As dendritic cells (DCs) are among the first cells to encounter antigens, these cells trigger both innate and T cell responses, and are the most potent antigen-presenting cells. Brucella spp., which is an intracellular facultative and stealthy pathogen, is able to evade the bactericidal activities of professional phagocytes. Several studies have demonstrated that Brucella can survive and replicate intracellularly, thereby provoking impaired maturation of DCs. Therefore, the interaction between DCs and Brucella becomes an interesting model to study the immune response. In this review, we first will describe the most common techniques for DCs differentiation in vitro as well as general features of brucellosis. Then, the interaction of DCs and Brucella, including pathogen recognition, molecular mechanisms of bacterial pathogenesis, and intracellular trafficking of Brucella to subvert innate response, will be reviewed. Finally, we will debate diversity in immunological DC response and the controversial role of DC activation against Brucella infection.
- MeSH
- Brucella imunologie patogenita MeSH
- brucelóza imunologie MeSH
- cytoplazma mikrobiologie MeSH
- dendritické buňky mikrobiologie MeSH
- interakce hostitele a patogenu imunologie MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named 'Candidatus Occultobacter vannellae' and 'Candidatus Nucleophilum amoebae'. While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria (85-88% 16S rRNA sequence similarity) but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host-derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts.
- MeSH
- Amoeba klasifikace mikrobiologie MeSH
- buněčné jádro mikrobiologie MeSH
- cytoplazma mikrobiologie MeSH
- druhová specificita MeSH
- Gammaproteobacteria klasifikace izolace a purifikace fyziologie MeSH
- symbióza fyziologie MeSH
- vodní organismy klasifikace izolace a purifikace mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Parasitism, aptly defined as one of the 'living-together' strategies (Trager, 1986), presents a dynamic system in which the parasite and its host are under evolutionary pressure to evolve new and specific adaptations, thus enabling the coexistence of the two closely interacting partners. Microsporidia are very frequently encountered obligatory intracellular protistan parasites that can infect both animals and some protists and are a consummate example of various aspects of the 'living-together' strategy. Microsporidia, relatives of fungi in the superkingdom Opisthokonta, belong to the relatively small group of parasites for which the host cell cytoplasm is the site of both reproduction and maturation. The structural and physiological reduction of their vegetative stage, together with the manipulation of host cell physiology, enables microsporidia to live in the cytosolic environment for most of their life cycle in a way resembling endocytobionts. The ability to form structurally complex spores and the invention and assembly of a unique injection mechanism enable microsporidia to disperse within host tissues and between host organisms, resulting in long-lasting infections. Microsporidia have adapted their genomes to the intracellular way of life, evolved strategies how to obtain nutrients directly from the host and how to manipulate not only the infected cells, but also the hosts themselves. The enormous variability of host organisms and their tissues provide microsporidian parasites a virtually limitless terrain for diversification and ecological expansion. This review attempts to present a general overview of microsporidia, emphasising some less known and/or more recently discovered facets of their biology.
- MeSH
- antibakteriální látky izolace a purifikace metabolismus MeSH
- antimetabolity metabolismus MeSH
- cytoplazma metabolismus mikrobiologie MeSH
- DNA-topoisomerasy genetika metabolismus MeSH
- financování vládou MeSH
- inhibitory syntézy nukleových kyselin izolace a purifikace MeSH
- inhibitory syntézy proteinů izolace a purifikace MeSH
- mikrobiální genetika metody MeSH
- mnohočetná léková rezistence fyziologie genetika MeSH
- molekulární biologie metody trendy MeSH
Hollow-core particles, forming crystals in nuclei, prevailed in HeLa cells infected with an attenuated strain of pseudorabies virus (PRV). After infection with a virulent PRV strain, the cells contained mainly fully infectious dense-core particles. These findings might explain the lower susceptibility of HeLa and some other human cells to infection with attenuated strains of PRV as compared to virulent strains.
- MeSH
- buněčné inkluze virové MeSH
- buněčné jádro mikrobiologie MeSH
- cytopatogenní efekt virový MeSH
- cytoplazma mikrobiologie MeSH
- elektronová mikroskopie MeSH
- HeLa buňky MeSH
- Herpesviridae růst a vývoj MeSH
- krystalografie MeSH
- prasečí herpesvirus 1 patogenita růst a vývoj ultrastruktura MeSH
- replikace viru MeSH
- virulence MeSH
- MeSH
- buněčné inkluze virové MeSH
- buněčné jádro mikrobiologie MeSH
- cytopatogenní efekt virový MeSH
- cytoplazma mikrobiologie MeSH
- elektronová mikroskopie MeSH
- HeLa buňky MeSH
- Herpesviridae růst a vývoj MeSH
- krystalografie MeSH
- prasečí herpesvirus 1 patogenita růst a vývoj ultrastruktura MeSH
- replikace viru MeSH
- virulence MeSH
- MeSH
- barvení a značení MeSH
- buněčné inkluze virové MeSH
- časové faktory MeSH
- cytoplazma mikrobiologie MeSH
- elektronová mikroskopie MeSH
- fluorescenční protilátková technika MeSH
- králíci MeSH
- kultivované buňky MeSH
- makrofágy mikrobiologie MeSH
- plicní alveoly MeSH
- počet buněk MeSH
- replikace viru MeSH
- virus vakcinie růst a vývoj MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
