An important potential application direction of cord blood is the application of NK cells from cord blood in tumor immunotherapy.
NK cells, also known as natural black cells, are a kind of white blood cells. NK cells are very important for killing tumor cells and virus-infected cells.
natural killer
There are two main methods of NK cell anti-tumor therapy, one is to use patients' own NK cells, and the other is to use others' NK cells.
There are two problems in using patients' own NK cells:
Tumor cells have immune escape mechanism, and patients' own NK cells often have abnormal functions due to interference.
Routine chemotherapy may lead to insufficient collection of healthy NK cells.
Therefore, there are two sources of allogeneic NK cells commonly used in clinical trials: NK cells donated by healthy volunteers and NK cells derived from umbilical cord blood.
Compared with volunteer donation, NK cells from umbilical cord blood are easier to obtain and prepare, and patients don't have to wait too long. Therefore, umbilical cord blood has been proved to be a promising source of non-invasive therapeutic NK cells.
It is very important to explore how to use umbilical cord blood preserved for a long time and understand its full potential as a therapeutic product.
NK cells of umbilical cord blood after long-term cryopreservation
In this experiment, the researchers isolated and expanded a large number of activated NK cells from umbilical cord blood in vitro, and then observed the killing effect of these NK cells on breast cancer cells.
According to the length of frozen storage, the researchers divided umbilical cord blood into three groups: frozen cord blood 1- 10 years (long-term group), less than 1 year (short-term group) and unfrozen cord blood.
The results showed that long-term cryopreservation had no effect on the expansion potential and anti-tumor activity of NK cells in cord blood. At the same time, these cells are particularly effective in attacking primary breast cancer cells.
Umbilical cord blood can be stored at birth to help treat children when needed. When children grow up, umbilical cord blood can continue to be preserved and can be used for immunotherapy to treat various diseases. "
NK cells are the most effective killers in the immune system, but they are short-lived ghosts. Cancer cells can often take the opportunity to escape the attack of patients' own NK cells, and the disease develops further. "
By using virus vectors, the researchers transferred the genes CD 19 CAR, IL- 15 and caspase -9-based induced suicide genes into NK cells obtained from umbilical cord blood, which significantly prolonged the survival time of experimental mice.
CD 19 is an antigen expressed on some blood cancer cells, and the chimeric antigen receptor is equivalent to loading NK cells with "guided missiles". Interleukin 15 can increase the durability and activity of NK cells. Suicide gene was introduced to control its toxicity.
Therefore, the researchers concluded that transgenic NK cells from umbilical cord blood provide an easy-to-prepare, amazing and safe method for allogeneic immunotherapy.
Since the first umbilical cord blood transplantation in 1988 successfully treated Fanconi anemia, tens of thousands of clinical transplantation data have confirmed the value of umbilical cord blood. With the progress of scientific research, especially the development of regenerative medicine and immune cell therapy technology, the potential of umbilical cord blood will be further explored by scientists.