Receptor-Mediated Endocytosis of Legionella Pneumophila

Summary

Principal Investigator: YOUSEF A ABU KWAIK
Abstract: Description (Adapted from applicant's abstract): The ability of Legionella pneumophila (Lpn) to cause pneumonia is dependent on intracellular replication within pulmonary phagocytic and epithelial cells. In the environment, the bacteria are ubiquitous where they multiply intracellularly with amoebae. Invasion and intracellular replication within protozoa play major factors in the amplification and dissemination of Lpn in the environment and in transmission and infectivity to humans. We have recently shown that uptake of Lpn by the protozoan Hartmannella vermiformis is mediated by bacterial attachment to a b2 integrin-like Galactose/N-acetyl-galactosamine lectin on the protozoan surface. Bacterial attachment to the lectin is associated with induction of protozoan gene expression and with tyrosine dephosphorylation of the lectin and several cytoskeletal proteins including actin, focal adhesion kinase, paxillin, and vinculin. Our data suggested a cytoskeletal disruption in the protozoan host upon bacterial attachment. Transmission electron microscopy showed that these bacterial-induced manipulations of cell processes in the protozoan host are associated with entry of the majority of the bacteria through a cup shape-like invagination that resemble receptor-mediated endocytosis, but some bacteria are internalized by coiling phagocytosis. Our preliminary data suggest that the mechanism of entry of Lpn is novel, which may contribute to its subsequent intracellular fate. Our hypothesis is that the lectin is a protozoan receptor involved in uptake of Lpn, and is dissociated from the cytoskeleton upon bacterial attachment and invasion. Our specific aims are, 1) to clone the lectin encoding gene and examine its regulation of expression; 2) to clone and characterize the bacterial ligand that binds the lectin receptor and the mode of ligand-receptor interaction; 3) to determine cellular distribution of the lectin receptor and its subsequent fate after internalization; and 4) to evaluate the interaction of the receptor with the cytoskeleton. The results derived for the proposed studies will uncover new paradigms of uptake of intracellular pathogens and will contribute to our understanding of targeting of molecules into a "protected vacuole" inside eukaryotic cells. Our proposed studies may also facilitate the design of future preventive strategies to control the amplification and spread of Lpn in the aquatic environment, which is the only source of bacterial transmission to humans. Our studies may uncover potential pathogenic evolution of Lpn to invade the more evolved mammalian cells, and may contribute to the understanding of invasion of protozoa by Mycobacterium and Chlamydia.
Funding Period: 2000-07-15 - 2006-05-31
more information: NIH RePORT

Top Publications

  1. pmc Amoeba host-Legionella synchronization of amino acid auxotrophy and its role in bacterial adaptation and pathogenic evolution
    Christopher T D Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY, 40202, USA
    Environ Microbiol 16:350-8. 2014
  2. ncbi Microbial quest for food in vivo: 'nutritional virulence' as an emerging paradigm
    Yousef Abu Kwaik
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Cell Microbiol 15:882-90. 2013
  3. pmc Molecular bases of proliferation of Francisella tularensis in arthropod vectors
    Rexford Asare
    Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Environ Microbiol 12:2587-612. 2010
  4. pmc Molecular complexity orchestrates modulation of phagosome biogenesis and escape to the cytosol of macrophages by Francisella tularensis
    Rexford Asare
    Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Environ Microbiol 12:2559-86. 2010
  5. pmc Functional diversity of ankyrin repeats in microbial proteins
    Souhaila Al-Khodor
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Trends Microbiol 18:132-9. 2010
  6. pmc Indispensable role for the eukaryotic-like ankyrin domains of the ankyrin B effector of Legionella pneumophila within macrophages and amoebae
    Christopher T D Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Infect Immun 78:2079-88. 2010
  7. pmc Host factors required for modulation of phagosome biogenesis and proliferation of Francisella tularensis within the cytosol
    Christine Akimana
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, Kentucky, USA
    PLoS ONE 5:e11025. 2010
  8. ncbi Triggering Ras signalling by intracellular Francisella tularensis through recruitment of PKCα and βI to the SOS2/GrB2 complex is essential for bacterial proliferation in the cytosol
    Souhaila Al-Khodor
    Department of Microbiology and Immunology, College of Medicine, Department of Biology, University of Louisville, Louisville, KY 40202, USA
    Cell Microbiol 12:1604-21. 2010
  9. pmc Exploitation of conserved eukaryotic host cell farnesylation machinery by an F-box effector of Legionella pneumophila
    Christopher T D Price
    Department of Microbiology and Immunology, School of Medicine and 2 Department of Biology, University of Louisville, Louisville, KY 40292, USA
    J Exp Med 207:1713-26. 2010
  10. ncbi Anchoring of bacterial effectors to host membranes through host-mediated lipidation by prenylation: a common paradigm
    Tasneem Al-Quadan
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY 40292, USA
    Trends Microbiol 19:573-9. 2011

