Dendritic cells generated either from CD34+ progenitor cells or from monocytes differ in their ability to activate antigen-specific CD8+ T cells.
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-gamma 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.
Ferlazzo
G
G
Karmanos Cancer Institute, Wayne State University, Detroit, MI 48201, USA.
Wesa
A
A
Wei
W Z
WZ
Galy
A
A
D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D018952:Antigens, CD34 / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D009000:Monocytes / Q000166:cytology / Q000276:immunology*; D009842:Oligopeptides / Q000276:immunology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology; D013234:Stem Cells / Q000166:cytology / Q000276:immunology*; D013997:Time Factors
D018952:Antigens, CD34; D018984:Epitopes, T-Lymphocyte; D009842:Oligopeptides; D018719:Erb-b2 Receptor Tyrosine Kinases