Effective Photoimmunotherapy of Murine Colon Carcinoma Induced by the Combination of Photodynamic Therapy and Dendritic Cells (original) (raw)
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Anti-tumor immune response after photodynamic therapy
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2009
Anti-tumor immunity is stimulated after PDT due a number of factors including: the acute inflammatory response caused by PDT, release of antigens from PDT-damaged tumor cells, priming of the adaptive immune system to recognize tumor-associated antigens (TAA), and induction of heat-shock proteins. The induction of specific CD8+ T-lymphocyte cells that recognize major histocompatibility complex class I (MHC-I) restricted epitopes of TAAs is a highly desirable goal in cancer therapy as it would allow the treatment of tumors that may have already metastasized. The PDT killed tumor cells may be phagocytosed by dendritic cells (DC) that then migrate to draining lymph nodes and prime naïve Tcells that recognize TAA epitopes. We have carried out in vivo PDT with a BPD-mediated vascular regimen using a pair of BALB/c mouse colon carcinomas: CT26 wild type expressing the naturally occurring retroviral antigen gp70 and CT26.CL25 additionally expressing beta-galactosidase (b-gal) as a model tumor rejection antigen. PDT of CT26.CL25 cured 100% of tumors but none of the CT26WT tumors (all recurred). Cured CT26.CL25 mice were resistant to rechallenge. Moreover mice with two bilateral CT26.CL25 tumors that had only one treated with PDT demonstrated spontaneous regression of 70% of untreated contralateral tumors. T-lymphocytes were isolated from lymph nodes of PDT cured mice that recognized a particular peptide specific to b-gal antigen. T-lymphocytes from LN were able to kill CT26.CL25 target cells in vitro but not CT26WT cells as shown by a chromium release assay. CT26.CL25 tumors treated with PDT and removed five days later had higher levels of Th1 cytokines than CT26 WT tumors showing a higher level of immune response. When mice bearing CT26WT tumors were treated with a regimen of low dose cyclophosphamide (CY) 2 days before, PDT led to 100% of cures (versus 0% without CY) and resistance to rechallenge. Low dose CY is thought to deplete regulatory T-cells (Treg, CD4+CD25+foxp3+) and potentiate immune response after PDT in the case of tumors that express self-antigens. These data suggest that PDT alone will stimulate a strong immune response when tumors express a robust antigen, and in cases where tumors express a self-antigen, T-reg depletion can unmask the immune response after PDT.
Journal of Immunotherapy, 2012
Recently, chemotherapy and radiotherapy are known to directly affect some immunosuppressive barriers within a tumor microenviroment. We used cyclophosphamide (CTX), which is known to enhance the immune response by suppressing CD4 + CD25 + regulatory T cells (Treg cells) when used at a low dose, as a chemotherapeutic agent to provide a synergic effect in the irradiation and dendritic cells (DC) combination therapy. Some previous studies observed that a single-dose CTX treatment significantly reduced the number of Treg cells in 3-5 days, however, the reduced Treg cells increased rapidly after 5 days. To overcome the disadvantages of a single-dose CTX, we used 30 mg/kg dose of CTX, which was treated intraperitoneally to mice 3 days before every immature DC (iDC) injection (known as "metronomic schedule CTX"). Irradiation was applied at a dose of 10 Gy to the tumor on the right thigh by a linear accelerator. Then, iDC was intratumorally injected into the irradiated tumor site. Growth of a distant tumor on the right and left flank was suppressed by an injection of iDC into the irradiated tumor, and this effect was increased by the metronomic schedule CTX. Also, combinations treated with the metronomic schedule CTX and ionizing radiation (IR)/iDC, showed the longest survival time compared with other groups. This antitumor immune response of IR/iDC was improved by metronomic schedule CTX and this result was associated with decreasing the proportion of CD4 + CD25 + Treg cells and increasing the number of tumor-specific interferon-g-secreting T cells. Our results demonstrated that metronomic schedule CTX improves the antitumor effect of immunization with an injection of DC s into the irradiated tumor.
Photodynamic therapy for cancer and activation of immune response
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2010
Anti-tumor immunity is stimulated after PDT for cancer due to the acute inflammatory response, exposure and presentation of tumor-specific antigens, and induction of heat-shock proteins and other danger signals. Nevertheless effective, powerful tumor-specific immune response in both animal models and also in patients treated with PDT for cancer, is the exception rather than the rule. Research in our laboratory and also in others is geared towards identifying reasons for this sub-optimal immune response and discovering ways of maximizing it. Reasons why the immune response after PDT is less than optimal include the fact that tumor-antigens are considered to be self-like and poorly immunogenic, the tumor-mediated induction of CD4+CD25+foxP3+ regulatory T-cells (T-regs), that are able to inhibit both the priming and the effector phases of the cytotoxic CD8 T-cell anti-tumor response and the defects in dendritic cell maturation, activation and antigen-presentation that may also occur. Alternatively-activated macrophages (M2) have also been implicated. Strategies to overcome these immune escape mechanisms employed by different tumors include combination regimens using PDT and immunostimulating treatments such as products obtained from pathogenic microorganisms against which mammals have evolved recognition systems such as PAMPs and toll-like receptors (TLR). This paper will cover the use of CpG oligonucleotides (a TLR9 agonist found in bacterial DNA) to reverse dendritic cell dysfunction and methods to remove the immune suppressor effects of T-regs that are under active study.
