Critical appraisal of the current status of dendritic cell based therapy

A set of historical circumstances has centred the field of cancer immunotherapy on dendritic cells (DC). The discovery of their central role in antigen presentation for immunization gave rise to their use as adjuvants for cancer vaccination in transplantable tumour models in mice. Tumour rejections of experimental transplantable tumour models were achieved. During the late 90s concurrence of (i) this encouraging preclinical data, (ii) the availability of hospital cell therapy facilities that have been mainly set up for bone marrow transplantation and (iii) simple culture means to differentiate DC from monocytes or myeloid precursors spurred many clinical trials worldwide. Early clinical experience has not met the great expectations raised, but many lessons are being learned in terms of biological activity and cases of clinical response in advanced cases are routinely reported. However, some of the trials that reported the most encouraging clinical responses have confronted controversy due to scientific misconduct or to accumulation of successful cases in the pilot groups of patients that were not so reproducible when more patients were studied under the same protocols. The current status of the field could be seen as a half empty or a half full bottle. In either case, improvements are needed from the lab bench to increase therapeutic potency, even at the risk of side effects.