Hypersensitivity to dietary components in young farm animals: immunisation of calves for IgE antibody responses

Bovine immunoglobulin E

The recognition of homocytotropic antibodies and their occurrence in response to parasite infection preceded the recognition of IgE as a distinct antibody isotype in the bovine species. Passive cutaneous anaphylaxis was an early reliable and antigen specific method to detect IgE in bovine serum. Yet studies on the role of IgE in bovine disease awaited the production of polyclonal and monoclonal antisera specific for the bovine epsilon chain. Applications of antigen specific ELISA and Western blot techniques have demonstrated IgE responses not only to parasite antigens, but also to viral and bacterial pathogens. The role of IgE in vaccine enhanced disease and in eliciting anaphylactic responses to some vaccines has been elucidated using these immunological assays.

Immunisation regimes used to elevate serum IgE in sheep

Six different immunisation regimes were used in an attempt to elevate the concentration of ovine IgE. The response was measured by a passive cutaneous anaphylaxis (PCA) test. These regimes included infection with Ascaris suum and the combination of infection and parenteral administration of Ascaris antigens and ovalbumin in adjuvants. The regime producing the highest titre of IgE was the combination of Ascaris infection with parenteral administration of Ascaris extract in Bordetella pertussis. This regime consistently produced a transient high titre (1:1280-1:2560) of serum IgE 9-12 days after immunisation. The response to ovalbumin was transient and the maximum PCA titre obtained was 1:10.