Stimulation of dendritic cells enhances immune response after photodynamic therapy
Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 2009
Photodynamic therapy (PDT) involves the administration of photosensitizers followed by illumination of the primary tumor with red light producing reactive oxygen species that cause vascular shutdown and tumor cell necrosis and apoptosis. Anti-tumor immunity is stimulated after PDT due to the acute inflammatory response, priming of the immune system to recognize tumor-associated antigens (TAA). The induction of specific CD8+ Tlymphocyte cells that recognize major histocompatibility complex class I (MHC-I) restricted epitopes of TAAs is a highly desirable goal in cancer therapy. The PDT killed tumor cells may be phagocytosed by dendritic cells (DC) that then migrate to draining lymph nodes and prime naïve T-cells that recognize TAA epitopes. This process is however, often sub-optimal, in part due to tumor-induced DC dysfunction. Instead of DC that can become mature and activated and have a potent antigen-presenting and immune stimulating phenotype, immature dendritic cells (iDC) are often found in tumors and are part of an immunosuppressive milieu including regulatory T-cells and immunosuppressive cytokines such as TGF-beta and IL10. We here report on the use of a potent DC activating agent, an oligonucleotide (ODN) that contains a non-methylated CpG motif and acts as an agonist of toll like receptor (TLR) 9. TLR activation is a danger signal to notify the immune system of the presence of invading pathogens. CpG-ODN (but not scrambled non-CpG ODN) increased bone-marrow DC activation after exposure to PDT-killed tumor cells, and significantly increased tumor response to PDT and mouse survival after peri-tumoral administration. CpG may be a valuable immunoadjuvant to PDT especially for tumors that produce DC dysfunction.
Photodynamic Therapy of Tumors Can Lead to Development of Systemic Antigen-Specific Immune Response
PLoS ONE, 2010
The mechanism by which the immune system can effectively recognize and destroy tumors is dependent on recognition of tumor antigens. The molecular identity of a number of these antigens has recently been identified and several immunotherapies have explored them as targets. Photodynamic therapy (PDT) is an anti-cancer modality that uses a non-toxic photosensitizer and visible light to produce cytotoxic reactive oxygen species that destroy tumors. PDT has been shown to lead to local destruction of tumors as well as to induction of anti-tumor immune response.
Photodynamic therapy plus low-dose cyclophosphamide generates antitumor immunity in a mouse model
Proceedings of the National Academy of Sciences, 2008
Photodynamic therapy (PDT) is a modality for the treatment of cancer involving excitation of nontoxic photosensitizers with harmless visible light-producing cytotoxic reactive oxygen species. PDT causes apoptosis and necrosis of tumor cells, destruction of the tumor blood supply, and activation of the immune system. The objective of this study was to compare in an animal model of metastatic cancer PDT alone and PDT combined with low-dose cyclophosphamide (CY) a treatment that has been proposed to deplete regulatory T cells (T-regs) and increase the immune response to some tumors. We used J774 tumors (a highly metastatic reticulum cell sarcoma line) and PDT with benzoporphyrin derivative monoacid ring A, verteporfin for injection (BPD; 1-mg/kg injected i.v. followed after 15 min by 150 J/cm 2 of 690-nm light). CY (50 or 150 mg/kg i.p.) was injected 48 h before light delivery. PDT alone led to tumor regressions and a survival advantage but no permanent cures were obtained. BPD-PDT in combination with low-dose CY (but not high-dose CY) led to 70% permanent cures. Low-dose CY alone gave no permanent cures but did provide a survival advantage and was shown to reduce CD4؉FoxP3؉ T-regs in lymph nodes, whereas high-dose CY reduced other lymphocyte classes as well. Cured animals were rechallenged with J774 cells, and the tumors were rejected in 71% of mice. Cured mice had tumor-specific T cells in spleens as determined by a 51 Cr release assay. We conclude that low-dose CY depletes T-regs and potentiates BPD-PDT, leading to tumor cures and memory immunity.
… journal of cancer, 2003
Here we have studied the effects of apoptotic cell death induced by chemotherapic agents on tumor phagocytosis by dendritic cells (DC) and presentation of the relevant antigen to T lymphocytes. Annexin-V-FITC (Ann-V) and propidium iodide (PI) staining was used to assess early apoptotic (Ann-V ؉ /PI ؊ ) vs. late apoptotic/secondary necrotic (Ann-V ؉ /PI ؉ ) death after a 24 hr observation of untreated and drug-treated gastric carcinoma cells. After treatments, the HLA-A*0201 ؉ tumor cell line KATO III was exposed for 24 hr to allogeneic, HLA-related GM-CSF, IL-4-driven immature (i) DC. Tumorloaded iDC were tested for IL-12 release in an ELISA assay, incubated with the DC-maturating factor TNF-␣ and used as stimulators for autologous T lymphocytes.
