Immune responses induced by oil-adjuvanted inactivated vaccine against Flavobacterium psychrophilum in ayu Plecoglossus altivelis.
Fish Shellfish Immunol
; 98: 585-594, 2020 Mar.
Article
in En
| MEDLINE
| ID: mdl-32004616
ABSTRACT
Oil-adjuvant formulated formalin killed cells of Flavobacterium psychrophilum (FKC + Adj) is strongly effective against bacterial cold-water disease (BCWD) in ayu Plecoglossus altivelis. In this study, we aimed to understand mechanisms underlying the strong protection by the vaccine in ayu. Antibody titer of FKC + Adj and formalin-killed cells (FKC) group was significantly higher than those of modified cytophaga broth injected (MCY) group and MCY with the adjuvant (MCY + Adj) group. The highest antibody titer was observed in FKC + Adj group. Granulomatous inflammation without lymphocyte cuff was observed in the spleen and trunk kidney of FKC + Adj and MCY + Adj group, while the size of the granuloma was bigger in FKC + Adj than in MCY + Adj group. Gene expression level for IL-8 was significantly up-regulated in FKC + Adj group at 4 weeks after the vaccination. In contrast, IL-10 gene expression level was significantly suppressed in FKC + Adj at 4 weeks after the vaccination. F. psychrophilum was almost cleared in the spleen and trunk kidney of FKC + Adj group within 2 days after the challenge. Fluorescent immunohistochemistry showed that a lot of bacterial signals were detected in the spleen and trunk kidney of challenged fish in MCY, FKC and MCY + Adj group. However, the fluorescent signal was not detected in the organs of FKC + Adj group after the challenge. These data suggest that F. psychrophilum is immediately cleared in FKC + Adj vaccinated fish and both specific antibody and activation of phagocytes are essential to clear F. psychrophilum in ayu.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oils
/
Bacterial Vaccines
/
Flavobacterium
/
Adjuvants, Immunologic
/
Osmeriformes
/
Flavobacteriaceae Infections
/
Adaptive Immunity
Limits:
Animals
Language:
En
Journal:
Fish Shellfish Immunol
Journal subject:
BIOLOGIA
/
MEDICINA VETERINARIA
Year:
2020
Type:
Article