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Haakon Ragde M.D. The Haakon Ragde Foundation. The Star Players Most potent cells of the immune system. Dendritic Cell. B Cell. T Cell. Antibodies. WHAT ARE ANTIGENS ( Kind of cell identity flags). Small parts of molecules from: mammals Viruses Bacteria Parasites
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Haakon Ragde M.D. The Haakon Ragde Foundation
The Star Players Most potent cells of the immune system Dendritic Cell B Cell T Cell Antibodies
WHAT ARE ANTIGENS (Kind of cell identity flags) • Small parts of molecules from: • mammals • Viruses • Bacteria • Parasites • Pollens
How does the immune “security patrol” checking the body determine that all is well (or not well?) IT INSPECTS CELL SURFACE ANTIGENS Cells have distinct landmarks on their surfaces (antigens) that generally betray the nature of the cell within - normal or malignant, or is it infected with a virus?
Preeminent Cells of The Immune System Cellular Immune System Dendritic Cell B Cell T Cell Humoral Immune System Antibodies
T CellsThe Major Player Responsible for Elimination of both Tumors and Viruses One trillion T cells in the human body
Two Types of T Cells • The Killer T-cell (cytotoxic or cytolytic T-cell) • The Helper T-cell.
Helper T Cells • Unlike Killer T-cells, helper T-cells are not assassins. • Like football quarterbacks, they are calling the plays of the immune response • They tell Killer T cells and B cells what cells to attack
Killer T Cells • Ability to identify and destroy cells harboring both viruses and cancers.
Tumor Cell Cytotoxic or Killer T Cell
The Dendritic CellsMaster Controllers of Immunity • Dendritic cells are specialized for: • Capture of antigens • Processing of antigens into small fragments • (peptides) • Presentation of the peptides at their cell surfaces in association with MHC moleculesso that an appropriate T cell can recognize the peptide-MHC complex and be activated
1 2 3 THE PROCEDURE IS READILY ADOPTABLE FOR CLINICAL USE Cryotherapy Leukapheresis Intratumoral Injection Dendritic Cells
RATIONALE Tumor Damage (Chemo/Cryo) Followed by Intratumoral Injection of Dendritic Cells • After treatment with Cryo/Chemotherapy: - Dying (apoptotic/necrotic) tumors cells release multiple tumor antigens and “danger signals” - Intratumorally injected immature dendritic cells aquire tumor antigens in situ - Dendritic cells become activated, mature and migrate to the regional lymph nodes to set in motion anti-tumor activity of Tcells
1 2 3 Studies of Chemotherapy + Intra-tumoral Injection of DCs • Tanaka F, et al. Int J Ca 101:265-9, 2002. • Song W, Levy R. ASCO 2004 #2509. • Tong, et al. Ca Res 61:7530-5, 2001.
Cryotherapy Tumor debulkingReduction of Immunosuppresive factorsIncrease antigen availability Intratumoral dendritic cell injection • Uptake of tumor antigens from apoptotic & necrotic tumor cells • Generation of immune response against tumor cells • Systemic elimination of remaining tumors
ADVANTAGESCryo/Chemotherapy + Intratumoral Injection of Dendritic Cells • Multiple antigens naturally selected from patient’s tumor by patient’s own dendritic cells • Antigen-loading and maturation of dendritic cells occurs in vivo • No need to search for tumor antigens (cost reduction) • Combination with conventional cryotherapy (a standard care) which also reduce tumor burden
WHY CRYOTHERAPY? • Freezing (cryotherapy) as a treatment for cancer has been around since the 1930s. • During the last decade, cryotherapy technologies have been markedly improved and are becoming choice treatments for many different cancers. • Unlike radiation and chemotherapy, cryotherapy does not damage the immune system and it can be repeated time and again.
Method of Action • Cryotherapy results in massive tumor cell breakdown without damaging the immune system. This gives rise to innumerable antigens. Process can be repeated. • Then, direct injection into the frozen tumorof millions of dendritic cells. The dendritic cells gobble up this mass of diverse antigens, and sensitize T cells that leads to tumor killing. Process can be repeated.
Human Phase I Trials in ProgressTumor Damage Followed by Intratumoral Injection of Autologous, Non-Loaded DCs • Stanford University (liver cancer, thermal ablation). • Sangretech Asia, Manila, The Philippines (prostate cancer, cryotherapy)
Cryoablation/Intra-Tumoral DC Combination uptake of dying tumor cells tumor bed cryoablation intra-tumoral DC injection migration to lymph nodes and tumor-specific T cell activation Benjamin Tjoa 2004
Conclusion • The immunotherapy illustrated is essentially non-toxic. • Can be added to other standard treatments • Can be repeated time and again. • Results in animals and humans are promising. • It may be the only way to control metastatic disease?