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Dr. David Duval - Biomphalysin, an immune toxin in schistosomiasis vector snails


David Duval

IHPE : Interactions Hôtes-Pathogènes-Environnements, UMR 5244, Perpignan

Biomphalysin, a novel family of snail effector proteins exhibiting common structural features with Aerolysin, a bacterial β-pore forming toxin

Aerolysins are virulence factors belonging to the β pore-forming toxin (β-PFT) superfamily that are abundantly distributed in bacteria. More rarely, β-PFTs have been described in eukaryotic organisms. We have identified in the Schistosomiasis vector snail Biomphalaria glabrata a cytolytic protein which we have named Biomphalysin.  This novel β-PFT displaying hemolytic and anti-schistosomal activities shares a common architecture with aerolysin, a well-known bacterial virulence factor. The availability of the recently sequenced and assembled genome of B. glabrata allowed us to investigate the presence of additional aerolysin-like genes, leading to the identification of a total of 23 intron-less biomphalysin genes located into 22 different scaffolds. A phylogenetic approach revealed that these genes could have resulted from horizontal transfer. These acquisitions were generally followed by gene amplification and diversification, allowing them to acquire different functions to become new weapons to fight against a high diversity of pathogens. Comparative analyses of their deduced amino acid sequences reveals an important range of sequence identity while a high degree of structural homology is predicted. Contrasting patterns of tissue-specific expression of the different biomphalysin genes is observed, which suggest potential non-redundant functions. Indeed, an interactome experiment, which consisted in putting in contact circulating proteins from the snail cell-free hemolymph with outer membrane proteins from living pathogens, indicates that biomphalysins are involved in the recognition of a large diversity of pathogens.

Selected references

  • Tetreau et al. 2017 Specific pathogen recognition by multiple innate immune sensors in an invertebrate Front Immunol 8:1249
  • Adema et al. 2017 Whole genome analysis of a schistosomiasis-transmitting freshwater snail Nat Commun 8:15451
  • Portet et al. 2017 Integrated multi-omic analyses in Biomphalaria-Schistosoma dialogue reveal the immunobiological significance of FREP-SmPoMuc interaction Dev Comp Immunol 75: 16-27
  • Galinier et al. 2017 A multistrain approach to studying the mechanisms underlying compatibility in the interaction between Biomphalaria glabrata and Schistosoma mansoni PLOS Negl Trop Dis 11: e0005398
  • Pinaud et al. 2016 A shift from cellular to humoral responses contributes to innate immune memory in the vector snail Biomphalaria glabrata PLOS Pathog doi: 10.1371/journal.ppat.1005361
  • Galinier et al. 2013 Biomphalysin, a new β pore-forming toxin involved in Biomphalaria glabrata immune defense against Schistosoma mansoni PLOS Pathog doi: 10.1371/journal.ppat.1003216


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26 Jun

11:00 - 12:00

Seminar room - IPBS - Campus 205