Search results for "CQ"

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 ‘off’ when in the resting state and ‘on’ when in the degranulating state. We propose a new vision of mast cells in which, by operating in a ‘rheostatic 

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…

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.

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…

2020

Mitochondria have emerged as key actors of innate and adaptive immunity. Mitophagy has a pivotal role in cell homeostasis, but its contribution to macrophage functions and host defense remains to be delineated. Here, we showed that lipopolysaccharide (LPS) in combination with IFN-γ inhibited PINK1-dependent mitophagy in macrophages through a STAT1-dependent activation of the inflammatory caspases 1 and 11. In addition, we demonstrated that the inhibition of mitophagy triggered classical macrophage activation in a mitochondrial ROS-dependent manner. In a murine model of polymicrobial infection (cecal ligature and puncture), adoptive transfer of Pink1-deficient bone marrow or pharmacological …

Oral epithelial cells orchestrate innate type 17 responses to Candida albicans through the virulence factor candidalysin

2017

Candida albicans is a dimorphic commensal fungus that causes severe oral infections in immunodeficient patients. Invasion of C. albicans hyphae into oral epithelium is an essential virulence trait. Interleukin-17 (IL-17) signaling is required for both innate and adaptive immunity to C. albicans. During the innate response, IL-17 is produced by γδ T cells and a poorly understood population of innate-acting CD4+ αβ T cell receptor (TCRαβ)+ cells, but only the TCRαβ+ cells expand during acute infection. Confirming the innate nature of these cells, the TCR was not detectably activated during the primary response, as evidenced by Nur77eGFP mice that report antigen-specific signaling through the …

2018

The catabolic process of autophagy plays important functions in inflammatory and immune responses by modulating innate immunity and adaptive immunity. Over the last decade, a cell-intrinsic role for autophagy in modulating CD4 T cell functions and differentiation was revealed. After the initial observation of autophagosomes in effector CD4 T cells, further work has shown that not only autophagy levels are modulated in CD4 T cells in response to environmental signals but also that autophagy critically affects the biology of these cells. Mouse models of autophagy deletion in CD4 T cells have indeed shown that autophagy is essential for CD4 T cell survival and homeostasis in peripheral lymphoi…

2019

Dendritic cells (DC) fulfill an essential sentinel function within the immune system, acting at the interface of innate and adaptive immunity. The DC family, both in mouse and man, shows high functional heterogeneity in order to orchestrate immune responses toward the immense variety of pathogens and other immunological threats. In this review, we focus on the Langerin+CD8+ DC subpopulation in the spleen. Langerin+CD8+ DC exhibit a high ability to take up apoptotic/dying cells, and therefore they are essential to prime and shape CD8+ T cell responses. Next to the induction of immunity toward blood-borne pathogens, i.e., viruses, these DC are important for the regulation of tolerance toward …