Fight Aging!

These days, the term "vaccine" covers a very broad range of immune system manipulations, especially when it comes to prospective treatments for cancer. The high level plan is to guide the immune system to aggressively destroy cancer cells without causing it to attack ordinary cells, but there are many different approaches that can achieve this goal. Here is one example:

Alpha-fetoprotein, or AFP - normally expressed during development and by liver cancer cells as well - has escaped attack in previous vaccine iterations because the body recognizes it as "self." AFP is expressed by about 80 percent of most common liver cancer cells but not typically by healthy adults. For cancer to flourish, cells must revert to an immature state, called dedifferentiation, which is why liver cancer cells express a protein during development and why the immune system can recognize AFP as "self."

In a process called antigen engineering, [researchers] tweaked AFP just enough to get the immune system to recognize it but still keep the AFP expressed by liver cancer cells in the bull's eye. [The] modified AFP was delivered in a vehicle with a proven record for getting into cells. The lentivector is the backbone of the human immunodeficiency virus, or HIV, minus most of its genes. It is particularly good at targeting dendritic cells, whose job is to show the immune system antigens then activate T cells to attack.

In a proven model where mice are exposed to chemicals known to induce liver cancer, the vaccine blocked cancer about 90 percent of the time. Mice receiving the vaccine had more T cells generally and more that targeted AFP, which could keep an eye out for re-emerging liver cancer. Recurring tumor cells is an unfortunately realistic scenario for liver cancer patients, who have a 70 percent recurrence rate in five years. Patients typically have surgery to remove the diseased portion of the liver, but there are currently no effective adjuvant therapies, such as chemotherapy, to reduce recurrence. Ideally, some version of [this] vaccine will one day provide that key missing piece and dramatically improve patient survival.

Link: http://www.sciencedaily.com/releases/2014/06/140603092535.htm