Search results for "immune system"
showing 10 items of 2885 documents
Retinoic Acid and the Gut Microbiota in Alzheimer’s Disease: Fighting Back-to-Back?
2019
Background:There is growing evidence that the gut microbiota may play an important role in neurodegenerative diseases such as Alzheimer’s disease. However, how these commensals influence disease risk and progression still has to be deciphered.Objective:The objective of this review was to summarize current knowledge on the interplay between gut microbiota and retinoic acid. The latter one represents one of the important micronutrients, which have been correlated to Alzheimer’s disease and are used in initial therapeutic intervention studies.Methods:A selective overview of the literature is given with the focus on the function of retinoic acid in the healthy and diseased brain, its metabolism…
T cell specificity and cross reactivity towards enterobacteria,Bacteroides,Bifidobacterium, and antigens from resident intestinal flora in humans
1999
BACKGROUNDT cell responses to normal intestinal bacteria or their products may be important in the immunopathogenesis of chronic enterocolitis.AIMSTo investigate the T cell specificity and cross reactivity towards intestinal bacteria.PATIENTS/METHODST cell clones were isolated with phytohaemagglutinin from peripheral blood and biopsy specimens of inflamed and non-inflamed colon from five patients with inflammatory bowel disease (IBD) and two controls. T cell clones were restimulated with anaerobicBacteroides andBifidobacteria species, enterobacteria, and direct isolates of aerobic intestinal flora. T cell phenotype was analysed by single-cell immunocyte assay.RESULTSAnalysis of 96 T cell cl…
Pathophysiology of Campylobacter jejuni infections of humans.
2000
Campylobacter jejuni and closely related organisms are major causes of human bacterial enteritis. These infections can lead to extraintestinal disease and severe long-term complications. Of these, neurological damage, apparently due to the immune response of the host, is the most striking. This review examines current knowledge of the pathophysiology of the organism. Diversity of C. jejuni isolates in genotypic and phenotypic characteristics now is recognized and clinically relevant examples are presented. Expected future directions are outlined.
The experimental antiphospholipid syndrome: an invaluable tool to study autoimmunity-induced neurodegeneration
2014
cells and its activation inhibits their differentiation and remyelination. These suggest a possible role of CNS TLR2 in progressive autoimmune demyelination. Methods: We examined the effects of intra-cerebro-ventricular (ICV) injection of Zymozan, a TLR2 agonist, on the clinical and pathological course of EAE. The survival and clinical scores were monitored; demyelination and axonal loss were quantified by gold-black and Bielschowsky stains, and the nature of neuro-inflammatory response was characterized by TLR2, IBA-1 and CD3 stainings and PCR for immune cytokines. Immune cells were isolated from EAE brain tissue and their proliferative response to the autoantigen (PLP peptide) or Concaval…
Immune Thrombocytopenia: Recent Advances in Pathogenesis and Treatments
2021
Immune thrombocytopenia (ITP) is a rare autoimmune disease due to both a peripheral destruction of platelets and an inappropriate bone marrow production. Although the primary triggering factors of ITP remain unknown, a loss of immune tolerance—mostly represented by a regulatory T-cell defect—allows T follicular helper cells to stimulate autoreactive splenic B cells that differentiate into antiplatelet antibody-producing plasma cells. Glycoprotein IIb/IIIa is the main target of antiplatelet antibodies leading to platelet phagocytosis by splenic macrophages, through interactions with Fc gamma receptors (FcγRs) and complement receptors. This allows macrophages to activate autoreactive T cells …
Modulation of immune responses ofRhynchophorus ferrugineus(Insecta: Coleoptera) induced by the entomopathogenic nematodeSteinernema carpocapsae(Nemat…
2014
Aim of this study was to investigate relationships between the red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) and the entomopathogenic nematode Steinernema carpocapsae (EPN); particularly, the work was focused on the immune response of the insect host in naive larvae and after infection with the EPN. Two main immunological processes have been addressed: the activity and modulation of host prophenoloxidase-phenoloxidase (proPO) system, involved in melanization of not-self and hemocytes recognition processes responsible for not-self encapsulation. Moreover, immune depressive and immune evasive strategies of the parasite have been investigated. Our results suggest that RPW possess a…
In Vitro Stimulation and Expansion of Human Tumour-Reactive CD8+ Cytotoxic T Lymphocytes by Anti-CD3/CD28/CD137 Magnetic Beads
2011
Adoptive immunotherapy with tumour-reactive CD8(+) cytotoxic T lymphocytes (CTLs) requires efficient in vitro approaches allowing the expansion of CTLs to large numbers prior infusion. Here, we investigated the antigen-independent activation and the expansion of human T cells in peripheral blood mononuclear cells (PBMCs) and in tumour-reactive CTLs using Dynabeads coated with monoclonal antibodies to CD3 and to the costimulatory molecules CD28 and CD137 (4-1BB). T cells in PBMCs showed an increased expansion rate of 15- to 17-fold during a 2-week culture period using antibody-conjugated beads with interleukin-2 (IL-2) added versus IL-2 alone. No significant difference between CD3/CD28 beads…
Targeting the Sortase A Transpeptidase to Tackle Gram-positive Pathogens
2013
The virulence factors include the cell-wall associated proteins called MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) that can promote the adhesion to host proteins, for example, the fibronectin that is very common in host tissues. The cellwall associated proteins are necessary for host colonization, invasion, immune evasion and biofilm formation [4]. The biofilms, multistratified bacterial communities that grow on a biological or artificial surface, are responsible for chronic infectious diseases and for device or biomaterial associated infections, and are more resistant to host immune defence system and to conventional antibiotics [5].
Immunoelectron Microscopy of Hemocyanin from the Keyhole Limpet (Megathura crenulata): A Parallel Subunit Model
1993
Abstract Immunoelectron microscopy has been performed using negatively stained immune complexes of keyhole limpet hemocyanin (KLH) subunit 2 di- and multidecamers with domain-specific monoclonal antibodies. One antibody (KLH2 a macr 1) links the hemocyanin molecules in a side-to-side pattern, whereas the other antibody (KLH2 fg macr 1) links the molecules end-to-end. From existing knowledge of the domain sequence of KLH subunit 2, these data provide support for a parallel arrangement of subunits within each decamer. Ten N-terminal a macr: domains are then present at the noncollar region of each decamer with 10 C-terminal g macr domains at the collar region. The immunonegative staining data …
Donor and host B cell-derived IL-10 contributes to suppression of graft-versus-host disease
2014
Graft-versus-host disease (GvHD) is a frequent life-threatening complication following allogeneic HSC transplantation (HSCT). IL-10 is a regulatory cytokine with important roles during GvHD, yet its relevant sources, and mode of action, remain incompletely defined in this disease. Using IL-10-deficient donor or host mice (BALB/c or C57BL/6, respectively) in a MHC-mismatched model for acute GvHD, we found a strongly aggravated course of the disease with increased mortality when either donor or host cells could not produce this cytokine. A lack of IL-10 resulted in increased allogeneic T-cell responses and enhanced activation of host DCs in spleen and MLNs. Remarkably, IL-10 was prominently p…