Q104814014
Dotaz
Zobrazit nápovědu
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
118 l. : tab., grafy ; 32 cm
LD50 pro transdermální infekci mikrobem F. tularensis je o několik řádů vyšší než při jiných cestách vstupu. Důvod je neznám. Předpokládá se účast lokálních faktorů imunity, které nejsou popsány. Transdermální cesta je přirozenou cestou šíření tularemieprostřednictvím klíštěcích vektorů, kteří se podílejí na překonání lokální dermální bariéry. Cílem studie je poznat lokální mechanismy obrany a jejich modulaci slinami ektoparazita.; LD50 of transdermal infection with Francisella tularensis is of several logs higher than of other ways of infection. The reason is unclear. Unknown local immune factors seem to participate. Transdermal infection is natural way for spreading of tularemiavia tick vectors, that can overcome local dermal barrier. The aim of this project is to define local defence mechanisms and their modulation by tick saliva.
- MeSH
- Francisella tularensis patogenita MeSH
- imunologická odpověď na dávku MeSH
- infekce přenášené vektorem MeSH
- interakce hostitele a parazita MeSH
- klíšťata MeSH
- kůže imunologie MeSH
- sliny imunologie MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- parazitologie
- alergologie a imunologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
139 l. : il. ; 32 cm
Studium imunomodulačního působení látek alternativními in vitro technikami založenými na korelaci funkčních testů s proteinovou analýzou imunokompetentních buněk a jejich produktů.Nalezení souboru vhodných metod a jejich aplikace. XXX XXX XXX
- Konspekt
- Lékařské vědy. Lékařství
- NLK Obory
- alergologie a imunologie
- toxikologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
The history of national tularemia research started in 1936 when the first outbreak was recognized in south-east Moravia. Since then in average about one hundred cases have been recorded annually. As tularemia was endemic in former Czechoslovakia, three research groups which concentrated on this disease were formed during decades. The first two groups have worked from sixties and were associated with Jiri Libich (Prague) and Darina Gurycova (Bratislava). The third group which concentrated on the research of natural foci started during late seventies in Valtice (Zdenek Hubalek). The experimental research was, and still is, mainly associated with military research, recently with the Proteomic Center (Faculty of Military Health Sciences, University of Defence) in Hradec Kralove. This center opens molecular approaches to the analysis of Francisella tularensis microbes on one side and the studies on mutual host-pathogen interaction on the other side. One of the significant aims of the research is searching for the new typing and diagnostic markers of Francisella tularensis for the military and medical practice. Thus, scientists from former Czechoslovakia and the Czech Republic contributed significantly to current knowledge on Francisella pathogenesis and their results were highly appraised by international scientific community.
- MeSH
- dějiny 20. století MeSH
- financování organizované MeSH
- Francisella tularensis patogenita MeSH
- lidé MeSH
- tularemie mikrobiologie prevence a kontrola MeSH
- výzkum dějiny trendy MeSH
- zvířata MeSH
- Check Tag
- dějiny 20. století MeSH
- lidé MeSH
- zvířata MeSH
- Geografické názvy
- Česká republika MeSH
- Československo MeSH
Pathogenic bacteria have developed various mechanisms to evade host immune defense systems. Invasion of pathogenic bacteria requires interaction of the pathogen with host receptors, followed by activation of signal transduction pathways and rearrangement of the cytoskeleton to facilitate bacterial entry. Numerous bacteria exploit specialized plasma membrane microdomains, commonly called membrane rafts, which are rich in cholesterol, sphingolipids and a special set of signaling molecules which allow entry to host cells and establishment of a protected niche within the host. This review focuses on the current understanding of the raft hypothesis and the means by which pathogenic bacteria subvert membrane microdomains to promote infection.
