Search results for "Innate Immune System"

2013

Vertebrate hosts often defend themselves against several co-infecting parasite genotypes simultaneously. This has important implications for the ecological dynamics and the evolution of host defence systems and parasite strategies. For example, it can drive the specificity of the adaptive immune system towards high genotype-specificity or cross-reactivity against several parasite genotypes depending on the sequence and probability of re-infections. However, to date, there is very little evidence on these interactions outside mammalian disease literature. In this study we asked whether genotype-specific or cross-reactive responses dominate in the adaptive immune system of a fish host towards…

Immune activation increases susceptibility to oxidative tissue damage in Zebra Finches.

2006

Summary 1The innate immune response involves the production of highly reactive molecules (reactive oxygen and nitrogen species, ROS and RNS). These toxic compounds can effectively destroy invading pathogens but can also, non-specifically, target host cells. Tissue damage caused by ROS and RNS can be substantial if the inflammatory response is overactive, potentially inducing a so-called immunopathology. 2In this study, we induced an inflammatory response in Zebra Finches by the way of a LPS injection (lipopolysaccharide of the cell wall of Escherichia coli), using as a control a group of birds injected with saline (phosphate-buffered saline). Body mass was measured both before and 24 h afte…

Rapid induction of immune density-dependent prophylaxis in adult social insects.

2009

The innate immune system provides defence against parasites and pathogens. This defence comes at a cost, suggesting that immune function should exhibit plasticity in response to variation in environmental threats. Density-dependent prophylaxis (DDP) has been demonstrated mostly in phase-polyphenic insects, where larval group size determines levels of immune function in either adults or later larval instars. Social insects exhibit extreme sociality, but DDP has been suggested to be absent from these ecologically dominant taxa. Here we show that adult bumble-bee workers ( Bombus terrestris ) exhibit rapid plasticity in their immune function in response to social context. These results sugges…

Lepidopteran species have a variety of defence strategies against bacterial infections

2017

The insect immune system has versatile ways of coping with microbial insults. Currently, innate immune priming has been described in several invertebrates, and the first insights into its mechanistic basis have been described. Here we studied infections with two different strains of Serratia marcescens bacteria in two different Lepidopteran hosts. The results reveal fundamental differences between the two hosts, a well-known model organism Galleria mellonella and a non-model species Arctia plantaginis. They differ in their strategies for resisting oral infections; priming their defences against a recurring sepsis; and upregulating immunity related genes as a response to the specific pathoge…

Altered distribution and function of splenic innate lymphoid cells in adult chronic immune thrombocytopenia

2018

IF 7.607; International audience; Innate lymphoid cells (ILCs) have been characterized as innate immune cells capable to modulate the immune response in the mucosae. Human ILCs have been rarely described in secondary lymphoid organs except in tonsils. Moreover, their function and phenotype in human secondary lymphoid organs during autoimmune diseases have never been studied. We took advantage of splenectomy as a treatment of immune thrombocytopenia (ITP) to describe and compare splenic ILC from 18 ITP patients to 11 controls. We first confirmed that ILC3 represented the most abundant ILC subset in human non-inflamed spleens, accounting for 90% of total ILC, and that they were mostly constit…

Triggering of Toll-like Receptors in Old Individuals. Relevance for Vaccination

2019

Aging is characterized by a general decline in a range of physiological functions, with a consequent increase in the risk of developing a variety of chronic diseases and geriatric syndromes. Additionally, increasing age is accompanied by a progressive decline in both innate and acquired immune system, referred to as immunosenescence. This impaired ability to mount an efficient immune response after exposure to microorganisms or vaccines represents a major challenge in acquiring protection against pathogens in aging. Therefore, there is still a great need for vaccines that are tailored to optimally stimulate the aged immune system, thus promoting more successful aging. Various strategies ca…

The emerging role of Notch pathway in ageing: Focus on the related mechanisms in age-related diseases

2016

Notch signaling is an evolutionarily conserved pathway, which is fundamental for the development of all tissues, organs and systems of human body. Recently, a considerable and still growing number of studies have highlighted the contribution of Notch signaling in various pathological processes of the adult life, such as age-related diseases. In particular, the Notch pathway has emerged as major player in the maintenance of tissue specific homeostasis, through the control of proliferation, migration, phenotypes and functions of tissue cells, as well as in the cross-talk between inflammatory cells and the innate immune system, and in onset of inflammatory age-related diseases. However, until …

Amylase–Trypsin Inhibitors in Wheat and Other Cereals as Potential Activators of the Effects of Nonceliac Gluten Sensitivity

2018

Nonceliac gluten sensitivity (NCGS) is a gluten-related gastrointestinal disorder distinct from celiac disease (CD) and gluten allergy that is not easy to diagnose due to the lack of biomarkers. It is characterized by intestinal symptoms and extraintestinal manifestations with the consumption of gluten-containing foods. In contrast to CD, NCGS patients do not present a genetic predisposition or intestinal villi atrophy. Recent studies question the proinflammatory triggering activity of α-gliadin fraction contained in wheat, since it has been demonstrated that the amylase-trypsin inhibitors (ATIs) exert a strong activating effect on the innate immune response. We aimed to analyze the role of…

Secretion of autoimmune antibodies in the human subcutaneous adipose tissue

2018

The adipose tissue (AT) contributes to systemic and B cell intrinsic inflammation, reduced B cell responses and secretion of autoimmune antibodies. In this study we show that adipocytes in the human obese subcutaneous AT (SAT) secrete several pro-inflammatory cytokines and chemokines, which contribute to the establishment and maintenance of local and systemic inflammation, and consequent suboptimal immune responses in obese individuals, as we have previously shown. We also show that pro-inflammatory chemokines recruit immune cells expressing the corresponding receptors to the SAT, where they also contribute to local and systemic inflammation, secreting additional pro-inflammatory mediators.…

Double methylation of tRNA-U54 to 2′-O-methylthymidine (Tm) synergistically decreases immune response by Toll-like receptor 7

2018

Abstract Sensing of nucleic acids for molecular discrimination between self and non-self is a challenging task for the innate immune system. RNA acts as a potent stimulus for pattern recognition receptors including in particular human Toll-like receptor 7 (TLR7). Certain RNA modifications limit potentially harmful self-recognition of endogenous RNA. Previous studies had identified the 2′-O-methylation of guanosine 18 (Gm18) within tRNAs as an antagonist of TLR7 leading to an impaired immune response. However, human tRNALys3 was non-stimulatory despite lacking Gm18. To identify the underlying molecular principle, interferon responses of human peripheral blood mononuclear cells to differentia…