scholarly journals Dampening the DAMPs: How Plants Maintain the Homeostasis of Cell Wall Molecular Patterns and Avoid Hyper-Immunity

2020 ◽  
Vol 11 ◽  
Author(s):  
Daniela Pontiggia ◽  
Manuel Benedetti ◽  
Sara Costantini ◽  
Giulia De Lorenzo ◽  
Felice Cervone
Keyword(s):  
Plant Immunity ◽  
Microbial Pathogens ◽  
General Strategy ◽  
Plant Cell Walls ◽  
Cellular Mechanisms ◽  
The Family ◽  
Cellulose Breakdown ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Hydrolysis Of

Several oligosaccharide fragments derived from plant cell walls activate plant immunity and behave as typical damage-associated molecular patterns (DAMPs). Some of them also behave as negative regulators of growth and development, and due to their antithetic effect on immunity and growth, their concentrations, activity, time of formation, and localization is critical for the so-called “growth-defense trade-off.” Moreover, like in animals, over accumulation of DAMPs in plants provokes deleterious physiological effects and may cause hyper-immunity if the cellular mechanisms controlling their homeostasis fail. Recently, a mechanism has been discovered that controls the activity of two well-known plant DAMPs, oligogalacturonides (OGs), released upon hydrolysis of homogalacturonan (HG), and cellodextrins (CDs), products of cellulose breakdown. The potential homeostatic mechanism involves specific oxidases belonging to the family of berberine bridge enzyme-like (BBE-like) proteins. Oxidation of OGs and CDs not only inactivates their DAMP activity, but also makes them a significantly less desirable food source for microbial pathogens. The evidence that oxidation and inactivation of OGs and CDs may be a general strategy of plants for controlling the homeostasis of DAMPs is discussed. The possibility exists of discovering additional oxidative and/or inactivating enzymes targeting other DAMP molecules both in the plant and in animal kingdoms.

scholarly journals Plant immunity triggered by engineered in vivo release of oligogalacturonides, damage-associated molecular patterns

2015 ◽  
Vol 112 (17) ◽  
pp. 5533-5538 ◽  
Author(s):  
Manuel Benedetti ◽  
Daniela Pontiggia ◽  
Sara Raggi ◽  
Zhenyu Cheng ◽  
Flavio Scaloni ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Plant Immunity ◽  
Inducible Promoter ◽  
Spectrometric Analysis ◽  
In Planta ◽  
Gene Encoding ◽  
Polygalacturonase Inhibiting Protein ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Oligogalacturonides (OGs) are fragments of pectin that activate plant innate immunity by functioning as damage-associated molecular patterns (DAMPs). We set out to test the hypothesis that OGs are generated in planta by partial inhibition of pathogen-encoded polygalacturonases (PGs). A gene encoding a fungal PG was fused with a gene encoding a plant polygalacturonase-inhibiting protein (PGIP) and expressed in transgenic Arabidopsis plants. We show that expression of the PGIP–PG chimera results in the in vivo production of OGs that can be detected by mass spectrometric analysis. Transgenic plants expressing the chimera under control of a pathogen-inducible promoter are more resistant to the phytopathogens Botrytis cinerea, Pectobacterium carotovorum, and Pseudomonas syringae. These data provide strong evidence for the hypothesis that OGs released in vivo act as a DAMP signal to trigger plant immunity and suggest that controlled release of these molecules upon infection may be a valuable tool to protect plants against infectious diseases. On the other hand, elevated levels of expression of the chimera cause the accumulation of salicylic acid, reduced growth, and eventually lead to plant death, consistent with the current notion that trade-off occurs between growth and defense.

