Adaptive immune responses in channel catfish exposed to Edwardsiella ictaluri live attenuated vaccine and wild type strains through the specific gene expression profiles

We extend the previous findings on the differential activity of immune-related genes in the lymphoid organs of channel catfish in the 7 days post-challenge (dpc) with E. ictaluri live attenuated vaccines (LAVs) and wild type (WT) strains by assessing the expression of these genes in the 21 dpc. The expression of T and B cell-specific genes were significantly elevated in the spleen at 14 dpc and in the AK at 21 dpc in catfish treated with E. ictaluri WT and LAV strains compared to a non-treated control group. The gene expression of IFN-gamma correlated with adaptive immunity genes in the lymphoid tissues of catfish. These data indicate that two novel LAVs were able to trigger the activation of T helperl polarization cytokine IFN-gamma gene and specific lymphocyte genes in the spleen followed by their activation in the AK of catfish without causing inflammation, thus providing protective immunity in E. ictaluri infection.

Automated summary

The study shows that two novel E. ictaluri live attenuated vaccines can induce elevated expression of T and B cell-specific genes in channel catfish, activating immune responses and providing protection against disease.