Abstract: The present inventors worked on elucidating the mechanism of antigen cross-presentation by dendritic cells, and revealed that foreign antigens taken up in dendritic cells are degraded by proteasomes after undergoing polyubiquitination. Based on the novel finding that polyubiquitination is involved in cross-presentation, the promotion of polyubiquitination was attempted by a number of methods, and the promotion of antigen presentation was confirmed. These methods enable the production of dendritic cells effective for inducing CTL activation.

Abstract: The present inventors worked on elucidating the mechanism of antigen cross-presentation by dendritic cells, and revealed that foreign antigens taken up in dendritic cells are degraded by proteasomes after undergoing polyubiquitination. They discovered a positive correlation between the uptake amount of an antigenic protein by dendritic cells or the level of polyubiquitination and the level of antigen presentation of the antigenic protein. Based on these findings, methods were developed for predicting the intensity of cross-presentation of an anti genic protein by measuring the amount of antigenic protein taken up or polyubiquitinated protein. The use of these methods allows selecting antigenic proteins that are readily presented as antigens from among a number of proteins. The methods of the present invention enable suitable cancer immune vaccines to be provided through selection of more suitable cancer-specific proteins.