AUTHOR=Kumar Vikash , Baruah Kartik , Nguyen Dung Viet , Smagghe Guy , Vossen Els , Bossier Peter 

TITLE=Phloroglucinol-Mediated Hsp70 Production in Crustaceans: Protection against Vibrio parahaemolyticus in Artemia franciscana and Macrobrachium rosenbergii

JOURNAL=Frontiers in Immunology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.01091

DOI=10.3389/fimmu.2018.01091

ISSN=1664-3224

ABSTRACT=<p>The halophilic aquatic bacterium, <italic>Vibrio parahaemolyticus</italic>, is an important aquatic pathogen, also capable of causing acute hepatopancreatic necrosis disease (AHPND) in shrimp resulting in significant economic losses. Therefore, there is an urgent need to develop anti-infective strategies to control AHPND. The gnotobiotic <italic>Artemia</italic> model is used to establish whether a phenolic compound phloroglucinol is effective against the AHPND strain <italic>V. parahaemolyticus</italic> MO904. We found that pretreatment with phloroglucinol, at an optimum concentration (30 µM), protects axenic brine shrimp larvae against <italic>V. parahaemolyticus</italic> infection and induced heat shock protein 70 (Hsp70) production (twofolds or more) as compared with the control. We further demonstrated that the <italic>Vibrio</italic>-protective effect of phloroglucinol was caused by its prooxidant effect and is linked to the induction of Hsp70. In addition, RNA interference confirms that phloroglucinol-induced Hsp70 mediates the survival of brine shrimp larvae against <italic>V. parahaemolyticus</italic> infection. The study was validated in xenic <italic>Artemia</italic> model and in a <italic>Macrobrachium rosenbergii</italic> system. Pretreatment of xenic brine shrimp larvae (30 µM) and <italic>Macrobrachium</italic> larvae (5 µM) with phloroglucinol increases the survival of xenic brine shrimp and <italic>Macrobrachium</italic> larvae against subsequent <italic>V. parahaemolyticus</italic> challenge. Taken together, our study provides substantial evidence that the prooxidant activity of phloroglucinol induces Hsp70 production protecting brine shrimp, <italic>A. franciscana</italic>, and freshwater shrimp, <italic>M. rosenbergii</italic>, against the AHPND <italic>V. parahaemolyticus</italic> strain MO904. Probably, phloroglucinol treatment might become part of a holistic strategy to control AHPND in shrimp.</p>