scholarly journals Neutrophils and Bacterial Immune Evasion

2018 ◽  
Vol 10 (5-6) ◽  
pp. 432-441 ◽  
Author(s):  
Scott D. Kobayashi ◽  
Natalia Malachowa ◽  
Frank R. DeLeo
Keyword(s):  
Immune System ◽  
Bacterial Infection ◽  
Immune Evasion ◽  
Bactericidal Activity ◽  
Innate Immune System ◽  
Bacterial Pathogens ◽  
Neutrophil Recruitment ◽  
Innate Immune ◽  
Front Line ◽  
And Function

Neutrophils are an important component of the innate immune system and provide a front line of defense against bacterial infection. Although most bacteria are killed readily by neutrophils, some bacterial pathogens have the capacity to circumvent destruction by these host leukocytes. The ability of bacterial pathogens to avoid killing by neutrophils often involves multiple attributes or characteristics, including the production of virulence molecules. These molecules are diverse in composition and function, and collectively have the potential to alter or inhibit neutrophil recruitment, phagocytosis, bactericidal activity, and/or apoptosis. Here, we review the ability of bacteria to target these processes.

scholarly journals A Novel Regulatory Player in the Innate Immune System: Long Non-Coding RNAs

2021 ◽  
Vol 22 (17) ◽  
pp. 9535
Author(s):  
Yuhuai Xie ◽  
Yuanyuan Wei
Keyword(s):  
Immune System ◽  
Immune Cells ◽  
Innate Immune System ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Immune Mediated ◽  
Development And Differentiation ◽  
Non Coding Rnas ◽  
And Function

Long non-coding RNAs (lncRNAs) represent crucial transcriptional and post-transcriptional gene regulators during antimicrobial responses in the host innate immune system. Studies have shown that lncRNAs are expressed in a highly tissue- and cell-specific- manner and are involved in the differentiation and function of innate immune cells, as well as inflammatory and antiviral processes, through versatile molecular mechanisms. These lncRNAs function via the interactions with DNA, RNA, or protein in either cis or trans pattern, relying on their specific sequences or their transcriptions and processing. The dysregulation of lncRNA function is associated with various human non-infectious diseases, such as inflammatory bowel disease, cardiovascular diseases, and diabetes mellitus. Here, we provide an overview of the regulation and mechanisms of lncRNA function in the development and differentiation of innate immune cells, and during the activation or repression of innate immune responses. These elucidations might be beneficial for the development of therapeutic strategies targeting inflammatory and innate immune-mediated diseases.

Neutrophil abnormalities

2018 ◽  
Author(s):  
Malini Bhole
Keyword(s):  
Clinical Practice ◽  
Immune System ◽  
Innate Immune System ◽  
Innate Immune ◽  
Bacterial Invasion ◽  
Systemic Diseases ◽  
First Line ◽  
Life Threatening ◽  
And Function

Neutrophils are an important component of the innate immune system, forming the first line of defence against bacterial invasion. Abnormalities in either neutrophil numbers or function lead to immunodeficiency disorders affecting the innate immune system, with a predisposition towards developing serious and often life-threatening infections. Alterations in neutrophil numbers and function may also be noted secondary to systemic diseases, where they may act as markers for ongoing disease processes. Most of the primary neutrophil disorders discussed in this chapter will present in childhood. In adults, acquired neutropenia is the commonest neutrophil abnormality encountered in clinical practice, although, rarely, some primary neutrophil defects may present.

scholarly journals Viral Modulation of TLRs and Cytokines and the Related Immunotherapies for HPV-Associated Cancers

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Marconi Rego Barros ◽  
Talita Helena Araújo de Oliveira ◽  
Cristiane Moutinho Lagos de Melo ◽  
Aldo Venuti ◽  
Antonio Carlos de Freitas
Keyword(s):  
Immune Response ◽  
Human Papillomavirus ◽  
Immune System ◽  
Immune Evasion ◽  
Innate Immune System ◽  
Innate Immune ◽  
Cell Maturation ◽  
Host Immune System ◽  
Key Factor ◽  
Infected Cells

