C.elegans as a model system forC.neoformans pathogenesis

Summary

Principal Investigator: E Mylonakis
Abstract: DESCRIPTION (provided by applicant): This Research Career Award application describes a mentored research program for the candidate, Dr. Mylonakis, in fungal pathogenesis. The candidate is trained in Infectious Diseases and proposes a research program to study virulence of Cryptococcus neoformans. The candidate's sponsor, Dr. Calderwood, has a Iongtime interest in using simple organisms as model hosts for the study of human pathogens, while the candidate's cosponsor, Dr. Heitman, has a Iongtime interest in the genetics of C. neoformans and has developed a number of related molecular biology protocols. The candidate has developed a novel system for studying genetic and molecular mechanisms of C. neoformans pathogenesis using the nematode model organism Caenorhabditis elegans. He has found that C. neoformans kills C. elegans, and several genes, such as those associated with signal transduction pathways, laccase production and the alpha mating type, previously shown to be involved in mammalian virulence, also play a role in C. elegans killing. He used this system to screen a bank of randominsertional mutants that were developed in the C. neoformans H99 background. From 350 mutants tested, 7 were identified as attenuated in C. elegans, with the hypovirulence persisting after the mutation was crossed to a clean genetic background. Genetic analysis of the first mutant revealed that the mutation occurred in a gene homologous to KIN1 of Saccharomyces cerevisiae. The SPECIFIC AIMS are as follows: 1) to develop and use the C. elegans system to screen a library of random C. neoformans insertional mutants and then to identify the disrupted genes and utilize a pathogenic wild type strain to make defined deletion mutations in each of the genes identified and develop the corresponding reconstituted strains, 2) to use the tail vein and lung inhalation murine models to test if the genes identified through the screen in C. elegans are involved in mammalian virulence, 3) to perform in-depth analysis for a limited number of selected mutants that demonstrate the most dramatic hypovirulence in both C. elegans and mice. The analysis will include evaluation of capsule, melanin production and mating. The research plan proposed with focus on the use of C. elegans as a facile model to study basic, evolutionarily conserved pathways associated with cryptococcal infection. Because C. neoformanshas similarities with other pathogenic yeasts, we expect that our findings will facilitate the study of fungus/host interaction in general.
Funding Period: 2005-07-01 - 2008-06-30
more information: NIH RePORT

Top Publications

  1. pmc Evolutionarily conserved recognition and innate immunity to fungal pathogens by the scavenger receptors SCARF1 and CD36
    Terry K Means
    Center for Immunology and Inflammatory Diseases and Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
    J Exp Med 206:637-53. 2009
  2. pmc The temperature-sensitive role of Cryptococcus neoformans ROM2 in cell morphogenesis
    Beth Burgwyn Fuchs
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
    PLoS ONE 2:e368. 2007
  3. pmc Reduced susceptibility to vancomycin influences pathogenicity in Staphylococcus aureus infection
    Anton Y Peleg
    Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02215, USA
    J Infect Dis 199:532-6. 2009
  4. pmc Prokaryote-eukaryote interactions identified by using Caenorhabditis elegans
    Anton Y Peleg
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
    Proc Natl Acad Sci U S A 105:14585-90. 2008
  5. ncbi Epidemiology and management of cryptococcal meningitis: developments and challenges
    Read Pukkila-Worley
    Massachusetts General Hospital, Division of Infectious Diseases, 55 Fruit Street, Boston, MA 02114 2696, USA
    Expert Opin Pharmacother 9:551-60. 2008
  6. pmc Exploiting amoeboid and non-vertebrate animal model systems to study the virulence of human pathogenic fungi
    Eleftherios Mylonakis
    PLoS Pathog 3:e101. 2007
  7. pmc Susceptibility of Cryptococcus neoformans to photodynamic inactivation is associated with cell wall integrity
    Beth Burgwyn Fuchs
    Infectious Diseases, Massachusetts General Hospital, Boston, MA 02144, USA
    Antimicrob Agents Chemother 51:2929-36. 2007
  8. pmc Eca1, a sarcoplasmic/endoplasmic reticulum Ca2+-ATPase, is involved in stress tolerance and virulence in Cryptococcus neoformans
    Weihua Fan
    Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
    Infect Immun 75:3394-405. 2007
  9. pmc Cryptococcus neoformans gene involved in mammalian pathogenesis identified by a Caenorhabditis elegans progeny-based approach
    Robin J Tang
    Division of Infectious Diseases, Massachusetts General Hospital, Gray Jackson 504, 55 Fruit Street, Boston, MA 02114, USA
    Infect Immun 73:8219-25. 2005
  10. pmc Galleria mellonella as a model host to study infection by the Francisella tularensis live vaccine strain
    George Aperis
    Division of Infectious Diseases, Massachusetts General Hospital, Gray Jackson 504, 55 Fruit Street, Boston, MA 02114, USA
    Microbes Infect 9:729-34. 2007