Taking Advantage of Plant Defense Mechanisms to Promote Human Health. The Plant Immune System. First of Two Parts

2020 ◽  
Vol 20 ◽  
Author(s):  
Thea Magrone ◽  
Manrico Magrone ◽  
Matteo Antonio Russo ◽  
Emilio Jirillo
Keyword(s):  
Immune Response ◽  
Plant Defense ◽  
Defense Mechanisms ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Early Response ◽  
Protein Receptors ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Background: Despite the evidence that plants do not possess sessile cells, they are able to mount a vigorous immune response against invaders or under stressful conditions. Mechanisms of action: Plants are endowed with pattern recognition receptors (PPRs) which perceive damage-associated molecular patterns and microbe-associated molecular patterns or pathogen-associated molecular patterns (PAMPs), respectively. PPR activation leads to either the initiation of PAMP-triggered immunity (PTI) (early response) or the effectortriggered immunity (ETI). Both PTI and ETI contribute to plant systemic acquired resistance as also an expression of immunological memory or trained immunity. Plant immune receptors: PTI is initiated by activation of both receptor-like kinases and receptor-like proteins, while ETI depends on nucleotide-binding leucine-rich-repeat protein receptors for microbe recognition. Peptides involved in plant defenses: Plant chloroplasts contribute to both PTI and ETI through production of peptides which act as hormones or phytocytokines. Salicylic acid, jasmonic acid and ethylene are the major compounds involved in plant defense. Specific aims: The interaction between plant receptors and/or their products and bacterial components will be discussed. Also emphasis will be placed on plant microbiome for its contribution to plant immune response. Finally, the mutual interplay between insects and plants will also be illustrated. Conclusion: A better knowledge on plant immunity may pave the way for the exploitation of plant derivatives in the field of agriculture and medicine, as well.

scholarly journals Toll-Like Receptors in Hepatic Ischemia/Reperfusion and Transplantation

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
John Evankovich ◽  
Timothy Billiar ◽  
Allan Tsung
Keyword(s):  
Tissue Injury ◽  
Ischemia Reperfusion ◽  
Innate Immune ◽  
Toll Like Receptors ◽  
Hepatic Ischemia ◽  
Danger Signals ◽  
The Family ◽  
Hepatic Ischemia Reperfusion ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

The family of Toll-like receptors (TLRs) function as pattern-recognition receptors (PRRs) that respond to a myriad of highly conserved ligands. These substrates include pathogen-associated molecular patterns (PAMPs) for the recognition of invading pathogens, as well as damage-associated molecular patterns (DAMPs) for the recognition of endogenous tissue injury. While the functions of TLRs are diverse, they have received much attention for their roles in ischemia/reperfusion (I/R) injury of the liver and other organs. The TLRs play central roles in sensing tissue damage and activating the innate immune system following I/R. Engagement of TLRs by endogenous DAMPs activates proinflammatory signaling pathways leading to the production of cytokines, chemokines and further release of endogenous danger signals. This paper focuses on the most recent findings regarding TLR family members in hepatic I/R injury and transplantation.

scholarly journals Poaceae-specific cell wall-derived oligosaccharides activate plant immunity via OsCERK1 during Magnaporthe oryzae infection in rice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Yang ◽  
Rui Liu ◽  
Jinhuan Pang ◽  
Bin Ren ◽  
Huanbin Zhou ◽  
...  
Keyword(s):  
Cell Wall ◽  
Immune Responses ◽  
Magnaporthe Oryzae ◽  
Plant Cell Wall ◽  
Plant Immunity ◽  
Host Cells ◽  
Specific Cell ◽  
Chitin Binding Protein ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

AbstractMany phytopathogens secrete cell wall degradation enzymes (CWDEs) to damage host cells and facilitate colonization. As the major components of the plant cell wall, cellulose and hemicellulose are the targets of CWDEs. Damaged plant cells often release damage-associated molecular patterns (DAMPs) to trigger plant immune responses. Here, we establish that the fungal pathogen Magnaporthe oryzae secretes the endoglucanases MoCel12A and MoCel12B during infection of rice (Oryza sativa). These endoglucanases target hemicellulose of the rice cell wall and release two specific oligosaccharides, namely the trisaccharide 31-β-D-Cellobiosyl-glucose and the tetrasaccharide 31-β-D-Cellotriosyl-glucose. 31-β-D-Cellobiosyl-glucose and 31-β-D-Cellotriosyl-glucose bind the immune receptor OsCERK1 but not the chitin binding protein OsCEBiP. However, they induce the dimerization of OsCERK1 and OsCEBiP. In addition, these Poaceae cell wall-specific oligosaccharides trigger a burst of reactive oxygen species (ROS) that is largely compromised in oscerk1 and oscebip mutants. We conclude that 31-β-D-Cellobiosyl-glucose and 31-β-D-Cellotriosyl-glucose are specific DAMPs released from the hemicellulose of rice cell wall, which are perceived by an OsCERK1 and OsCEBiP immune complex during M. oryzae infection in rice.

