Search results for "Innate Immunity"
showing 10 items of 115 documents
CNS-localized myeloid cells capture living invading T cells during neuroinflammation
2020
Using an in vivo real-time approach, the authors show that local myeloid cells remove early CNS-invading T cells via an engulfment pathway that is dependent on N-acetyl-D-glucosamine (GlcNAc) and lectin. These results reveal a novel capacity of myeloid cells to counteract neuroinflammation.
Immunological properties of oxygen-transport proteins: hemoglobin, hemocyanin and hemerythrin
2016
It is now well documented that peptides with enhanced or alternative functionality (termed cryptides) can be liberated from larger, and sometimes inactive, proteins. A primary example of this phenomenon is the oxygen-transport protein hemoglobin. Aside from respiration, hemoglobin and hemoglobin-derived peptides have been associated with immune modulation, hematopoiesis, signal transduction and microbicidal activities in metazoans. Likewise, the functional equivalents to hemoglobin in invertebrates, namely hemocyanin and hemerythrin, act as potent immune effectors under certain physiological conditions. The purpose of this review is to evaluate the true extent of oxygen-transport protein dy…
An evolutionary perspective on the role of mesencephalic astrocyte-derived neurotrophic factor (MANF): At the crossroads of poriferan innate immune a…
2017
The mesencephalic astrocyte-derived neurotrophic factor (MANF) belongs to a recently discovered family of neurotrophic factors. MANF can be secreted but is generally resident within the endoplasmic reticulum (ER) in neuronal and non-neuronal cells, where it is involved in the ER stress response with pro-survival effects. Here we report the discovery of the MANF homolog SDMANF in the sponge Suberites domuncula. The basal positioning of sponges (phylum Porifera) in the animal tree of life offers a unique vantage point on the early evolution of the metazoan-specific genetic toolkit and molecular pathways. Since sponges lack a conventional nervous system, SDMANF presents an enticing opportunity…
Microvesicles released from Giardia intestinalis disturb host-pathogen response in vitro
2017
Giardia intestinalis (G.I), is an anaerobic protozoan and the aetiological agent of giardiasis, a diarrhoea present worldwide and associated with poverty. G.I has a simple life cycle alternating between cyst and trophozoite. Cysts are transmitted orally to the stomach and transform to trophozoites in the intestine by a multifactorial process. Recently, microvesicles (MVs) have been found to be released from a wide range of eukaryotic cells. We have observed a release of MVs during the life cycle of G.I., identifying MVs from active trophozoites and from trophozoites differentiating to the cyst form. The aim of the current work was to investigate the role of MVs from G.I in the pathogenesis …
Rheostatic Functions of Mast Cells in the Control of Innate and Adaptive Immune Responses
2017
Mast cells are evolutionarily ancient cells, endowed with a unique developmental, phenotypic, and functional plasticity. They are resident cells that participate in tissue homeostasis by constantly sampling the microenvironment. As a result of their large repertoire of receptors, they can respond to multiple stimuli and selectively release different types and amounts of mediator. Here, we present and discuss the recent mast cell literature, focusing on studies that demonstrate that mast cells are more than a switch that is turned âoffâ when in the resting state and âonâ when in the degranulating state. We propose a new vision of mast cells in which, by operating in a ârheostaticâ…
Danger signals: Chemotherapy enhancers?
2017
IF 9.614; International audience; Endogenous danger signals are molecules normally present in a given cell compartment that are rapidly released following cell stress and induce immune responses. We and others have shown that dying tumor cells treated with some chemotherapies are able to induce anticancer immune responses, which rely on their release of danger signals such as the nuclear protein HMGB1. DNA can also be released from chemotherapy-treated tumor cells, act as a danger signal, and boost anticancer immunity. While the immunostimulatory properties of DNA have been identified for decades, the recent discovery of a novel family of receptors, cytosolic DNA sensors, has provided a nov…
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…
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…
Keratinocyte-derived IκBζ drives psoriasis and associated systemic inflammation.
2019
The transcriptional activator IκBζ is a key regulator of psoriasis, but which cells mediate its pathogenic effect remains unknown. Here we found that IκBζ expression in keratinocytes triggers not only skin lesions but also systemic inflammation in mouse psoriasis models. Specific depletion of IκBζ in keratinocytes was sufficient to suppress the induction of imiquimod- or IL-36–mediated psoriasis. Moreover, IκBζ ablation in keratinocytes prevented the onset of psoriatic lesions and systemic inflammation in keratinocyte-specific IL-17A–transgenic mice. Mechanistically, this psoriasis protection was mediated by IκBζ deficiency in keratinocytes abrogating the induction of specific proinflammato…
Gut inflammation in spondyloarthritis
2017
Abstract Spondyloarthritis (SpA) is a group of related diseases sharing common etiopathogenic mechanisms and clinical manifestations supported by a complex genetic predisposition. Gut inflammation is present in patients with SpA including patients showing clinically evident intestinal inflammation in the form of Crohn's disease or ulcerative colitis and patients who despite the absence of signs and symptoms of intestinal inflammation display a subclinical gut inflammation. Emerging evidence suggests that subclinical gut inflammation in patients with SpA, apparently driven by intestinal dysbiosis, is not the consequence of the systemic inflammatory process but rather an important pathophysio…