scholarly journals Eosinophils and Neutrophils—Molecular Differences Revealed by Spontaneous Raman, CARS and Fluorescence Microscopy

Cells ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2041
Author(s):  
Aleksandra Dorosz ◽  
Marek Grosicki ◽  
Jakub Dybas ◽  
Ewelina Matuszyk ◽  
Marko Rodewald ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Fungal Infections ◽  
Innate Immune ◽  
Lipid Bodies ◽  
Blood Samples ◽  
Cars Microscopy ◽  
Specific Granules ◽  
Anti Stokes

Leukocytes are a part of the immune system that plays an important role in the host’s defense against viral, bacterial, and fungal infections. Among the human leukocytes, two granulocytes, neutrophils (Ne) and eosinophils (EOS) play an important role in the innate immune system. For that purpose, eosinophils and neutrophils contain specific granules containing protoporphyrin-type proteins such as eosinophil peroxidase (EPO) and myeloperoxidase (MPO), respectively, which contribute directly to their anti-infection activity. Since both proteins are structurally and functionally different, they could potentially be a marker of both cells’ types. To prove this hypothesis, UV−Vis absorption spectroscopy and Raman imaging were applied to analyze EPO and MPO and their content in leukocytes isolated from the whole blood. Moreover, leukocytes can contain lipidic structures, called lipid bodies (LBs), which are linked to the regulation of immune responses and are considered to be a marker of cell inflammation. In this work, we showed how to determine the number of LBs in two types of granulocytes, EOS and Ne, using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy. Spectroscopic differences of EPO and MPO can be used to identify these cells in blood samples, while the detection of LBs can indicate the cell inflammation process.

scholarly journals Innate immunity and the pneumococcus

Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 285-293 ◽  
Author(s):  
Gavin K. Paterson ◽  
Tim J. Mitchell
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Streptococcus Pneumoniae ◽  
Immune Responses ◽  
Innate Immune System ◽  
Innate Immune ◽  
First Line ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Made In

The innate immune system provides a non-specific first line of defence against microbes and is crucial both in the development and effector stages of subsequent adaptive immune responses. Consistent with its importance, study of the innate immune system is a broad and fast-moving field. Here we provide an overview of the recent key advances made in this area with relation to the important pathogen Streptococcus pneumoniae (the pneumococcus).

scholarly journals Phenoloxidase activity and haemolymph cytology in honeybees challenged with a virus suspension (deformed wings virus DWV) or phosphate buffered suspension (PBS)

2019 ◽  
Vol 49 (2) ◽  
Author(s):  
Francesca Millanta ◽  
Simona Sagona ◽  
Maurizio Mazzei ◽  
Mario Forzan ◽  
Alessandro Poli ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Innate Immune ◽  
Additional Stress ◽  
Varroa Mite ◽  
Virus Suspension ◽  
Phenoloxidase Activity ◽  
Cell Immunity

ABSTRACT: The innate immune system of honeybees mainly consists in antimicrobial peptides, cellular immunity and melanisation. In order to investigate the immune response of honeybees to immune stressors, three stress degrees were tested. Newly emerged bees naturally DWV-infected were collected from a Varroa mite-free apiary and divided into three experimental groups: naturally DWV infected bees, PBS injected bees, and artificially DWV super infected bees. Phenoloxidase activity and haemolymph cellular subtype count were investigated. Phenoloxidase activity was highest (P<0.05) in DWV-superinfected bees, and the haemocyte population differed within the three observed groups. Although, immune responses following DWV infection have still not been completely clarified, this investigation sheds light on the relation between cell immunity and the phenoloxidase activity of DWV-naturally infected honeybees exposed to additional stress such as injury and viral superinfection.

The innate immune system

2020 ◽  
pp. 307-314
Author(s):  
Paul Bowness
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Cell Types ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Innate Immune Responses ◽  
Adaptive Immune ◽  
System P ◽  
Different Cell Types

The innate immune system comprises evolutionarily ancient mechanisms that mediate first-line responses against microbial pathogens, and are also important in priming and execution of adaptive immune responses, and in defence against tumours. These responses, which recognize microbial non-self, damaged self, and absent self, are characterized by rapidity of action and they involve various different cell types, cell-associated receptors, and soluble factors. Previously thought to lack plasticity or memory, certain innate immune responses have recently been shown to be capable of ‘learning’ or ‘training’. Most cells of the innate immune system are derived from the myeloid precursors in the bone marrow. These include monocytes and their derivatives—macrophages and dendritic cells, blood granulocytes (neutrophils, basophils, and eosinophils), and tissue mast cells.

