LvBlimp1 and LvHes1 coregulate the function of macrophage-like phagocytes in shrimp hemolymph

B-lymphocyte-induced maturation protein 1 (Blimp1) is a highly conserved transcription factor that governs cell fate specification in metazoan. In this study, we identified LvBlimp1 as a stress-responsive protein in shrimp hemolymph. Functional knockdown assays revealed that LvBlimp1 silencing significantly impaired cellular immunity, as evidenced by reduced total hemocyte counts, decreased hemocyte viability and phagocytic efficiency, accompanied by elevated intracellular ROS levels and diminished lysozyme expression. Fluorescence activated cell sorter (FACS) analysis demonstrated that LvBlimp1 is predominantly enriched in phagocytic hemocytes. Comparative transcriptomic profiling and qPCR validation further demonstrated that depletion of LvBlimp1 downregulated the expression of key marker genes associated with shrimp macrophage-like phagocytes, including CHF, NPC2, NLRP3, Casp1, zfh1, and CHIT1. Mechanistically, co-immunoprecipitation assays confirmed that LvHes1 physically interacts with LvBlimp1 and is functionally associated with the regulation of a set of common immune genes. Functional ablation of either LvHes1 or LvBlimp1 in shrimp hemocytes compromised host antibacterial defense. These two TFs synergistically regulated the expression of key genes including CIB1 and IMC1. Taken together, our data indicate that LvBlimp-1 and LvHes1 synergistically regulate shrimp macrophage-like phagocyte activity.