Search results for "Immune system"
showing 10 items of 2885 documents
<p>Isolation and Functions of Extracellular Vesicles Derived from Parasites: The Promise of a New Era in Immunotherapy, Vaccination, and Diagno…
2020
Experimental and epidemiological evidence shows that parasites, particularly helminths, play a central role in balancing the host immunity. It was demonstrated that parasites can modulate immune responses via their excretory/secretory (ES) and some specific proteins. Extracellular vesicles (EVs) are nano-scale particles that are released from eukaryotic and prokaryotic cells. EVs in parasitological studies have been mostly employed for immunotherapy of autoimmune diseases, vaccination, and diagnosis. EVs can carry virulence factors and play a central role in the development of parasites in host cells. These molecules can manipulate the immune responses through transcriptional changes. Moreo…
Costs of parasite resistance for female survival and parental care in a freshwater isopod
2006
Parasite resistance is expected to be costly because activation and maintenance of immune system requires energy that will not be available for other fitness related functions. Here, we experimentally exposed gravid female isopods from two lake populations to trophically transmitted acanthocephalan parasite. Successful establishment of the parasite requires penetration to body cavity; therefore, it is likely to induce an immune response. Resistant females from a lake where the parasite occurs as well as from a lake without the parasite experienced higher mortality than susceptible or control females. Parasite exposure reduced the offspring size at birth in both susceptible, but especially, …
Revisiting CD8 T-cell ‘Memory Inflation’: New Insights with Implications for Cytomegaloviruses as Vaccine Vectors
2020
Murine models of cytomegalovirus (CMV) infection have revealed an exceptional kinetics of the immune response. After resolution of productive infection, transient contraction of the viral epitope-specific CD8 T-cell pool was found to be followed by a pool expansion specific for certain viral epitopes during non-productive &lsquo
Crosstalk of the plasma contact system with bacteria.
2012
Activation of the plasma contact system triggers several cascade systems such as the kallikrein-kinin system, the intrinsic pathway of coagulation, the classical complement cascade and the fibrinolytic system. Recent studies have shown a critical role of the contact system for arterial and venous thrombus formation and thromboembolic disease. In contrast, the function of the contact system for host-defense reactions and its physiological functions have remained enigmatic. Experimental animal studies and clinical data have linked the contact system to bacterial infections with implications for sepsis disease. The present review summarizes the role of the contact system and its activation for…
An integrated humoral and cellular response is elicited in pancreatic cancer by alpha-enolase, a novel pancreatic ductal adenocarcinoma-associated an…
2009
Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with a very poor 5-year survival rate. alpha-Enolase is a glycolytic enzyme that also acts as a surface plasminogen receptor. We find that it is overexpressed in PDAC and present on the cell surface of PDAC cell lines. The clinical correlation of its expression with tumor status has been reported for lung and hepatocellular carcinoma. We have previously demonstrated that sera from PDAC patients contain IgG autoantibodies to alpha-enolase. The present work was intended to assess the ability of alpha-enolase to induce antigen-specific T cell responses. We show that alpha-enolase-pulsed dendritic cells (DC) specifically stimulate healt…
Keratinocytes Determine Th1 Immunity during Early Experimental Leishmaniasis
2010
Experimental leishmaniasis is an excellent model system for analyzing Th1/Th2 differentiation. Resistance to Leishmania (L.) major depends on the development of a L. major specific Th1 response, while Th2 differentiation results in susceptibility. There is growing evidence that the microenvironment of the early affected tissue delivers the initial triggers for Th-cell differentiation. To analyze this we studied differential gene expression in infected skin of resistant and susceptible mice 16h after parasite inoculation. Employing microarray technology, bioinformatics, laser-microdissection and in-situ-hybridization we found that the epidermis was the major source of immunomodulatory mediat…
Epigenetic control of IL-23 expression in keratinocytes is important for chronic skin inflammation
2018
The chronic skin inflammation psoriasis is crucially dependent on the IL-23/IL-17 cytokine axis. Although IL-23 is expressed by psoriatic keratinocytes and immune cells, only the immune cell-derived IL-23 is believed to be disease relevant. Here we use a genetic mouse model to show that keratinocyte-produced IL-23 is sufficient to cause a chronic skin inflammation with an IL-17 profile. Furthermore, we reveal a cell-autonomous nuclear function for the actin polymerizing molecule N-WASP, which controls IL-23 expression in keratinocytes by regulating the degradation of the histone methyltransferases G9a and GLP, and H3K9 dimethylation of the IL-23 promoter. This mechanism mediates the inducti…
Effects of ultraviolet light on immune parameters of the roach
2000
Ultraviolet B radiation penetrates into water and can affect fish health and the immune system, as is the case with mammals. Teleost fish, the roach, were exposed to UVB irradiation in aquariums and a panel of immune parameters was determined. In addition to altered blood picture and respiratory burst by blood leukocytes, changes were noted also in major lymphatic organs. Respiratory burst and natural cytotoxicity activity of head kidney granulocytes and mitogen-activated proliferation of splenic lymphocytes were suppressed. Although mostly transitory, some parameters remained suppressed for the following 2 weeks. Ultraviolet A radiation had only minor effects. The stress induced by UVB may…
Co-occurrence of resonant activation and noise-enhanced stability in a model of cancer growth in the presence of immune response.
2006
We investigate a stochastic version of a simple enzymatic reaction which follows the generic Michaelis-Menten kinetics. At sufficiently high concentrations of reacting species, the molecular fluctuations can be approximated as a realization of a Brownian dynamics for which the model reaction kinetics takes on the form of a stochastic differential equation. After eliminating a fast kinetics, the model can be rephrased into a form of a one-dimensional overdamped Langevin equation. We discuss physical aspects of environmental noises acting in such a reduced system, pointing out the possibility of coexistence of dynamical regimes where noise-enhanced stability and resonant activation phenomena …
Endomicroscopy of Small Bowel Diseases: Coeliac Disease, Lymphoma
2007
The different components making up the complement of immune elements within the alimentary tract vary greatly. In contrast to the Waldeyer’s ring region, the oesophagus and stomach are normally almost devoid of such immune apparatus, presumably because of the rapid transit of food and the chemically hostile environment for micro-organisms provided by salivary and gastric secretions. Only in pathological conditions, such as viral or fungal oesophageal infections, reflux oesophagitis or Helicobacter gastritis, does one encounter acquired mucosa-associated lymphoid tissue in these sites [1]. By contrast, the large and small bowel normally possess mucosa-associated lymphoid tissue (MALT), most …