In Vitro Stimulation and Expansion of Human Tumour-Reactive CD8+ Cytotoxic T Lymphocytes by Anti-CD3/CD28/CD137 Magnetic Beads

Adoptive immunotherapy with tumour-reactive CD8(+) cytotoxic T lymphocytes (CTLs) requires efficient in vitro approaches allowing the expansion of CTLs to large numbers prior infusion. Here, we investigated the antigen-independent activation and the expansion of human T cells in peripheral blood mononuclear cells (PBMCs) and in tumour-reactive CTLs using Dynabeads coated with monoclonal antibodies to CD3 and to the costimulatory molecules CD28 and CD137 (4-1BB). T cells in PBMCs showed an increased expansion rate of 15- to 17-fold during a 2-week culture period using antibody-conjugated beads with interleukin-2 (IL-2) added versus IL-2 alone. No significant difference between CD3/CD28 beads…