Antigen design and immunization strategies

The key to development of diagnostic immunoassays is production of high quality antibodies. Antibody production begins with antigen design and selection of effective immunization strategies.

The Diagnostics Development Laboratory has considerable experience in production of antibodies to polysaccharide antigens of bacteria and fungi. Polysaccharide antigens are poorly immunogenic and are often T-cell independent in their induction of immune responses. As a consequence, antigen design often includes coupling of polysaccharides to potent T-cell dependent protein or cellular carriers. As an alternative, CD40 agonist antibodies can be used to substitute for T cell help.

Proteins are a second class of antigens under study. Diagnostics that target proteins often require production of antibodies to epitopes that determine the specificity of the immunoassays. As a consequence, the first step in antigen design is selection of epitopes that have the specificity needed for a particular objective. Criteria for selection include uniqueness and immunogenicity. Both characteristics are determined by bioinformatics analysis of the protein target.

Once a peptide is selected for antibody production, the peptide is synthesized by commercial vendors. The peptide is then coupled to a highly immunogenic protein carrier, usually bovine serum albumin or keyhole limpet hemocyanin. Mice are immunized with the peptide-protein conjugate and antibody production is evaluated by a variety of immunochemical assays.