CpG-ODN promotes specific anti-prostate cancer induced by dendritic cells vaccine

Abstract

Objective To observe cytosine-phosphorothioate-guanine oligodeoxynucleotides (CpG-ODN) for the anti-prostate cancer effect induced by dendritic cells (DCs) transduced with recombinant adenovirus vector bearing truncated human prostate specific membrane antigen (tPSMA) gene. Methods Replication deficient adenovirus AdEasy-1 system was used to construct recombination adenovirus Ad-tPSMA and Ad-eGFP. Mouse derived DCs were transduced with Ad-tPSMA and Ad-eGFP, and cultured for 6 days in the presence of 10 μg/L GM-CSF and IL4 in RPMI 1640 containing 10% FCS. After culture with 1 mg/L CpG-ODN for 1 day, DCs were further matured with lipopolysaccharide (LPS) at a concentration of 1μg/L for 1 day. The phenotype of DCs was analyzed by using flow cytometry. T cells proliferation stimulated by DCs in allogeneic mixed lymphocyte reactions and the level of interleukin (IL)-2, interferon (IFN)-γ were detected by ELISA kit, and cytotoxic CTL activity induced by DCs was tested by CCK-8 assay. Results CpG-ODN up-regulated the expression of MHCⅡ (83. 8 ±3. 7)% , CD80 (79. 8 ±5. 6)% and CD86 (78. 3 ±2. 8)% in Ad-tPSMA-tranduced DCs (CpG/DCs-Ad-tPSMA). T cells proliferation stimulated by CpG/DCs-Ad-tPSMA was significantly higher than that in DCs control group, DCs-Ad-tPSMA group and DCs-Ad-eGFP group (P ＜0.05). CpG/DCs-Ad-tPSMA induced increased IL-2 (179. 64 ±2. 72) ng/L, and INF-7 (1581.75 ±28. 61) ng/L expression levels as compared to DCs control group, DCs-Ad-tPSMA group, and DCs-Ad-eGFP group (P＜0. 05), and induced more outstanding RM-1-tPSMA cell specific cytotoxic rate (40.7 ±1.4)%than DCs control group (10. 8 ± 1.7) % , DCs-Ad-tPSMA group (40.7 ± 1.4)% , and DCs-Ad-eGFP group (12.7 ± 1. 2)% (P＜0.05). Conclusion CpG-ODN can promote specific anti-prostate cancer induced by DCs modified with recombinant adenovirus vector bearing tPSMA gene. Key words: Prostate carcinoma; Dendritic cells; CpG-ODN