ABSTRACT

To measure specific T cell responses against to carcinoembryonic antigen (CEA) in transgenic mice that were immunized by a recombinant vector expressing CEA gene, and to evaluate expe-rimental parameters.

Splenocytes were isolated from spleens of HLA-A2 transgenic mice that were immunized with a recombinant vector, ALVAC-CEA. Cells were pulsed with an irrelevant pep-tide for controls or with two different CEA-specific peptides to activate and expand CEA-specific CD8+ cytotoxic T lymphocytes in cultures. Various concentrations of peptides and various cell numbers were tested to find optimum parameters for a standard evaluation procedure of measu-ring CEA-specific T cell responses. Responding T cells were assessed by IFN-γ secretion in ELISPOT assay.

Transgenic mice immunized by ALVAC-CEA developed efficient specific T-cell responses to CEA. Parameters such as peptide concentration and cell number used in in vitro experimental procedure were found to be significant in terms of obtaining optimal measurements.

Experimental parameters should be optimized to measure CEA-specific T cell respon-ses. ALVAC-CEA is an efficient vector to induce specific T cell responses. Therefore, it can be a very useful vaccine in immunotherapy of cancers that express CEA.

Keywords: CEA, HLA-A*0201 transgenic mice, ELISPOT