scholarly journals Nuclear Alarmin Cytokines in Inflammation

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lili Jiang ◽  
Yijia Shao ◽  
Yao Tian ◽  
Changsheng Ouyang ◽  
Xiaohua Wang
Keyword(s):  
Inflammatory Response ◽  
Physiological Stress ◽  
Physiological State ◽  
High Mobility ◽  
Molecular Structures ◽  
Sterile Inflammation ◽  
Microbial Pathogens ◽  
Endogenous Proteins ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Pathogen-associated molecular patterns (PAMPs) are some nonspecific and highly conserved molecular structures of exogenous specific microbial pathogens, whose products can be recognized by pattern recognition receptor (PRR) on innate immune cells and induce an inflammatory response. Under physiological stress, activated or damaged cells might release some endogenous proteins that can also bind to PRR and cause a harmful aseptic inflammatory response. These endogenous proteins were named damage-associated molecular patterns (DAMPs) or alarmins. Indeed, alarmins can also play a beneficial role in the tissue repair in certain environments. Besides, some alarmin cytokines have been reported to have both nuclear and extracellular effects. This group of proteins includes high-mobility group box-1 protein (HMGB1), interleukin (IL)-33, IL-1α, IL-1F7b, and IL-16. In this article, we review the involvement of nuclear alarmins such as HMGB1, IL-33, and IL-1α under physiological state or stress state and suggest a novel activity of these molecules as central initiators in the development of sterile inflammation.

scholarly journals NLR members NLRC4 and NLRP3 mediate sterile inflammasome activation in microglia and astrocytes

2017 ◽  
Vol 214 (5) ◽  
pp. 1351-1370 ◽  
Author(s):  
Leslie Freeman ◽  
Haitao Guo ◽  
Clément N. David ◽  
W. June Brickey ◽  
Sushmita Jha ◽  
...  
Keyword(s):  
Neurological Diseases ◽  
Microbial Pathogens ◽  
Inflammasome Activation ◽  
Potassium Efflux ◽  
Caspase 1 ◽  
Physiological Relevance ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Pronounced Reduction ◽  
The Brain

Inflammation in the brain accompanies several high-impact neurological diseases including multiple sclerosis (MS), stroke, and Alzheimer’s disease. Neuroinflammation is sterile, as damage-associated molecular patterns rather than microbial pathogens elicit the response. The inflammasome, which leads to caspase-1 activation, is implicated in neuroinflammation. In this study, we reveal that lysophosphatidylcholine (LPC), a molecule associated with neurodegeneration and demyelination, elicits NLRP3 and NLRC4 inflammasome activation in microglia and astrocytes, which are central players in neuroinflammation. LPC-activated inflammasome also requires ASC (apoptotic speck containing protein with a CARD), caspase-1, cathepsin-mediated degradation, calcium mobilization, and potassium efflux but not caspase-11. To study the physiological relevance, Nlrc4−/− and Nlrp3−/− mice are studied in the cuprizone model of neuroinflammation and demyelination. Mice lacking both genes show the most pronounced reduction in astrogliosis and microglial accumulation accompanied by decreased expression of the LPC receptor G2A, whereas MS patient samples show increased G2A. These results reveal that NLRC4 and NLRP3, which normally form distinct inflammasomes, activate an LPC-induced inflammasome and are important in astrogliosis and microgliosis.

