title: Generation of minor histocompatibility antigen HA-1-specific cytotoxic T cells restricted by nonself HLA molecules: a potential strategy to treat relapsed leukemia after HLA-mismatched stem cell transplantation.
abstract: Successful stem cell transplantation (SCT) across HLA barriers can be performed with cord blood, megadoses of stem cells, or with nonmyeloablative conditioning strategies. Because the HLA-mismatched transplants are often T-cell depleted, leukemia relapse rates are high. Treatment of relapsed leukemia after HLA-mismatched SCT is difficult. A novel potential strategy to treat relapsed leukemia after HLA-mismatched SCT is the use of patients' mismatched HLA molecules as antigen-presenting molecules to generate hematopoietic system-specific cytotoxic T cells (CTLs) from the stem cell donor. Adoptive transfer of these hematopoietic system-specific CTLs that are restricted by nonself HLA molecules may eliminate leukemia without affecting the patient's nonhematopoietic cells or donor hematopoietic cells. We investigated the feasibility of this strategy using the hematopoietic system-specific minor histocompatibility antigen HA-1, which is known to induce HLA-A2-restricted CTLs. HLA-A2(-) peripheral blood mononuclear cells were stimulated with HLA-A2(+) T2 cells pulsed with synthetic HA-1 peptide or with dendritic cells transduced with the HA-1 cDNA. Tetrameric HLA-A2/HA-1 peptide complexes were used to monitor and enrich HA-1-specific CTLs. In the alloreactive cultures, HA-1-specific CTLs were enriched up to 7% by 3 rounds of antigen-specific stimulations and up to 87% by fluorescence-activated cell sorting of tetramer-positive T cells. The HA-1-specific CTLs showed specific lysis of the relevant target cells, including leukemic cells. Because the polyclonal CTL cultures also contained natural killer cells and allo-HLA-A2-specific CTLs, CTL clones were generated that showed the expected HA-1 specificity only. Thus, HA-1-specific CTLs restricted by nonself HLA-A2 molecules can be generated in an HLA-A2-mismatched setting.
authors.affiliation: Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, The Netherlands. t.mutis@lumc.nl
authors.forename: Tuna
authors.initials: T
authors.lastname: Mutis
authors.forename: Els
authors.initials: E
authors.lastname: Blokland
authors.forename: Michel
authors.initials: M
authors.lastname: Kester
authors.forename: Ellen
authors.initials: E
authors.lastname: Schrama
authors.forename: Els
authors.initials: E
authors.lastname: Goulmy
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods; D002999:Clone Cells / Q000166:cytology / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006680:HLA Antigens / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology; D018380:Hematopoietic Stem Cell Transplantation; D006648:Histocompatibility; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D007938:Leukemia / Q000628:therapy; D015778:Minor Histocompatibility Antigens / Q000276:immunology*; D009842:Oligopeptides / Q000276:immunology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D016879:Salvage Therapy; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology*
chemical_list: C110615:HA-1 antigen; D006680:HLA Antigens; D015789:HLA-A2 Antigen; D015778:Minor Histocompatibility Antigens; D009842:Oligopeptides; D010446:Peptide Fragments