Search results for " Immunity"
showing 10 items of 618 documents
The relative abundance of hemocyte types in a polyphagous moth larva depends on diet.
2016
7 pages; International audience; Hemocytes are crucial cells of the insect immune system because of their involvement in multiple immune responses including coagulation, phagocytosis and encapsulation. There are various types of hemocytes, each having a particular role in immunity, such that variation in their relative abundance affects the outcome of the immune response. This study aims to characterize these various types of hemocytes in larvae of the grapevine pest insect Eupoecilia ambiguella, and to assess variation in their concentration as a function of larval diet and immune challenge. Four types of hemocytes were found in the hemolymph of 5th instar larvae: granulocytes, oenocytoids…
NANOG Plays a Hierarchical Role in the Transcription Network Regulating the Pluripotency and Plasticity of Adipose Tissue-Derived Stem Cells
2017
The stromal vascular cell fraction (SVF) of visceral and subcutaneous adipose tissue (VAT and SAT) has increasingly come into focus in stem cell research, since these compartments represent a rich source of multipotent adipose-derived stem cells (ASCs). ASCs exhibit a self-renewal potential and differentiation capacity. Our aim was to study the different expression of the embryonic stem cell markers NANOG (homeobox protein NANOG), SOX2 (SRY (sex determining region Y)-box 2) and OCT4 (octamer-binding transcription factor 4) and to evaluate if there exists a hierarchal role in this network in ASCs derived from both SAT and VAT. ASCs were isolated from SAT and VAT biopsies of 72 consenting pat…
Role of Immunogenetics in the Outcome of HCMV Infection: Implications for Ageing
2019
The outcome of host-virus interactions is determined by a number of factors, some related to the virus, others to the host, such as environmental factors and genetic factors. Therefore, different individuals vary in their relative susceptibility to infections. Human cytomegalovirus (HCMV) is an important pathogen from a clinical point of view, as it causes significant morbidity and mortality in immunosuppressed or immunosenescent individuals, such as the transplanted patients and the elderly, respectively. It is, therefore, important to understand the mechanisms of virus infection control. In this review, we discuss recent advances in the immunobiology of HCMV-host interactions, with partic…
IL-33/IL-31 Axis: A Potential Inflammatory Pathway
2018
Cytokines play an important role in the regulation of the immune system (adaptive and innate). Given their importance in proinflammatory processes, cytokines have been used for understanding the pathogenesis and as biomarkers in many diseases. IL-31 and IL-33 are still considered novel cytokines. IL-31 controls signalling and regulates a huge amount of biological functions: it induces proinflammatory cytokines, regulates cell proliferation, and is involved also in tissue remodelling. On the other hand, IL-33 has been identified as an “alarmin” released from the epithelial cells and from different human tissues and organs after a damage following, that is, an inflammatory process. The aim of…
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…
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…
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…