Immunotherapy is a promising treatment. It activates a child's own immune system in order to attack cancer cells. Immunotherapies are being developed for more and more types of childhood cancer to further increase the chances of a cure. The type of immunotherapy in this specific study is T-cell therapy.
Dr. Annelisa Cornel, a postdoctoral researcher in Stefan Nierkens' research group at the Princess Máxima Center for Pediatric Oncology, explains how she came up with the idea for this research: 'About three years ago, I read about a new discovery. Researchers had found a type of immune cell in adults that could attack various types of cancer without harming healthy cells. I wanted to investigate if this also works for pediatric cancer. During my doctoral research, I started working with this so-called MR1 T-cell.'
This month, Cornel's research was published in the Journal for ImmunoTherapy of Cancer. The research received funding from Villa Joep.
Versatile approach
Most T-cells recognize cancer cells through a molecule called MHC1. Everyone has slightly different MHC1 molecules, which is one reason why T-cell therapy for cancer often has to be very specific. With MR1, this is different. Almost everybody has the same molecule. 'This means that the MR1 T-cell could work for various types of cancer. And that we might be able to treat many different types of cancer in many people with one form of treatment,' as Cornel explains.
'We discovered that the MR1 T-cell unfortunately does not work for all kinds of childhood cancer. But it does for some. Herein, we found a dissimilarity between embryonal tumors and other types of childhood cancer. Embryonal tumors can arise during a child's development in the womb. The immune system often does not recognize them as harmful cells. My expectation was that the MR1 T-cells would not be able to recognize them either, and that indeed turned out to be the case. However, MR1 T-cells do seem to work well for other types of childhood cancer. We found an effect in leukemia and high-grade gliomas, which are aggressive brain tumors.'
The potential of MR1
Principal investigator Dr. Stefan Nierkens adds: 'Although the MR1 therapy is not suitable for all forms of childhood cancer, our research does show potential for certain types. Children with these types of cancer desperately need better treatments.'
'MR1 T-cells were discovered a few years ago. Knowledge about this is still in its infancy,' Nierkens says. 'We performed an exploratory study into the possibilities of this therapy. As a next step, we want to investigate whether we can further develop and test this therapy. It is all very new, and it challenges existing ideas on how we can use the immune system against childhood cancer.'
Continuing the development
Cornel has several plans for further developing this therapy. 'First, I want to understand better which molecule of the cancer cells the MR1 T-cells exactly recognize,' she says. 'In addition, I want to study more of these types of T-cells, and see how broad their recognition is. This will help us understand how we can adapt and improve this therapy. Hopefully, we can further develop these special cells into immunotherapy for children with leukemia or a brain tumor. And ultimately use them for more types of childhood cancer.'