INDUCING INNATE PROTECTION IN GREEN MUSSELS BY MANIPULATION OF HEAT SHOCK TREATMENTS

Small aquatic animals are known to have lack of systemic immune system in protection against pathogenic microorganism.  Most of aquatic species depend on innate immunity, which are non-specific in nature and would prevent different types of pathogen in disease pathogenesis. A study was conducted to determine the non-lethal heat shock (NLHS) of P. viridis, and to observe if the treatment could promote the production of Hsp70, which will be then enhanced its resistance towards stresses and V. alginolyticus infection.  The LT50 and LHT were determined to be at  42°C and 44°C, respectively, with no mortality to the animals exposed to heat shock treatment compared to the untreated group.  Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery.  Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus, suggesting Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.