Applications of virus-specific T cell therapies post-BMT

Hematopoietic stem cell transplantation (HSCT) has been used as a curative standard of care for moderate to severe primary immunodeficiency disorders as well as relapsed hematologic malignancies for over 50 years [1,2]. However, chronic and refractory viral infections remain a leading cause of morbidity and mortality in the immune deficient period following HSCT, where use of available antiviral pharmacotherapies is limited by toxicity and emerging resistance [3]. Adoptive immunotherapy using virus-specific T cells (VSTs) has been explored for over 2 decades [4,5] in patients post-HSCT and has been shown prior phase I-II studies to be safe and effective for treatment or preventions of viral infections including cytomegalovirus, Epstein-Barr virus, BK virus, and adenovirus with minimal toxicity and low risk of graft vs host disease [6-9]. This review summarizes methodologies to generate VSTs the clinical results utilizing VST therapeutics and the challenges and future directions for the field.