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 Fetal Lymphoid Organ Immune Responses to Transient and Persistent Infection with Bovine Viral Diarrhea Virus

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 816 ◽  
Author(s):  
Katie J. Knapek ◽  
Hanah M. Georges ◽  
Hana Van Campen ◽  
Jeanette V. Bishop ◽  
Helle Bielefeldt-Ohmann ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Bovine Viral Diarrhea ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Adaptive Immune ◽  
Viral Diarrhea Virus

Bovine Viral Diarrhea Virus (BVDV) fetal infections occur in two forms; persistent infection (PI) or transient infection (TI), depending on what stage of gestation the fetus is infected. Examination of lymphoid organs from both PI and TI fetuses reveals drastically different fetal responses, dependent upon the developmental stage of the fetal immune system. Total RNA was extracted from the thymuses and spleens of uninfected control, PI, and TI fetuses collected on day 190 of gestation to test the hypothesis that BVDV infection impairs the innate and adaptive immune response in the fetal thymus and spleen of both infection types. Transcripts of genes representing the innate immune response and adaptive immune response genes were assayed by Reverse Transcription quatitative PCR (RT-qPCR) (2−ΔΔCq; fold change). Genes of the innate immune response, interferon (IFN) inducible genes, antigen presentation to lymphocytes, and activation of B cells were downregulated in day 190 fetal PI thymuses compared to controls. In contrast, innate immune response genes were upregulated in TI fetal thymuses compared to controls and tended to be upregulated in TI fetal spleens. Genes associated with the innate immune system were not different in PI fetal spleens; however, adaptive immune system genes were downregulated, indicating that PI fetal BVDV infection has profound inhibitory effects on the expression of genes involved in the innate and adaptive immune response. The downregulation of these genes in lymphocytes and antigen-presenting cells in the developing thymus and spleen may explain the incomplete clearance of BVDV and the persistence of the virus in PI animals while the upregulation of the TI innate immune response indicates a more mature immune system, able to clear the virus.

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.

Plant Phenolics and Lectins as Vaccine Adjuvants

2019 ◽  
Vol 20 (15) ◽  
pp. 1236-1243 ◽  
Author(s):  
Hernández-Ramos Reyna-Margarita ◽  
Castillo-Maldonado Irais ◽  
Rivera-Guillén Mario-Alberto ◽  
Ramírez-Moreno Agustina ◽  
Serrano-Gallardo Luis-Benjamín ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Adaptive Immune Response ◽  
The Body ◽  
Innate Immune ◽  
Vaccine Adjuvants ◽  
Plant Phenolics ◽  
Adaptive Immune ◽  
Foreign Substance

Background: The immune system is responsible for providing protection to the body against foreign substances. The immune system divides into two types of immune responses to study its mechanisms of protection: 1) Innate and 2) Adaptive. The innate immune response represents the first protective barrier of the organism that also works as a regulator of the adaptive immune response, if evaded the mechanisms of the innate immune response by the foreign substance the adaptive immune response takes action with the consequent antigen neutralization or elimination. The adaptive immune response objective is developing a specific humoral response that consists in the production of soluble proteins known as antibodies capable of specifically recognizing the foreign agent; such protective mechanism is induced artificially through an immunization or vaccination. Unfortunately, the immunogenicity of the antigens is an intrinsic characteristic of the same antigen dependent on several factors. Conclusion: Vaccine adjuvants are chemical substances of very varied structure that seek to improve the immunogenicity of antigens. The main four types of adjuvants under investigation are the following: 1) Oil emulsions with an antigen in solution, 2) Pattern recognition receptors activating molecules, 3) Inflammatory stimulatory molecules or activators of the inflammasome complex, and 4) Cytokines. However, this paper addresses the biological plausibility of two phytochemical compounds as vaccine adjuvants: 5) Lectins, and 6) Plant phenolics whose characteristics, mechanisms of action and disadvantages are addressed. Finally, the immunological usefulness of these molecules is discussed through immunological data to estimate effects of plant phenolics and lectins as vaccine adjuvants, and current studies that have implanted these molecules as vaccine adjuvants, demonstrating the results of this immunization.

