The complex of damage-associated molecular pattern and its inducer, pathogen-associated molecular pattern enhance triggering innate immunity in shrimp (VET1P.1128)

Abstract

Abstract Peptidoglycan (PG) derived commonly from Gram-positive bacteria, is one of pathogen-associated molecular pattern (PAMP). Incubating hemocytes of shrimp in PG caused degranulation, changes in cell size, reduction in the percentage of cell viability, necrosis of hemocytes, and released intracellular molecules containing damage-associated molecular pattern (DAMP) that is well known in mammals and teleosts. Incubating shrimp hemocytes in PAMP, DAMP or the mixture of PAMPs plus DAMPs all induced significant increases in phenoloxidase (PO) activity and respiratory burst (RB, release of superoxide anion) in vitro. The PO activity and RB induced by the mixture of DAMP-PAMP were much greater than that induced by DAMP alone or PAMP alone. In conclusion, the mixture of DAMP-PAMP cause enhancement in eliciting innate immunity of shrimp. This is the first study to confirm that cell necrosis caused by PAMPs releases intracellular molecules, DAMPs, and the mixture of DAMP-PAMP elicit the innate immunity in an invertebrate.