title: CD4+ and CD8+ T cells each can utilize a perforin-dependent pathway to mediate lethal graft-versus-host disease in major histocompatibility complex-disparate recipients.
abstract: Perforin-deficient (-/-) mice were used as T-cell donors for infusion into irradiated major histocompatibility complex (MHC)-disparate recipients to investigate the requirement for perforin-mediated cytolysis during graft-versus-host disease (GVHD) generation. Administration of 5x10(6) C57BL/6 (H2b) perforin -/- splenocytes was significantly less effective in inducing GVHD lethality when given to MHC class I + II disparate B10.BR (H2k) recipients, as compared with wild-type (+/+) controls. Perforin expression by donor T cells was not required for GVHD induction because recipients given fivefold higher numbers of perforin -/- donor splenocytes uniformly succumbed to lethal GVHD. Because both CD4+ and CD8+ donor T cells are required for optimal GVHD lethality in this strain combination, to discern the relative contribution of perforin-mediated cytolysis by CD4+ and CD8+ T cells, additional studies were performed. For these latter studies, we used a sensitive assay involving the infusion of highly purified CD4+ or CD8+ T cells into sublethally irradiated MHC class II or I disparate recipients, respectively. As compared with recipients of perforin +/+ T cells, recipients of either CD4+ or CD8+ perforin -/- T-cell subsets had a significant reduction in GVHD-mediated lethality at T-cell doses that were uniformly lethal. T-cell dose titration studies established that GVHD lethality in recipients of perforin -/- CD4+ or CD8+ T cells was reduced by approximately threefold. These data are the first to indicate that approaches to limit perforin-mediated cytolysis should be similarly effective in situations in which CD4+ or CD8+ T cells dominate the GVHD response.
authors.affiliation: Department of Pediatrics, University of Minnesota Hospital and Clinic, Minneapolis 55455, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Blazar
authors.forename: P A
authors.initials: PA
authors.lastname: Taylor
authors.forename: D A
authors.initials: DA
authors.lastname: Vallera
mesh_terms: D000818:Animals; D001835:Body Weight; D016026:Bone Marrow Transplantation / Q000009:adverse effects; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D006086:Graft vs Host Disease / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology*; D000949:Histocompatibility Antigens Class II / Q000528:radiation effects; D008285:Major Histocompatibility Complex / Q000502:physiology* / Q000528:radiation effects; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013154:Spleen / Q000166:cytology; D015996:Survival Rate; D014916:Whole-Body Irradiation
chemical_list: D000949:Histocompatibility Antigens Class II; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin