The Dynamic Immune Response of Yellow Catfish (Pelteobagrus fulvidraco) Infected With Edwardsiella ictaluri Presenting the Inflammation Process

Abstract

Edwardsiella ictaluri is a highly destructive pathogen in cultured yellow catfish, thus it was very necessary to study the immune response of yellow catfish against bacterial infection. In this study, RNA-Seq technology was used to study the immune response in two distinct tissues of yellow catfish at eight different time points (h) after E. ictaluri infection. The number of differentially expressed genes (DEGs) in the spleen and liver was low at 3 h and 6 h post-infection, respectively. Afterwards, the most number of DEGs in the spleen was detected at 72 h, while the number of DEGs in the liver maintained a high level from 24 h to 120 h. The GO and KEGG enrichment analyses of DEGs at different time points uncovered that cytokines were continuously transcribed at 6 h to 120 h; whereas the liver is the main organ that secretes the components of the complement system, and metabolic regulation was activated from 12 h to 120 h. Moreover, an overview of the inflammation response of yellow catfish was exhibited including pattern-recognition receptors, inflammatory cytokines, chemokines, complements, and inflammation-related signal pathways. The similar expression tendency of nine genes by qRT-PCR validated the accuracy of transcriptome analyses. The different transcriptomic profiles obtained from the spleen and liver will help to better understand the dynamic immune response of fish against bacterial infection, and will provide basic information for establishing effective measures to prevent and control diseases in fish.

Pathogenicity of Streptococcus iniae causing mass mortalities of yellow catfish (Tachysurus fulvidraco) and its induced host immune response

“…The complement has been viewed as a part of the innate immune system which can help to fight microbial intruders, and can quickly tag and remove them directly (Ricklin et al, 2010). Previous studies have showed that the C3 and C4 in the liver were induced significantly at transcription level after E. ictaluri invasion (Zhou et al, 2021). In this study, the expression levels of C3 and C4 genes in the head kidney and liver were upregulated distinctly and then downregulated post S. iniae infection.…”

Nocardia seriolae mediates liver granulomatous chronic inflammation in Micropterus salmoides through pyroptosis

“…For example, Wang et al (2021) found that multifocal necrosis and non‐suppurative inflammation occurred in the hepatopancreas of fish after infection with spring viraemia of carp virus caused by water quality problems, resulting in reduced food intake, weakened stress capacity and eventually death (Liu et al, 2020). Zhou et al (2021) reported that after Edwardsiella invaded fish, it reached the brain along the olfactory nervous system, leading to granulomatous chronic inflammation in the brain. Encephalitis led to abnormal behaviour of diseased fish, such as spastic spiral swimming.…”

RNA-Sequencing Analysis of the Spleen and Gill of Takifugu rubripes in Response to Vibrio harveyi Infection

“…RNA-sequencing technology can effectively reveal genes that are engaged in immune responses and expressed in response to the presence of toxicants or infection (25)(26)(27). Many studies have focused on the transcriptomic changes in different fish tissues after bacterial infection (15,28). However, few studies have reported the combined analysis of RNA-sequencing in the spleen and gill of T. rubripes after V. harveyi infection.…”