Scientific Experts

  • Anton Y Peleg
  • Terry K Means
  • Eleftherios Mylonakis
  • Beth Burgwyn Fuchs
  • George Aperis
  • Julia Breger
  • Elias K Spanakis
  • Robin J Tang
  • Read Pukkila-Worley
  • Amy J Reese
  • Frederick M Ausubel
  • Weihua Fan
  • Alexander Idnurm
  • Stephen B Calderwood
  • Joseph Heitman
  • Roanna London
  • Julia A Breger
  • Aki Yoneda
  • Christine A Anderson
  • Indrani Bose
  • George P Tegos
  • Colleen Skau
  • Cara L Griffith
  • Anne Beauvais
  • Arturo Casadevall
  • Michael R Hamblin
  • Tamara L Doering
  • Sarah Yang
  • Myoung Ju Kim
  • Julianne A Sefko
  • Hong Liu
  • Jean Paul Latge
  • John E Warner
  • Masako Osumi
  • Terence I Moy
  • Nikolaos Myriounis
  • Benjamin Samuel Orozco
  • Kimberly J Gerik
  • Jennifer K Lodge

Detail Information

Publications17

  1. pmc Evolutionarily conserved recognition and innate immunity to fungal pathogens by the scavenger receptors SCARF1 and CD36
    Terry K Means
    Center for Immunology and Inflammatory Diseases and Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
    J Exp Med 206:637-53. 2009
    ..Binding of these pathogens to SCARF1 and CD36 was beta-glucan dependent. Thus, CED-1/SCARF1 and C03F11.3/CD36 are beta-glucan binding receptors and define an evolutionarily conserved pathway for the innate sensing of fungal pathogens...
  2. pmc The temperature-sensitive role of Cryptococcus neoformans ROM2 in cell morphogenesis
    Beth Burgwyn Fuchs
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
    PLoS ONE 2:e368. 2007
    ..These results indicate that in C. neoformans, ROM2 is important at restrictive temperature conditions and is involved in several cell maintenance functions...
  3. pmc Reduced susceptibility to vancomycin influences pathogenicity in Staphylococcus aureus infection
    Anton Y Peleg
    Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02215, USA
    J Infect Dis 199:532-6. 2009
    ..These results show that G. mellonella can be effectively used to facilitate the in vivo study of S. aureus virulence and, more specifically, the relationship between antibiotic drug resistance and the pathogenesis of infection...
  4. pmc Prokaryote-eukaryote interactions identified by using Caenorhabditis elegans
    Anton Y Peleg
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
    Proc Natl Acad Sci U S A 105:14585-90. 2008
    ..elegans and by use of genetic manipulation, provides a whole-animal model system to investigate the complex dynamics of a polymicrobial infection...
  5. ncbi Epidemiology and management of cryptococcal meningitis: developments and challenges
    Read Pukkila-Worley
    Massachusetts General Hospital, Division of Infectious Diseases, 55 Fruit Street, Boston, MA 02114 2696, USA
    Expert Opin Pharmacother 9:551-60. 2008
    ..However, the mortality from this infection remains unacceptably high and we are faced with the specific challenges in the management of this disease...
  6. pmc Exploiting amoeboid and non-vertebrate animal model systems to study the virulence of human pathogenic fungi
    Eleftherios Mylonakis
    PLoS Pathog 3:e101. 2007
    ..This review aims to assist researchers in identifying appropriate invertebrate systems for the study of particular aspects of fungal pathogenesis...
  7. pmc Susceptibility of Cryptococcus neoformans to photodynamic inactivation is associated with cell wall integrity
    Beth Burgwyn Fuchs
    Infectious Diseases, Massachusetts General Hospital, Boston, MA 02144, USA
    Antimicrob Agents Chemother 51:2929-36. 2007
    ..These studies demonstrated that C. neoformans is sensitive to photodynamic therapy and illustrated the significance of cell wall integrity in microbial susceptibility to antimicrobial photodynamic inactivation...
  8. pmc Eca1, a sarcoplasmic/endoplasmic reticulum Ca2+-ATPase, is involved in stress tolerance and virulence in Cryptococcus neoformans
    Weihua Fan
    Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
    Infect Immun 75:3394-405. 2007
    ..Eca1 is likely involved in maintaining ER function, thus contributing to stress tolerance and virulence acting in parallel with Ca2+-calcineurin signaling...
