Umbilical cord blood-derived dendritic cells infected by adenovirus for SP17 expression induce antigen-specific cytotoxic T cells against NSCLC cells

Sperm protein 17 (SP17), a cancer/testis antigen, is expressed by non-small cell lung cancer (NSCLC). This study examined whether dendritic cells (DC) from human umbilical cord blood (UCB) could be induced for SP17 expression and induce antigen-specific CD8+ cytotoxic T lymphocytes (CTLs) against NSCLC in vitro. We generated recombinant adenovirus of Ad-SP17 and control Ad-null. Infection with Ad-SP17, but not control, induced higher levels of SP17 expression in UCB-derived DC-Ad-SP17. Infection with Ad-SP17 significantly increased the frequency of CD80+, CD83+, CD86+, and HLA-DR+ DC that produced higher levels of IL-12, but lower IL-10. Co-culture of DC-Ad-SP17 with autologous UCB lymphocytes induced high frequency of IFNγ+ CD8+ CTLs, which had selective cytotoxicity against SP17+ lung cancer CRL-5922 cells in a HLA-I restrictive manner. Thus, UCB-derived DC modulated for SP17 expression induced antigen-specific anti-tumor immunity against SP17+ NSCLC, and SP17 may be a valuable target for development of immunotherapy against SP17+ NSCLC.