Final Report Summary - ARIADNE (Signaling circuitry controlling fungal virulence: identification and characterization of conserved and specific fungal virulence genes as common antifungal targets)
EU-ITN-Ariadne at www.eu-itn-ariadne.eu
Publishable Summary
Fungi are microorganisms with devastating impact on agriculture and human health. Agricultural production worth billions of euros is destroyed annually by fungal diseases. Rice blast caused by Magnaporthe results in crop losses each year that are estimated to be sufficient to feed more than 60 million people. On the other hand, there are human fungal infections which have severe consequences on the growing number of immuno-compromised patients. Particularly high mortality rates are associated with Aspergillus and Candida infections. There is a critical need to further the development of new antifungals, which requires a comprehensive molecular knowledge on fungal pathogenesis and signal transduction. This in turn requires increased efforts in training and educating new generations of international scientists in the fields of fungal pathogenesis, genetics and biology.
ARIADNE focused on central signaling cascades, which are evolutionarily conserved among all fungal pathogens and play crucial roles during infection. Proteins acting downstream of these major signaling routes thus represent a rich and largely untapped source of new antifungal drug targets and will reveal novel virulence mechanisms, which can be exploited in specific assays e.g. for the screening of inhibitors using large compound libraries. ARIADNE used a comparative biological approach at the systems biology level to identify and validate signaling target genes that play an essential causative role in fungal virulence on both plant and human hosts. On a broad basis ARIADNE established a comprehensive overview of fungal pathogenesis by working with seven pathogenic species, including the two major fungal pathogens of humans Aspergillus fumigatus and Candida albicans, the devastating plant pathogens Fusarium oxysporum, Magnaporthe grisea and Mycospherella graminicola, as well as two established model pathogens of filamentous and dimorphic fungi, Ashbya gossypii and Ustilago maydis. This array of fungal species cuts across diverse taxonomic groups, covering several hundred million years of evolution.
ARIADNE dealt with three central scientific and technological challenges 1) integration of parallel transcriptomics, proteomics, and chemical genetics to generate a sufficiently large data base for the set of major fungal pathogens, 2) identification of evolutionarily conserved and species specific signaling effectors which act as key players in fungal virulence, 3) validation of candidate targets for small molecule inhibitors. This groundbreaking scientific and teaching approach has opened up new avenues on how to look at fungal pathogenicity and knowledge platform established within the consortium will facilitate the discovery and validation of antifungal targets based on our improved understanding of fungal genomics, ecology and infection biology.
The Ariadne network established an interactive group consisting of 13 Early Stage Researchers in nine European laboratories, two each in France, Germany, Spain, and the UK and one from Denmark. Details can be viewed on the network homepage at www.eu-it-ariadne.eu which also display our project’s logo and additional information on the participants and the project. The students have been trained in three intensive summer schools covering Fungal Genetics & Biology and Fungal Transcriptomics & Bioinformatics, and Proteomics in Fungi. Further training was provided with four workshops, one on Scientific writing, presentational skills & management, the second on Fungal Pathogenicity, the third on Working with Fungal Pathogens, Grants & Fellowships as well as IPR, and finally a workshop on Cell cycle and Signaling in Fungi. These were accompanied by annual network meetings and a final network meeting with public presentations of all scientists in conjunction with the Fungal Genetics Conference in Asilomar in 2013.
After the recruitment phase and the initial training efforts each participant started with local research efforts according to the research objectives of Ariadne. The Ariadne program was divided into six workpackages: (i) generation of strains to study signal transduction pathways, (ii) identification of target genes e.g. via transcript profiling, chemical genetics or phosphor-proteomics, (iii) functional analyses of target genes, (iv) verification and validation of novel targets in pathogenicity assays, (v) identification of novel molecular mechanisms, and finally (vi) the identification and the testing of novel compounds.
Work in the first half of the project period was focused on the first three tasks and several breakthroughs had been achieved that were further evaluated in the second period. Several partners generated large scale datasets using genome wide transcript profiling based on DNA-arrays or RNA-sequencing technology and phosphor-proteomics. These datasets resulted in subsequent functional analyses studies. In the second half of the project several lines of research were followed and several unexpected and fascinating results have been obtained.
