Capture and generation of adenovirus specific T cells for adoptive immunotherapy

Adenoviral infections represent a major cause of morbidity and mortality following haematopoietic stem cell transplantation. Current anti-viral agents are virostatic and it is evident that elimination of adenovirus (ADV) infection is only achieved by recovery of cellular immunity. Using an interferon-gamma (IFN-gamma) secretion and capture assay to isolate ADV-specific T cells, followed by a 2 week expansion and restimulation protocol, we generated ADV T cells that may be used for cellular immunotherapy. In contrast to virus-specific T cells for cytomegalovirus or Epstein-Barr virus, the ADV response was dominated by CD4(+) T cells and the majority of captured cells exhibited an effector/memory immunophenotype. Highly specific antigen responses were demonstrated by intracellular IFN-gamma expression and cytotoxicity assays when the expanded cells underwent restimulation with ADV-pulsed target cells. Although T cells were initially generated in response to ADV species C, the expanded populations also showed strong activity against ADV species B, suggesting cross-reactivity across ADV species; a finding that has important clinical consequences in the paediatric setting, where the majority of infections are caused by ADV type B and C. The protocols can be readily translated to generate ADV-specific T cells suitable for clinical use and offer an effective immunotherapeutic strategy to control ADV infection.