In vivo CTL immunity can be elicited by OVA-linker-beta2m fusion protein

To study the effect of OVA-linker-beta2m fusion protein as an immunogen to induce CTL mediated immune response in mice. The beta2m gene was amplified by PCR. OVA(257-264) peptide sequence and an 8-amino acid linker were added to the COOH-terminus of beta2m gene, and then cloned into pE42b(+) vector. After that, gene expression, protein purification and refolding were conducted. Then the protein product was used as an immunogen to induce an efficient CTL mediated immune response in vivo. Specific CTL responses were demonstrated by H-2K(b)-OVA tetramer staining and cytotoxicity assay. Extracelluar IFN-gamma was also quantitatively analyzed. The results showed that specific CTL response could be induced in vivo by OVA-linker-beta2m fusion protein. Generation of terameric peptide-MHC complexes in vitro is a powerful tool to stain specific CTL.