1. Dendritic Cells Generated Either from CD34+ Progenitor Cells or from Monocytes Differ in Their Ability to Activate Antigen-Specific CD8+ T Cells
- Author
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Ferlazzo, Guido, Wesa, A, Wei, Wz, and Galy, A.
- Subjects
Antigen Presentation ,Time Factors ,Receptor, ErbB-2 ,Stem Cells ,Immunology ,Antigen-Presenting Cells ,Epitopes, T-Lymphocyte ,Antigens, CD34 ,Cell Differentiation ,Dendritic Cells ,CD8-Positive T-Lymphocytes ,Lymphocyte Activation ,Monocytes ,Humans ,Immunology and Allergy ,Oligopeptides ,Cells, Cultured - Abstract
Dendritic cells (DC) can be generated in vitro from monocytes (M-DC) or from CD34+ hemopoietic progenitor cells (CD34-DC) but their precursors are not equivalent cells, prompting a comparison of the functional capacities of these APC. Both types of DCs established from the same individuals using the same cytokines displayed a comparable phenotype of mature DC (CD1a+, CD83+, CD86+, CD4+, HLA-DR++, CD14−, CD15− ) and were equally potent stimulators of allogeneic T cell proliferation, being both more powerful than immature M-DCs. An autologous panel of APCs produced in HLA-A2+ individuals, including CD34-DC, M-DC, monocytes, and EBV-lymphoid cell line was comparatively evaluated for presentation of the Erb-B2 peptide E75 to a CTL line. After short exposures (5 h) to E75-loaded APCs, similar levels of intracellular IFN-γ were induced in Ag-specific CD8+ T cells regardless of APC type. In sustained cultures (4–14 days), more Ag-specific T cells were obtained when peptide was presented on CD34-DC (p < 0.05) rather than on M-DC, EBV-lymphoid cell lines, or monocytes, and these effects were dose-dependent. Activated T cells expressed 4-1BB, and the presence of 4-1BB-Ig fusion protein partially blocked Ag-specific CD8+ cell activation after CD34-DC or M-DC presentation. Our results show that 34-DC have a preferential capacity to activate CD8+ T cells and that this property is not strictly correlated to their ability to induce allogeneic T cell proliferation but due to mechanisms that remain to be defined.
- Published
- 1999
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