"The immune response to cancer
The immune system is our natural defense against disease. It destroys harmful bacteria and viruses that enter our bodies. In order to do this it has to recognize and label them as “foreign”. Once this happens, special types of cells in the immune system move in and destroy the invaders.
Our natural immune system can also detect cancer, because cancer cells are different from normal cells. In many cases, it will destroy these cancer cells before they turn into a detectable cancer.
Helping the immune system fight cancer
Sometimes our immune response to cancer fails and the cancer continues to grow. This can happen when cancer cells are not recognized by the immune system, or develop ways to cheat the system and escape detection. As a result, our immune system mistakes them for healthy cells and does not react.
Cancer immunotherapy aims to teach our natural defenses to identify cancer cells correctly – and then kill them.
ASCI*: a new approach that targets cancer antigens
ASCI* (Antigen-Specific Cancer Immunotherapeutics) is a new type of immunotherapy in development that targets cancer antigens and potentially destroys the cancer cells that bear these antigens. Cancer antigens are substances found on the surface of cancer cells, and are recognized as “foreign” by the body’s immune system.
ASCI* uses our own immune system to attack cancer. It does this by educating our immune system to identify and attack antigens displayed on cancer cells.
The immune system reacts towards the antigen in ASCI* – a reaction called immune response – and then attacks the cancer cells where this antigen is found."
Source:GlaxoSmithKline
http://www.immunotherapyforcancer.info/melanoma/index.shtml
There is only one major problem. Each melanoma patient has his or her own set of antigens based on their own tumors. Reseachers are trying to discover what are the major antigens that Melanoma patients exibit. For instance, MAGE-A3. There are literally thousands to choose from.
What if you get your body to produce them for you from your tumors. It sounds hard to believe but, radiation, chemotherapy with Dacarbazine plus (Patrin-2) Lomeguatrib and oblimersen sodium may help shed the right antigenic peptides. You have to get the right antigen to be presented on the dendritic cells acting as Antigen Presenting Cells (APCs) in order for the immune response to the cancer. The concentration of the antigen plays a major role in the intensity of the response.
Another problem is that you have to deplete or Block the suppressive function of the Tregs cells. This can be accomplished by lymphodepletion by preconditioning with cyclophosphamide and fludarabine or Anti-CTLA-4 blockade.
The final step of this process is the addition of interleukin-2 to activate and maintain the function of the CD8 + T-cells that mature into Cytotoxic T Lymphocytes (CTL’s). Dosing schedule and concentration of the drugs also play major role in weather an immune response is generated.
The Making of an Immune Response by Combinatorial Therapy Using Anti-CTLA-4 Blockade and Interleukin-2
"Mike Weber was kind to forward your paper and email. It appears that you have a very good sense of, and interest in, the immune response to melanoma and to cancer in general. I believe you are right that timing of the various components of the immune response, especially with combination therapies, is important, just as it is in the orchestration of a beautiful symphony."
~ Dr. Craig Slingluff ~
Melanoma and the Magic Bullet (Monoclonal Antibodies)
Take Care,
Jimmy B
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