Antigen adsorbed surface modified poly-ɛ-caprolactone microspheres stimulates both adaptive and innate immune response in fish

Surface modified poly-ɛ-caprolactone microspheres as an antigen carrier was explored in a fish model. Outer membrane vesicles of Edwardsiella tarda adsorbed on to surface modified poly-ɛ-caprolactone microspheres with chitosan and alginate induces both innate and adaptive immune responses which persist up to 63 days of post immunization through parenteral immunization unlike that of free and FIA adjuvented antigens. These results highlight the role of these microspheres as an adjuvant/antigen carrier in fish.

► Outer membrane vesicles as an antigen was adsorbed on both the alginate and chitosan coated PCL microspheres.
► It stimulates both specific antibody and innate immune responses on single shot parenteral immunization.
► Immune response persists up to 9 weeks of post immunizations unlike that of FIA adjuvented and free antigens.
► Gives protection upon challenge study.
► No adverse side effects on fish health.