Beta2-microglobulin is involved in the immune response of large yellow croaker to Aeromonas hydrophila: A proteomic based study

Outbreaks of infectious diseases in cultured large yellow croaker have resulted in great economic losses. However, information regarding its immune defense is limited. In the present study, an approach by the combination of differential proteomics with EST resource was applied for investigation of a profile of serum immune response by large yellow croaker to Aeromonas hydrophila challenge after immunization and for characterizing of one of the targeted immune molecules. Of the twelve altered proteins involved in the response, eight were identified by MS, in which three were randomly selected for antiserum preparation and were further confirmed by Western blotting. Furthermore, three β2m clones, one of the altered molecules, were obtained from a previously constructed Kidney Smart cDNA library of this fish, and were compared for their identity, which contributed to the identification of β2m cDNA diversity. Meanwhile, the up-regulated β2m in response to the bacterial immunization and challenge was further confirmed by Western blotting. Our results indicate that β2m is involved in the immune response of large yellow croaker to the challenge by A. hydrophila after immunization, which suggests an efficient approach for characterizing of targeted molecules at both the gene and protein levels.