Preliminary study of BF/C2 on immune mechanism of grass carp against GCRV infection

• Published in: BMC genomics Vol. 25; no. 1; pp. 715 - 20
• Main Authors: Wei, Yuling, Xiao, Yu, Liu, Qiaolin, Du, Zongjun, Xiao, Tiaoyi
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 24.07.2024; BioMed Central; BMC
• Subjects: Amino acids; Analysis; Animals; Apoptosis; BF/C2; Biosynthesis; Carp; Carps - genetics; Carps - immunology; Carps - virology; Coagulation; Complement component C2; Complement system; Critical point; Ctenopharyngodon idella; Dengue fever; Disease; Down-regulation; Endoplasmic reticulum; Fish; Fish Diseases - genetics; Fish Diseases - immunology; Fish Diseases - virology; Fish Proteins - genetics; Fish Proteins - metabolism; Fishing; Gene expression; Gene Expression Profiling; Gene Expression Regulation; Gene sequencing; Gene set enrichment analysis; Genes; Gluconeogenesis; Glycolysis; Grass carp; Immune response; Immune system; Immunity; In vivo methods and tests; Infections; Interferon; Kidney cell; Kidneys; Lectins; Mortality; Prevention; Protein biosynthesis; Proteins; Reoviridae - physiology; Reoviridae Infections - genetics; Reoviridae Infections - immunology; Reoviridae Infections - veterinary; Reoviridae Infections - virology; Replication; Risk factors; Sequence analysis; Signal processing; Signal transduction; Toll-like receptors; Transcriptome; Transcriptomes; Virus diseases; Virus Replication; West Nile virus; China; BF/C2; Grass carp; Kidney cell; Immunity; Transcriptome
• ISSN: 1471-2164; 1471-2164
• DOI: 10.1186/s12864-024-10609-3

BF/C2 is a crucial molecule in the coagulation complement cascade pathway and plays a significant role in the immune response of grass carp through the classical, alternative, and lectin pathways during GCRV infection. In vivo experiments demonstrated that the mRNA expression levels of BF/C2 (A, B) in grass carp positively correlated with GCRV viral replication at various stages of infection. Excessive inflammation leading to death coincided with peak levels of BF/C2 (A, B) mRNA expression and GCRV viral replication. Correspondingly, BF/C2 (A, B) recombinant protein, CIK cells and GCRV co-incubation experiments yielded similar findings. Therefore, 3 h (incubation period) and 9 h (death period) were selected as critical points for this study. Transcriptome sequencing analysis revealed significant differences in the expression of BF/C2A and BF/C2B during different stages of CIK infection with GCRV and compared to the blank control group (PBS). Specifically, the BF/C2A_3 and BF/C2A_9 groups exhibited 2729 and 2228 differentially expressed genes (DEGs), respectively, with 1436 upregulated and 1293 downregulated in the former, and 1324 upregulated and 904 downregulated in the latter. The BF/C2B_3 and BF/C2B_9 groups showed 2303 and 1547 DEGs, respectively, with 1368 upregulated and 935 downregulated in the former, and 818 upregulated and 729 downregulated in the latter. KEGG functional enrichment analysis of these DEGs identified shared pathways between BF/C2A and PBS groups at 3 and 9 h, including the C-type lectin receptor signaling pathway, protein processing in the endoplasmic reticulum, Toll-like receptor signaling pathway, Salmonella infection, apoptosis, tight junction, and adipocytokine signaling pathway. Additionally, the BF/C2B groups at 3 and 9 h shared pathways related to protein processing in the endoplasmic reticulum, glycolysis/gluconeogenesis, and biosynthesis of amino acids. The mRNA levels of these DEGs were validated in cellular models, confirming consistency with the sequencing results. In addition, the mRNA expression levels of these candidate genes (mapk1, il1b, rela, nfkbiab, akt3a, hyou1, hsp90b1, dnajc3a et al.) in the head kidney, kidney, liver and spleen of grass carp immune tissue were significantly different from those of the control group by BF/C2 (A, B) protein injection in vivo. These candidate genes play an important role in the response of BF/C2 (A, B) to GCRV infection and it also further confirmed that BF/C2 (A, B) of grass carp plays an important role in coping with GCRV infection.