The long non-coding RNA LTCONS32135 mediates dual antiviral and antibacterial immunity in the Miichthys miiuy

Long non-coding RNAs (lncRNAs), as emerging regulators of gene expression, serve as important regulatory factors of immune responses. Despite extensive research in mammals, its role in defence against pathogens in fish remains an area in urgent need of exploration. This study focuses on the regulation of innate immune responses by lncRNAs in fish. We identified a novel lncRNA LTCONS32135 in the Miichthys miiuy (miiuy croaker). This lncRNA exhibited significantly increased expression following LPS or Poly(I: C) stimulation, suggesting its potential for broad-spectrum immune responses. To explore its function, we demonstrated in the miiuy croaker and zebrafish ( Danio rerio ) infection model that overexpression of lncRNA LTCONS32135 effectively suppressed Vibrio anguillarum colonization and VSV viral replication, while simultaneously significantly enhancing the expression levels of pro-inflammatory cytokines (such as IL-6) and antiviral factors (such as ISG15), thereby positively regulating innate immunity and promoting the NF-κB and IRF3 pathway. In summary, lncRNA LTCONS32135 functions as a dual-immunity defence molecule within fish, positively regulating both antiviral and antibacterial responses. This discovery provides novel theoretical groundwork for understanding the innate immune mechanisms in fish.