Francisella tularensis (F. tularensis) is highly infectious for humans via aerosol route and untreated infections with the highly virulent subsp. tularensis can be fatal. Our knowledge regarding key virulence determinants has increased recently but is still somewhat limited. Surface proteins are potential virulence factors and therapeutic targets, and in this study, we decided to target three genes encoding putative membrane lipoproteins in F. tularensis LVS. One of the genes encoded a protein with high homology to the protein family of disulfide oxidoreductases DsbA. The two other genes encoded proteins with homology to the VacJ, a virulence determinant of Shigella flexneri. The gene encoding the DsbA homologue was verified to be required for survival and replication in macrophages and importantly also for in vivo virulence in the mouse infection model for tularemia. Using a combination of classical and shotgun proteome analyses, we were able to identify several proteins that accumulated in fractions enriched for membrane-associated proteins in the dsbA mutant. These proteins are substrate candidates for the DsbA disulfide oxidoreductase as well as being responsible for the virulence attenuation of the dsbA mutant.
- MeSH
- bakteriální proteiny genetika chemie metabolismus MeSH
- buněčné linie MeSH
- chromatografie kapalinová metody MeSH
- faktory virulence genetika chemie metabolismus MeSH
- Francisella tularensis genetika metabolismus patogenita MeSH
- hmotnostní spektrometrie metody MeSH
- isoelektrická fokusace MeSH
- lidé MeSH
- makrofágy cytologie metabolismus MeSH
- membránové proteiny genetika chemie metabolismus MeSH
- míra přežití MeSH
- molekulární sekvence - údaje MeSH
- mutace MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- peptidy genetika chemie metabolismus MeSH
- proteindisulfidisomerasy genetika chemie metabolismus MeSH
- proteom analýza MeSH
- proteomika metody MeSH
- tularemie metabolismus mortalita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
Immunity to Francisella tularensis is largely mediated by T lymphocytes but an important role of B lymphocytes in early stage of infection was previously uncovered. We wanted to find out if F. tularensis is able to infect B cells and/or influence them by direct contact. To investigate this possibility we infected B cell lines from mouse (A20) or humans (Ramos RA-1), or primary mouse spleen cells, with F. tularensis LVS and F. tularensis FSC200 in vitro. In all cases, we detected bacteria on the cell surface and inside the B cells using transmission electron microscopy. More than 20% cells were infected by microbes after 24h. The number of bacteria, determined by CFU, increased about 1 log during 24h. Infection with live bacteria led to apoptosis of Ramos cells and mouse CD19(+) spleen cells. Approximately 30% of cells were apoptotic after 24h and 70% after 48 h, independently of the F. tularensis strain, while only 10% of non-infected cell were apoptotic at either time point. Apoptosis was confirmed by Western blot using anti-PARP antibodies. Thus, this study demonstrates unique phenomenon - namely, the ability of the intracellular pathogen F. tularensis to invade and induce apoptosis in B cells.
The Francisella tularensis strain LVS phagosome disintegrates during the first few hours after bacterial entry and microbes are released to the cytosol. Within 12 h both rapid multiplication of microbes and a steep increase of apoptosis of infected macrophages occur. We searched for signals involved in the death of macrophages and detected molecules associated with the autophagy machinery cathepsin D, PTEN, p53 and LC3, whose levels or modification were influenced by ongoing in vitro tularemic infection. The sequestration of cytoplasmic F. tularensis LVS into autophagosomes was confirmed by co-localization of the LVS strain containing vacuoles with LC3 (an autophagosomal marker). We also demonstrated the presence of MHC II antigens in these autophagosomes, indicating that they might act as a source of endogenous tularemic antigens for presentation to CD4+ T lymphocytes.
- MeSH
- buněčná smrt genetika imunologie MeSH
- cytosol fyziologie imunologie mikrobiologie MeSH
- financování organizované využití MeSH
- fluorescenční mikroskopie využití MeSH
- fosfohydroláza PTEN genetika imunologie izolace a purifikace MeSH
- Francisella tularensis imunologie izolace a purifikace MeSH
- imunoblotting metody využití MeSH
- kathepsin D genetika imunologie izolace a purifikace MeSH
- makrofágy imunologie mikrobiologie MeSH
- tularemie etiologie imunologie mikrobiologie MeSH