Scientific Experts

  • YOUSEF A ABU KWAIK
  • Marina Santic
  • Souhaila Al-Khodor
  • Christopher T D Price
  • Tasneem Al-Quadan
  • Rexford Asare
  • Christopher T Price
  • Alaeddin Abu-Zant
  • Maelle Molmeret
  • Awdhesh Kalia
  • Fabien Habyarimana
  • Yousef Abu Kwaik
  • Christine Akimana
  • Snake Jones
  • James E Graham
  • Dina M Bitar
  • Masaki Miyake
  • Hala A Samara
  • Juanita E Von Dwingelo
  • Ashley M Richards
  • Yousef Abukwaik
  • Ora Schueler-Furman
  • Ilan Rosenshine
  • Nir London
  • Snake C Jones
  • Maria Teresa Garcia
  • Christopher Price
  • James Graham
  • Jill Suttles
  • Takurou Watanabe
  • Michael Wagner
  • Matthias Horn
  • Hitomi Koike
  • Jürgen Helbig
  • Yasuyuki Imai

Detail Information

Publications27

  1. pmc Amoeba host-Legionella synchronization of amino acid auxotrophy and its role in bacterial adaptation and pathogenic evolution
    Christopher T D Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY, 40202, USA
    Environ Microbiol 16:350-8. 2014
    ..Understanding microbial strategies of nutrient generation and acquisition in the host will provide novel antimicrobial strategies to disrupt pathogen access to essential sources of carbon and energy...
  2. ncbi Microbial quest for food in vivo: 'nutritional virulence' as an emerging paradigm
    Yousef Abu Kwaik
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Cell Microbiol 15:882-90. 2013
    ..Host-pathogen synchronization of amino acid auxotrophy indicates that this nutritional synchronization has been a major driving force in the evolution of many intracellular bacterial pathogens...
  3. pmc Molecular bases of proliferation of Francisella tularensis in arthropod vectors
    Rexford Asare
    Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Environ Microbiol 12:2587-612. 2010
    ..Our studies will facilitate deciphering the molecular aspects of F. tularensis-arthropod vector interaction and its patho-adaptation to infect mammals...
  4. pmc Molecular complexity orchestrates modulation of phagosome biogenesis and escape to the cytosol of macrophages by Francisella tularensis
    Rexford Asare
    Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Environ Microbiol 12:2559-86. 2010
    ..tularensis-mediated modulation of phagosome biogenesis, phagosomal escape and bacterial proliferation within the cytosol is novel, complex and involves an unusually large portion of the genome of an intracellular pathogen...
  5. pmc Functional diversity of ankyrin repeats in microbial proteins
    Souhaila Al-Khodor
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Trends Microbiol 18:132-9. 2010
    ..Studying the molecular and biochemical functions of this family of proteins will enhance our understanding of important host-microbe interactions...
  6. pmc Indispensable role for the eukaryotic-like ankyrin domains of the ankyrin B effector of Legionella pneumophila within macrophages and amoebae
    Christopher T D Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40202, USA
    Infect Immun 78:2079-88. 2010
    ..We conclude that the two eukaryotic-like ANK domains of AnkB are essential for intracellular proliferation, for targeting AnkB to the host membranes, and for decoration of the LCV with polyubiquitinated proteins...
  7. pmc Host factors required for modulation of phagosome biogenesis and proliferation of Francisella tularensis within the cytosol
    Christine Akimana
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, Kentucky, USA
    PLoS ONE 5:e11025. 2010
    ..tularensis. Our data will facilitate deciphering molecular ecology, patho-adaptation of F. tularensis to the arthropod vector and its role in bacterial ecology and patho-evolution to infect mammals...
  8. ncbi Triggering Ras signalling by intracellular Francisella tularensis through recruitment of PKCα and βI to the SOS2/GrB2 complex is essential for bacterial proliferation in the cytosol
    Souhaila Al-Khodor
    Department of Microbiology and Immunology, College of Medicine, Department of Biology, University of Louisville, Louisville, KY 40202, USA
    Cell Microbiol 12:1604-21. 2010
    ..Temporal and rapid trigger of Ras signalling by intracellular F. tularensis is essential for intracellular bacterial proliferation within the cytosol, and this is associated with downregulation of early caspase-3 activation...
