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Two-Step Vibrio parahaemolyticus Challenge Reveals Transcriptional Reprogramming of Trained Immunity in Shrimp Hemocytes
1
School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao 266109, China
2
State Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266000, China
3
Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
4
Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266000, China
*
Author to whom correspondence should be addressed.
Biology 2026, 15(12), 956; https://doi.org/10.3390/biology15120956 (registering DOI)
Submission received: 1 May 2026
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Revised: 8 June 2026
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Accepted: 12 June 2026
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Published: 18 June 2026
(This article belongs to the Section Marine and Freshwater Biology)
Simple Summary
Whiteleg shrimp are a key farmed seafood, but they frequently suffer severe disease and economic losses from Vibrio parahaemolyticus infection. Like other invertebrates, shrimp lack vertebrate-like adaptive immune memory, yet they can develop enhanced protection after an initial exposure, a response known as trained immunity. We investigated this defense by administering two sequential doses of formaldehyde-inactivated Vibrio parahaemolyticus and analyzing gene expression in shrimp hemocytes. We found that the second exposure triggered widespread gene expression changes: genes related to cell divide and grow, as well as immune effectors, were activated. The data may provide candidate genes for disease-resistant breeding research in shrimp aquaculture.
Abstract
Invertebrates rely exclusively on innate immunity but exhibit memory-like responses termed immune priming or trained immunity. In the commercially vital whiteleg shrimp (Litopenaeus vannamei), infection by Vibrio parahaemolyticus causes severe economic losses, yet the molecular networks driving secondary immune recall remain poorly understood. In this study, we established a two-step immune challenge model in L. vannamei using formaldehyde-inactivated V. parahaemolyticus and performed transcriptomic analysis on hemocytes to compare primary and secondary immune responses. Differentially expressed gene (DEG) screening and enrichment analyses (GO, KEGG, and GSEA) suggest that shrimp hemocytes undergo a broad and coordinated transcriptional reprogramming rather than uniform upregulation of immune genes. Transcriptomic data show potential associations between secondary immune priming and the modulation of cell fate processes: genes related to cell cycle progression (e.g., CDK1, CCNB3) and spindle assembly (e.g., MPS1) were significantly upregulated alongside apoptosis inhibition (CASP6 downregulation). Concurrently, metabolic remodeling was observed through the upregulation of lipid synthesis (SREBF1, FASN) and carbohydrate uptake pathways, potentially providing anabolic support for hemocyte growth and immune activation. Furthermore, the humoral effector responses appear to be strengthened, characterized by upregulated antimicrobial peptides (PEN, ALF) and the proPO melanization cascade (PPAF3, PPO3), whereas the expression of intracellular NLR was relatively suppressed, which might help mitigate excessive immune inflammation and immunopathological damage. Collectively, these transcriptomic findings identify a putative coordinated transcriptional signature of hemocyte recall responses in L. vannamei. This study expands our understanding of innate immune memory in invertebrates and provides candidate molecular markers for further study in disease-resistant breeding research in shrimp aquaculture.
Keywords:
hemocyte; innate immune memory; cell cycle; lipid metabolism; immune effector
