Monoclonal antibodies epitope specificity analysis

Nevertheless, the potential for autoimmune disease would clearly exist if one considers the polyspecificity of immune recognition molecules such as B cell receptors, antibodies, T cell receptors and MHC molecules. Further, the polyspecificity of immune receptors is also able to transcend the biochemically defined classes of biomolecules. For instance, the monoclonal antibody SYA/J6 has been demonstrated to have a dual specificity, binding a specific carbohydrate or a specific peptide with comparable affinity.68 Detailed analysis of the interatomic interactions between the antibody combining site and either the carbohydrate or the peptide antigens demonstrated that functional mimicry is possible without exact structural mimicry. This example underlines the case that it is not possible to predict with certainty whether the molecular surfaces of all potentially cross-reactive epitopes, whether of foreign or self molecules, will, or will not, be able to bind to a specific antibody. 

Another interesting application is the analysis of the specificity of monoclonal antibodies, i.e., whether they recognize different epitopes on the antigen (Friguet et al., 1983). After coating the antigen, two monoclonal antibodies are added, either to separate or to the same well and the amount of bound antibody is quantitated with enzyme-labeled anti-mouse IgG. Additivity of enzyme activity is observed when the monoclonal antibodies bind to distinct epitopes. The additivity index (A/) for a pair of antibodies is then defined as ... 

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