A defined serum-free medium useful for monitoring anti-melanoma responses induced by dendritic cell immunotherapy

Animal sera provide a non-defined source of nutrients and growth factors for mammalian cell culture. Animal serum supplementation may also introduce experimental artefacts, including immune responses against foreign serum proteins. This artefact is particularly apparent in turnout immunotherapy experiments using dendritic cells (DC) and melanoma cells cultured in fetal calf serum (FCS)-replete media. FCS culture of both DC and melanoma cells significantly enhanced anti-tumour responses in mice immunized with DC that had not been pulsed with turnout antigen. Although serum-free media (SFM) may be used for short term culture of cells, most SFM do not support long term culture of turnout cell lines. In addition, in vivo propagation and re-isolation of turnout cells from rodents is expensive, time consuming and only low numbers of viable turnout cells can be recovered from solid tumours. We show that a defined SFM medium is ideal for routine culture of B16 for use in prophylactic DC immunizations, negating the need for in vivo propagation of tumours to avoid FCS effects in turnout implantation experiments. (C) 2009 Elsevier B.V. All rights reserved.