scholarly journals Functional characterisation of the Nep1-like protein effectors of the necrotrophic pathogen - Alternaria brassicae

2021 ◽  
Author(s):  
Deepak Duhan ◽  
Shivani Gajbhiye ◽  
Rajdeep Jaswal ◽  
Ravindra Pal Singh ◽  
Tilak Raj Sharma ◽  
...  
Keyword(s):  
Cell Death ◽  
Genome Sequence ◽  
Systematic Study ◽  
Subcellular Location ◽  
Ethylene Biosynthesis ◽  
Alternaria Brassicae ◽  
Necrotrophic Pathogen ◽  
Molecular Pattern ◽  
Functional Characterisation ◽  
Pathogen Associated Molecular Pattern

Alternaria brassicae is an important necrotrophic pathogen that infects the Brassicaceae family. A. brassicae, like other necrotrophs also secretes various proteinaceous effectors and metabolites that cause cell death to establish itself in the host. However, there has been no systematic study of A. brassicae effectors and their roles in pathogenesis. The availability of the genome sequence of A. brassicae has enabled the search for effectors and their functional characterisation. Nep1-like proteins are a superfamily of proteins that induce necrosis and ethylene biosynthesis. They have been reported from a variety of microbes including bacteria, fungi, and oomycetes. In this study, we identified two NLPs from A. brassicae viz. AbrNLP1 and AbrNLP2 and functionally characterised them. Although both AbrNLPs were found to be secretory in nature, they localised differentially inside the plant. AbrNLP2 was found to induce necrosis in both host and nonhost species, while AbrNLP1 could not induce necrosis in both species. Additionally, AbrNLP2 was shown to induce pathogen-associated molecular pattern (PAMP)-triggered immunity in both host and nonhost species. Overall, our study indicates that AbrNLPs are functionally and spatially (subcellular location) distinct and may play different but important roles during the pathogenesis of A. brassicae.

scholarly journals Functional Characterization of the Nep1-Like Protein Effectors of the Necrotrophic Pathogen – Alternaria brassicae

2021 ◽  
Vol 12 ◽  
Author(s):  
Deepak Duhan ◽  
Shivani Gajbhiye ◽  
Rajdeep Jaswal ◽  
Ravindra Pal Singh ◽  
Tilak Raj Sharma ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Species ◽  
Functional Characterization ◽  
Subcellular Location ◽  
Ethylene Biosynthesis ◽  
Alternaria Brassicae ◽  
Necrotrophic Pathogen ◽  
Molecular Pattern ◽  
Pathogen Associated Molecular Pattern

Alternaria brassicae is an important necrotrophic pathogen that infects the Brassicaceae family. A. brassicae, like other necrotrophs, also secretes various proteinaceous effectors and metabolites that cause cell death to establish itself in the host. However, there has been no systematic study of A. brassicae effectors and their roles in pathogenesis. The availability of the genome sequence of A. brassicae in public domain has enabled the search for effectors and their functional characterization. Nep1-like proteins (NLPs) are a superfamily of proteins that induce necrosis and ethylene biosynthesis. They have been reported from a variety of microbes including bacteria, fungi, and oomycetes. In this study, we identified two NLPs from A. brassicae viz. AbrNLP1 and AbrNLP2 and functionally characterized them. Although both AbrNLPs were found to be secretory in nature, they localized differentially inside the plant. AbrNLP2 was found to induce necrosis in both host and non-host species, while AbrNLP1 could not induce necrosis in both species. Additionally, AbrNLP2 was shown to induce pathogen-associated molecular pattern (PAMP)-triggered immunity in both host and non-host species. Overall, our study indicates that AbrNLPs are functionally and spatially (subcellular location) distinct and may play different but important roles during the pathogenesis of A. brassicae.

scholarly journals Identification of Nicotiana benthamiana Genes Involved in Pathogen-Associated Molecular Pattern–Triggered Immunity

2010 ◽  
Vol 23 (6) ◽  
pp. 715-726 ◽  
Author(s):  
Suma Chakravarthy ◽  
André C. Velásquez ◽  
Sophia K. Ekengren ◽  
Alan Collmer ◽  
Gregory B. Martin
Keyword(s):  
Cell Death ◽  
Nicotiana Benthamiana ◽  
Large Scale ◽  
Forward Genetics ◽  
Hormone Signaling ◽  
Virus Induced Gene Silencing ◽  
Molecular Pattern ◽  
Cell Death Response ◽  
A Cell ◽  
Pathogen Associated Molecular Pattern

In order to identify components of pathogen-associated molecular pattern–triggered immunity (PTI) pathways in Nicotiana benthamiana, we conducted a large-scale forward-genetics screen using virus-induced gene silencing and a cell-death-based assay for assessing PTI. The assay relied on four combinations of PTI-inducing nonpathogens and cell-death-causing challenger pathogens and was first validated in plants silenced for FLS2 or BAK1. Over 3,200 genes were screened and 14 genes were identified that, when silenced, compromised PTI as judged by the cell-death-based assay. Further analysis indicated that the 14 genes were not involved in a general cell death response. A subset of the genes was found to act downstream of FLS2-mediated PTI induction, and silencing of three genes compromised production of reactive oxygen species in leaves exposed to flg22. The 14 genes encode proteins with potential functions in defense and hormone signaling, protein stability and degradation, energy and secondary metabolism, and cell wall biosynthesis and provide a new resource to explore the molecular basis for the involvement of these processes in PTI.

