Immunological responses of fluke-infected and fluke-free cattle to Salmonella dublin and other antigens.
Immune responses to heat-killed Brucella abortus strain 19 and to ovalbumin were compared in 15 fluke-infected and 15 fluke-free Friesian heifers. B abortus was injected 16 weeks and ovalbumin 19 weeks after the oral administration of 1000 metacercariae of Fasciola hepatica. Agglutinating antibody responses to B abortus were similar in both groups. Immediate type hypersensitivity to ovalbumin was apparently suppressed in fluke-infected animals when assessed by active and passive cutaneous anaphylaxis two weeks after sensitisation. However, when assessed by Schultz-Dale responses of intestine, in vitro, 36 weeks after sensitisation there was no difference between the groups. The heifers were subsequently given live Salmonella dublin intravenously. The fluke-infected animals which became carriers of S dublin had the most persistently elevated titres of agglutinating antibodies in their sera and the highest incidence of immediate-type hypersensitivity, as assessed by Schultz-Dale responses of intestine, but the weakest cutaneous delayed hypersensitivity reactions to S dublin. The latter might have been related to lymphopenia which developed after fluke infection. The increased susceptibility of fluke-infected cattle to S dublin cannot be attributed to impaired agglutinin responses but may result from effects on cell-mediated mechanisms.
D000373:Agglutinins / Q000032:analysis; D000818:Animals; D000941:Antigens / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology; D002003:Brucella abortus / Q000276:immunology; D002417:Cattle / Q000276:immunology*; D002418:Cattle Diseases / Q000276:immunology*; D005209:Fasciola / Q000276:immunology; D005211:Fascioliasis / Q000276:immunology / Q000662:veterinary*; D005260:Female; D009130:Muscle, Smooth / Q000276:immunology; D010047:Ovalbumin / Q000276:immunology; D010323:Passive Cutaneous Anaphylaxis; D012475:Salmonella / Q000276:immunology*; D012882:Skin Tests
D000373:Agglutinins; D000941:Antigens; D000942:Antigens, Bacterial; D010047:Ovalbumin