ABSTRACT

Aim:

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.

Materials and Methods:

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.

Results:

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.

Conclusion:

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.