title: Generation of an effective anti-lung cancer vaccine by DTPP-mediated photodynamic therapy and mechanistic studies.
abstract: The objective of this study was to generate an effective vaccine against lung cancer using photosensitizing drug-mediated photodynamic therapy (PDT) and to study the mechanism. The efficiency of a photosensitizing drug (DTPP) was investigated by singlet oxygen yield determination, killing effect analysis, and cell apoptosis induction effect assessment. DTPP-based PDT tumor cell lysates and cell surface antigens obtained from acid-eluted adherent cells were then used as vaccines to prevent lung cancer using LA795 murine lung cells. The optimal protocol for PDT vaccine preparation was selected based on the tumor growth retardation effect of the vaccines, DTPP concentration, illumination dose, and numbers of DTPP-based PDT cells. To study the mechanism of the anti-tumor effect of vaccines, host anti-tumor immune responses were studied, including CD4(+)/CD8(+) ratios and percentage of NK cells and serum cytokine levels. A comparison of cytokine (IFN-γ and IL-1) secretion from splenocytes and tumor pathologic features from mice immunized with vaccines were compared with controls and showed that the optimal protocol for PDT vaccine preparation was LA795 cells exposed to 10 μg/ml DTPP photosensitizer for 24 h, illuminated with 7.2 J/cm(2) at 20 mW/cm(2) (630 nm) and 2 × 10(7) PDT cell lysates injected per mouse. DTPP-based PDT cell lysate vaccination had a significant inhibitory effect on tumor growth based on increased CD4(+)/CD8(+) ratios, NK cell percentages, elevated serum IFN-γ and IL-1 levels, and lymphocyte aggregation at the edge of tumors. Thus, DTPP-based PDT can induce LA795 cell apoptosis that can generate anti-tumor effects without use of an adjuvant.
authors: Laboratory of Laser Medicine, Institute of Biomedical Engineering, Peking Union Medical College and Chinese Academy of Medical Sciences, Tianjin, 300192, China.
authors: Liqing
authors: L
authors: Zheng
authors: Yingxin
authors: Y
authors: Li
authors: Yuxiao
authors: Y
authors: Cui
authors: Huijuan
authors: H
authors: Yin
authors: Tianjun
authors: T
authors: Liu
authors: Guoqiang
authors: G
authors: Yu
authors: Feng
authors: F
authors: Lv
authors: Jichun
authors: J
authors: Yang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D019496:Cancer Vaccines / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D007371:Interferon-gamma / Q000097:blood; D007375:Interleukin-1 / Q000097:blood; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D016131:Lymphocyte Subsets / Q000187:drug effects; D051379:Mice; D009368:Neoplasm Transplantation; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011166:Porphyrins / Q000627:therapeutic use
chemical_list: C588132:5-(4-N,N-diacetoxylphenyl)-10,15,20-tetraphenylporphyrin; D019496:Cancer Vaccines; D007375:Interleukin-1; D017319:Photosensitizing Agents; D011166:Porphyrins; D007371:Interferon-gamma