Immunohistochemistry (IHC) showed first appearance of Ig+ cells in the head kidney (HK) of 50 days post-hatch (dph) sea bass larvae. Rare Ig+ cells were also found in spleen and thymus. Till 70 dph these became numerous in the HK (70±9 cells/section) and spleen (34±6), less frequent in the thymus (12±4) and absent in the GI tract. RT-PCR with specific primers for the constant region of sea bass Ig H chain and β-actin (housekeeping gene) confirmed Ig transcripts at 50 dph and their rise till 70 dph. Therefore, a vaccine trial vs. Vibrio anguillarum was established using AQUAVAC VIBRIO VAB (biotypes I-II, Shering Plough). Fry were immersion vaccinated (1:10, 1-min) at 95 dph, immersion boosted (same dose) at 165 dph and i.p. boosted (0.1 ml) at 233 dph. Final samplings were made at 291 dph. Bacterial agglutination (BA) by sera and quantitative IHC showed significantly higher BA activity and numbers of mAb DLIg3+ cells in the HK of fish immersion boosted (233 dph) than in age-matched untreated controls and immersion vaccinated only (165 dph). The higher BA lasted till 291 dph, without any further enhancement by i.p. boost, whereas more numerous Ig+ cells were in the HK and spleen of i.p. boosted group at 291 dph. Experimental challenges against biotype I Vibrio anguillarum 77/I03 strain (2.4-6.2 million CFU/ml, 200 ul i.p.) of fish treated as above showed significant protective effect exerted by immersion boost, and almost complete protection (survival) following further i.p. boost.
Experimental vaccine trial against vibriosis in Dicentrarchus labrax (L.).
ABELLI, Luigi;BERTONI, Fabrizio;MARCHETTI, Maria Gabriella;ZENI, Cristina;
2009
Abstract
Immunohistochemistry (IHC) showed first appearance of Ig+ cells in the head kidney (HK) of 50 days post-hatch (dph) sea bass larvae. Rare Ig+ cells were also found in spleen and thymus. Till 70 dph these became numerous in the HK (70±9 cells/section) and spleen (34±6), less frequent in the thymus (12±4) and absent in the GI tract. RT-PCR with specific primers for the constant region of sea bass Ig H chain and β-actin (housekeeping gene) confirmed Ig transcripts at 50 dph and their rise till 70 dph. Therefore, a vaccine trial vs. Vibrio anguillarum was established using AQUAVAC VIBRIO VAB (biotypes I-II, Shering Plough). Fry were immersion vaccinated (1:10, 1-min) at 95 dph, immersion boosted (same dose) at 165 dph and i.p. boosted (0.1 ml) at 233 dph. Final samplings were made at 291 dph. Bacterial agglutination (BA) by sera and quantitative IHC showed significantly higher BA activity and numbers of mAb DLIg3+ cells in the HK of fish immersion boosted (233 dph) than in age-matched untreated controls and immersion vaccinated only (165 dph). The higher BA lasted till 291 dph, without any further enhancement by i.p. boost, whereas more numerous Ig+ cells were in the HK and spleen of i.p. boosted group at 291 dph. Experimental challenges against biotype I Vibrio anguillarum 77/I03 strain (2.4-6.2 million CFU/ml, 200 ul i.p.) of fish treated as above showed significant protective effect exerted by immersion boost, and almost complete protection (survival) following further i.p. boost.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
