Successful immunotherapy of HCMV disease using virus-specific T cells expanded from an allogeneic stem cell transplant recipient.

Opportunistic infection remains the principal cause of mortality in allogeneic stem cell transplant recipients with active extensive chronic graft-versus-host disease. Human cytomegalovirus (HCMV) represents an important cause of disease in this setting and the toxicity of protracted and recurrent antiviral treatment together with eventual drug resistance represents a significant limitation to therapy. Although the expansion and adoptive transfer of HCMV-specific T cells from the healthy original donor can be an effective strategy to control viral replication, this is not possible when donors are seronegative or are subsequently inaccessible. Here we demonstrate for the first time, the successful expansion of HCMV-specific T cells from a seropositive transplant recipient of a seronegative graft with active HCMV disease and the long-term reconstitution of protective antiviral immunity following their adoptive transfer back into the patient.