Impact of culture medium on the expansion of T cells for immunotherapy

Background aims Encouraging evidence of clinical benefits from cancer immunotherapy is beginning to accumulate in several clinical trials. Cancer immunotherapy is based on two main methods, active vaccination and cell-transfer therapy. The ex vivo expansion of T cells is required to monitor vaccine-induced antigen-specific T cells or prepare large numbers of reactive lymphocytes for adoptive transfer. Methods We examined the influence of culture medium on T-cell growth, cytotoxicity and phenotype after activation using immobilized anti-CD3 monoclonal antibody or Zoledronate stimulation. Peripheral blood mononuclear cells (PBMC) were cultured in RPMI, AIM-V or OpTmizer with or without autologous serum. Results When supplemented with sufficient serum, RPMI was a good culture medium for T-cell expansion following anti-CD3 stimulation. Addition of autologous serum to AIM-V or OpTmizer increased the numbers of cells obtained to a similar extent, but their phenotype and function were quite different. Activated T cells cultured with OpTmizer mediated greater cytotoxicity than any other culture. Regardless of the media used, the main population expanded after CD3 stimulation was CD3(+) CD8(+). While more CD3(+) CD4(+) T cells were induced in RPMI and AIM-V, more CD3(-) CD56(+) cells and CD3(+) CD56(+) T cells were induced in OpTmizer. When cells were stimulated by Zoledronate for 14 days, approximately 7.2 times and 11.5 times more gamma delta T cells were obtained in OpTmizer than AIM-V or RPMI, respectively. Conclusions Successful immunotherapy depends on the selection of appropriate culture media to support efficient expansion of the type of T cell desired.