Expression and distribution of penaeidin antimicrobial peptides are regulated by haemocyte reactions in microbial challenged shrimp

摘要: Penaeidins are a family of antimicrobial peptides constitutively produced and stored in the haemocytes penaeid shrimp. In response to microbial stimulation, they released into blood circulation further attach shrimp cuticle surfaces through chitin-binding property. present paper, we have analysed their expression, regulation distribution tissues experimental challenge. We shown that penaeidin mRNA protein restricted granular expression regulated dramatic changes haemocyte populations, both circulating infiltrating tissues. Two distinct phases immune reactions were evidenced: (a) migration towards infection site within first 12 h following injection, with local massive release peptides; (b) appearance population displaying increased penaeidin-transcriptional activity, which may correspond systemic reaction involving proliferation process. Finally, vitro confrontation bacteria revealed penaeidins from by novel phenomenon intracellular degranulation, probably followed lysis cells. Furthermore, covering bacterial suggesting could be involved opsonic activity. Penaeidin-positive observed phagocytosed mainly hyaline cells, does not express penaeidins.