Funded by the Dick Vitale Gala
Over the past several decades, there has been a steady increase in cure rates in children with the so- called B-cell acute lymphoblastic leukemia (B-ALL), a type of blood cancer. Yet many B-ALL patients who failed the initial chemotherapy still die from their disease. Five years ago many of these high-risk patients began to benefit from immunotherapy, whereby patients’ own immune systems are trained to recognize and destroy the leukemic cells. One common form of immunotherapy is based on recognition of CD19, a protein residing on the surface of most leukemic cells. However, even this breakthrough treatment fails in about a third of patients, suggesting that other leukemia proteins need to be targeted in parallel. One alternative protein target is called CD22. CD22-directed immunotherapies show promise, but are not without their own record of failures. Our previous studies led us to believe that one common cause of treatment failure is improper assembly of the CD22 protein, resulting in re-shuffling of its key parts called ectodomains. This re-shuffling could result in CD22 becoming unrecognizable to the immune system. On the other hand, improperly assembled CD22 could be targeted using a new type of immunotherapeutics, which are trained to recognize improper junctions between ectodomains. The proposed work will test these ideas using leukemic cells grown in Petri dishes and in mice and samples from ongoing clinical trials. It will also extend our current studies to other cell surface proteins. In the end, the TVF-funded work would lead to a more precise matching of future patients to best possible treatments and thus much better outcomes.