Characterization of myeloperoxidase and its contribution to antimicrobial effect on extracellular traps in flounder (Paralichthys olivaceus)

• DOI: 10.3389/fimmu.2023.1124813
• Publication Date: 2023-01-26T05:07:55Z
• Authors: Qiujie Gan; Heng Chi; Roy Ambli Dalmo; Xianghu Meng; Xiaoqian Tang; Jing Xing; Xiuzhen Sheng; Wenbin Zhan
• Keywords: Neutrophil Extracellular Traps

Myeloperoxidase (MPO) is a cationic leukocyte haloperoxidase and together with other proteins, they possess activities against various microorganisms are involved in extracellular trap (ET) formation. The present work describes the gene deduced protein sequences, functions of MPO flounder ( Po MPO). possesses 2313 bp open reading frame (ORF) that encodes 770 amino acids. highest PoMPO mRNA expression levels were found head kidney, followed by peritoneal cells, gill, spleen, skin, muscle, liver. was expressed MHCII + GCSFR cells which indicated mainly macrophages granulocytes. Bacterial lipopolysaccharide-stimulated leukocytes showed an increased level while it seemed LPS also promoted migration from kidney into peripheral blood cavity. After phorbol 12-myristate 13-acetate (PMA) or bacterial stimulation, produced typical ET structures containing DNA decoration MPO. ETs effectively inhibited proliferation ET-trapped bacteria. Blocking antibodies decreased enzymatic activity, attenuated antibacterial activity ETs. This study pinpoints involvement innate responses to pathogens.