WAKsing plant immunity, waning diseases

2021 ◽  
Author(s):  
Christopher Stephens ◽  
Kim E Hammond-Kosack ◽  
Kostya Kanyuka
Keyword(s):  
Plant Immunity ◽  
Durable Resistance ◽  
Transmembrane Proteins ◽  
Plant Growth And Development ◽  
Cell Wall Modification ◽  
Central Pillar ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Global Population ◽  
Extracellular Environment

Abstract With the requirement to breed more productive crop plants in order to feed a growing global population, compounded by increasingly widespread resistance to pesticides exhibited by pathogens, plant immunity is becoming an increasingly important area of research. Of the genes that contribute to disease resistance, the wall-associated receptor-like kinases (WAKs) are increasingly shown to play a major role, in addition to their contribution to plant growth and development or tolerance to abiotic stresses. Being transmembrane proteins, WAKs form a central pillar of a plant cell’s ability to monitor and interact with the extracellular environment. Found in both dicots and monocots, WAKs have been implicated in defence against pathogens with diverse lifestyles and contribute to plant immunity in a variety of ways. Whilst some act as cell surface-localized immune receptors recognizing either pathogen- or plant-derived invasion molecules (e.g. effectors or damage-associated molecular patterns, respectively), others promote innate immunity through cell wall modification and strengthening, thus limiting pathogen intrusion. The ability of some WAKs to provide both durable resistance against pathogens and other agronomic benefits makes this gene family important targets in the development of future crop ideotypes and important to a greater understanding of the complexity and robustness of plant immunity.

scholarly journals Phytocytokines function as immunological modulators of plant immunity

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Shuguo Hou ◽  
Derui Liu ◽  
Ping He
Keyword(s):  
Plasma Membrane ◽  
Signaling Pathway ◽  
Plant Pathogen ◽  
Plant Immunity ◽  
Current Understanding ◽  
Endogenous Peptides ◽  
Immune Receptors ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Plant Plasma Membrane

AbstractPlant plasma membrane-resident immune receptors regulate plant immunity by recognizing microbe-associated molecular patterns (MAMPs), damage-associated molecular patterns (DAMPs), and phytocytokines. Phytocytokines are plant endogenous peptides, which are usually produced in the cytosol and released into the apoplast when plant encounters pathogen infections. Phytocytokines regulate plant immunity through activating an overlapping signaling pathway with MAMPs/DAMPs with some unique features. Here, we highlight the current understanding of phytocytokine production, perception and functions in plant immunity, and discuss how plants and pathogens manipulate phytocytokine signaling for their own benefits during the plant-pathogen warfare.

scholarly journals Release mechanisms of major DAMPs

APOPTOSIS ◽  
2021 ◽  
Vol 26 (3-4) ◽  
pp. 152-162
Author(s):  
Atsushi Murao ◽  
Monowar Aziz ◽  
Haichao Wang ◽  
Max Brenner ◽  
Ping Wang
Keyword(s):  
Rna Binding ◽  
High Mobility ◽  
Live Cells ◽  
Membrane Channel ◽  
Membrane Rupture ◽  
Underlying Mechanisms ◽  
Shock Proteins ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns ◽  
Secretory Lysosomes

AbstractDamage-associated molecular patterns (DAMPs) are endogenous molecules which foment inflammation and are associated with disorders in sepsis and cancer. Thus, therapeutically targeting DAMPs has potential to provide novel and effective treatments. When establishing anti-DAMP strategies, it is important not only to focus on the DAMPs as inflammatory mediators but also to take into account the underlying mechanisms of their release from cells and tissues. DAMPs can be released passively by membrane rupture due to necrosis/necroptosis, although the mechanisms of release appear to differ between the DAMPs. Other types of cell death, such as apoptosis, pyroptosis, ferroptosis and NETosis, can also contribute to DAMP release. In addition, some DAMPs can be exported actively from live cells by exocytosis of secretory lysosomes or exosomes, ectosomes, and activation of cell membrane channel pores. Here we review the shared and DAMP-specific mechanisms reported in the literature for high mobility group box 1, ATP, extracellular cold-inducible RNA-binding protein, histones, heat shock proteins, extracellular RNAs and cell-free DNA.

Sign in / Sign up

Export Citation Format

Share Document