scholarly journals Pathogen Recognition by the Long Pentraxin PTX3

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Federica Moalli ◽  
Sebastien Jaillon ◽  
Antonio Inforzato ◽  
Marina Sironi ◽  
Barbara Bottazzi ◽  
...  
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Pathogen Recognition ◽  
Evolutionarily Conserved ◽  
Infection And Inflammation ◽  
Molecular Patterns

Innate immunity represents the first line of defence against pathogens and plays key roles in activation and orientation of the adaptive immune response. The innate immune system comprises both a cellular and a humoral arm. Components of the humoral arm include soluble pattern recognition molecules (PRMs) that recognise pathogen-associated molecular patterns (PAMPs) and initiate the immune response in coordination with the cellular arm, therefore acting as functional ancestors of antibodies. The long pentraxin PTX3 is a prototypic soluble PRM that is produced at sites of infection and inflammation by both somatic and immune cells. Gene targeting of this evolutionarily conserved protein has revealed a nonredundant role in resistance to selected pathogens. Moreover, PTX3 exerts important functions at the cross-road between innate immunity, inflammation, and female fertility. Here, we review the studies on PTX3, with emphasis on pathogen recognition and cross-talk with other components of the innate immune system.

Role of Toll-like receptors in liver health and disease

2011 ◽  
Vol 121 (10) ◽  
pp. 415-426 ◽  
Author(s):  
Ruth Broering ◽  
Mengji Lu ◽  
Joerg F. Schlaak
Keyword(s):  
Immune System ◽  
Liver Disease ◽  
Innate Immune System ◽  
Innate Immune ◽  
Toll Like Receptors ◽  
Evolutionarily Conserved ◽  
Liver Health ◽  
Health And Disease ◽  
Molecular Patterns

TLRs (Toll-like receptors), as evolutionarily conserved germline-encoded pattern recognition receptors, have a crucial role in early host defence by recognizing so-called PAMPs (pathogen-associated molecular patterns) and may serve as an important link between innate and adaptive immunity. In the liver, TLRs play an important role in the wound healing and regeneration processes, but they are also involved in the pathogenesis and progression of various inflammatory liver diseases, including autoimmune liver disease, alcoholic liver disease, non-alcoholic steatohepatitis, fibrogenesis, and chronic HBV (hepatitis B virus) and HCV (hepatitis C virus) infection. Hepatitis viruses have developed different evading strategies to subvert the innate immune system. Thus recent studies have suggested that TLR-based therapies may represent a promising approach in the treatment in viral hepatitis. The present review focuses on the role of the local innate immune system, and TLRs in particular, in the liver.

scholarly journals Insights into Innate Immune Response Against SARS-CoV-2 Infection

2021 ◽  
Vol 29 (3) ◽  
pp. 255-269
Author(s):  
Adina Huțanu ◽  
Anca Meda Georgescu ◽  
Akos Vince Andrejkovits ◽  
William Au ◽  
Minodora Dobreanu
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Innate Immune System ◽  
Time Course ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Interferon Response ◽  
Humoral Factors ◽  
Key Steps

Abstract The innate immune system is mandatory for the activation of antiviral host defense and eradication of the infection. In this regard, dendritic cells, natural killer cells, macrophages, neutrophils representing the cellular component, and cytokines, interferons, complement or Toll-Like Receptors, representing the mediators of unspecific response act together for both activation of the adaptive immune response and viral clearance. Of great importance is the proper functioning of the innate immune response from the very beginning. For instance, in the early stages of viral infection, the defective interferon response leads to uncontrolled viral replication and pathogen evasion, while hypersecretion during the later stages of infection generates hyperinflammation. This cascade activation of systemic inflammation culminates with cytokine storm syndrome and hypercoagulability state, due to a close interconnection between them. Thus an unbalanced reaction, either under- or over- stimulation of the innate immune system will lead to an uncoordinated response and unfavorable disease outcomes. Since both cellular and humoral factors are involved in the time-course of the innate immune response, in this review we aimed to address their gradual involvement in the antiviral response with emphasis on key steps in SARS-CoV-2 infection.

scholarly journals SARS-CoV-2 and interferon blockade

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Betty Diamond ◽  
Bruce T. Volpe ◽  
Sonya VanPatten ◽  
Yousef Al Abed
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune System ◽  
Neutralizing Antibodies ◽  
Cytotoxic T Cells ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Interferon Production ◽  
Therapeutic Implications ◽  
Adaptive Immune

Abstract The response to viral infection generally includes an activation of the adaptive immune response to produce cytotoxic T cells and neutralizing antibodies. We propose that SARS-CoV-2 activates the innate immune system through the renin-angiotensin and kallikrein-bradykinin pathways, blocks interferon production and reduces an effective adaptive immune response. This model has therapeutic implications.

scholarly journals Orchestration of Adaptive T Cell Responses by Neutrophil Granule Contents