The role of the innate immune system on pulmonary infections

2019 ◽  
Vol 400 (4) ◽  
pp. 443-456 ◽  
Author(s):  
Michelle Galeas-Pena ◽  
Nathaniel McLaughlin ◽  
Derek Pociask
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Innate Immune System ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Resistant Bacteria ◽  
Upper Respiratory Tract ◽  
Phagocytic Cells ◽  
Mucus Production

Abstract Inhalation is required for respiration and life in all vertebrates. This process is not without risk, as it potentially exposes the host to environmental pathogens with every breath. This makes the upper respiratory tract one of the most common routes of infection and one of the leading causes of morbidity and mortality in the world. To combat this, the lung relies on the innate immune defenses. In contrast to the adaptive immune system, the innate immune system does not require sensitization, previous exposure or priming to attack foreign particles. In the lung, the innate immune response starts with the epithelial barrier and mucus production and is reinforced by phagocytic cells and T cells. These cells are vital for the production of cytokines, chemokines and anti-microbial peptides that are critical for clearance of infectious agents. In this review, we discuss all aspects of the innate immune response, with a special emphasis on ways to target aspects of the immune response to combat antibiotic resistant bacteria.

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.

scholarly journals Biomaterials-Mediated Regulation of Macrophage Cell Fate

2020 ◽  
Vol 8 ◽  
Author(s):  
Yining Liu ◽  
Tatiana Segura
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Cell Fate ◽  
Innate Immune Response ◽  
Inflammatory Responses ◽  
Macrophage Polarization ◽  
Adaptive Immune Response ◽  
Material Design ◽  
Innate Immune ◽  
Macrophage Phenotype

Endogenous regeneration aims to rebuild and reinstate tissue function through enlisting natural self-repairing processes. Promoting endogenous regeneration by reducing tissue-damaging inflammatory responses while reinforcing self-resolving inflammatory processes is gaining popularity. In this approach, the immune system is recruited as the principal player to deposit a pro-reparative matrix and secrete pro-regenerative cytokines and growth factors. The natural wound healing cascade involves many immune system players (neutrophils, macrophages, T cells, B cells, etc.) that are likely to play important and indispensable roles in endogenous regeneration. These cells support both the innate and adaptive arms of the immune system and collectively orchestrate host responses to tissue damage. As the early responders during the innate immune response, macrophages have been studied for decades in the context of inflammatory and foreign body responses and were often considered a cell type to be avoided. The view on macrophages has evolved and it is now understood that macrophages should be directly engaged, and their phenotype modulated, to guide the timely transition of the immune response and reparative environment. One way to achieve this is to design immunomodulating biomaterials that can be placed where endogenous regeneration is desired and actively direct macrophage polarization. Upon encountering these biomaterials, macrophages are trained to perform more pro-regenerative roles and generate the appropriate environment for later stages of regeneration since they bridge the innate immune response and the adaptive immune response. This new design paradigm necessitates the understanding of how material design elicits differential macrophage phenotype activation. This review is focused on the macrophage-material interaction and how to engineer biomaterials to steer macrophage phenotypes for better tissue regeneration.

scholarly journals Modeling Virus-Induced Inflammation in Zebrafish: A Balance Between Infection Control and Excessive Inflammation

2021 ◽  
Vol 12 ◽  
Author(s):  
Con Sullivan ◽  
Brandy-Lee Soos ◽  
Paul J. Millard ◽  
Carol H. Kim ◽  
Benjamin L. King
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Inflammatory Response ◽  
Viral Infection ◽  
Innate Immune Response ◽  
Innate Immune System ◽  
Innate Immune ◽  
Zebrafish Model ◽  
Infection Models

