Role of cyclophilin A as an immunostimulator in responses to Vibrio parahaemolyticus AHPND infection in the black tiger shrimp Penaeus monodon

Abstract

Cyclophilin A (CypA) is a highly conserved peptidyl-prolyl isomerase that plays a crucial role in protein folding, immune regulation, and cellular stress responses. In shrimp, CypA has been implicated in innate immunity, particularly in response to viral and bacterial infections. This study investigates the role of the Penaeus monodon cyclophilin A (PmCypA) in shrimp infected with V. parahaemolyticus AHPND (VP<inf>AHPND</inf>). During VP<inf>AHPND</inf> infection, the expression levels of PmCypA gene and PmCypA protein were significantly increased at 24 h post-infection (h.p.i.) in shrimp hemocyte. To investigate the role of PmCypA in shrimp immune response, shrimp were administrated with the recombinant PmCypA protein (rPmCypA) and submerged in VP<inf>AHPND</inf> suspension. The results showed that the rPmCypA could rapidly stimulate the expression of immune-related genes involved in several immune pathways, such as immune recognition receptors, clotting system, phagocytosis and homeostasis. Moreover, the injected rPmCypA led to an increase in the proportion of hyaline cells and the greater quantity of granulocytes that contained PmCypA. Furthermore, the rPmCypA could prolong shrimp survival during VP<inf>AHPND</inf> infection. These results suggest that the PmCypA is a bacterial-responsive gene in shrimp immune defense response and potentially an immunostimulator in shrimp.