title: Effect of crude lipopolysaccharide from Escherichia coli O127:B8 on the amebocyte-producing organ of Biomphalaria glabrata (Mollusca).
abstract: Lipopolysaccharide (LPS) is a pathogen associated molecular pattern (PAMP) to which the internal defense system (IDS) of both vertebrates and invertebrates responds. We measured the mitotic response of the hematopoietic tissue of the schistosome-transmitting snail, Biomphalaria glabrata, to crude LPS from Escherichia coli 0127:B8. In a dose-response study, snails were injected with a range of concentrations of crude LPS, and mitotic figures were enumerated in histological sections of amebocyte-producing organ (APO) fixed at 24h post-injection (PI) following a 6h treatment with 0.1% colchicine. In APOs from Salvador strain snails, which are genetically resistant to infection with Schistosoma mansoni, LPS concentrations of 0.01 mg/ml and above triggered a large increase in mitotic activity, whereas in APOs from schistosome-susceptible NIH albino snails, concentrations of 0.1mg/ml elicited a much smaller, but statistically significant increase. A time course study, without colchicine treatment, revealed that in Salvador APOs the mitotic response to 0.1mg/ml occurred by 18 h PI, peaked at 24h, and returned to control levels by 72 h; NIH albino APOs showed no detectible response. When Salvador APOs were exposed to crude LPS in vitro, no increase in mitotic activity occurred, a result suggesting the possible requirement for a peripheral tissue or hemolymph factor. The increased cell proliferation induced by crude LPS represents a novel systemic response of an invertebrate IDS to one or more PAMPs from a Gram-negative bacterium.
authors.affiliation: Department of Biology, University of San Francisco, San Francisco, CA 94117, USA. sullivan@usfca.edu
authors.forename: John T
authors.initials: JT
authors.lastname: Sullivan
authors.forename: Christina A
authors.initials: CA
authors.lastname: Bulman
authors.forename: Zahra
authors.initials: Z
authors.lastname: Salamat
mesh_terms: D000818:Animals; D001700:Biomphalaria / Q000276:immunology*; D049109:Cell Proliferation; D003078:Colchicine / Q000494:pharmacology; D004926:Escherichia coli / Q000276:immunology; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000276:immunology*; D008938:Mitosis; D051192:Receptors, Pattern Recognition / Q000276:immunology* / Q000378:metabolism; D012550:Schistosoma mansoni / Q000276:immunology / Q000472:pathogenicity / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides; D051192:Receptors, Pattern Recognition; D003078:Colchicine