Impact of antigen-unloaded immature dendritic cells on antileukemic T-cell cytotoxicity.
BACKGROUND
Immature dendritic cells (iDC) loaded with antigens are able to induce tolerance in antigen-specific T-cells. The potential of antigen-unloaded iDC to regulate the antileukemic cytotoxicity of autologous T-cells was determined.


METHODS
iDC generated with 50 U/ml granulocyte-macrophage colony-stimulating factor (GM-CSF) and very immature DC (viDC) generated with 10 U/ml GM-CSF from the bone marrow of Balb/c mice were used for T-cell co-culture.


RESULTS
The measurement of cellular cytotoxicity against the syngeneic murine B-cell leukemia line A20 revealed that T-cells without co-culture or after co-culture with iDC exerted a similar cytotoxicity, whereas T-cells co-incubated with viDC showed a significantly diminished lysis of A20 cells (p<0.05).


CONCLUSIONS
Antigen-unloaded iDC in contrast to antigen-loaded iDC may not affect antileukemic T-cell cytotoxicity, whereas antigen-unloaded DC cultures generated with a low dose of GM-CSF are able to impair the T-cell-mediated cytolysis of leukemic cells.
Harnack
Ulf
U
Medical Clinic of Oncology and Hematology, Charité-Universitätsmedizin Berlin, Campus Mitte, 10117 Berlin, Germany.
Pecher
Gabriele
G
D000818:Animals; D018122:B7-1 Antigen / Q000276:immunology; D051940:B7-2 Antigen / Q000276:immunology; D039521:CD11c Antigen / Q000276:immunology; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology / Q000494:pharmacology; D015448:Leukemia, B-Cell / Q000276:immunology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000276:immunology*
D018122:B7-1 Antigen; D051940:B7-2 Antigen; D039521:CD11c Antigen; D016178:Granulocyte-Macrophage Colony-Stimulating Factor