Gene discovery and expression analysis of immune-relevant genes from Biomphalaria glabrata hemocytes

• Published in: Developmental and comparative immunology Vol. 29; no. 5; pp. 393 - 407
• Main Authors: Mitta, G., Galinier, R., Tisseyre, P., Allienne, J.-F., Girerd-Chambaz, Y., Guillou, F., Bouchut, A., Coustau, C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 2005; Elsevier
• Subjects: Animals; Biodiversity; Biomphalaria; Biomphalaria - genetics; Biomphalaria - immunology; Biomphalaria - parasitology; Biomphalaria glabrata; Cytokine-like; Echinostoma; Echinostoma - immunology; Echinostoma caproni; EST; Expressed Sequence Tags; Gene Expression Profiling; Gene Library; Host-Parasite Interactions; Host-Parasite Relations; Immune System; Immune System - immunology; Immune System - metabolism; Innate immunity; Invertebrate; Life Sciences; Pattern recognition receptor; Populations and Evolution; Research Support, Non-U.S. Gov't; RNA, Messenger; RNA, Messenger - metabolism; Invertebrate; Biomphalaria glabrata; Echinostoma caproni; EST; Innate immunity; Cytokine-like; Host–parasite interactions; Pattern recognition receptor; Host-parasite interactions
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2004.10.002

The immune effector cells (hemocytes) of the snail host
Biomphalaria glabrata are known to play a key role in recognition and elimination of larval helminths such as the human blood fluke
Schistosoma mansoni. To identify novel immune-relevant genes, we undertook an expressed sequence tag program. A hemocyte cDNA library was constructed using snails that were not exposed to a particular pathogen or parasite but maintained in non-axenic conditions. Putative function could be assigned to 53% of the 1613 high quality cDNAs analysed. Based on sequence similarities, we identified 31 immune-relevant genes corresponding either to cellular defence effectors, proteases and protease inhibitors, pattern recognition receptors, cell adhesion molecules or immune regulators. In order to further investigate the potential involvement of these genes in snail–trematode immunobiological interactions, we analysed their expression in unchallenged and parasite-challenged snails, using the immunosuppressive trematode
Echinostoma caproni and snail strains selected for resistance or susceptibility to this parasite. Real-time PCR analysis of expression ratios at 7 time-points post-exposure revealed both (i) genes displaying constitutive expression differences between the two strains; and (ii) genes differentially modulated after parasite exposure.