Production of antibody to homologous -fetoprotein in rabbits, rats and horses by immunization with human -fetoprotein.

The research article addresses the production of antibodies to homologous alpha fetoprotein (AFP) in various animals like rabbits, rats, and horses by administering human AFP. The antigen was injected multiple times and the immune response was evaluated utilizing specific methods, revealing that high-titre antibodies were formed in all animals except dogs.

Immunization Process

• The study involves immunizing rabbits, rats and horses with human alpha-fetoprotein (AFP). This is an important cancer marker that can serve as a diagnostic tool for oncologists.
• The antigens were administered to the animals subcutaneously, which means under the skin. This was done 5 times at intervals of 7-10 days to maximize the immune response.
• Depending on the species, different doses of human AFP were used. For example, rabbits and dogs got 1 mg of human AFP/ml of serum with each injection whereas the rats received 1/2 of this dose and the horses were given 5 mg/ml/injection.

Research Findings

• Two weeks after the last injection, antisera were collected from the immunized animals and subjected to immunologic assays. These tests assess the strength and specificity of the immune response generated by the immunization process.
• The methods used for these assays were the Ouchterlony technique (a classic method to visualize antigen-antibody precipitations in agar plates) and a modified version of the Mancini technique. These provide reliable data on the immune response of the animals.
• The results showed the production of high titered antibodies in all animals except for the dog. A ‘high titer’ refers to a large quantity of antibodies in the blood, indicating an effective immune response to the antigen.
• The antibodies generated in the rabbit, rat, and horse showed cross-reactivity with their own homologous AFP. Cross-reactivity is when an antibody reacts with an antigen other than the one that induced its production, in this case, the species-specific AFP.
• Attempts to produce an immune response with homologous AFP in rabbits, rats, and dogs turned out to be unsuccessful, meaning the antigen used in these animals was not able to trigger antibody production.