Arggh! November was hectic! I haven’t abandoned you Omnimmune! Sometimes getting a paper published takes precedence. But I just came across this Time article with exciting news that Washington University scientists are closer to a vaccine to target breast cancer. The original article was published at Clinical Cancer Research here, and once again highlights the power of the immune system!
This was a Phase I clinical trial to determine the safety of a vaccine targeting a protein called MAM-A. The vaccine is a DNA vaccine that makes use of little circular bits of DNA that can be made in bacterial cells. The bacteria are engineered so that they have the “DNA code” for MAM-A. MAM-A is a protein that is specific to breast cancer as opposed to other cancers, and 40-80% of primary breast cancers make too much of it. Using bacteria allows for the production of lots of this DNA relatively easily. An added benefit is that DNA from humans and bacteria look slightly different. That means the immune system will see this DNA as foreign (danger! danger!)….basically it amps up your immune cells. When the vaccine is injected into a patient, cells (usually muscle) take up the DNA and make the protein (MAM-A). Immune cells “eat” these proteins and present bits of MAM-A to T cells and B cells. The T cells, particularly CD8+ T cells, then circulate throughout the body until they encounter breast cancer cells that make MAM-A. Because the CD8+ T cells have been “activated” (they’ve already been educated about the danger) they are able to kill those cancerous cells.
This study showed that the vaccine was safe to use. But the most exciting part is that the vaccine caused CD8+ T cells specific to MAM-A to increase in number and to make the weapons needed to kill cancerous cells (one of those weapons being Interferon-γ). They were in fact also able to kill cancerous cells, and patients receiving the vaccine had improved “Progression Free Survival” compared to patients not receiving the vaccine.
This is a great example of cancer therapies taking advantage of the immune system!