title: Anti-tumor immunity of BAM-SiPc-mediated vascular photodynamic therapy in a BALB/c mouse model.
abstract: In recent decades, accumulating evidence from both animal and clinical studies has suggested that a sufficiently activated immune system may strongly augment various types of cancer treatment, including photodynamic therapy (PDT). Through the generation of reactive oxygen species, PDT eradicates tumors by triggering localized tumor damage and inducing anti-tumor immunity. As the major component of anti-tumor immunity, the involvement of a cell-mediated immune response in PDT has been well investigated in the past decade, whereas the role of humoral immunity has remained relatively unexplored. In the present investigation, using the photosensitizer BAM-SiPc and the CT26 tumor-bearing BALB/c mouse model, it was demonstrated that both cell-mediated and humoral adaptive immune components could be involved in PDT. With a vascular PDT (VPDT) regimen, BAM-SiPc could eradicate the tumors of ∼70% of tumor-bearing mice and trigger an anti-tumor immune response that could last for more than 1 year. An elevation of Th2 cytokines was detected ex vivo after VPDT, indicating the potential involvement of a humoral response. An analysis of serum from the VPDT-cured mice also revealed elevated levels of tumor-specific antibodies. Moreover, this serum could effectively hinder tumor growth and protect the mice against further re-challenge in a T-cell-dependent manner. Taken together, these results show that the humoral components induced after BAM-SiPc-VPDT could assist the development of anti-tumor immunity.
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
authors.forename: Hing-Yuen
authors.initials: HY
authors.lastname: Yeung
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
authors.forename: Pui-Chi
authors.initials: PC
authors.lastname: Lo
authors.affiliation: Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
authors.forename: Dennis K P
authors.initials: DK
authors.lastname: Ng
authors.affiliation: School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
authors.forename: Wing-Ping
authors.initials: WP
authors.lastname: Fong
mesh_terms: D000067531:Alarmins / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology; D004195:Disease Models, Animal; D007109:Immunity / Q000187:drug effects*; D056724:Immunity, Humoral / Q000187:drug effects; D007211:Indoles / Q000494:pharmacology / Q000627:therapeutic use*; D008807:Mice, Inbred BALB C; D009369:Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000276:immunology*; D009389:Neovascularization, Pathologic / Q000188:drug therapy*; D017646:Organosilicon Compounds / Q000494:pharmacology / Q000627:therapeutic use*; D010778:Photochemotherapy; D018417:Th1 Cells / Q000187:drug effects / Q000378:metabolism; D018418:Th2 Cells / Q000187:drug effects / Q000378:metabolism
chemical_list: D000067531:Alarmins; D000970:Antineoplastic Agents; C516359:BAM-SiPc; D016207:Cytokines; D007211:Indoles; D017646:Organosilicon Compounds