Hematological cancer has many forms, of which leukemia and lymphoma are the most well-known. The prognosis of patients with hematological cancer has improved due to developments in chemotherapy, targeted drugs and stem cell transplantation. However, there is still much to gain. Harry Dolstra of the Department of Laboratory Medicine at Radboudumc focuses on a promising new form of treatment for these and other tumors: cellular immunotherapy.
This type of therapy uses cells of the immune system that attack the cancer. ‘Ideally, these cells only attack cancer cells and do not target healthy tissues’, says Dolstra. ‘However, that is a very delicate balance. We aim to optimize that balance, so that the immune response against the cancer cells is as strong as possible, without having adverse consequences for the patient.'
Dolstra uses vaccines and specialized immune cells obtained from the patient or from a donor. He cultures these cells in the laboratory and modifies them, after which they are administered to the patient. For example, certain proteins are placed on the outer membrane of immune cells, so that they better recognize cancer cells and elicit a stronger immune response. With this therapy, patients can stay cancer-free for longer.
Killer cells from umbilical cord blood
Another intriguing development is the use of stem cells isolated from umbilical cord blood. Dolstra developed a specific protocol to expand so-called 'natural killer cells' from these highly potent stem cells. These immune cells have the favorable property that they attack cancer cells in a very targeted way and cause less damage to healthy tissues.
‘Umbilical cord blood is normally not used for anything, but it contains very potent stem cells’, says Dolstra. ‘Our application is very promising for the treatment of certain forms of leukemia where stem cell transplantation cannot be employed and for ovarian cancer. The first patient studies into this type of therapy have now started. My dream is that we can develop this treatment in such a way that in ten years' time, we will have a product that can be used in regular healthcare.
Dolstra (Smallingerland, 1965) studied Biology at Utrecht University. He obtained his PhD cum laude at Radboud University on the effects of donor lymphocytes on leukemia (dissertation title: 'Donor cytotoxic T cell responses against leukemia in allogeneic bone marrow recipients'). He worked as a postdoc at the CRC Institute for Cancer Studies in Birmingham. He has been working at Radboud university medical center from 1999 onwards. Since 2017, he has been director of the Stem Cell Therapy facility at Radboudumc. Dolstra received several grants, including from KWF, ZonMw, and NWO. He is also project leader of DARE-NL, a national knowledge platform for the development of cell therapy medicines against cancer.
Dolstra has been appointed Professor of Translational Immunohematology for a period of five years, effective June 1, 2023.