Paving the Way to Tospovirus Infection: Multilined Interplays with Plant Innate Immunity

2019 ◽  
Vol 57 (1) ◽  
pp. 41-62 ◽  
Author(s):  
Min Zhu ◽  
Irene Louise van Grinsven ◽  
Richard Kormelink ◽  
Xiaorong Tao
Keyword(s):  
Innate Immunity ◽  
Life Cycle ◽  
Rna Silencing ◽  
Plant Pathogens ◽  
State Of The Art ◽  
Innate Immune ◽  
Silencing Suppressor ◽  
Viral Genes ◽  
Effector Triggered Immunity ◽  
Cellular Machinery

Tospoviruses are among the most important plant pathogens and cause serious crop losses worldwide. Tospoviruses have evolved to smartly utilize the host cellular machinery to accomplish their life cycle. Plants mount two layers of defense to combat their invasion. The first one involves the activation of an antiviral RNA interference (RNAi) defense response. However, tospoviruses encode an RNA silencing suppressor that enables them to counteract antiviral RNAi. To further combat viral invasion, plants also employ intracellular innate immune receptors (e.g., Sw-5b and Tsw) to recognize different viral effectors (e.g., NSm and NSs). This leads to the triggering of a much more robust defense against tospoviruses called effector-triggered immunity (ETI). Tospoviruses have further evolved their effectors and can break Sw-5b-/Tsw-mediated resistance. The arms race between tospoviruses and both layers of innate immunity drives the coevolution of host defense and viral genes involved in counter defense. In this review, a state-of-the-art overview is presented on the tospoviral life cycle and the multilined interplays between tospoviruses and the distinct layers of defense.

scholarly journals Dodging the Host Interferon-Stimulated Gene Mediated Innate Immunity by HIV-1: A Brief Update on Intrinsic Mechanisms and Counter-Mechanisms

2021 ◽  
Vol 12 ◽  
Author(s):  
Kumaraswami Chintala ◽  
Krishnaveni Mohareer ◽  
Sharmistha Banerjee
Keyword(s):  
Innate Immunity ◽  
Life Cycle ◽  
Innate Immune ◽  
Therapeutic Interventions ◽  
Innate Immune Responses ◽  
Restriction Factors ◽  
Host Restriction ◽  
Interferon Stimulated Genes ◽  
Host Restriction Factors ◽  
Hiv 1

Host restriction factors affect different phases of a viral life cycle, contributing to innate immunity as the first line of defense against viruses, including HIV-1. These restriction factors are constitutively expressed, but triggered upon infection by interferons. Both pre-integration and post-integration events of the HIV-1 life cycle appear to play distinct roles in the induction of interferon-stimulated genes (ISGs), many of which encode antiviral restriction factors. However, HIV-1 counteracts the mechanisms mediated by these restriction factors through its encoded components. Here, we review the recent findings of pathways that lead to the induction of ISGs, and the mechanisms employed by the restriction factors such as IFITMs, APOBEC3s, MX2, and ISG15 in preventing HIV-1 replication. We also reflect on the current understanding of the counter-mechanisms employed by HIV-1 to evade innate immune responses and overcome host restriction factors. Overall, this mini-review provides recent insights into the HIV-1-host cross talk bridging the understanding between intracellular immunity and research avenues in the field of therapeutic interventions against HIV-1.

scholarly journals The Critical Role of Small RNAs in Regulating Plant Innate Immunity

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 184
Author(s):  
Saquib Waheed ◽  
Muhammad Anwar ◽  
Muhammad Asif Saleem ◽  
Jinsong Wu ◽  
Muhammad Tayyab ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Small Rnas ◽  
Plant Immunity ◽  
Critical Role ◽  
Innate Immune ◽  
Genes Encoding ◽  
Effector Triggered Immunity ◽  
Available Information ◽  
Regulatory Functions

Plants, due to their sessile nature, have an innate immune system that helps them to defend against different pathogen infections. The defense response of plants is composed of a highly regulated and complex molecular network, involving the extensive reprogramming of gene expression during the presence of pathogenic molecular signatures. Plants attain proper defense against pathogens through the transcriptional regulation of genes encoding defense regulatory proteins and hormone signaling pathways. Small RNAs are emerging as versatile regulators of plant development and act in different tiers of plant immunity, including pathogen-triggered immunity (PTI) and effector-triggered immunity (ETI). The versatile regulatory functions of small RNAs in plant growth and development and response to biotic and abiotic stresses have been widely studied in recent years. However, available information regarding the contribution of small RNAs in plant immunity against pathogens is more limited. This review article will focus on the role of small RNAs in innate immunity in plants.

scholarly journals Single-cell virus sequencing of influenza infections that trigger innate immunity

2018 ◽  
Author(s):  
Alistair B. Russell ◽  
Jacob R. Kowalsky ◽  
Jesse D. Bloom
Keyword(s):  
Immune Response ◽  
Innate Immunity ◽  
Genetic Variation ◽  
Amino Acid ◽  
Innate Immune ◽  
New Approach ◽  
Viral Genes ◽  
A Cell ◽  
Infected Cells ◽  
Amino Acid Mutations

SUMMARYThe outcome of viral infection is extremely heterogeneous, with infected cells only sometimes activating innate immunity. Here we develop a new approach to assess how the genetic variation inherent in viral populations contributes to this heterogeneity. We do this by determining both the transcriptome and full-length sequences of all viral genes in single influenza-infected cells. Most cells are infected by virions with defects such as amino-acid mutations, internal deletions, or failure to express a gene. We identify instances of each type of defect that increase the likelihood that a cell activates an innate-immune response. However, immune activation remains stochastic in cells infected by virions with these defects, and sometimes occurs even when a cell is infected by a virion that expresses unmutated copies of all genes. Our work shows that viral genetic variation substantially contributes to but does not fully explain the heterogeneity in single influenza-infected cells.

