Further purification and characterisation of horse IgE.

The researchers purified a substance known as IgE from the blood of horses infected with parasites, and demonstrated that rabbit antibodies had a cross-reaction to this horse IgE, as well as to human, mouse, and rat IgE.

Purification of Horse IgE

• In this research, Horse Immunoglobulin E (IgE), a type of antibody, was isolated from a pool of serum collected from young horses (foals) that were infected with parasites.
• Initial purification was achieved using several methods: ammonium sulfate precipitation, delipidation with dextran sulfate, gel filtration, anionic exchange, immunosorption, and preparative polyacrylamide gel electrophoresis. Using these techniques, IgE could be purified to 81% purity.

Antibody Reaction Testing

• Once the IgE was purified, the serum samples were injected into rabbits to stimulate the production of anti-horse IgE antibodies.
• The serum from these rabbits, now containing the antibodies, was tested using two methods: reversed passive cutaneous anaphylaxis (a test that observes the allergic response) and an enzyme-linked immunosorbent assay (ELISA), a common laboratory method used to detect the presence of antibodies.

Cross-reactivity Evaluation

• The ELISA test in particular was used to determine if the antibodies produced by the rabbits in response to the horse IgE also reacted to IgE from humans, mice, and rats.
• The researchers found that there was indeed a cross-reaction, meaning that the antibodies the rabbits produced in response to horse IgE also recognized and bound to IgE from humans, mice, and rats.
• Rat myeloma IgE (a type of IgE constantly produced by cancerous rat cells) was used to continuously monitor the production of antibodies against the horse IgE in rabbits.

Conclusion

• This research displays successful purification of horse IgE and demonstrates that antibodies against horse IgE also show cross-reactivity to human, mouse, and rat IgE. This revelation could be significant in the understanding of several allergic diseases and the development of potential treatments.