title: In vivo alloreactive potential of ex vivo-expanded primary T lymphocytes.
abstract: BACKGROUND
  We are presently investigating the therapeutic potential of herpes simplex-thymidine kinase-expressing donor T cells in the setting of a T cell-depleted allogeneic bone marrow transplantation. The generation, expansion, and selection of the gene-modified T cells require a 12-day ex vivo culture period in high-dose interleukin (IL)-2 that could significantly alter their in vivo alloreactivity.
  
  
  METHODS
  We evaluated the alloreactive potential of such cultured cells in a murine allogeneic bone marrow transplantation model.
  
  
  RESULTS
  The present studies demonstrate that ex vivo-expanded cultured T cells are capable of strong alloreactivity as evidenced by the occurrence of lethal acute graft-versus-host disease (GVHD). However, GVHD mortality after administration of the cultured T cells occurred later than after the administration of a same number of fresh T cells. Similar kinetics of GVHD-induced mortality between cultured and fresh T cells required a 10-fold increase in the number of cultured T cells, indicating a reduced alloreactive potential of these cells. The addition of a 2-day "resting" period in low-dose IL-2 resulted in T cells with enhanced alloreactive potential identical to the alloreactivity observed with fresh T cells.
  
  
  CONCLUSIONS
  Ex vivo IL-2-expanded T cells are capable of significant in vivo alloreactivity. However, an increase in the number of cultured T cells administered or the introduction of a short resting culture period prior to infusion is necessary in order to achieve in vivo alloreactivity identical to the alloreactivity observed with fresh T cells.
authors.affiliation: Laboratoire de Thérapeutique Immuno-moléculaire, Etablissement de Transfusion Sanguine de Franche-Comté, Besançon, France.
authors.forename: E
authors.initials: E
authors.lastname: Contassot
authors.forename: W
authors.initials: W
authors.lastname: Murphy
authors.forename: R
authors.initials: R
authors.lastname: Angonin
authors.forename: J J
authors.initials: JJ
authors.lastname: Pavy
authors.forename: M C
authors.initials: MC
authors.lastname: Bittencourt
authors.forename: E
authors.initials: E
authors.lastname: Robinet
authors.forename: C W
authors.initials: CW
authors.lastname: Reynolds
authors.forename: J Y
authors.initials: JY
authors.lastname: Cahn
authors.forename: P
authors.initials: P
authors.lastname: Hervé
authors.forename: P
authors.initials: P
authors.lastname: Tiberghien
mesh_terms: D000208:Acute Disease; D000818:Animals; D016026:Bone Marrow Transplantation; D017690:Cell Transplantation; D018014:Gene Transfer Techniques; D006086:Graft vs Host Disease / Q000401:mortality / Q000601:surgery / Q000628:therapy; D006561:Herpes Simplex / Q000201:enzymology*; D007376:Interleukin-2 / Q000494:pharmacology; D008212:Lymphocyte Depletion; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology*; D013937:Thymidine Kinase / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014019:Tissue Donors; D014184:Transplantation, Homologous
chemical_list: D007376:Interleukin-2; D013937:Thymidine Kinase