title: Directly selected cytomegalovirus-reactive donor T cells confer rapid and safe systemic reconstitution of virus-specific immunity following stem cell transplantation.
abstract: BACKGROUND
  Adoptive transfer of virus-specific T cells may accelerate reconstitution of antigen-specific immunity and limit the morbidity and mortality of viral infections following allogeneic hematopoietic stem cell transplantation. The logistics of producing virus-specific T cells has, however, limited the application of cellular therapies, particularly following the introduction of more-recent regulatory stipulations.
  
  
  METHODS
  We investigated the ability of cytomegalovirus-specific T cells, directly isolated from donor leucapheresates on the basis of interferon γ secretion, to restore antiviral immunity in a group of 25 patients following related-donor transplantation in a single-arm phase I-II study. Selected cells were administered early following transplantation, either after the detection of cytomegalovirus DNA by polymerase chain reaction-based surveillance or prophylactically between day 40 and day 50.
  
  
  RESULTS
  Cell selection was successful in all cases, yielding a product biased towards CD4(+) over CD8(+) T cells. The target cell dose of 1 × 10(4) CD3(+) T cells/kg of recipient weight contained a median of 2840 cytomegalovirus-specific CD4(+) cells/kg and 630 cytomegalovirus-specific CD8(+) cells/kg, with a median purity of 43.9% interferon γ-secreting cells. Expansions of both CD4(+) and CD8(+) cytomegalovirus-specific T cells were observed in vivo within days of adoptive transfer. These cells were predominantly terminally differentiated effector-memory cells and showed the same T cell receptor variable β chain (TCRBV) -restriction as the infused cells. They offered protection from reinfection in the majority of patients.
  
  
  CONCLUSIONS
  These data indicate that application of cytomegalovirus-specific T cells generated by direct selection using γ-capture is both feasible and effective in a clinical environment. These simple in vitro methodologies should allow more widespread application of virus-specific T cell immunotherapies.
authors.affiliation: Department of Haematology, University College London Medical School, University College London, London, United Kingdom.
authors.forename: Karl S
authors.initials: KS
authors.lastname: Peggs
authors.forename: Kirsty
authors.initials: K
authors.lastname: Thomson
authors.forename: Edward
authors.initials: E
authors.lastname: Samuel
authors.forename: Gemma
authors.initials: G
authors.lastname: Dyer
authors.forename: Julie
authors.initials: J
authors.lastname: Armoogum
authors.forename: Ronjon
authors.initials: R
authors.lastname: Chakraverty
authors.forename: Kwok
authors.initials: K
authors.lastname: Pang
authors.forename: Stephen
authors.initials: S
authors.lastname: Mackinnon
authors.forename: Mark W
authors.initials: MW
authors.lastname: Lowdell
mesh_terms: D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology* / Q000628:therapy*; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D033581:Stem Cell Transplantation; D013601:T-Lymphocytes / Q000276:immunology*; D016896:Treatment Outcome
chemical_list: D007371:Interferon-gamma