A new study published in PLoS Medicine describes a way to measure the immune response in people treated with an experimental vaccine to melanoma.
The technique involves monitoring how individual immune cells isolated from the patient’s blood respond to the vaccine by stimulating the cells on a biological chip and looking at a range of compounds they secrete.
The most surprising finding was the very wide range of responses seen in patients’ cells. Although the numbers were small – just 10 patients who had been enrolled in a trial of vaccination against melanoma – the authors were able to pick out some patterns of responses by the cells that also determined how the patient responded clinically to the vaccine. For example in patients whose tumors did not get bigger their cells secreted two particular compounds – Interferon gamma and Tumour Necrosis factor alpha.
Tumor vaccination against melanoma is being extensively investigated and several different vaccines are being assessed in early clinical trials. Unlike vaccinations against infectious diseases however, different people respond very differently to these vaccines, and so far it has not been possible to predict who will and who will not respond. This technique may provide a better way of monitoring response to treatment.