  9. pmc Exploitation of conserved eukaryotic host cell farnesylation machinery by an F-box effector of Legionella pneumophila
    Christopher T D Price
    Department of Microbiology and Immunology, School of Medicine and 2 Department of Biology, University of Louisville, Louisville, KY 40292, USA
    J Exp Med 207:1713-26. 2010
    ..In conclusion, this study shows novel localized recruitment of the host farnesylation machinery and its anchoring of an F-box effector to the LCV membrane, and this is essential for biological function in vitro and in vivo...
  10. ncbi Anchoring of bacterial effectors to host membranes through host-mediated lipidation by prenylation: a common paradigm
    Tasneem Al-Quadan
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY 40292, USA
    Trends Microbiol 19:573-9. 2011
    ..We also propose utilization of the CaaX motif as a membrane-targeting tag for proteins expressed in eukaryotic cells to facilitate deciphering of biological function...
  11. ncbi Host proteasomal degradation generates amino acids essential for intracellular bacterial growth
    Christopher T D Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, KY 40202, USA
    Science 334:1553-7. 2011
    ..Therefore, Legionella promotes eukaryotic proteasomal degradation to generate amino acids needed as carbon and energy sources for bacterial proliferation within evolutionarily distant hosts...
  12. pmc Exploitation of evolutionarily conserved amoeba and mammalian processes by Legionella
    Tasneem Al-Quadan
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Louisville, KY 40292, USA
    Trends Microbiol 20:299-306. 2012
    ....
  13. pmc Regulation of apoptosis and anti-apoptosis signalling by Francisella tularensis
    Marina Santic
    Department of Microbiology and Parasitology, University of Rijeka, Medical Faculty, Brace Branchetta 20, 51000 Rijeka, Croatia
    Microbes Infect 12:126-34. 2010
    ..We conclude that although caspase-1 and capsase-3 are triggered within F. tularensis-infected hMDMs during early stages of infection, cell death is delayed, which is correlated with simultaneous activation of NF-kappaB...
  14. ncbi Cell biology and molecular ecology of Francisella tularensis
    Marina Santic
    Department of Microbiology and Parasitology, Medical Faculty, Brace Branchetta 20, University of Rijeka, Rijeka, Croatia
    Cell Microbiol 12:129-39. 2010
    ..The past few years have witnessed a quantum leap in our understanding of various aspects of this organism and this review will discuss these remarkable advances...
  15. pmc Amoebae as training grounds for intracellular bacterial pathogens
    Maelle Molmeret
    Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA
    Appl Environ Microbiol 71:20-8. 2005
  16. pmc Maturation of the Legionella pneumophila-containing phagosome into a phagolysosome within gamma interferon-activated macrophages
    Marina Santic
    Department of Microbiology and Immunology, Room 316, University of Louisville College of Medicine, 319 Abraham Flexner Way 55A, Louisville, KY 40202, USA
    Infect Immun 73:3166-71. 2005
    ..We conclude that IFN-gamma-activated macrophages override the ability of L. pneumophila to evade endocytic fusion and that the LCP is processed through the "default" endosomal-lysosomal degradation pathway...
  17. ncbi Modulation of biogenesis of the Francisella tularensis subsp. novicida-containing phagosome in quiescent human macrophages and its maturation into a phagolysosome upon activation by IFN-gamma
    Marina Santic
    Department of Microbiology and Immunology, Room 316, University of Louisville College of Medicine, 319 Abraham Flexner Way 55A, Louisville, KY 40202, USA
    Cell Microbiol 7:957-67. 2005
    ..tularensis. In IFN-gamma-activated hMDMs, the organism fails to escape into the cytoplasm and its phagosome fuses to lysosomes, similar to inert particles...
  18. ncbi The Francisella tularensis pathogenicity island protein IglC and its regulator MglA are essential for modulating phagosome biogenesis and subsequent bacterial escape into the cytoplasm
    Marina Santic
    Department of Microbiology and Immunology, Room 316, University of Louisville College of Medicine, 319 Abraham Flexner Way 55A, Louisville, KY 40202, USA
