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Dictyostelium discoideum amoeboid cells respond to microbial ligands
Author(s) -
Snyder Michelle Dykstra,
Cassilly Daniel,
Samaroo Dave,
Walk Alex,
Sanborn Keri
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.864.6
Subject(s) - dictyostelium discoideum , biology , microbiology and biotechnology , peptidoglycan , chemotaxis , multicellular organism , receptor , innate immune system , pattern recognition receptor , dictyostelium , gene , biochemistry
Mammalian innate immune cells detect pathogen‐associated molecular patterns (PAMPs) using evolutionarily‐conserved pattern‐recognition receptors that can be studied using a variety of model organisms. Dictyostelium discoideum is a unique model organism that exists for part of its lifecycle as single‐celled amoebae, but is induced to form a multicellular sporulating body upon starvation. As amoeboid cells, D. discoideum phagocytose bacteria for nutrient uptake; however, it has not been appreciated whether D. discoideum use pattern‐recognition receptors to detect bacterial prey. Here we show that D. discoideum cells indeed respond to known PAMPs, as exposure to the bacterial cell wall products LPS and peptidoglycan induces the production of reactive oxygen species. Furthermore, pretreatment of starving cells with LPS delays the development of sporulating bodies. Finally, as measured by qRT‐PCR, exposure of amoeboid cells to LPS and peptidoglycan upregulates the expression of genes homologous to those known to function in microbial recognition. Upregulated genes include a putative scavenger receptor and a gene containing the toll/interleukin‐1 receptor domain. We are currently creating D. discoideum cells that overexpress or are deficient for these gene products. The characterization of such genes should provide insight into conserved molecular mechanisms underlying microbial detection.