dendritic cells
Cellular Microbiology: Pathogen-Host Cell Molecular InteractionsMicrobial Lipid A Remodeling Controls Cross-Presentation Efficiency and CD8 T Cell Priming by Modulating Dendritic Cell FunctionThe majority of Gram-negative bacteria elicit a potent immune response via recognition of lipid A expressed on the outer bacterial membrane by the host immune receptor Toll-like receptor 4 (TLR4). However, some Gram-negative bacteria evade detection by TLR4 or alter the outcome of TLR4 signaling by modification of lipid A species.
Host Response and InflammationEnterococcus faecalis Induces Differentiation of Immune-Aberrant Dendritic Cells from Murine Bone Marrow-Derived Stem CellsEnterococcus faecalis, long implicated in serious systemic infections and failure of root canal treatment, is a persistent inhabitant of oral periapical lesions. Dendritic cells (DCs) and other innate immune cells patrol the oral mucosa for infecting microbes. Dendritic cells are efficient at capturing microbes when immature, whereupon they can transform into potent...
Host Response and InflammationThe Ubiquitin-Modifying Enzyme A20 Terminates C-Type Lectin Receptor Signals and Is a Suppressor of Host Defense against Systemic Fungal InfectionC-type lectin receptors (CLRs) play key roles in antifungal defense. CLR-induced NF-κB is central to CLR functions in immunity, and thus, molecules that control the amplitude of CLR-induced NF-κB could profoundly influence host defense against fungal pathogens. However, little is known about the mechanisms that negatively regulate CLR-induced NF-κB, and molecules which act on the CLR family broadly and which directly regulate acute CLR-...
Host Response and InflammationActivation of the NLRP3 Inflammasome by Particles from the Echinococcus granulosus Laminated LayerThe interaction of dendritic cells and macrophages with a variety of rigid noncellular particles triggers activation of the NLRP3 inflammasome and consequent secretion of interleukin 1β (IL-1β). Noncellular particles can also be generated in the context of helminth infection, since these large pathogens often shed their outermost structures during growth and/or molting. One such structure is the massive, mucin-based, soft, flexible...
Host Response and InflammationChlamydia Lipooligosaccharide Has Varied Direct and Indirect Roles in Evading both Innate and Adaptive Host Immune ResponsesChlamydia bacteria are obligate intracellular pathogens which can cause a variety of disease in humans and other vertebrate animals. To successfully complete its life cycle, Chlamydia must evade both intracellular innate immune responses and adaptive cytotoxic T cell responses. Here, we report on the role of the chlamydial lipooligosaccharide (LOS) in evading the immune response. Chlamydia infection is known...
Host Response and InflammationThe Nature of Antibacterial Adaptive Immune Responses against Staphylococcus aureus Is Dependent on the Growth Phase and Extracellular PeptidoglycanStaphylococcus aureus has evolved different strategies to evade the immune response, which play an important role in its pathogenesis. The bacteria express and shed various cell wall components and toxins during different stages of growth that may affect the protective T cell responses to extracellular and intracellular...
Host Response and InflammationChlamydia psittaci-Infected Dendritic Cells Communicate with NK Cells via Exosomes To Activate Antibacterial ImmunityDendritic cells (DCs) and natural killer (NK) cells are critically involved in the early response against various bacterial microbes. Functional activation of infected DCs and NK cell-mediated gamma interferon (IFN-γ) secretion essentially contribute to the protective immunity against Chlamydia. How DCs and NK cells cooperate during the antichlamydial response is not fully understood.
Host Response and InflammationParticles from the Echinococcus granulosus Laminated Layer Inhibit CD40 Upregulation in Dendritic Cells by Interfering with Akt ActivationThe larval stage of the cestode Echinococcus granulosus causes cystic echinococcosis in humans and livestock. This larva is protected by the millimeter-thick, mucin-based laminated layer (LL), from which materials have to be shed to allow parasite growth. We previously reported that dendritic cells (DCs) respond to microscopic pieces of the mucin gel of the LL (pLL) with unconventional maturation phenotypes, in the absence or...
Host Response and InflammationInterleukin-21 (IL-21) Downregulates Dendritic Cell Cytokine Responses to Helicobacter pylori and Modulates T Lymphocyte IL-17A Expression in Peyer’s Patches during InfectionInterleukin-21 (IL-21), a cytokine produced by many subsets of activated immune cells, is critical for driving inflammation in several models. Using Helicobacter pylori infection as a model for chronic mucosal infection, we previously published that IL-21 is required for the development of gastritis in response to infection. Concomitant with protection from chronic...
Host Response and InflammationCD40 in Endothelial Cells Restricts Neural Tissue Invasion by Toxoplasma gondiiLittle is known about whether pathogen invasion of neural tissue is affected by immune-based mechanisms in endothelial cells. We examined the effects of endothelial cell CD40 on Toxoplasma gondii invasion of the retina and brain, organs seeded hematogenously. T. gondii circulates in the bloodstream...