Targeted T-cell therapy for human leukemia: cytotoxic T lymphocytes specific for a peptide derived from proteinase 3 preferentially lyse human myeloid leukemia cells.
Proteinase 3 is present in high concentration in the primary granules of acute and chronic myeloid leukemia blasts, and may represent a potential T-cell target antigen. We screened proteinase 3 against the binding motif of HLA-A2.1. Based on its high predicted binding, a 9-mer peptide, "PR-1," was synthesized and tested for binding to HLA-A2.1 using the T2 cell line. PR-1 at 100 micrograms/mL significantly increased expression of HLA-A2.1, with median channel of fluorescence increasing from 22 to 294. Binding half-life was determined to be 1,460 minutes by I125-labeled beta 2-microglobulin incorporation. HLA-A2.1+ peripheral blood mononuclear cells from a normal donor were used to generate a T-cell line specific for PR-1. The line demonstrated 85% PR-1-specific lysis at an E:T ratio of 50:1, compared with 20% lysis without PR-1, using T2 cells as targets. It also showed 79% specific lysis to fresh chronic myelogenous leukemia blasts, 54% to fresh acute myelogenous leukemia blasts, and only background lysis (< 20%) to HLA-A2.1+ normal allogeneic marrow cells. The amount of lysis of HLA-A2.1+ myeloid cells was proportional to cytoplasmic proteinase 3 expression. Thus, HLA-A2.1-restricted cytotoxic T cells, raised against a peptide contained in proteinase 3, preferentially lysed fresh human leukemic cells.
Molldrem
J
J
Bone Marrow Transplant Unit, National Heart, Lung and Blood Institute, Bethesda, MD 20892-1652, USA.
Dermime
S
S
Parker
K
K
Jiang
Y Z
YZ
Mavroudis
D
D
Hensel
N
N
Fukushima
P
P
Barrett
A J
AJ
D000595:Amino Acid Sequence; D000754:Anemia, Refractory, with Excess of Blasts / Q000201:enzymology / Q000473:pathology; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D016219:Immunotherapy, Adoptive; D007951:Leukemia, Myeloid / Q000201:enzymology / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D053146:Myeloblastin; D009363:Neoplasm Proteins / Q000276:immunology*; D012697:Serine Endopeptidases / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured / Q000276:immunology
D000939:Epitopes; D015789:HLA-A2 Antigen; D009363:Neoplasm Proteins; D012697:Serine Endopeptidases; D053146:Myeloblastin