Among them were:
a.) The identification novel target genes downstream of MAP kinase signaling pathways in several of the studied fungal pathogens.
b.) The identification of Ustilago maydis Sho1/Msb2-dependent genes that are essential for virulence or play a role during plant penetration.
c.) Sensitivity profiling of Magnaporthe Cell Wall Integrity genes against cell wall degrading enzymes (CWDE) and cell wall biosynthesis inhibitors identified a novel role of pH 5-induced resistance of fungal cell walls to CWDE requiring the Mps1 pathway.
d.) Identification of Magnaporthe Ste12-dependent effector proteins involved in suppression of plant immunity.
e.) A novel non-vertebrate animal infection model for Fusarium oxysporum has been introduced and very successfully applied.
f.) The importance of MAPK-signaling for chemotropic sensing of host signals in Fusarium has been established.
g.) A new tool amenable to study the pharmacological effect of inhibitors was established with murine macrophages and phagocytosed Fusarium oxysporum cells.
h.) Rewiring of the pheromone signal transduction cascade in Ashbya gossypii has been revealed.
Additionally, several roads of research are on the finishing line that will have major impact on e.g. treatment of fungal infections by Magnaporthe or have implications on future research on fungal biology and pathogenicity.
All training activities have been completed successfully and based on the ARIADNE publication record in peer-reviewed journals we can conclude that ARIADNE has generated a new generation of highly motivated and talented, well-trained, multi-disciplinary scientists that are experienced in intersectorial transfers and have developed also a science-to-business mind set.
On top of that, several ARIADNE ESRs have already obtained their PhD degrees, the others will follow suit. This will allow them to take up leading roles in industry and academia and influence business decisions and scientific progress in the future.
Overall, ARIADNE has been an exceptional program at the cutting edge of science that has intensified international European ties in the field of fungal pathogenicity research and brought science and industry closer together.
On behalf of the ARIADNE consortium,
the coordinator Prof. Dr. Jürgen Wendland,
Carlsberg Laboratory,
Copenhagen, Denmark
Publishable Summary
Fungi are microorganisms with devastating impact on agriculture and human health. Agricultural production worth billions of euros is destroyed annually by fungal diseases. Rice blast caused by Magnaporthe results in crop losses each year that are estimated to be sufficient to feed more than 60 million people. On the other hand, there are human fungal infections which have severe consequences on the growing number of immuno-compromised patients. Particularly high mortality rates are associated with Aspergillus and Candida infections. There is a critical need to further the development of new antifungals, which requires a comprehensive molecular knowledge on fungal pathogenesis and signal transduction. This in turn requires increased efforts in training and educating new generations of international scientists in the fields of fungal pathogenesis, genetics and biology.
ARIADNE focused on central signaling cascades, which are evolutionarily conserved among all fungal pathogens and play crucial roles during infection. Proteins acting downstream of these major signaling routes thus represent a rich and largely untapped source of new antifungal drug targets and will reveal novel virulence mechanisms, which can be exploited in specific assays e.g. for the screening of inhibitors using large compound libraries. ARIADNE used a comparative biological approach at the systems biology level to identify and validate signaling target genes that play an essential causative role in fungal virulence on both plant and human hosts. On a broad basis ARIADNE established a comprehensive overview of fungal pathogenesis by working with seven pathogenic species, including the two major fungal pathogens of humans Aspergillus fumigatus and Candida albicans, the devastating plant pathogens Fusarium oxysporum, Magnaporthe grisea and Mycospherella graminicola, as well as two established model pathogens of filamentous and dimorphic fungi, Ashbya gossypii and Ustilago maydis. This array of fungal species cuts across diverse taxonomic groups, covering several hundred million years of evolution.
