Cancer is still the deadliest disease on the planet and millions people struggle with it each day. The survival rate of this disease is higher when it is detected at an early stage, and that is of vital importance for every cancer patient.
It seems that there is a hope on the horizon and that is quickly and early detection of cancer in the human body. Namely, the Australian researchers at the Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute have found out that MR1 proteins may help cancer cells hide from our immune system.
What are MR1?
They are major histocompatibility complex (MHC) class I-related proteins that bind themselves to T cells, also referred as to mucosal-associated invariant T (MAIT) cells. In addition to this, they are related to several immune responses, against a variety of pathogens. The MAIT cells regulate and inform the T and NK cells about a disease in the body and tell them to attack the ongoing disease or sickness.
MR1 restricted T-cells take a great part in autoimmune and inflammatory diseases, diabetes, lupus, and rheumatoid arthritis. The scientific team at QIMR discovered that if MAIT cells were turned on, they could prevent the attacks of NK and T cells to tumors. But, cancer tumors can also turn on the MAIT cells by showing the MR1 molecules on their surface. This will prevent the T and NK cells to identify cancer cells thereby allowing the spreading of cancer. The findings of this study have been released in Cancer Discovery.
According to the Michele Teng, the senior researcher of this study:
“The cancer is effectively creating its own defense mechanism to evade immune attack and survive. The display of MR1 activates the MAIT cells, which in turn switch off cancer-fighting T and NK cells. While other regulatory cells of the immune system are known to stop T and NK cells from killing tumor cells, this is the first time it’s been shown that these regulatory MAIT cells can do this job.”
This is a great breakthrough in medicine as it will allow the creation of more effective treatments in immunotherapy. The scientists have done lab testing on mice that have been given antibodies that blocked MR1 and it was successful. The MAIT cells were not turn on, and thus the abilities of the T and NK cells were significantly increased that lead to slower growth and spread of new cancer cells.
In addition to this, Dr. Teng adds:
“This work demonstrates that antibodies that block MR1 could in the future be an effective new immunotherapy. It probably won’t work on every cancer, but it looks like it could be effective in treating cancers that can display the MR1 molecule. It also means this display of MR1 could be used to screen which patients would respond to this immunotherapy.”
This is an incredible discovery, now the next step is to test it on humans and establishing the efficacy on a particular type of cancer. The researchers need to find out which cancers use MR1 and thus administrate this method. This would be of great assistance in the treatment of diseases such as lupus, where the immune system attacks itself.