Search results for "Immunity"
showing 10 items of 1537 documents
Past, Present, and Future of Gastrointestinal Microbiota Research in Cats
2020
The relationship between microbial community and host has profound effects on the health of animals. A balanced gastrointestinal (GI) microbial population provides nutritional and metabolic benefits to its host, regulates the immune system and various signaling molecules, protects the intestine from pathogen invasion, and promotes a healthy intestinal structure and an optimal intestinal function. With the fast development of next-generation sequencing, molecular techniques have become standard tools for microbiota research, having been used to demonstrate the complex intestinal ecosystem. Similarly to other mammals, the vast majority of GI microbiota in cats (over 99%) is composed of the pr…
Role of bacteria-specific T cells in the immunopathogenesis of reactive arthritis.
1994
Reactive arthritis is a usually self-limited sterile inflammation of joints that follows certain bacterial gastrointestinal or urogenital infections. The immunopathogenesis involves CD4+ T cells, which mediate an antigen-specific TH1 response to bacterial constituents within the joint. Properties of the arthritogenic bacteria and the physicochemical characteristics of the bacterial antigens may contribute to the development of reactive arthritis.
Serologic Response to Cell Wall Mannoproteins and Proteins of Candida albicans
1998
SUMMARY The cell wall of Candida albicans not only is the structure in which many biological functions essential for the fungal cells reside but also is a significant source of candidal antigens. The major cell wall components that elicit a response from the host immune system are proteins and glycoproteins, the latter being predominantly mannoproteins. Both the carbohydrate and protein moieties are able to trigger immune responses. Although cell-mediated immunity is often considered to be the most important line of defense against candidiasis, cell wall protein and glycoprotein components also elicit a potent humoral response from the host that may include some protective antibodies. Prot…
Normal interleukin-12 production in individuals with antibodies toHelicobacter pylori
1997
It is increasingly recognized that the inability of the immune system to clear H. pylori infection is caused by an inadequate immune response and is associated with chronic gastric inflammation. To further investigate the cellular immune response to H. pylori, we studied PBMC from 31 H. pylori antibody-negative and 16 H. pylori antibody-positive individuals for H. pylori-induced DNA synthesis, secretion of the Th1-type cytokine IFN-gamma and secretion of IL-12, a cytokine produced by bacteria-stimulated monocyte/macrophages and a potent inducer of antibacterial immune responses and Th1-type T cells. All experiments were performed using Y. enterocolitica 03 as control. Our results demonstrat…
Does Autoimmunity Play a Role in the Immunopathogenesis of Vasculitis Associated With Chronic Chagas Disease?
2021
Chagas disease (CD) is a chronic systemic vector-borne infection caused by the protozoan Trypanosoma cruzi. It has spread from Latin America through migration, becoming a global issue (Perez-Molina and Molina, 2018). Its prevalence is ∼7 million people worldwide, of whom 30-40% will develop severe chronic complications such as cardiomyopathy or megaviscerae, with a considerable impact on morbimortality (WHO, 2020; WHO, 2021). The parasite is transmitted after metacyclic trypomastigotes in the feces of a triatomine insect enter the host through the bite wound. They penetrate cells and transform into amastigotes, where they multiply by binary fission and differentiate again into circulating t…
Replicating phages in the epidermal mucosa of the eel (Anguilla anguilla)
2015
In this work, we used the eel (Anguilla anguilla) as an animal model to test the hypothesis of Barr et al. (2013a,b) about the putative role of the epidermal mucosa as a phage enrichment layer. To this end, we analyzed the microbial content of the skin mucus of wild and farmed eels by using a metagenomic approach. We found a great abundance of replicating phage genomes (concatemers) in all the samples. They were assembled in four complete genomes of three Myovirus and one Podovirus. We also found evidences that ΦKZ and Podovirus phages could be part of the resident microbiota associated to the eel mucosal surface and persist on them over the time. Moreover, the viral abundance estimated by …
Generation of immune responses against hepatitis C virus by dendritic cells containing NS5 protein-coated microparticles.
2009
ABSTRACTDendritic cells (DCs) internalize and process antigens as well as activate cellular immune responses. The aim of this study was to determine the capacity of DCs that contain antigen-coated magnetic beads to induce immunity against the nonstructural hepatitis C virus (HCV) antigen 5 (NS5). Splenocytes derived from Fms-like tyrosine kinase receptor 3 (Flt3) ligand-pretreated BALB/c mice were incubated with magnetic beads coated with HCV NS5, lipopolysaccharide (LPS), and/or anti-CD40; purified; and used for immunization. Cellular immunity was measured using cytotoxic T-lymphocyte (CTL) and T-cell proliferation assays, intracellular cytokine staining, and a syngeneic tumor challenge us…
The Fish Pathogen Vibrio vulnificus Biotype 2: Epidemiology, Phylogeny, and Virulence Factors Involved in Warm-Water Vibriosis
2015
ABSTRACT Vibrio vulnificus biotype 2 is the etiological agent of warm-water vibriosis, a disease that affects eels and other teleosts, especially in fish farms. Biotype 2 is polyphyletic and probably emerged from aquatic bacteria by acquisition of a transferable virulence plasmid that encodes resistance to innate immunity of eels and other teleosts. Interestingly, biotype 2 comprises a zoonotic clonal complex designated as serovar E that has extended worldwide. One of the most interesting virulence factors produced by serovar E is RtxA1 3 , a multifunctional protein that acts as a lethal factor for fish, an invasion factor for mice, and a survival factor outside the host. Two practically id…
Methodology and significance of the detection of liver-kidney-microsomal (lkm) autoantibodies in autoimmune-type chronic active hepatitis
1987
Liver-kidney-microsomal (LKM) autoantibodies are diagnostic markers for a subgroup of HBsAg-negative chronic active hepatitis, presumably owing to autoimmunity. They were originally detected by indirect immunofluorescence and can now be evaluated by radioimmunoassay, enzyme-linked immunosorbent assay, and immunoblotting. In immunoblotting LKM-positive sera react strongly with a 50-kilodalton (KD) polypeptide band of microsomes. In immunoelectron microscopy, LKM-positive sera show a binding with membranes of the endoplasmic reticulum. The LKM antigen was further identified on various isoenzymes of cytochrome P-450. Immunofluorescence is still the method of choice for screening sera routinely…