Transcriptome Analysis of Plectropomus leopardus Erythrocytes Reveals Transcriptional Immune Suppression Induced by Vibrio harveyi Infection
by
, ,
Jingmiao Yang
1,†,
An Li
3,†,
Zhenyi An
4,
Xiaowei Zhou
4,
Qiang Chen
2,
Lijuan Zhang
2,
Kai Feng
4,
Fen Zeng
4,
Xiaojuan Chen
4,* and
Bin Sun
1,2,* 1
Fujian Provincial Key Lab of Coastal Basin Environment, Fujian Polytechnic Normal University, Fuqing 350300, China
2
Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China
3
Zhejiang Key Laboratory of Coastal Biological Germplasm Resources Conservation and Utilization, Zhejiang Mariculture Research Institute, Wenzhou 325000, China
4
State Key Laboratory of Mariculture Breeding, Key Laboratory of Marine Biotechnology of Fujian Province, College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
*
Authors to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Animals 2026, 16(18), 2831; https://doi.org/10.3390/ani16182831
Submission received: 31 July 2026
/
Revised: 25 August 2026
/
Accepted: 7 September 2026
/
Published: 9 September 2026
(This article belongs to the Topic Immunology and Disease Prevention and Control in Aquatic Animals)
Simple Summary
Unlike human red blood cells, fish red blood cells have a nucleus and can fight pathogens. The leopard coral grouper is a valuable farmed fish, but it often dies from infections caused by a bacterium called Vibrio harveyi, which hurts the fish farming industry. In this study, we found that leopard coral grouper red blood cells can swallow Vibrio harveyi. However, Vibrio harveyi also suppress the immune defenses of the fish at the transcriptional level by turning down important immune genes. These findings help explain why this fish gets sick so easily and may lead to better ways to protect farmed fish from the bacterial infection.
Abstract
Unlike mammalian erythrocytes, teleost erythrocytes are nucleated and transcriptionally active, yet their immune functions remain not fully understood. The leopard coral grouper (Plectropomus leopardus) is an economically important marine fish and is highly susceptible to Vibrio harveyi infection. In this study, we aim to investigate the immune role of erythrocytes during V. harveyi infection. Flow cytometry analysis showed that erythrocytes actively internalize V. harveyi in a dose-dependent manner. Transcriptome profiling of erythrocytes from control and V. harveyi-infected groups was performed to reveal the host immune responses after bacterial internalization. A total of 5995 differentially expressed genes (DEGs) were identified and significantly enriched in immune-related pathways, with the MAPK signaling pathway, apoptosis, and NF-κB signaling pathway as the three core pathways. Heatmap analysis further revealed transcriptional downregulation of MAPK kinases, apoptotic components, and cytokines (interleukins, chemokines, TNFs, and interferons). These findings provide transcriptional evidence for the immune involvement of teleost erythrocytes and offer insights into host–pathogen interactions during V. harveyi infection.
