PHILADELPHIA − Human white blood cells, engineered to recognize other malignant immune cells, could provide a novel therapy for patients with highly lethal B cell cancers such as acute lymphoblastic leukemia (ALL), according to researchers at Memorial Sloan-Kettering Cancer Center (MSKCC). By administering repeated doses of T cells designed to express an artificial receptor which recognizes human B cells, the researchers were able to eradicate cancer in 44 percent of mice bearing human ALL tumors.
Their findings, published in the September 15 issue of Clinical Cancer Research, a journal of the American Association for Cancer Research, show that modified T cells the white blood cells that actively fight infections can be effective in fighting malignancies associated with B cells (immune cells that create antibodies) such as chronic lymphocytic leukaemia (CLL), ALL, non-Hodgkin's lymphoma (NHL). The researchers have an ongoing study using these T cells in CLL, and have recently begun the planning stages for a trial in patients with ALL.
The immune system has evolved to police the body for infections and diseased cells, but it has a difficult time recognizing malignant cells since they largely appear normal to the immune system, said lead study author, Renier J. Brentjens, M.D., Ph.D., medical oncologist in the Leukemia Service at MSKCC. The idea is that we can take a patients own T cells, re-educate them by inserting a gene into them that will enable them to produce a receptor to recognize B cell cancers, and then return them to the patient where they should be able to attack and kill the tumor cells.
Because the technique uses a patients own T cells, there is little risk of compatibility issues or rejection, as there might be with human stem cell transplant, Dr. Brentjens adds. Human stem cell transplant, following radiation or chemotherapy, is currently incorporated into the treatment of several B cell malignancies.
|Contact: Greg Lester|
American Association for Cancer Research