Jump to Main Content
Use of a lipid-emulsion carrier for immunisation of dab (Limanda limanda) by bath and oral routes: an assessment of systemic and mucosal antibody responses
- Lin, S.H., Davidson, G.A., Secombes, C.J., Ellis, A.E.
- Aquaculture 2000 no.1/2 pp. 11-24
- immunization, oral administration, application methods, emulsions, lipids, antibody formation, antibodies, gills, intestinal mucosa, leukocytes, kidneys, cell suspension culture, immunoglobulins, duration
- The ability of a novel fish-oil emulsion antigen-delivery system administered orally and by immersion, to stimulate antibody responses in the dab was measured. In addition, the kinetics of antibody secreting cell (ASC) responses were monitored by ELISPOT in single cell suspensions derived from perfused gill filaments, gut mucosa peripheral blood leucocytes (PBL) and head kidney to investigate if the mucosal (gill and gut) and systemic (PBL and head kidney) compartments responded in a linked or independent manner. Oral intubation of human gamma globulin (HGG) (25 mg) in saline induced no detectable responses. Immersion in a bath containing HGG in lipid emulsion induced a transient ASC response in the blood only. Anal intubation of HGG (25 mg) in saline induced a slight response in the gut and blood. Oral intubation of HGG (25 mg) in lipid emulsion induced ASC responses in the gut from weeks 2 to 10 post-immunisation and transiently in the gill (week 2 only) but no response (above background) in the head kidney. None of the above methods of immunisation induced serum antibody titres. Intraperitoneal injection of HGG (1 mg) in saline induced high numbers of ASC in the head kidney, gut and gill as well as serum antibody. The ASC response in the head kidney was detected from weeks 5 to 10, peaking at week 5. The response in the gill was from weeks 3 to 10, peaking at week 6, and the response in the gut was from weeks 5 to 10 peaking at week 8. The numbers of ASC in gut and gill following i.p. immunisation were larger than after oral-in-lipid administration, but the latter induced a more rapid response. The results indicate that systemic stimulation (i.p. injection) induced ASC responses in both systemic and mucosal compartments. The orally protected HGG in lipid emulsion was more effective than oral HGG in saline and anal HGG in saline in inducing ASC responses in the gut and the gill suggesting that oral immunisation can induce a common mucosal response independently of the head kidney.