The modulation of the host innate immune system is a well-established carcinogenesis feature of several tumors, including human papillomavirus- (HPV-) related cancers. This virus is able to interrupt the initial events of the immune response, including the expression of Toll-like receptors (TLRs), cytokines, and inflammation. Both TLRs and cytokines play a central role in HPV recognition, cell maturation and differentiation as well as immune signalling. Therefore, the imbalance of this sensitive control of the immune response is a key factor for developing immunotherapies, which strengthen the host immune system to accomplish an efficient defence against HPV and HPV-infected cells. Based on this, the review is aimed at exposing the HPV immune evasion mechanisms involving TLRs and cytokines and at discussing existing and potential immunotherapeutic TLR- and cytokine-related tools.

scholarly journals Toll-Like Receptors, Tissue Injury, and Tumourigenesis

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Savvas Ioannou ◽  
Michael Voulgarelis
Keyword(s):  
Immune System ◽  
Innate Immune System ◽  
Tissue Injury ◽  
Healing Process ◽  
Critical Role ◽  
Tumour Microenvironment ◽  
Innate Immune ◽  
Wound Healing Process ◽  
Toll Like Receptors ◽  
And Function

Toll-like receptors (TLRs) belong to a class of molecules known as pattern recognition receptors, and they are part of the innate immune system, although they modulate mechanisms that impact the development of adaptive immune responses. Several studies have shown that TLRs, and their intracellular signalling components, constitute an important cellular pathway mediating the inflammatory process. Moreover, their critical role in the regulation of tissue injury and wound healing process as well as in the regulation of apoptosis is well established. However, interest in the role of these receptors in cancer development and progression has been increasing over the last years. TLRs are likely candidates to mediate effects of the innate immune system within the tumour microenvironment. A rapidly expanding area of research regarding the expression and function of TLRs in cancer cells and its association with chemoresistance and tumourigenesis, and TLR-based therapy as potential immunotherapy in cancer treatment is taking place over the last years.

Arming the enemy: the evolution of resistance to self-proteins

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1367-1375 ◽  
Author(s):  
Graham Bell ◽  
Pierre-Henri Gouyon
Keyword(s):  
Immune System ◽  
Bacterial Infection ◽  
Innate Immune System ◽  
Membrane Structure ◽  
Innate Immune ◽  
Bacterial Membrane ◽  
Evolution Of Resistance ◽  
Defence Proteins ◽  
Toxic Peptides ◽  
Novel Antibiotics

A remarkable range of novel antibiotics is attracting increasing interest as a major new weapon in the campaign against bacterial infection. They are based on the toxic peptides that provide the innate immune system of animals, and it is claimed that bacteria will be unable to evolve resistance to them because they attack the ‘Achilles' heel’ of bacterial membrane structure. Both experimental evidence and theoretical arguments suggest that this claim is doubtful. If so, the introduction of these substances into general use may provoke the evolution of resistance to our own defence proteins and thus compromise our natural defences against infection.

Innate immune system favors emergency monopoiesis at the expense of DC-differentiation to control systemic bacterial infection in mice

2015 ◽  
Vol 45 (10) ◽  
pp. 2821-2833 ◽  
Author(s):  
Karina A. Pasquevich ◽  
Kristin Bieber ◽  
Manina Günter ◽  
Matthias Grauer ◽  
Oliver Pötz ◽  
...  
Keyword(s):  
Immune System ◽  
Bacterial Infection ◽  
Innate Immune System ◽  
Innate Immune ◽  
Systemic Bacterial Infection

scholarly journals Retrovirus-derived acquired genes, RTL5 and RTL6, are novel constituents of the innate immune system in the eutherian brain.