RNA Silencing Suppressor p19 Regulates The Expressions of Cell Cycle Related Genes*

2009 ◽  
Vol 36 (5) ◽  
pp. 541-548 ◽  
Author(s):  
Li LIU ◽  
Jian LI ◽  
Yu-Ping XU ◽  
Wen-Tao QIAO ◽  
Qi-Min CHEN ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Rna Silencing ◽  
Silencing Suppressor ◽  
Rna Silencing Suppressor

scholarly journals Special Issue: “Innate Immune Sensing of Viruses and Viral Evasion”

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 567
Author(s):  
Renate König ◽  
Carsten Münk
Keyword(s):  
Innate Immunity ◽  
Innate Immune ◽  
Special Issue ◽  
First Line ◽  
Review Articles ◽  
Immune Sensing ◽  
Innate Immune Sensing ◽  
Viral Evasion

In this Special Issue, a wide variety of original and review articles provide a timely overview of how viruses are recognized by and evade from cellular innate immunity, which represents the first line of defense against viruses [...]

Identification of RNA silencing suppressor encoded by wheat blue dwarf (WBD) phytoplasma

Plant Biology ◽  
2021 ◽  
Author(s):  
Licheng Wang ◽  
Wenbao Chen ◽  
Huan Ma ◽  
Jingyuan Li ◽  
Xingan Hao ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Silencing Suppressor ◽  
Rna Silencing Suppressor

scholarly journals Sustainable Agri-Food Processes and Circular Economy Pathways in a Life Cycle Perspective: State of the Art of Applicative Research

2021 ◽  
Vol 13 (5) ◽  
pp. 2472
Author(s):  
Teodora Stillitano ◽  
Emanuele Spada ◽  
Nathalie Iofrida ◽  
Giacomo Falcone ◽  
Anna Irene De Luca
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Circular Economy ◽  
Social Life ◽  
Food Systems ◽  
State Of The Art ◽  
Terrestrial Ecosystems ◽  
Point Of View ◽  
Social Life Cycle Assessment ◽  
Qualitative Synthesis

This study aims at providing a systematic and critical review on the state of the art of life cycle applications from the circular economy point of view. In particular, the main objective is to understand how researchers adopt life cycle approaches for the measurement of the empirical circular pathways of agri-food systems along with the overall lifespan. To perform the literature review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol was considered to conduct a review by qualitative synthesis. Specifically, an evaluation matrix has been set up to gather and synthesize research evidence, by classifying papers according to several integrated criteria. The literature search was carried out employing scientific databases. The findings highlight that 52 case studies out of 84 (62% of the total) use stand-alone life cycle assessment (LCA) to evaluate the benefits/impacts of circular economy (CE) strategies. In contrast, only eight studies (9.5%) deal with the life cycle costing (LCC) approach combined with other analyses while no paper deals with the social life cycle assessment (S-LCA) methodology. Global warming potential, eutrophication (for marine, freshwater, and terrestrial ecosystems), human toxicity, and ecotoxicity results are the most common LCA indicators applied. Only a few articles deal with the CE assessment through specific indicators. We argue that experts in life cycle methodologies must strive to adopt some key elements to ensure that the results obtained fit perfectly with the measurements of circularity and that these can even be largely based on a common basis.

scholarly journals Meningococcal Outer Membrane Vesicle Composition-Dependent Activation of the Innate Immune Response

2016 ◽  
Vol 84 (10) ◽  
pp. 3024-3033 ◽  
Author(s):  
Afshin Zariri ◽  
Joep Beskers ◽  
Bas van de Waterbeemd ◽  
Hendrik Jan Hamstra ◽  
Tim H. E. Bindels ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Outer Membrane ◽  
Lipid A ◽  
Membrane Vesicle ◽  
Outer Membrane Vesicles ◽  
Factor H ◽  
Innate Immune ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Detergent Treatment

Meningococcal outer membrane vesicles (OMVs) have been extensively investigated and successfully implemented as vaccines. They contain pathogen-associated molecular patterns, including lipopolysaccharide (LPS), capable of triggering innate immunity. However,Neisseria meningitidiscontains an extremely potent hexa-acylated LPS, leading to adverse effects when its OMVs are applied as vaccines. To create safe OMV vaccines, detergent treatment is generally used to reduce the LPS content. While effective, this method also leads to loss of protective antigens such as lipoproteins. Alternatively, genetic modification of LPS can reduce its toxicity. In the present study, we have compared the effects of standard OMV isolation methods using detergent or EDTA with those of genetic modifications of LPS to yield a penta-acylated lipid A (lpxL1andpagL) on thein vitroinduction of innate immune responses. The use of detergent decreased both Toll-like receptor 4 (TLR4) and TLR2 activation by OMVs, while the LPS modifications reduced only TLR4 activation. Mutational removal of PorB or lipoprotein factor H binding protein (fHbp), two proteins known to trigger TLR2 signaling, had no effect, indicating that multiple TLR2 ligands are removed by detergent treatment. Detergent-treated OMVs andlpxL1OMVs showed similar reductions of cytokine profiles in the human monocytic cell line MM6 and human dendritic cells (DCs). OMVs with the alternative penta-acylated LPS structure obtained after PagL-mediated deacylation showed reduced induction of proinflammatory cytokines interleukin-6 (IL-6) and IL-1β but not of IP-10, a typical TRIF-dependent chemokine. Taken together, these data show that lipid A modification can be used to obtain OMVs with reduced activation of innate immunity, similar to what is found after detergent treatment.

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