Immunosuppressive action of dendritic cells sensitized by oligodeoxynucleotides and CA125 on human OVCAR3 ovarian carcinoma xenografts in nude mice

Abstract

To explore the immunosuppressive action of dendritic cells (DC) sensitized by oligodeoxynucleotides containing "un-methylated cytosine phosphodiester bond-guanylic acid" motif (CpG ODN) and CA125 on human ovarian carcinoma xenografts in nude mice. Human peripheral blood-derived dendritic cells were isolated and identified by flow cytometry. The DC sensitized by CpG ODN and CA125 were then co-cultured with T cells and finally cytotoxic T lymphocytes (CTL) were induced. Nude mice bearing OVCAR3 transplanted tumor were immunized with induced CTL by subcutaneous injection and tumor growth and cell apoptosis observed. Premature DC had a low expression of CD83 and CD86. In vivo, delayed growth of OVCAR3 xenografts was observed after immunotherapy with CTL induced by DC pulsed by CpG ODN and CA125. The inhibition rate of tumor was 50.71% and it was better than CpG ODN-pulsed and CA125-pulsed groups (P < 0.05). Cell apoptotic rate was (29.6 ± 3.0)% in CpG ODN+CA125-pulsed group versus (21.8 ± 2.7)% in CpG ODN-pulsed group. And both were more than those of unpulsed and CA125-pulsed groups (P < 0.05). CTL induced by DC sensitized by CpG ODN and CA125 can inhibit the growth of ovarian carcinoma xenografts and promote tumor cell apoptosis.