The hematopoietic cytokine Astakine play a vital role in hemocyte proliferation and innate immunity in Scylla paramamosain

Astakine may induce hematopoietic response in crustaceans, as it is necessary for hemocyte proliferation. In this study, we produced the recombinant Scylla paramamosain Astakine (rspAstakine) and assessed its immuno-modulatory function. We analyzed its amino acid sequences and generated a three-dimensional model, then ligand binding sites and enzyme commission of spAstakine were predicted. The rspAstakine was identified at 21.3 kDa by Western blot and liquid chromatography-mass spectrometry. The results showed that rspAstakine induced proliferation of hemocytes in mud crab in vivo and in vitro. The expression of immune-related genes was up-regulated after rspAstakine treatment, similarly to the immunity-related parameters, activities of superoxide dismutase, phenoloxidase, lysozyme, and peroxidase. Additionally, the intracellular content of reactive oxygen species was higher in the rspAstakine treatment group than PBS group. The rspAstakine also enhanced the rate of phagocytosis, while reduced the apoptosis rate of hemocytes after Vibrio alginolyticus infection. The mortalities of the V. alginolyticus only group and rspAstakine + V. alginolyticus group were 83.3 % and 58.3 %, respectively, which illustrated that rspAstakine plays a protective role against V. alginolyticus infection in S. paramamosain. Our results demonstrate the potential of Astakine to enhance the proliferation and immunomodulatory function of hemocytes in crustaceans.

Automated summary

This study demonstrates the role of Astakine in inducing hematopoietic response and promoting immune function in crustaceans. Recombinant Scylla paramamosain Astakine was produced and its immuno-modulatory function was assessed. The results showed that Astakine can enhance hemocyte proliferation, up-regulate immune-related genes expression, and increase the activities of antioxidative enzymes. Astakine also improves the phagocytosis rate and reduces hemocyte apoptosis after V. alginolyticus infection, providing protection against the infection. These findings highlight the potential of Astakine in enhancing hemocyte proliferation and immune response in crustaceans.