The inflammatory response to viral infection in humans is a dynamic process with complex cell interactions that are governed by the immune system and influenced by both host and viral factors. Due to this complexity, the relative contributions of the virus and host factors are best studied in vivo using animal models. In this review, we describe how the zebrafish (Danio rerio) has been used as a powerful model to study host-virus interactions and inflammation by combining robust forward and reverse genetic tools with in vivo imaging of transparent embryos and larvae. The innate immune system has an essential role in the initial inflammatory response to viral infection. Focused studies of the innate immune response to viral infection are possible using the zebrafish model as there is a 4-6 week timeframe during development where they have a functional innate immune system dominated by neutrophils and macrophages. During this timeframe, zebrafish lack a functional adaptive immune system, so it is possible to study the innate immune response in isolation. Sequencing of the zebrafish genome has revealed significant genetic conservation with the human genome, and multiple studies have revealed both functional conservation of genes, including those critical to host cell infection and host cell inflammatory response. In addition to studying several fish viruses, zebrafish infection models have been developed for several human viruses, including influenza A, noroviruses, chikungunya, Zika, dengue, herpes simplex virus type 1, Sindbis, and hepatitis C virus. The development of these diverse viral infection models, coupled with the inherent strengths of the zebrafish model, particularly as it relates to our understanding of macrophage and neutrophil biology, offers opportunities for far more intensive studies aimed at understanding conserved host responses to viral infection. In this context, we review aspects relating to the evolution of innate immunity, including the evolution of viral pattern recognition receptors, interferons and interferon receptors, and non-coding RNAs.

scholarly journals How the Innate Immune System Fights for Your Health

2021 ◽  
Vol 9 ◽  
Author(s):  
Mieke C. Louwe ◽  
Pål Aukrust
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Innate Immune System ◽  
The Body ◽  
Innate Immune ◽  
Response Activation

When your body encounters intruders like viruses, bacteria, fungi, or parasites, this invasion triggers a complex and amazing process called the immune response. Activation of the body’s immune system is necessary to fight off these intruders, but it must also distinguish them from the body’s own healthy tissues. The goal of the immune response is to keep the body healthy. The earliest responses that occur to protect the body from invading organisms is called the innate immune response. In this article, we explain the components of the innate immune system and how this system helps to keep the body safe from dangerous invaders.

scholarly journals Effects of antibiotics on acquired immunity in vivo – current state of knowledge

2012 ◽  
Vol 15 (3) ◽  
pp. 583-588 ◽  
Author(s):  
M. Pomorska-Mól ◽  
Z. Pejsak
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Innate Immune Response ◽  
Ex Vivo ◽  
Animal Experiments ◽  
Adaptive Immune Response ◽  
Innate Immune ◽  
Antimicrobial Drugs

AbstractAntibiotics are widely used in the therapy of infections. Besides the respective interactions between antibiotics and pathogens it seems that antibiotics also directly interact with the immune system. Some commonly used antibiotics are currently known to have effects on the innate immune response, as shown byin vitro, ex vivoand alsoin vivoanimal experiments and clinical studies. Most of the experimental papers published to date, as well as most reviews, relate to how antibiotics affect the innate immune response or non-specific monocyte or lymphocyte proliferation. However the effects of antibiotics on the adaptive immune response are still not well characterized. This review of the literature considering differentin vivoexperiments indicate the real importance of interrelations existing between acquired immune responses and antibiotics, however, the mechanism of immunomodulatory effects of antibiotics are still poorly understood. Currently, data on the immunomodulating effects of antibiotics often remain heterogeneous, contradictory or insufficient, but most results published to date revealed the immunosuppressive effect of antibiotics on the antigen- specific immune responsein vivo. In pigs as well as in poultry herds, it is not uncommon practice to add antibiotics to drinking water or feed at the time of vaccination. Information on the effects of such practices on the immune system of animals is restricted and morein vivostudies are needed to investigate the effects of antimicrobial drugs on the immune system, especially in the field conditions.

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