scholarly journals Tweaking Innate Immunity: The Promise of Innate Immunologicals as Anti-Infectives

2006 ◽  
Vol 17 (5) ◽  
pp. 307-314 ◽  
Author(s):  
Kenneth L Rosenthal
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Immune Defense ◽  
Innate Immune ◽  
Parasitic Infections ◽  
Type I ◽  
Adaptive Immune Responses ◽  
Adaptive Immune

New and exciting insights into the importance of the innate immune system are revolutionizing our understanding of immune defense against infections, pathogenesis, and the treatment and prevention of infectious diseases. The innate immune system uses multiple families of germline-encoded pattern recognition receptors (PRRs) to detect infection and trigger a variety of antimicrobial defense mechanisms. PRRs are evolutionarily highly conserved and serve to detect infection by recognizing pathogen-associated molecular patterns that are unique to microorganisms and essential for their survival. Toll-like receptors (TLRs) are transmembrane signalling receptors that activate gene expression programs that result in the production of proinflammatory cytokines and chemokines, type I interferons and antimicrobial factors. Furthermore, TLR activation facilitates and guides activation of adaptive immune responses through the activation of dendritic cells. TLRs are localized on the cell surface and in endosomal/lysosomal compartments, where they detect bacterial and viral infections. In contrast, nucleotide-binding oligomerization domain proteins and RNA helicases are located in the cell cytoplasm, where they serve as intracellular PRRs to detect cytoplasmic infections, particularly viruses. Due to their ability to enhance innate immune responses, novel strategies to use ligands, synthetic agonists or antagonists of PRRs (also known as 'innate immunologicals') can be used as stand-alone agents to provide immediate protection or treatment against bacterial, viral or parasitic infections. Furthermore, the newly appreciated importance of innate immunity in initiating and shaping adaptive immune responses is contributing to our understanding of vaccine adjuvants and promises to lead to improved next-generation vaccines.

scholarly journals Structural aspects of molecular recognition in the immune system. Part II: Pattern recognition receptors (IUPAC Technical Report)

2014 ◽  
Vol 86 (10) ◽  
pp. 1483-1538 ◽  
Author(s):  
John A. Robinson ◽  
Kerstin Moehle
Keyword(s):  
Pattern Recognition ◽  
Immune System ◽  
Immune Responses ◽  
Signaling Pathways ◽  
Innate Immune System ◽  
Pattern Recognition Receptors ◽  
Innate Immune ◽  
Helicase Domain ◽  
Downstream Signaling ◽  
Adaptive Immune

Abstract The vertebrate immune system uses pattern recognition receptors (PRRs) to detect a large variety of molecular signatures (pathogen-associated molecular patterns, PAMPs) from a broad range of different invading pathogens. The PAMPs range in size from relatively small molecules, to others of intermediate size such as bacterial lipopolysaccharide, lipopeptides, and oligosaccharides, to macromolecules such as viral DNA, RNA, and pathogen-derived proteins such as flagellin. Underlying this functional diversity of PRRs is a surprisingly small number of structurally distinct protein folds that include leucine-rich repeats in Toll-like receptors (TLRs) and NOD-like receptors (NLRs), the DExH box helicase domain in RIG-like receptors (RLRs), and C-type lectin domains (CTLDs) in the C-type lectins. Following PAMP recognition by the PRRs, downstream signaling pathways activate the innate immune system to respond to invading pathogenic organisms. The resulting stimulatory response is also vital for a balanced adaptive immune response to the pathogen, mediated by circulating antibodies and/or cytotoxic T cells. However, an aberrant stimulation of the innate immune system can also lead to excessive inflammatory and toxic stress responses. Exciting opportunities are now arising for the design of small synthetic molecules that bind to PRRs and influence downstream signaling pathways. Such molecules can be useful tools to modulate immune responses, for example, as adjuvants to stimulate adaptive immune responses to a vaccine, or as therapeutic agents to dampen aberrant immune responses, such as inflammation. The design of agonists or antagonists of PRRs can now benefit from a surge in knowledge of the 3D structures of PRRs, many in complexes with their natural ligands. This review article describes recent progress in structural studies of PRRs (TLRs, NLRs, CTLs, and RLRs), which is required for an understanding of how they specifically recognize structurally diverse “foreign” PAMPs amongst a background of other “self” molecules, sometimes closely related in structure, that are present in the human body.

