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

Abstract

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 gammadelta 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.