ARIADNE dealt with three central scientific and technological challenges 1) integration of parallel transcriptomics, proteomics, and chemical genetics to generate a sufficiently large data base for the set of major fungal pathogens, 2) identification of evolutionarily conserved and species specific signaling effectors which act as key players in fungal virulence, 3) validation of candidate targets for small molecule inhibitors. This groundbreaking scientific and teaching approach has opened up new avenues on how to look at fungal pathogenicity and knowledge platform established within the consortium will facilitate the discovery and validation of antifungal targets based on our improved understanding of fungal genomics, ecology and infection biology.
The Ariadne network established an interactive group consisting of 13 Early Stage Researchers in nine European laboratories, two each in France, Germany, Spain, and the UK and one from Denmark. Details can be viewed on the network homepage at www.eu-it-ariadne.eu which also display our project’s logo and additional information on the participants and the project. The students have been trained in three intensive summer schools covering Fungal Genetics & Biology and Fungal Transcriptomics & Bioinformatics, and Proteomics in Fungi. Further training was provided with four workshops, one on Scientific writing, presentational skills & management, the second on Fungal Pathogenicity, the third on Working with Fungal Pathogens, Grants & Fellowships as well as IPR, and finally a workshop on Cell cycle and Signaling in Fungi. These were accompanied by annual network meetings and a final network meeting with public presentations of all scientists in conjunction with the Fungal Genetics Conference in Asilomar in 2013.
After the recruitment phase and the initial training efforts each participant started with local research efforts according to the research objectives of Ariadne. The Ariadne program was divided into six workpackages: (i) generation of strains to study signal transduction pathways, (ii) identification of target genes e.g. via transcript profiling, chemical genetics or phosphor-proteomics, (iii) functional analyses of target genes, (iv) verification and validation of novel targets in pathogenicity assays, (v) identification of novel molecular mechanisms, and finally (vi) the identification and the testing of novel compounds.
Work in the first half of the project period was focused on the first three tasks and several breakthroughs had been achieved that were further evaluated in the second period. Several partners generated large scale datasets using genome wide transcript profiling based on DNA-arrays or RNA-sequencing technology and phosphor-proteomics. These datasets resulted in subsequent functional analyses studies. In the second half of the project several lines of research were followed and several unexpected and fascinating results have been obtained.
Among them were:
a.) The identification novel target genes downstream of MAP kinase signaling pathways in several of the studied fungal pathogens.
b.) The identification of Ustilago maydis Sho1/Msb2-dependent genes that are essential for virulence or play a role during plant penetration.
c.) Sensitivity profiling of Magnaporthe Cell Wall Integrity genes against cell wall degrading enzymes (CWDE) and cell wall biosynthesis inhibitors identified a novel role of pH 5-induced resistance of fungal cell walls to CWDE requiring the Mps1 pathway.
d.) Identification of Magnaporthe Ste12-dependent effector proteins involved in suppression of plant immunity.
e.) A novel non-vertebrate animal infection model for Fusarium oxysporum has been introduced and very successfully applied.
f.) The importance of MAPK-signaling for chemotropic sensing of host signals in Fusarium has been established.
g.) A new tool amenable to study the pharmacological effect of inhibitors was established with murine macrophages and phagocytosed Fusarium oxysporum cells.
h.) Rewiring of the pheromone signal transduction cascade in Ashbya gossypii has been revealed.
Additionally, several roads of research are on the finishing line that will have major impact on e.g. treatment of fungal infections by Magnaporthe or have implications on future research on fungal biology and pathogenicity.
All training activities have been completed successfully and based on the ARIADNE publication record in peer-reviewed journals we can conclude that ARIADNE has generated a new generation of highly motivated and talented, well-trained, multi-disciplinary scientists that are experienced in intersectorial transfers and have developed also a science-to-business mind set.
On top of that, several ARIADNE ESRs have already obtained their PhD degrees, the others will follow suit. This will allow them to take up leading roles in industry and academia and influence business decisions and scientific progress in the future.
Overall, ARIADNE has been an exceptional program at the cutting edge of science that has intensified international European ties in the field of fungal pathogenicity research and brought science and industry closer together.
On behalf of the ARIADNE consortium,
the coordinator Prof. Dr. Jürgen Wendland,
Carlsberg Laboratory,
Copenhagen, Denmark