CXCL8 and bacterial infectious disease: In this study, we further explore the adjuvant potential of IL-8 of channel catfish from several aspects by co-injecting with a DNA vaccine encoding α-enolase (pcENO) against Streptococcus iniae infection based on our previous report that IL-8 hold promise for use as potential immunopotentiator against bacterial infections but insufficient to extend the immune protection for long time in a subunit vaccine model [21].