Search results for "Immunity"
showing 10 items of 1537 documents
Molecular evolution of the metazoan protein kinase C multigene family
1996
Protein kinases C (PKCs) comprise closely related Ser/Thr kinases, ubiquitously present in animal tissues ; they respond to second messengers, e.g., Ca2+ and/or diacylglycerol, to express their activities. Two PKCs have been sequenced from Geodia cydonium, a member of the lowest multicellular animals, the sponges (Porifera). One sponge G. cydonium PKC, GCPKC1, belongs to the ''novel'' (Ca2+-independent) PKC (nPKC) subfamily while the second one, GCPKC2, has the hall-marks of the ''conventional'' (Ca2+-dependent) PKC (cPKC) subfamily. The alignment of the Ser/Thr catalytic kinase domains, of the predicted aa sequences for these cDNAs with respective segments from previously reported sequence…
Molecular study of porcine transmissible gastroenteritis virus after serial animal passages revealed point mutations in S protein
2010
Porcine respiratory coronavirus is related genetically to porcine transmissible gastroenteritis virus with a large deletion in S protein. The respiratory virus is a mutated form that may be a consequence of the gastroen- teritis virus's evolution. Intensive passages of the virus in its natural host may enhance the appearance of mutations and therefore may contribute to any attenuated form of the virus. The objective of this study was to characterize the porcine transmissible gastroenteritis virus TMK22 strain after passages in piglets from 1992 until 2007. A typical experimental infection, molecular characterization, and serological analysis were also carried out to further char- acterize a…
Autoimmunity to the p53 protein is a feature of systemic lupus erythematosus (SLE) related to anti-DNA antibodies.
2001
The induction of anti-DNA autoantibodies in systemic lupus erythematosus (SLE) patients is problematic because mammalian DNA is poorly immunogenic at best. Here we demonstrate a chain of connected antibodies in SLE patient sera that could account for the induction of anti-DNA antibody, and possibly for some of the pathogenic features of SLE. We now report that SLE patients, in addition to anti-DNA, produce antibodies to the carboxy-terminal domain of the tumour suppressor molecule p53; this p53 domain recognizes damaged DNA. Hence, these anti-p53 antibodies could mimic damaged DNA immunologically. Indeed, SLE sera do contain anti-idiotypic antibodies to a prototypic anti-p53 antibody. Moreo…
Autoreactivity to mouse C1q in a murine model of SLE.
1995
A large proportion of systemic lupus erythematosus (SLE) patients develop glomerulonephritis, coincident with the appearance of autoantibodies to C1q, the Fc-recognizing collagen-like subcomponent of the first component of complement, C1. The MRL/lpr/lpr mouse is an established model for SLE, developing both antinuclear and anti-type II collagen autoantibodies, and rheumatoid factors(s), exhibiting reduced complement levels and later on developing glomerulonephritis and often arthritis. We report here an age-dependent decrease in serum C1q levels coincident with the development of IgG2b autoantibodies reactive with mouse C1q in MRL/lpr/lpr mice. Unlike IgG2b, although high levels of IgM, Ig…
Analysis of Epitope Spreading over an Eleven-year Period in a Patient with Systemic Lupus Erythematosus: CASE REPORT
1998
During a period of more than eleven years serum samples of a patient with Systemic Lupus Erythematosus were collected and analyzed for anti-nuclear autoantibodies. High titer of anti-La/SS-B were detectable in all serum samples. The La/SS-B epitopes remained constant. Besides anti-La/SS-B antibodies all serum samples contained traces of anti-Ro/SS-A including anti-Ro52 and anti-Ro60 antibodies. During disease flares anti-Ro/SS A antibodies were upregulated and anti-dsDNA antibodies appeared, thus supporting the concept of an antigen driven intermolecular epitope spreading to Ro/SS-A and dsDNA.
Wheat Amylase Trypsin Inhibitors as Nutritional Activators of Innate Immunity
2015
While the central role of an adaptive, T cell-mediated immune response to certain gluten peptides in celiac disease is well established, the innate immune response to wheat proteins remains less well defined. We identified wheat amylase trypsin inhibitors (ATIs), but not gluten, as major stimulators of innate immune cells (dendritic cells > macrophages > monocytes), while intestinal epithelial cells were nonresponsive. ATIs bind to and activate the CD14-MD2 toll-like receptor 4 (TLR4) complex. This activation occurs both in vitro and in vivo after oral ingestion of purified ATIs or gluten, which is usually enriched in ATIs. Wheat ATIs represent a family of up to 17 proteins with molec…
Immature, but not inactive: the tolerogenic function of immature dendritic cells.
2002
The induction of antigen-specific T cell tolerance and its maintenance in the periphery is critical for the prevention of autoimmunity. Recent evidence shows that dendritic cells (DC) not only initiate T cell responses, but are also involved in silencing of T cell immune responses. The functional activities of DC are mainly dependent on their state of activation and differentiation, that is, terminally differentiated mature DC can efficiently induce the development of T effector cells, whereas immature DC are involved in maintenance of peripheral tolerance. The means by which immature DC maintain peripheral tolerance are not entirely clear, however, their functions include the induction of …
Dendritic cells as a tool to induce anergic and regulatory T cells
2001
Abstract The induction of antigen-specific T-cell tolerance in the thymus and its maintenance in the periphery is crucial for the prevention of autoimmunity. As well as their stimulatory functions, there is growing evidence that dendritic cells, acting as professional antigen-presenting cells, also maintain and regulate T-cell tolerance in the periphery. This control function is exerted by certain maturation stages and subsets of different ontogeny, and can be influenced by immunomodulatory agents. What is the current state of knowledge of the ‘immunoregulatory' properties of dendritic cells and how might tolerance-inducing dendritic cells be relevant to therapeutic applications in humans?
Beta-Catenin mediates tumor-induced immunosuppression by inhibiting cross-priming of CD8(+) T cells
2014
Tumors activate -catenin in DCs to suppress CD8 immunity by inhibiting cross-priming; -catenin-suppressed CD8 immunity could be rescued by enhancing cross-priming. Whereas CD8(+) T cells are essential for anti-tumor immunity, tumors often evade CD8(+) T cell surveillance by immunosuppression. As the initiators of antigen-specific immune responses, DCs are likely to play a central role in regulating the balance between immunity and tolerance to tumor antigens and are specialized in their ability to cross-present exogenous tumor antigens on MHC class I molecules to initiate CD8(+) T cell immunity. However, it remains unclear whether and how tumors modulate DC functions to suppress CD8(+) T ce…
Ankylosing spondylitis: an autoimmune or autoinflammatory disease?
2021
Ankylosing spondylitis (AS) is a chronic inflammatory disease with hallmarks of both autoimmune and autoinflammatory pathology. In this Review, the authors examine the evidence for both disease processes and aim to reconcile the two.Ankylosing spondylitis (AS) is a chronic inflammatory disorder of unknown aetiology. Unlike other systemic autoimmune diseases, in AS, the innate immune system has a dominant role characterized by aberrant activity of innate and innate-like immune cells, including gamma delta T cells, group 3 innate lymphoid cells, neutrophils, mucosal-associated invariant T cells and mast cells, at sites predisposed to the disease. The intestine is involved in disease manifesta…