scholarly journals A new proteinaceous pathogen-associated molecular pattern (PAMP) identified in Ascomycete fungi induces cell death in Solanaceae

2017 ◽  
Vol 214 (4) ◽  
pp. 1657-1672 ◽  
Author(s):  
Barbara Franco-Orozco ◽  
Adokiye Berepiki ◽  
Olaya Ruiz ◽  
Louise Gamble ◽  
Lucie L. Griffe ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Pattern ◽  
Pathogen Associated Molecular Pattern ◽  
Ascomycete Fungi

scholarly journals Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis

2013 ◽  
Vol 64 (12) ◽  
pp. 3615-3625 ◽  
Author(s):  
Mathieu Larroque ◽  
Elodie Belmas ◽  
Thomas Martinez ◽  
Sophie Vergnes ◽  
Nathalie Ladouce ◽  
...  
Keyword(s):  
Phytophthora Parasitica ◽  
Root Pathogen ◽  
Molecular Pattern ◽  
Pathogen Associated Molecular Pattern

TRMmaintenance is regulated by tissue damage via P2RX7

2018 ◽  
Vol 3 (30) ◽  
pp. eaau1022 ◽  
Author(s):  
Regina Stark ◽  
Thomas H. Wesselink ◽  
Felix M. Behr ◽  
Natasja A. M. Kragten ◽  
Ramon Arens ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Tissue Damage ◽  
Extracellular Nucleotides ◽  
Critical Pathway ◽  
Rna Profiling ◽  
Molecular Pattern ◽  
History Of ◽  
Circulating T Cells

Tissue-resident memory T cells (TRM) are noncirculating immune cells that contribute to the first line of local defense against reinfections. Their location at hotspots of pathogen encounter frequently exposes TRM to tissue damage. This history of danger-signal exposure is an important aspect of TRM-mediated immunity that has been overlooked so far. RNA profiling revealed that TRM from liver and small intestine express P2RX7, a damage/danger-associated molecular pattern (DAMP) receptor that is triggered by extracellular nucleotides (ATP, NAD+). We confirmed that P2RX7 protein was expressed in CD8+ TRM but not in circulating T cells (TCIRC) across different infection models. Tissue damage induced during routine isolation of liver lymphocytes led to P2RX7 activation and resulted in selective cell death of TRM. P2RX7 activation in vivo by exogenous NAD+ led to a specific depletion of TRM while retaining TCIRC. The effect was absent in P2RX7-deficient mice and after P2RX7 blockade. TCR triggering down-regulated P2RX7 expression and made TRM resistant to NAD-induced cell death. Physiological triggering of P2RX7 by sterile tissue damage during acetaminophen-induced liver injury led to a loss of previously acquired pathogen-specific local TRM in wild-type but not in P2RX7 KO T cells. Our results highlight P2RX7-mediated signaling as a critical pathway for the regulation of TRM maintenance. Extracellular nucleotides released during infection and tissue damage could deplete TRM locally and free niches for new and infection-relevant specificities. This suggests that the recognition of tissue damage promotes persistence of antigen-specific over bystander TRM in the tissue niche.

Novel adjuvant based on a proteoliposome‐derived cochleate structure containing native lipopolysaccharide as a pathogen‐associated molecular pattern

2004 ◽  
Vol 82 (6) ◽  
pp. 603-610 ◽  
Author(s):  
Oliver Pérez ◽  
Gustavo Bracho ◽  
Miriam Lastre ◽  
Nestor Mora ◽  
Judith Del Campo ◽  
...  
Keyword(s):  
Molecular Pattern ◽  
Pathogen Associated Molecular Pattern

scholarly journals Heterogeneous NLRP3 inflammasome signature in circulating myeloid cells as a biomarker of COVID-19 severity

2021 ◽  
Vol 5 (5) ◽  
pp. 1523-1534
Author(s):  
Johan Courjon ◽  
Océane Dufies ◽  
Alexandre Robert ◽  
Laurent Bailly ◽  
Cédric Torre ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Myeloid Cells ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Molecular Pattern ◽  
Nlrp3 Inflammasome Activation ◽  
Healthy Donors ◽  
Activation Potential ◽  
Key Factor ◽  
Pathogen Associated Molecular Pattern

Abstract Dysregulated immune response is the key factor leading to unfavorable coronavirus disease 2019 (COVID-19) outcome. Depending on the pathogen-associated molecular pattern, the NLRP3 inflammasome can play a crucial role during innate immunity activation. To date, studies describing the NLRP3 response during severe acute respiratory syndrome coronavirus 2 infection in patients are lacking. We prospectively monitored caspase-1 activation levels in peripheral myeloid cells from healthy donors and patients with mild to critical COVID-19. The caspase-1 activation potential in response to NLRP3 inflammasome stimulation was opposed between nonclassical monocytes and CD66b+CD16dim granulocytes in severe and critical COVID-19 patients. Unexpectedly, the CD66b+CD16dim granulocytes had decreased nigericin-triggered caspase-1 activation potential associated with an increased percentage of NLRP3 inflammasome impaired immature neutrophils and a loss of eosinophils in the blood. In patients who recovered from COVID-19, nigericin-triggered caspase-1 activation potential in CD66b+CD16dim cells was restored and the proportion of immature neutrophils was similar to control. Here, we reveal that NLRP3 inflammasome activation potential differs among myeloid cells and could be used as a biomarker of a COVID-19 patient’s evolution. This assay could be a useful tool to predict patient outcome. This trial was registered at www.clinicaltrials.gov as #NCT04385017.

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