Low antigen-dependent activity of T cells after repeated stimulation using dendritic cells and expansion with interleukin-2.
Both CD8+ and CD4+ T cells with specific activity against tumor antigens are needed for an efficient antitumor immune response. Activation and proliferation of T cells require cellular interactions including adhesion, recognition of peptides presented by MHC molecules to the T cells receptor, and costimulation. In a series of experiments we attempted to generate and expand specific T cells by repeated stimulation using antigen-loaded autologous dendritic cells (DCs). DCs were obtained from peripheral blood mononuclear cells (PBMC) in the presence of IL-4 and GM-CSF. TNF-a was added to induce maturation. A conjugate of myeloma idiotypic protein with keyhole limpet hemocyanin was used as antigen. Nonadherent peripheral blood mononuclear cells were cultured in the presence of Il-2 and IL-7. Autologous DCs were added to the lymphocyte cultures on days 3, 10, and 17. The lymphocytes were stimulated by high concentration of IL-2 between days 21 and 27. Lymphocytes harvested on day 27 proliferated in response to antigen-loaded DC but failed to do so if less than 0.3 x 10(6) DCs were added for stimulation during culture. However, no cytotoxic activity against autologous DCs was detected and IFN-g production in the T cell cultures was low at the end of culture. In conclusion, the generation and expansion of T cells using repeated stimulation by autologous DCs is feasible but defective cytotoxic response of these cells occurs, possibly as a consequence of repeated frequent exposure to antigen.
Büchler
T
T
Laboratory of Experimental Hematology and Immunotherapy, Department of Clinical Hematology, University Hospital Brno-Bohunice, Brno, Czech Republic. tbuchler@fnbrno.cz
Hájek
R
R
Kovárova
L
L
Musilová
R
R
Bourková
L
L
Cech
Z
Z
Vánová
P
P
Tůzová
E
E
Vidláková
P
P
Vorlícek
J
J
Penka
M
M
D015703:Antigens, CD / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D018664:Interleukin-12 / Q000097:blood; D007376:Interleukin-2 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D012016:Reference Values; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; D016207:Cytokines; D007376:Interleukin-2; D016753:Interleukin-10; D018664:Interleukin-12