Open AccessPhotodynamic therapy‐generated tumor cell lysates with CpG‐oligodeoxynucleotide enhance immunotherapy efficacy in human papillomavirus 16 (E6/E7) immortalized tumor cells
Author(s) -
Bae SuMi,
Kim YongWan,
Kwak SunYoung,
Kim YongWook,
Ro DuckYeong,
Shin JongChul,
Park ChoongHak,
Han SeiJun,
Oh ChungHun,
Kim ChongKook,
Ahn WoongShick
Publication year - 2007
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2007.00447.x
Subject(s) - cytotoxic t cell , immune system , ctl* , immunotherapy , biology , cancer research , t cell , photodynamic therapy , cpg oligodeoxynucleotide , cd8 , microbiology and biotechnology , immunology , chemistry , in vitro , biochemistry , gene expression , dna methylation , organic chemistry , gene
Immunotherapy with photodynamic therapy (PDT) offers great promise as a new alternative for cancer treatment; however, its use remains experimental. In this study, we examined the immunotherapeutic significance of human papillomavirus (HPV)‐immortalized tumor cell lysates induced by PDT with CpG‐oligodeoxynucleotide (ODN). PDT‐cell lysates were generated by irradiating Radachlorin (5 µg/mL) preloaded TC‐1 cells carrying HPV 16 E7. PDT‐cell lysates plus ODN coinjection for protection against E7‐expressing tumors as well as specific immune responses were evaluated with the following tests: heat shock protein 70 (HSP70) enzyme‐linked immunosorbent assay, in vitro and in vivo tumor growth inhibition, interferon‐γ (IFN‐γ) and tumor necrosis factor‐α (TNF‐α) assay, cytotoxic T‐lymphocyte assay, and fluorescence activated cell sorting (FACS) analysis. PDT‐cell lysates plus ODN coinjection showed a significant suppression of tumor growth at both prophylactic and therapeutic levels, compared to PDT (or F/T)‐cell lysates or ODN alone. In addition, we evaluated the level of the immune response with the coinjection. HSP70, an important regulator of inflammatory and immune response, was observed in abundance in the PDT‐cell lysates. IFN‐γ production and cytotoxic T lymphocytes (CTL) responses were induced by PDT‐cell lysates plus ODN injection. The coinjection resulted in PDT‐cell lysate‐specific antibodies (IgG1, IgG2a, IgG2b, and IgG3) and T‐helper cell responses significantly higher than PDT‐cell lysates alone. Moreover, IFN‐γ production and CTL responses were significantly induced in the PDT‐cell lysate plus ODN immunized groups. These enhanced immune responses appeared to be mediated by CD8+ T cells only. These data suggest that PDT‐cell lysates plus ODN injection may be an effective approach to induce CTL immune responses as a possible immunotherapeutic strategy for cancer therapy. ( Cancer Sci 2007; 98: 747–752)