scholarly journals lncRNAs Regulate Innate Immune Responses and Their Roles in Macrophage Polarization

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Zhen Wang ◽  
Ying Zheng
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Macrophage Polarization ◽  
Noncoding Rnas ◽  
Innate Immune ◽  
Microbial Pathogens ◽  
Innate Immune Responses ◽  
First Line ◽  
New Class

The innate immune system is the first line of defense against microbial pathogens. The activated innate immune system plays important roles in eliciting antimicrobial defenses. Despite the benefits of innate immune responses, excessive inflammation will cause host damage. Thus, tight regulation of these processes is required for the maintenance of immune homeostasis. Recently, a new class of long noncoding RNAs (lncRNAs) has emerged as important regulators in many physiological and pathological processes. Dysregulated lncRNAs have been found to be associated with excessive or uncontrolled inflammation. In this brief review, we summarize the roles of functional lncRNAs in regulating innate immune responses. We also discuss the roles of lncRNAs in macrophage polarization, an important molecular event in the innate immune responses.

scholarly journals Innate Immune Responses to Influenza Virus Infections in the Upper Respiratory Tract

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2090
Author(s):  
Edin J. Mifsud ◽  
Miku Kuba ◽  
Ian G. Barr
Keyword(s):  
Influenza Virus ◽  
Immune System ◽  
Epithelial Cells ◽  
Immune Responses ◽  
Respiratory Tract ◽  
Innate Immune System ◽  
Innate Immune ◽  
Upper Respiratory Tract ◽  
Adaptive Immune ◽  
Upper Respiratory

The innate immune system is the host’s first line of immune defence against any invading pathogen. To establish an infection in a human host the influenza virus must replicate in epithelial cells of the upper respiratory tract. However, there are several innate immune mechanisms in place to stop the virus from reaching epithelial cells. In addition to limiting viral replication and dissemination, the innate immune system also activates the adaptive immune system leading to viral clearance, enabling the respiratory system to return to normal homeostasis. However, an overzealous innate immune system or adaptive immune response can be associated with immunopathology and aid secondary bacterial infections of the lower respiratory tract leading to pneumonia. In this review, we discuss the mechanisms utilised by the innate immune system to limit influenza virus replication and the damage caused by influenza viruses on the respiratory tissues and how these very same protective immune responses can cause immunopathology.

scholarly journals β-(1,3)-Glucan Unmasking in Some Candida albicans Mutants Correlates with Increases in Cell Wall Surface Roughness and Decreases in Cell Wall Elasticity

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Sahar Hasim ◽  
David P. Allison ◽  
Scott T. Retterer ◽  
Alex Hopke ◽  
Robert T. Wheeler ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Immune System ◽  
Innate Immune System ◽  
Fungal Infections ◽  
Innate Immune ◽  
Surface Topology ◽  
Wild Type ◽  
Content Type ◽  
Cell Wall Elasticity

ABSTRACT Candida albicans is among the most common human fungal pathogens, causing a broad range of infections, including life-threatening systemic infections. The cell wall of C. albicans is the interface between the fungus and the innate immune system. The cell wall is composed of an outer layer enriched in mannosylated glycoproteins (mannan) and an inner layer enriched in β-(1,3)-glucan and chitin. Detection of C. albicans by Dectin-1, a C-type signaling lectin specific for β-(1,3)-glucan, is important for the innate immune system to recognize systemic fungal infections. Increased exposure of β-(1,3)-glucan to the immune system occurs when the mannan layer is altered or removed in a process called unmasking. Nanoscale changes to the cell wall during unmasking were explored in live cells with atomic force microscopy (AFM). Two mutants, the cho1Δ/Δ and kre5Δ/Δ mutants, were selected as representatives that exhibit modest and strong unmasking, respectively. Comparisons of the cho1Δ/Δ and kre5Δ/Δ mutants to the wild type reveal morphological changes in their cell walls that correlate with decreases in cell wall elasticity. In addition, AFM tips functionalized with Dectin-1 revealed that the forces of binding of Dectin-1 to all of the strains were similar, but the frequency of binding was highest for the kre5Δ/Δ mutant, decreased for the cho1Δ/Δ mutant, and rare for the wild type. These data show that nanoscale changes in surface topology are correlated with increased Dectin-1 adhesion and decreased cell wall elasticity. AFM, using tips functionalized with immunologically relevant molecules, can map epitopes of the cell wall and increase our understanding of pathogen recognition by the immune system.

Sign in / Sign up

Export Citation Format

Share Document