Search results for " immune system"
showing 10 items of 893 documents
Primary sjogren syndrome: Focus on innate immune cells and inflammation
2020
Primary Sjogren Syndrome (pSS) is a complex, multifactorial rheumatic disease that mainly targets salivary and lacrimal glands, inducing epithelitis. The cause behind the autoimmunity outbreak in pSS is still elusive; however, it seems related to an aberrant reaction to exogenous triggers such as viruses, combined with individual genetic pre-disposition. For a long time, autoantibodies were considered as the hallmarks of this disease; however, more recently the complex interplay between innate and adaptive immunity as well as the consequent inflammatory process have emerged as the main mechanisms of pSS pathogenesis. The present review will focus on innate cells and on the principal mechani…
Feedback Regulation of Syk by Protein Kinase C in Human Platelets
2019
The spleen tyrosine kinase (Syk) is essential for immunoreceptor tyrosine-based activation motif (ITAM)-dependent platelet activation, and it is stimulated by Src-family kinase (SFK)-/Syk-mediated phosphorylation of Y352 (interdomain-B) and Y525/526 (kinase domain). Additional sites for Syk phosphorylation and protein interactions are known but remain elusive. Since Syk S297 phosphorylation (interdomain-B) was detected in platelets, we hypothesized that this phosphorylation site regulates Syk activity via protein kinase C (PKC)-and cyclic adenosine monophosphate (cAMP)-dependent pathways. ADP, the GPVI-agonist convulxin, and the GPIb&alpha
Regulation of kynurenine biosynthesis during influenza virus infection.
2017
Influenza A viruses (IAVs) remain serious threats to public health because of the shortage of effective means of control. Developing more effective virus control modalities requires better understanding of virus–host interactions. It has previously been shown that IAV induces the production of kynurenine, which suppresses T-cell responses, enhances pain hypersensitivity and disturbs behaviour in infected animals. However, the regulation of kynurenine biosynthesis during IAV infection remains elusive. Here we showed that IAV infection induced expression of interferons (IFNs), which upregulated production of indoleamine-2,3-dioxygenase (IDO1), which catalysed the kynurenine biosynthesis. Furt…
A unique view of SARS-CoV-2 through the lens of ORF8 protein
2021
Immune evasion is one of the unique characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) attributed to its ORF8 protein. This protein modulates the adaptive host immunity through down-regulation of MHC-1 (Major Histocompatibility Complex) molecules and innate immune responses by surpassing the host's interferon-mediated antiviral response. To understand the host's immune perspective concerning the ORF8 protein, a comprehensive study of the ORF8 protein and mutations possessed by it have been performed. Chemical and structural properties of ORF8 proteins from different hosts, such as human, bat, and pangolin, suggest that the ORF8 of SARS-CoV-2 is much closer to OR…
Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases
2021
The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition…
Early inflammatory players in cutanous fibrosis.
2017
Systemic sclerosis (SSc) is one of the most complex systemic autoimmune diseases with multi-organ involvement and heterogeneous clinical manifestations. The exact etiology of SSc is still unknown. However, identified target structures are components of endothelial cells, the innate/adaptive immune systems and fibroblasts, resulting in the hallmarks of the disease in form of inflammation/autoimmunity, vasculopathy and fibrosis of the skin and internal organs. There has been a large body of evidence that the adaptive immune system with autoreactive T and B cells producing autoantibodies plays a central role in the pathogenesis of SSc but the role of earlier pathogenic processes involving the …
Innate immune response to tick-borne pathogens: Cellular and molecular mechanisms induced in the hosts
2020
This article belongs to the Special Issue Inflammasome.
Role of subclinical gut inflammation in the pathogenesis of spondyloarthritis
2018
Subclinical gut inflammation occurring in patients affected by spondyloarthritis (SpA) is correlated with the severity of spine inflammation. Several evidences indicate that dysbiosis occurs in SpA, and that may modulate intestinal permeability and intestinal immune responses. The presence of intestinal dysbiosis is accompanied in SpA patients with the presence of zonulin-dependent alterations of gut-epithelial and gut-vascular barriers. The leakage of epithelial and endothelial surface layers is followed by the translocation of bacterial products, such as lipopolysaccharide and intestinal fatty acid binding protein, in the systemic circulation. These bacterial products may downregulate the…
The Inflammatory Response of Urochordata: The Basic Process of the Ascidians’ Innate Immunity
2018
Ascidians form a widespread marine invertebrate group and are heterogeneous in terms of the taxonomic groups’ evolutionary lineages. The ascidian genomes lack significant homologies for rearranging genes of the vertebrate adoptive immunity. Genome analysis, gene sequencing, and transcriptional profiling have allowed us to disclose upregulation of innate immunity genes and cell labeling with riboprobes and antibodies has identified hemocyte types in tunic and pharynx inflammatory responses. Lymphocyte-like cells are stem cells and their immunocompetence has been proposed. Granulocyte types (compartment/morula cells) and hemocytes with large granules/vacuoles (compartment/morula cells) are ma…
A presumed antagonistic LPS identifies distinct functional organization of TLR4 in mouse microglia
2017
Microglia as principle innate immune cells of the central nervous system (CNS) are the first line of defense against invading pathogens. They are capable of sensing infections through diverse receptors, such as Toll-like receptor 4 (TLR4). This receptor is best known for its ability to recognize bacterial lipopolysaccharide (LPS), a causative agent of gram-negative sepsis and septic shock. A putative, naturally occurring antagonist of TLR4 derives from the photosynthetic bacterium Rhodobacter sphaeroides. However, the antagonistic potential of R. sphaeroides LPS (Rs-LPS) is no universal feature, since several studies suggested agonistic rather than antagonistic actions of this molecule depe…