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Danielle Minns ◽  
Katie Jane Smith ◽  
Emily Gwyer Findlay
Keyword(s):  
Immune Response ◽  
Immune System ◽  
T Cell ◽  
Innate Immune System ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
T Cell Immunity ◽  
Cell Responses ◽  
Adaptive Immune ◽  
Cell Immunity

Neutrophils are the most abundant leukocytes in peripheral blood and respond rapidly to danger, infiltrating tissues within minutes of infectious or sterile injury. Neutrophils were long thought of as simple killers, but now we recognise them as responsive cells able to adapt to inflammation and orchestrate subsequent events with some sophistication. Here, we discuss how these rapid responders release mediators which influence later adaptive T cell immunity through influences on DC priming and directly on the T cells themselves. We consider how the release of granule contents by neutrophils—through NETosis or degranulation—is one way in which the innate immune system directs the phenotype of the adaptive immune response.

scholarly journals Combinational clustering of receptors following stimulation by bacterial products determines lipopolysaccharide responses

2004 ◽  
Vol 381 (2) ◽  
pp. 527-536 ◽  
Author(s):  
Martha TRIANTAFILOU ◽  
Klaus BRANDENBURG ◽  
Shoichi KUSUMOTO ◽  
Koichi FUKASE ◽  
Alan MACKIE ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune System ◽  
Imaging Techniques ◽  
Innate Immune ◽  
Surface Receptors ◽  
Wide Range ◽  
Species Specific ◽  
Receptor Clusters ◽  
Molecular Patterns

The innate immune system has the capacity to recognize a wide range of pathogens based on conserved PAMPs (pathogen-associated molecular patterns). In the case of bacterial LPS (lipopolysaccharide) recognition, the best studied PAMP, it has been shown that the innate immune system employs at least three cell-surface receptors: CD14, TLR4 (Toll-like receptor 4) and MD-2 protein. CD14 binds LPS from Enterobacteriaceae and then transfers it to MD-2, leading to TLR4 aggregation and signal transduction. LPS analogues such as lipid IVa seem to act as LPS antagonists in human cells, but exhibit LPS mimetic activity in mouse cells. Although TLR4 has been shown to be involved in this species-specific discrimination, the mechanism by which this is achieved has not been elucidated. The questions that remain are how the innate immune system can discriminate between LPS from different bacteria as well as different LPS analogues, and whether or not the structure of LPS affects its interaction with the CD14–TLR4–MD-2 cluster. Is it possible that the ‘shape’ of LPS induces the formation of different receptor clusters, and thus a different immune response? In the present study, we demonstrate using biochemical as well as fluorescence-imaging techniques that different LPS analogues trigger the recruitment of different receptors within microdomains. The composition of each receptor cluster as well as the number of TLR4 molecules that are recruited within the cluster seem to determine whether an immune response will be induced or inhibited.

scholarly journals Self-harm caused by an insect's innate immunity

2006 ◽  
Vol 273 (1600) ◽  
pp. 2571-2574 ◽  
Author(s):  
Ben M Sadd ◽  
Michael T Siva-Jothy
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Life History ◽  
Immune System ◽  
Innate Immune System ◽  
Innate Immune ◽  
Pathogen Invasion ◽  
Potential Disadvantage ◽  
Self Harm ◽  
Fast Acting

It has been a long-held assumption that the innate immune system of insects causes self-harm when used to combat an immune insult. We show empirically that this assumption is correct. Invertebrate innate immunity relies heavily on effector systems which, on activation, produce cytotoxins that kill pathogens. Reliance on these robust, fast-acting, generic killing mechanisms ensures a potent and rapid response to pathogen invasion, but has the potential disadvantage of causing self-damage. We show that the innate immune response against an immune insult produces measurable phenotypic and functional damage to self-tissue in the beetle Tenebrio molitor . This type of self-harm (autoreactivity) and the life-history implications that arise from it are important to understand evolutionary phenomena such as the dynamics between hosts and parasites as well as the nature of immune system costs.

scholarly journals The Yin and Yang of Innate Immunity in Stroke

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaomeng Xu ◽  
Yongjun Jiang
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Ischemic Stroke ◽  
Immune System ◽  
Innate Immune Response ◽  
Time Window ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Yin And Yang ◽  
Molecular Patterns

Immune system plays an elementary role in the pathophysiological progress of ischemic stroke. It consists of innate and adaptive immune system. Activated within minutes after ischemic onset, innate immunity is responsible for the elimination of necrotic cells and tissue repair, while it is critically involved in the initiation and amplification of poststroke inflammation that amplifies ischemic damage to the brain tissue. Innate immune response requires days to be fully developed, providing a considerable time window for therapeutic intervention, suggesting prospect of novel immunomodulatory therapies against poststroke inflammation-induced brain injury. However, obstacles still exist and a comprehensive understanding of ischemic stroke and innate immune reaction is essential. In this review, we highlighted the current experimental and clinical data depicting the innate immune response following ischemic stroke, mainly focusing on the recognition of damage-associated molecular patterns, activation and recruitment of innate immune cells, and involvement of various cytokines. In addition, clinical trials targeting innate immunity were also documented regardless of the outcome, stressing the requirements for further investigation.

