title: T-Cell activation by t(9;22) acute lymphoblastic leukemia-derived dendritic-like cells is associated with increased tapasin expression.
abstract: Dendritic-like cells from t(9;22) acute lymphoblastic leukemia (ALL) blasts can activate T cells, while the original unmodified leukemic blasts cannot. To determine whether these functional differences were associated with differences in antigen-processing machinery (APM) component expression, we have measured the level of APM component expression in unmodified blasts and ALL-derived dendritic-like cells. Seven t(9;22) ALL patient samples and one cell line were studied for APM component expression utilizing a unique panel of recently developed monoclonal antibodies and a recently developed intracellular staining technique. In addition, the HLA class I antigen cell surface expression was measured. HLA class I antigens were similarly expressed on the unmodified blasts and on the autologous dendritic-like cells. Intracellular HLA class I antigen and tapasin expression (P=0.03 for both) were upregulated in all t(9;22) ALL-derived dendritic-like cells, in comparison to the unmodified blasts. These results provide a potential mechanism for the ability of t(9;22) ALL-derived dendritic-like cells to induce T-cell activation and, suggest that tapasin upregulation may serve as a marker to standardize and monitor the quality of the dendritic-like cells used in immunotherapy.
authors: Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors: Jonathan A
authors: JA
authors: Claus
authors: Michael T
authors: MT
authors: Brady
authors: Jaewoo
authors: J
authors: Lee
authors: Kathleen A
authors: KA
authors: Donohue
authors: Sheila N
authors: SN
authors: Sait
authors: Soldano
authors: S
authors: Ferrone
authors: Meir
authors: M
authors: Wetzler
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D017951:Antigen Presentation / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology; D017920:Antiporters / Q000096:biosynthesis* / Q000276:immunology; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis* / Q000276:immunology; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D026901:Membrane Transport Proteins; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology*; D014178:Translocation, Genetic / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D017920:Antiporters; D015395:Histocompatibility Antigens Class I; D007136:Immunoglobulins; D026901:Membrane Transport Proteins; C107762:tapasin