Use of isothermal titration calorimetry in the development of molecularly defined vaccines

An uptake or a release of heat accompanies practically all molecular bindin g interactions. Therefore isothermal titration microcalorimetry is universa lly applicable for the characterisation of such binding processes. Calorime tric analyses do not require marker molecules or intrinsic spectroscopic re porter groups, which can modify the analysed interactions. Furthermore, mea -surements are carried out in solution and the adsorption of reactants to a solid phase is thus avoided. At variance with most other analytical approa ches, titration calorimetry determines simultaneously enthalpy and entropy contributions of the binding interactions, as well as the binding constant and stoichiometry. In our analyses of the interactions between monoclonal a ntibodies and candidate antigens for vaccines vs. malaria and malignant mel anoma, isothermal titration calorimetry has turned out to be a very valuabl e technique. The obtained quantitative data on biomolecular interactions ca n substantially support the rational design of epitope-focused vaccines.