Cellular Immunology, 1997
numbers in lymphoid and nonlymphoid organs, as well as in the circulation. They play a crucial role in the Dendritic cells (DC) are highly efficient antigen-preinitiation of immune responses, including the sensitisenting cells able to capture, process, and present antization of T-cells restricted by MHC molecules and the gens to naive and primed T-cells. In this study, we have development of T-cell-dependent antibodies (1-6). DC investigated the ability of DC, derived from murine bone marrow and pulsed with tumor cell extracts, to originate in bone marrow and migrate to many noninduce regression of preexisting tumors. In an experilymphoid tissues, such as skin (Langerhans cells), tumental model of B16 melanoma in B6 mice, a signifimors, and mucosa (7, 8). After capturing antigens, DC cant reduction in metastatic nodules in the lungs was migrate through afferent lymph or the bloodstream to observed in tumor-bearing animals treated with either lymphoid organs where, in the context of MHC gene DC alone or DC pulsed with tumor extracts. Kinetic products, they efficiently present antigens to T-cells studies demonstrate that the efficacy of these tumor (2). In addition to expressing high levels of MHC antivaccines is inversely related to tumor burden. In this gens, DC express high levels of accessory molecules model, tumor-specific cytotoxic T-cells (CTL) could including ICAM-1, LFA-3, and B7, which are required also be induced in vitro from spleen cells derived from for T-cell activation (9-11). Thus, the high efficiency tumor-bearing animals treated with DC pulsed with of DC in antigen presentation is attributed to the high tumor extracts. Untreated mice had no CTL. Furtherexpression of MHC and accessory molecules, as well as more, DC alone elicited tumor-specific CTL responses their capacity to deliver costimulatory signals (2, 4, 12). in tumor-bearing mice, but not in naive mice. Immune DC pulsed with intact proteins (13) or peptides (14) cell depletion experiments show that the therapeutic are able to elicit primary CTL responses in vitro. These effects of DC are primarily mediated by CD8 / T-cells, while CD4 / T-cells and NK cells are involved in DC-cells are capable of priming naive T-cells and inducing mediated antitumor immunity to a limited extent. potent CTL following injection into mice . These These results illustrate the potential use of DC and results have led investigators to propose using DC DC pulsed with tumor extracts as potent therapeutic pulsed with tumor antigens or peptides to induce antireagents for cancer and provide a rationale for using tumor immunity in vivo or to induce tumor antigen-DC in vivo to eliminate disseminated tumors or residspecific CTL in vitro .
Induction of potent antitumor immunity by in situ targeting of intratumoral DCs
Journal of Clinical Investigation, 2004
Nonstandard abbreviations used: antigen (Ag); bone marrow (BM); CG-rich motif (CpG); complete medium (CM); control oligonucleotide (ODN-CTR); effector/target (E/T); Fms-like thyrosine kinase 3 ligand (Flt3L); Langerhans cell (LC); macrophage inflammatory protein-3α (MIP-3α); mean fluorescence intensity (MFI); T cell receptor (TCR).
Photodynamic therapy-generated vaccine for cancer therapy
Cancer Immunology, Immunotherapy, 2006
A target tumor-derived whole cancer cell therapeutic vaccine was developed based on an in vitro pre-treatment by photodynamic therapy (PDT) and was investigated using a poorly immunogenic tumor model. The vaccine was produced by incubating in vitro expanded mouse squamous cell carcinoma SCCVII cells for 1 h with photosensitizer benzoporphyrin derivative (BPD), then exposing to light (690 nm, 1 J/cm 2 ) and finally to a lethal X-ray dose. Treatment of established subcutaneous SCCVII tumors growing in syngeneic C3H/HeN mice with 2x10 7 PDT-vaccine cells per mouse by a peritumoral injection produced a significant therapeutic effect, including growth retardation, regression and cures. Tumor specificity of this PDT-generated vaccine was demonstrated by its ineffectiveness when prepared from a mismatched tumor cell line. Vaccine cells retrieved from the treatment site at 1 h postinjection were intermixed with dendritic cells (DC), exhibited heat shock protein 70 on their surface, and were opsonized by complement C3. Tumor-draining lymph nodes treated by the PDT-vaccine contained dramatically increased numbers of DC as well as B and T lymphocytes (with enlarged memory phenotype fraction in the latter), while high levels of surface-bound C3 were detectable on DC and to a lesser extent on B cells. The PDT-vaccine produced no therapeutic benefit against tumors growing in C3-deficient hosts. It is suggested that surface expression of heat shock proteins and complement opsonization are the two unique features of PDTtreated cells securing avid immune recognition of vaccinated tumor and the development of a strong and effective antitumor adaptive immune response.