccine efficacy. In this study, a p24 protein fused to the C- or N-terminus of murine hsp70 was produced as a recombinant protein and administered without any adjuvant to experimental BALB/c mice. Consequently, p24-specific cellular and humoral immune responses were measured. To minimize the effect of bacterial endotoxin, each protein was subjected to a repeated endotoxin phase extraction until each preparation contained less than 2.5 endotoxin unit (EU) per mg of antigen. In addition, endocytosis of p24 fused to hsp70 by dendritic cells and their activation were characterized. The fusion to hsp70 protein enhanced endocytosis of p24 as well as activation of dendritic cells in vitro. After immunization of mice, hsp70-p24 fusion protein induced the strongest p24-specific CD4(+) and CD8(+) T cells (IFN-γ production) and humoral (IgG2b) responses corresponding to Th1 type dominance, whereas p24-hsp70 or p24 itself induced weaker responses.
- MeSH
- antigeny virové imunologie MeSH
- CD8-pozitivní T-lymfocyty imunologie MeSH
- dendritické buňky imunologie MeSH
- endocytóza imunologie MeSH
- endotoxiny imunologie MeSH
- HIV korový protein p24 imunologie metabolismus MeSH
- imunizace MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- nepřímá aktivace imunologie MeSH
- proteiny tepelného šoku HSP70 imunologie metabolismus MeSH
- rekombinantní fúzní proteiny imunologie MeSH
- Th1 buňky imunologie MeSH
- vakcíny proti AIDS imunologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Liu - Epithelial cells in antogen sampling and presentation in mucosal tissues / D. MacDonald - Bacterial epithelial cell cross talk / B. Raupach ... . -- Sampling and Presentation in Mucosal Tissues . 55 -- C. CZERKINSKY and J.-B. SuN, and J. FINLAY -- Bacterial Epithelial Cell Cross Talk 137 -- A. PHALIPON and P.J.
Current topics in microbiology and immunology, ISSN 0070-217X 236
viii, 296 stran : ilustrace ; 25 cm
The publication is a collection of works that focus on mucosal surfaces and immunity and on related vaccines. Intended for professional public.
- MeSH
- sliznice MeSH
- slizniční imunita MeSH
- vakcíny MeSH
- vyvíjení léků MeSH
- Publikační typ
- sborníky MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- alergologie a imunologie
- preventivní medicína
Notes to the user -- User guide / Mode d\'utilisation Warning -- Abbreviations and codes used Presentation working languages) -- Subject keywords in organization names (English/French/Spanish/German/Russian) cross-referencing Vol 3 -- Country names (English/French) cross-referencing Vol 2 Former names of organizations (all languages
27th ed. 1774 s.
- MeSH
- organizace MeSH
- Publikační typ
- adresáře MeSH
- Konspekt
- Organizace všeobecné povahy
- NLK Obory
- všeobecná příručková díla a encyklopedie
Cross-classification with SNA classifications 131 -- Annex 9.3. Cross-classification of ICHA-HP with ISIC, Rev. 3 149 -- 11. Transfers in health care: a matrix presentation .74-75 -- Table 7.1. Cross-classification of ICHA-HC and SNA 93 classifications 132 -- Table 9.6. Cross-classification of EPHFs, ICHA-HC and COFOG 133 -- Table 10.1.
Health
205 s.
- Konspekt
- Veřejné zdraví a hygiena
- NLK Obory
- ekonomie, ekonomika, ekonomika zdravotnictví
- NLK Publikační typ
- studie
variability 31 -- 3.5 Two variables 38 -- 3.6 The effect of transforming the data 41 -- 3.7 Data presentation Observational studies 91 -- 5.10 The case-control study 93 -- 5.11 The cohort study 96 -- 5.12 The cross-sectional 174 -- 8.9 Strategy for analysing data 175 -- 8.10 Presentation of results 176 -- 8.11 Summary 177 -- tables - analysis of matched variables 266 -- 10.11 Comparing risks 266 -- 10.12 Presentation of results 311 -- 11.14 Interpretation of regression 316 -- 11.15 Relation to other analyses 318 -- 11.16 Presentation
First edition xii, 611 stran : ilustrace ; 25 cm
This book is primarily aimed at medical researchers and clinicians who wish to gain insight into statistical principles and methods. Nakladatelská anotace. Kráceno