  9. pmc Cryptococcus neoformans gene involved in mammalian pathogenesis identified by a Caenorhabditis elegans progeny-based approach
    Robin J Tang
    Division of Infectious Diseases, Massachusetts General Hospital, Gray Jackson 504, 55 Fruit Street, Boston, MA 02114, USA
    Infect Immun 73:8219-25. 2005
    ..We propose that a screen for progeny-permissive mutants of microorganisms can serve as a high-throughput method for identifying novel loci related to mammalian pathogenesis...
  10. pmc Galleria mellonella as a model host to study infection by the Francisella tularensis live vaccine strain
    George Aperis
    Division of Infectious Diseases, Massachusetts General Hospital, Gray Jackson 504, 55 Fruit Street, Boston, MA 02114, USA
    Microbes Infect 9:729-34. 2007
    ..Delayed drug treatment reduced the efficacy of antibacterials and especially streptomycin. The G. mellonella-F. tularensis LVS system may facilitate the in vivo study of F. tularensis, efficacy with antibacterial agents...
  11. pmc Antifungal chemical compounds identified using a C. elegans pathogenicity assay
    Julia Breger
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, United States of America
    PLoS Pathog 3:e18. 2007
    ..Compounds identified in the screen that affect the virulence of Candida in vivo can potentially be used as "probe compounds" and may have antifungal activity against other fungi...
  12. pmc Loss of cell wall alpha(1-3) glucan affects Cryptococcus neoformans from ultrastructure to virulence
    Amy J Reese
    Department of Biological Sciences, Cedar Crest College, Allentown, PA 18104 6196, USA
    Mol Microbiol 63:1385-98. 2007
    ..The mutants were unable to grow ina mouse model of infection, but caused death in nematodes. These studies integrate morphological and biochemical investigations of the role of alpha glucan in the cryptococcal cell wall...
  13. ncbi Developments in the treatment of candidiasis: more choices and new challenges
    George Aperis
    Massachusetts General Hospital, Division of Infectious Diseases, Gray Jackson 504, 55 Fruit Street, Boston, MA 02114, USA
    Expert Opin Investig Drugs 15:1319-36. 2006
    ..causing the infection. Studies are needed to investigate the possible development of resistance and the efficacy of these antifungal agents against the more resistant Candida spp...
  14. ncbi New agents for the treatment of fungal infections: clinical efficacy and gaps in coverage
    Elias K Spanakis
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
    Clin Infect Dis 43:1060-8. 2006
    ..However, significant questions remain, including the management of breakthrough infections and treatment failures and the efficacy of the new antifungal agents against less common fungi...
  15. ncbi Using non-mammalian hosts to study fungal virulence and host defense
    Beth Burgwyn Fuchs
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA 02114, USA
    Curr Opin Microbiol 9:346-51. 2006
    ..These heterologous non-mammalian hosts highlight the similarities and differences between different hosts in fungal pathogenesis and they complement studies in mammalian systems and those using other genetic approaches...
  16. ncbi The pursuit of cryptococcal pathogenesis: heterologous hosts and the study of cryptococcal host-pathogen interactions
    Roanna London
    Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
    FEMS Yeast Res 6:567-73. 2006
    ..The study of host-pathogen interactions using these model hosts has allowed rapid screening of mutant libraries and can be used for the study of evolutionarily preserved aspects of microbial virulence and host response...
  17. pmc Galleria mellonella as a model system to study Acinetobacter baumannii pathogenesis and therapeutics
    Anton Y Peleg
    Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
    Antimicrob Agents Chemother 53:2605-9. 2009
    ..G. mellonella is a relatively simple, nonmammalian model system that can be used to facilitate the in vivo study of host-pathogen interactions in A. baumannii and the efficacy of antibacterial agents...