Immune cells can be carolled into fighting cancer even in patients who have endured years of disease and debilitating treatments, new research in
'Immunotherapy' is a way of sending in reserves to help out an ailing immune system. From a few 'seed' immune cells taken from a person, armies of immune cells, specially designed to destroy certain tumour cells, say, can be raised outside the body and then re-injected into that person.
But producing enough cells has always been a stumbling block in using this approach to fight cancer. Now Laurence Chaperot and his colleagues of ETS l'Isére-Savoie, France, think that they may have found the answer.
The cells that have proved elusive to those wishing to send reinforcements into the cancer battlefield are 'antigen-presenting cells' or 'APCs'. These are the lookouts of the immune system, bringing invaders or traitors to the attention of the system, and inciting it to attack.
But it is difficult to grow large amounts of APCs suitable for clinical use. Cancer victims often endure years of chemotherapy which severely damages normal immune cells as well as cancerous cells, making it hard to harvest starter cells.
Chaperot's team show that APCs can be coaxed out of the blood of cancer victims. APCs descend from 'mononuclear' cells. The team grew mononuclear cells extracted from patient's blood, and were able to turn these into APCs. This is much more efficient than previous methods, which have tried to extract the APCs directly.
APCs generated in this way worked just as well as cells from healthy volunteers. Chaperot now hopes to begin a clinical trial, using APCs to fight a type of cancer called lymphoma.
"Although promising, this work should be viewed with caution. APCs can 'tolerise' the immune system as well as immunise against tumours," notes Caetano Reis e Sousa of the Imperial Cancer Research Fund Immunobiology lab in London, UK. In other words, APCs could make the immune system actually ignore tumours, instead of attacking them.
Bert Vogelstein of the Howard Hughes Medical Center, Baltimore, is another hopeful sceptic. "Though history suggests that most immunotherapies don't work well in [cancer] patients, The [APC] approach has enough potential to warrant cautious optimism. [APC]-based therapy represent one of the most promising approaches to come out of modern immunology research."