Immunological importance of the second gut segment of carp. III. Systemic and/or mucosal immune responses after immunization with soluble or particulate antigen

Abstract

Mucosal and systemic (serum) immune responses were studied after oral, anal or intramuscular ( i m ) immunization with particulate (Vibrio anguillarum) or soluble (ferritin) antigen. Antigenspecific antibodies were found by ELISA in skin mucus after repeated oral or anal administration of bacteria, but not after immunization with ferritin. Daily feeding with bacteria did not give detectable antibodies in serum, while regular oral administration of ferritin resulted in an increase of specific antibodies during the first 3 weeks. From that time immunosuppression was observed, as the antibody titre decreased despite the continued ferritin feeding. Immunosuppression was also found after a second anal intubation or i.m. injection with ferritin, independent of the route of priming(i.m. or anal). On thecontrary, asecondanalintubationofbacteriaresultedinasecondary serum response. Theseresultscombined withthosereportedin PartsIandIIofthestudyindicatean important immunological role for the second gut segment. Because mucosal as well as serum responses can be obtained by anal immunization with bacteria, the significance for oral vaccination is discussed.

Oral vaccination of juvenile carp (Cyprinus carpio) and gilthead seabream (Sparus aurata) with bioencapsulatedVibrio anguillarumbacterin

“…In the case of vaccination against V. anguillarum, the humoral response is strongly related to final protection against vibriosis (Viele et al, 1980;Harrel et al, 1975;Dec et al, 1990). In addition, a mucosal immune response resulting in specific antibodies at mucosal surfaces may also be induced after oral vaccination (Rombout et al, 1989c) and could contribute to a higher level of protection. Consequently, these results indicate that oral vaccination with bioencapsulated bacterin may result in good protection of young fish against vibriosis.…”

“…This feature together with the occurrence of many mucosal lymphoid cells (Rombout et al, 1989b may explain the induction of a mucosal immune response after intestinal immunisation (Rombout et al, 1986(Rombout et al, , 1989. In addition, orally or anally administered antigens can also induce a systemic immune response (Rombout et al, 1986(Rombout et al, , 1989c. Consequently, when antigens can be delivered to the hindgut in su$cient quantities, both systemic and mucosal immune responses can be achieved by oral immunisation.…”

Detection of a distinct gill-surface antibody response following horizontal infection and bath challenge of brook trout Salvelinus fontinalis with Flavobacterium branchiophilum. the causative agent of bacterial gill disease

“…This is unfortunate because mucosae are probably the route of infection for all horizontally transmitted fish pathogens (Chilmoncyzk & Monge 1980, Kanno et al 1989, LaPatra et al 1989). In addition, vaccination of mucosae likely preferentially stimulates a mucosal immune response as well as a systemic response, with the quality of the systemic response depending on the nature of the antigen(s), their dose, and their route of presentation (Lobb 1987, Rombout et al 1989.…”

“…Effective vaccination for many fish diseases, particularly mucosal diseases, will require an understanding of the mucosal antibody response. Several studies have investigated the antibody responses of the skin (Ourth 1980, Lobb & Clem 1981a, b, St. Louis-Cormier et al 1984, of the intestine (Georgopoulou & Vernier 1986, Rombout et al 1989) and of bile (Lobb & Clem 1981a, c). In most instances, specific mucosal antibody has been detected following parenteral immunization or 'local' exposure (Ourth 1980, Lobb 1987.…”

Anal immunisation of carp and rainbow trout with different fractions of aVibrio anguillarumbacterin

“…Although previous reports suggest that the posterior part of the gut is important to induce a su$cient immune response, uptake of LPS in the anterior part of the gut of brown trout has been demonstrated and it is suggested that this can induce a systemic immune response (O'Donnell et al, 1994). Anally and orally administered antigens can induce mucosal as well as systemic immune responses (Rombout et al, 1986(Rombout et al, , 1989b. Consequently, when antigens can be delivered to and taken up by the hindgut in su$cient quantities, better immunological memory may be achieved by oral administration.…”