Assessing Antigen-Specific CD8+ and CD4+ T-Cell Responses in Mice After Immunization with Recombinant Viruses

To determine the immunogenicity of vaccine candidates, it is essential to establish an accurate and convenient methodology for assessing the level of antigen-specific T-cell responses, and several methodologies have been developed. These include the T-cell proliferative assay as determined by tritium-labeled thymidine (³ H-TdR) incorporation, cytotoxic assays such as the chromium release assay, cytokine enzyme-linked immunosorbent assays (ELISAs) or the T-cell enzyme-linked immunospot (ELISPOT) assay to determine the amounts of cytokines released by activated T cells, and most recently, the newly developed tetramer assay. All these methods, each of which have both advantages and disadvantages, have been used to measure the level of cell-mediated immune responses in animals and humans infected with microbes or immunized with microbial antigens or various vaccines.