scholarly journals Mice, men and the relatives: cross-species studies underpin innate immunity

Open Biology ◽  
2012 ◽  
Vol 2 (4) ◽  
pp. 120015 ◽  
Author(s):  
Clare E. Bryant ◽  
Tom P. Monie
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Germ Line ◽  
Receptor Activation ◽  
Innate Immune ◽  
Forward Genetics ◽  
Model Organisms ◽  
Current Increase

The innate immune response is the first line of defence against infection. Germ-line-encoded receptors recognize conserved molecular motifs from both exogenous and endogenous sources. Receptor activation results in the initiation of a pro-inflammatory immune response that enables the resolution of infection. Understanding the inner workings of the innate immune system is a fundamental requirement in the search to understand the basis of health and disease. The development of new vaccinations, the treatment of pathogenic infection, the generation of therapies for chronic and auto-inflammatory disorders, and the ongoing battle against cancer, diabetes and atherosclerosis will all benefit from a greater understanding of innate immunity. The rate of knowledge acquisition in this area has been outstanding. It has been underpinned and driven by the use of model organisms. Information obtained from Drospohila melanogaster , knock-out and knock-in mice, and through the use of forward genetics has resulted in discoveries that have opened our eyes to the functionality and complexity of the innate immune system. With the current increase in genomic information, the range of innate immune receptors and pathways of other species available to study is rapidly increasing, and provides a rich resource to continue the development of innate immune research. Here, we address some of the highlights of cross-species study in the innate immune field and consider the benefits of widening the species-field further.

scholarly journals Innate immunity in plants and animals: Differences and similarities

2014 ◽  
Vol 36 (5) ◽  
pp. 40-45 ◽  
Author(s):  
Cara H. Haney ◽  
Frederick M. Ausubel ◽  
Jonathan M. Urbach
Keyword(s):  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Convergent Evolution ◽  
Common Ancestor ◽  
Innate Immune ◽  
Strict Sense ◽  
Molecular Tools ◽  
Similar Solutions ◽  
Molecular Patterns

Plants and animals must avoid becoming a free meal to microbes, which vastly outnumber eukaryotic life in both quantity and diversity. Adaptive immunity in the strict sense, whereby the host creates an immunological memory after exposure to a pathogen, is limited to vertebrates. Both plants and animals (including insects and mammals) have an innate immune system, which helps protect hosts from the majority of microbes they encounter during their lifetime. Plant and animal innate immune systems recognize an overlapping set of conserved microbe-associated molecular patterns (MAMPs). This observation suggests that the innate immune system in plants and animals may have been derived from a common ancestor. However, the majority of data indicate that innate immunity has arisen independently in plants and animals and that functional overlap is the result of convergent evolution: confronted with the same problem, and given the same molecular tools, plants and animals have independently derived similar solutions. This review discusses the functional and mechanistic details of the innate immune system in plants and animals including receptor-mediated immunity, endolysosomal immunity, and the interplay of the innate immune system and host-associated microbial communities.

A molecular analysis of ascidian metamorphosis reveals activation of an innate immune response

Development ◽  
2002 ◽  
Vol 129 (20) ◽  
pp. 4739-4751
Author(s):  
Brad Davidson ◽  
Billie J. Swalla
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Immune System ◽  
Innate Immune System ◽  
Heart Tissue ◽  
Innate Immune ◽  
Differentially Expressed ◽  
Protein Coding ◽  
Settlement Cues ◽  
Immunity Genes

Ascidian metamorphosis represents a powerful model for comparative work on chordate development that has remained largely unexplored. We isolated transcripts differentially expressed during metamorphosis in the ascidian Boltenia villosa by suppressive PCR subtractions of staged larval and juvenile cDNAs. We employed a series of three subtractions to dissect gene expression during metamorphosis. We have isolated 132 different protein coding sequences, and 65 of these transcripts show significant matches to GenBank proteins. Some of these genes have putative functions relevant to key metamorphic events including the differentiation of smooth muscle, blood cells, heart tissue and adult nervous system from larval rudiments. In addition, a significant fraction of the differentially expressed transcripts match identified genes from the innate immune system. Innate immunity confers a rapid response to pathogen-specific molecules and/or compromised self-tissues. The activation of innate immunity genes during metamorphosis may represent the programmed maturation of the adult immune system. In addition, this immune response may be necessary for phagocytosis and re-structuring of larval tissues. An innate immune-related inflammatory response may also underlie two waves of trans-epidermal blood cell migration that occur during the swimming larval period and immediately upon settlement. We characterized these trans-epidermal migrations and discovered that some migratory cells leave the animal entirely through an anterior tunnel in the tunic. We show that these cells are positioned to detect external settlement cues and hypothesize that the innate immune system may also be employed to detect and rapidly respond to environmental settlement cues.

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