title: Disruption of ERK signalling in Biomphalaria glabrata defence cells by Schistosoma mansoni: implications for parasite survival in the snail host.
abstract: Biomphalaria glabrata is an intermediate snail host for the human blood fluke Schistosoma mansoni. To survive in B. glabrata, S. mansoni must suppress the snail's haemocyte-mediated defence response; the molecular mechanisms by which this is achieved remain largely unknown. We report here that S. mansoni excretory-secretory products (ESPs) attenuate phosphorylation of extracellular signal-regulated kinase (ERK) in haemocytes from a B. glabrata strain susceptible to S. mansoni. Whole S. mansoni sporocysts also impair ERK signalling in these cells. In striking contrast, ERK signalling in haemocytes from a B. glabrata strain refractory to schistosome infection is unaffected by ESPs or sporocysts. Effects of ESPs on ERK are similar in the presence or absence of snail plasma, thus ESPs seem to affect haemocytes directly. These findings reveal novel schistosome interference mechanisms; as ERK regulates various haemocyte defence reactions, we propose that disruption of ERK signalling in haemocytes facilitates S. mansoni survival within susceptible B. glabrata.
authors.affiliation: School of Life Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey, KT1 2EE, UK.
authors.forename: Zahida
authors.initials: Z
authors.lastname: Zahoor
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Davies
authors.forename: Ruth S
authors.initials: RS
authors.lastname: Kirk
authors.forename: David
authors.initials: D
authors.lastname: Rollinson
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Walker
mesh_terms: D000818:Animals; D001700:Biomphalaria / Q000201:enzymology / Q000276:immunology* / Q000469:parasitology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors* / Q000502:physiology; D006790:Host-Parasite Interactions / Q000276:immunology*; D020935:MAP Kinase Signaling System / Q000276:immunology*; D012550:Schistosoma mansoni / Q000254:growth & development* / Q000472:pathogenicity*; D012555:Schistosomiasis mansoni / Q000201:enzymology / Q000276:immunology / Q000469:parasitology
chemical_list: D048049:Extracellular Signal-Regulated MAP Kinases