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Start Over Descriptor "PICI" Publisher elsevier
3 results on '"PICI"'

1. Bacteriophages benefit from mobilizing pathogenicity islands encoding immune systems against competitors

Author

Alfred Fillol-Salom, Jakob T. Rostøl, Adaeze D. Ojiogu, John Chen, Gill Douce, Suzanne Humphrey, José R. Penadés, Biotechnology and Biological Sciences Research Council (BBSRC), Medical Research Council (MRC), EMBO, and Biotechnology and Biological Sciences Research Cou

Subjects
Bacteria, Gene Transfer, Horizontal, Genomic Islands, mobile genetic elements, 06 Biological Sciences, General Biochemistry, Genetics and Molecular Biology, defense islands, bacteriophage, Immune System, horizontal gene transfer, Bacteriophages, 11 Medical and Health Sciences, Plasmids, PICI, Developmental Biology
Abstract

Bacteria encode sophisticated anti-phage systems that are diverse and versatile and display high genetic mobility. How this variability and mobility occurs remains largely unknown. Here, we demonstrate that a widespread family of pathogenicity islands, the phage-inducible chromosomal islands (PICIs), carry an impressive arsenal of defense mechanisms, which can be disseminated intra- and inter-generically by helper phages. These defense systems provide broad immunity, blocking not only phage reproduction, but also plasmid and non-cognate PICI transfer. Our results demonstrate that phages can mobilize PICI-encoded immunity systems to use them against other mobile genetic elements, which compete with the phages for the same bacterial hosts. Therefore, despite the cost, mobilization of PICIs may be beneficial for phages, PICIs, and bacteria in nature. Our results suggest that PICIs are important players controlling horizontal gene transfer and that PICIs and phages establish mutualistic interactions that drive bacterial ecology and evolution.

Published
2022

2. Hijacking the Hijackers: Escherichia coli Pathogenicity Islands Redirect Helper Phage Packaging for Their Own Benefit

Author

Ministerio de Economía y Competitividad (España), Medical Research Council (UK), Biotechnology and Biological Sciences Research Council (UK), Wolfson Foundation, Royal Society (UK), European Research Council, Marina, Alberto [0000-0002-1334-5273], Ciges-Tomas, J. Rafael [0000-0003-2647-3052], Fillol-Salom, Alfred, Bacarizo, Julio, Alqasmi, Mohammed, Ciges-Tomas, J. Rafael, Martínez-Rubio, Roser, Roszak, Aleksander W., Cogdell, Richard J., Chen, John, Marina, Alberto, Penadés, José R., Ministerio de Economía y Competitividad (España), Medical Research Council (UK), Biotechnology and Biological Sciences Research Council (UK), Wolfson Foundation, Royal Society (UK), European Research Council, Marina, Alberto [0000-0002-1334-5273], Ciges-Tomas, J. Rafael [0000-0003-2647-3052], Fillol-Salom, Alfred, Bacarizo, Julio, Alqasmi, Mohammed, Ciges-Tomas, J. Rafael, Martínez-Rubio, Roser, Roszak, Aleksander W., Cogdell, Richard J., Chen, John, Marina, Alberto, and Penadés, José R.

Abstract

Phage-inducible chromosomal islands (PICIs) represent a novel and universal class of mobile genetic elements, which have broad impact on bacterial virulence. In spite of their relevance, how the Gram-negative PICIs hijack the phage machinery for their own specific packaging and how they block phage reproduction remains to be determined. Using genetic and structural analyses, we solve the mystery here by showing that the Gram-negative PICIs encode a protein that simultaneously performs these processes. This protein, which we have named Rpp (for redirecting phage packaging), interacts with the phage terminase small subunit, forming a heterocomplex. This complex is unable to recognize the phage DNA, blocking phage packaging, but specifically binds to the PICI genome, promoting PICI packaging. Our studies reveal the mechanism of action that allows PICI dissemination in nature, introducing a new paradigm in the understanding of the biology of pathogenicity islands and therefore of bacterial pathogen evolution.

Published
2019

3. Evidence that low protein C contributes to the procoagulant imbalance in cirrhosis.

Author

Tripodi A, Primignani M, Lemma L, Chantarangkul V, and Mannucci PM

Subjects
Aged, Aged, 80 and over, Blood Coagulation Factors metabolism, Blood Coagulation Tests, Female, Humans, Intercellular Signaling Peptides and Proteins, Liver Cirrhosis complications, Male, Middle Aged, Peptides pharmacology, Protein C therapeutic use, Protein C Deficiency blood, Protein C Deficiency complications, Protein C Deficiency drug therapy, Risk Factors, Thrombin biosynthesis, Thrombomodulin blood, Venous Thromboembolism blood, Venous Thromboembolism etiology, Venous Thromboembolism prevention & control, Blood Coagulation drug effects, Blood Coagulation physiology, Liver Cirrhosis blood, Protein C metabolism
Abstract

Background & Aims: Cirrhosis is associated with a plasmatic procoagulant imbalance, detected in vitro by thrombin generation tests performed in the presence vs. absence of such activators of protein C as thrombomodulin or Protac. This imbalance is thought to be due to decreased protein C and increased factor VIII, but this has never been directly demonstrated. To test this hypothesis we analyzed plasma from 50 patients with cirrhosis before and after in vitro addition of purified protein C meant to restore normal levels., Methods: Results for two thrombin generation assays were expressed as ratios of endogenous thrombin potential (ETP) with-to-without thrombomodulin or as Protac-induced coagulation inhibition (PICI%). By definition, high ETP ratios or low PICI% reflect a resistance to the anticoagulant action of thrombomodulin or Protac, respectively, and can be taken as indexes of in vitro procoagulant imbalance., Results: The median (range) protein C level before addition was 40% (4-101%) and increased to 156% (110-305) after addition (p<0.001). The procoagulant imbalance, which was high before protein C addition [ETP ratio=0.83 (0.44-1.00)], was reduced after addition [ETP ratio=0.60 (0.14-0.84)], p<0.001. ETP-ratios were inversely correlated with protein C activity (rho=-0.46, p<0.001). Similar results were obtained with the Protac assay., Conclusions: The results provide evidence that low protein C contributes to the procoagulant imbalance in plasma from patients with cirrhosis. The findings may have clinical implications for the treatment or prophylaxis of thrombosis in these patients., (Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Published
2013
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