    Cell Microbiol 7:969-79. 2005
    ..tularensis to evade lysosomal fusion within human macrophages and cause tularemia. This is the first example of specific virulence factors of F. tularensis that are essential for evasion of fusion of the FCP to lysosomes...
  19. pmc Incomplete activation of macrophage apoptosis during intracellular replication of Legionella pneumophila
    Alaeddin Abu-Zant
    Department of Microbiology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Infect Immun 73:5339-49. 2005
    ..pneumophila, apoptotic cell death is not executed until late stages of the infection, concomitant with the termination of intracellular replication...
  20. pmc Characterization of Legionella pneumophila pmiA, a gene essential for infectivity of protozoa and macrophages
    Masaki Miyake
    Department of Microbiology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga ku, Shizuoka shi, Japan
    Infect Immun 73:6272-82. 2005
    ..These results suggest that PmiA is a novel virulence factor that is involved in intracellular survival and replication of L. pneumophila in macrophages and protozoan cells...
  21. pmc Role for RpoS but not RelA of Legionella pneumophila in modulation of phagosome biogenesis and adaptation to the phagosomal microenvironment
    Alaeddin Abu-Zant
    Department of Microbiology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Infect Immun 74:3021-6. 2006
    ..Thus, there is no functional link between the stringent response and RpoS in the pathogenesis of L. pneumophila...
  22. ncbi Anti-apoptotic signalling by the Dot/Icm secretion system of L. pneumophila
    Alaeddin Abu-Zant
    Department of Microbiology, University of Louisville Collage of Medicine, Louisville, KY 40202, USA
    Cell Microbiol 9:246-64. 2007
    ....
  23. ncbi Early trafficking and intracellular replication of Legionella longbeachaea within an ER-derived late endosome-like phagosome
    Rexford Asare
    Department of Microbiology, Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
    Cell Microbiol 9:1571-87. 2007
    ..pneumophila. In addition, re-routing biogenesis of the L. pneumophila phagosome into a late endosome controlled by L. longbeachaea has no effect on intracellular replication...
  24. ncbi Role for the Ankyrin eukaryotic-like genes of Legionella pneumophila in parasitism of protozoan hosts and human macrophages
    Fabien Habyarimana
    Department of Microbiology and Immunology, Room MS 410, College of Medicine, University of Louisville, Louisville, KY 40292, USA
    Environ Microbiol 10:1460-74. 2008
    ..polyphaga. Our data suggest a role for AnkH and AnkJ in modulation of phagosome biogenesis by L. pneumophila independent of evasion of lysosomal fusion and recruitment of the rough endoplasmic reticulum...
  25. pmc Molecular mimicry by an F-box effector of Legionella pneumophila hijacks a conserved polyubiquitination machinery within macrophages and protozoa
    Christopher T Price
    Department of Microbiology and Immunology, College of Medicine, University of Louisville, Kentucky, USA
    PLoS Pathog 5:e1000704. 2009
    ..Therefore, AnkB exhibits a novel molecular and functional mimicry of eukaryotic F-box proteins that exploits conserved polyubiquitination machinery for intracellular proliferation within evolutionarily distant hosts...
  26. pmc A Dot/Icm-translocated ankyrin protein of Legionella pneumophila is required for intracellular proliferation within human macrophages and protozoa
    Souhaila Al-Khodor
    Department of Microbiology and Immunology, Room 413, College of Medicine, University of Louisville, KY 40202, USA
    Mol Microbiol 70:908-23. 2008
    ..pneumophila within macrophages and protozoa, and its expression is temporally controlled by regulators of the postexponential phase of growth...
  27. ncbi Structure-function analysis of the C-terminus of IcmT of Legionella pneumophila in pore formation-mediated egress from macrophages
    Dina M Bitar
    Department of Medical Microbiology and Immunology, Faculty of Medicine, Al Quds University, Jerusalem, Israel
    FEMS Microbiol Lett 242:177-84. 2005
    ..However, certain single amino acid substitutions in the C-terminus reduce the pore-forming activity when tested in vitro, but may or may not have a detectable effect on egress of L. pneumophila from U937 macrophages...