2021 ◽  
Author(s):  
Masahito Irie ◽  
Johbu Itoh ◽  
Ayumi Matsuzawa ◽  
Masahito Ikawa ◽  
Toru Suzuki ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Innate Immune System ◽  
Basic Protein ◽  
Innate Immune ◽  
Hazardous Substances ◽  
Innate Immune Responses ◽  
Front Line ◽  
Cpg Dna ◽  
Mature Brain

Retrotransposon Gag-like 5 (RTL5, also known as sushi-ichi-related retrotransposon homolog 8 (SIRH8)) and RTL6 (aka SIRH3) are eutherian-specific genes presumably derived from a retrovirus and phylogenetically related to each other. RTL5 encodes a strongly acidic protein while RTL6 encodes an extremely basic protein, and the former is well conserved and the latter extremely well conserved among the eutherians, indicating their unique and critically important roles as acquired genes. Here we report that RTL5 and RTL6 are microglial genes playing roles in the front line of brain innate immune responses against distinct pathogens. Venus and mCherry knock-in mice exhibited expression of RTL5-mCherry and RTL6-Venus fusion proteins in microglia and as extracellular granules in the central nervus system (CNS), and displayed a rapid response to pathogens such as lipopolysaccharide (LPS), double-stranded (ds) RNA analog and non-methylated CpG DNA. These proteins trapped pathogens in microglia in a variety of RTL-pathogen complexes depending on the pathogens. These results demonstrate that RTL5 and RTL6 exert functional effects against different hazardous substances cooperatively and/or independently to protect the developing and/or mature brain. This provides the first evidence that retrovirus-derived genes play a role in the innate immune system of the eutherian brain.

scholarly journals Fish Immunology. The modification and manipulation of the innate immune system: Brazilian studies

2014 ◽  
Vol 86 (3) ◽  
pp. 1484-1506 ◽  
Author(s):  
JAQUELINE D. BILLER-TAKAHASHI ◽  
ELISABETH C. URBINATI
Keyword(s):  
Immune System ◽  
Innate Immune System ◽  
New Technologies ◽  
Disease Outbreaks ◽  
Innate Immune ◽  
System Structure ◽  
Economic Losses ◽  
Massive Growth ◽  
And Function ◽  
Brazilian Studies

The understanding of fish immune system structure and function is essential for the development of new technologies and products to improve productivity. This is the first review on immune system of fish with Brazilian studies. Aquaculture in Brazil has shown massive growth in recent years due to methods of culture intensification. However, these procedures led to disease outbreaks, as well as the chemotherapy and the misuse of antibiotics. A viable alternative to avoid the use of chemicals and prevent economic losses is the administration of immunostimulants and prebiotcs, which act by increasing the innate immune system. In Brazil there is a lack of studies on fish immune system, except by some groups that have studied the effects of the immunostimulants administration in various species.

scholarly journals LAPped in Proof: LC3‐Associated Phagocytosis and the Arms Race Against Bacterial Pathogens

2022 ◽  
Vol 11 ◽  
Author(s):  
Bart J. M. Grijmans ◽  
Sander B. van der Kooij ◽  
Monica Varela ◽  
Annemarie H. Meijer
Keyword(s):  
Immune System ◽  
Innate Immune System ◽  
Bacterial Pathogens ◽  
Host Immunity ◽  
Arms Race ◽  
Innate Immune ◽  
Immune Mechanism ◽  
Lysosomal Degradation ◽  
Innate Immune Mechanism ◽  
Extracellular Environment

Cells of the innate immune system continuously patrol the extracellular environment for potential microbial threats that are to be neutralized by phagocytosis and delivery to lysosomes. In addition, phagocytes employ autophagy as an innate immune mechanism against pathogens that succeed to escape the phagolysosomal pathway and invade the cytosol. In recent years, LC3-associated phagocytosis (LAP) has emerged as an intermediate between phagocytosis and autophagy. During LAP, phagocytes target extracellular microbes while using parts of the autophagic machinery to label the cargo-containing phagosomes for lysosomal degradation. LAP contributes greatly to host immunity against a multitude of bacterial pathogens. In the pursuit of survival, bacteria have developed elaborate strategies to disarm or circumvent the LAP process. In this review, we will outline the nature of the LAP mechanism and discuss recent insights into its interplay with bacterial pathogens.

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