One of the challenges is identifying a discrete cellular target to stop cancer growth without inactivating the immune system. Scientists at UNC Lineberger Comprehensive Cancer Center report a laboratory finding that has the potential to increase the effectiveness of therapeutic cancer vaccines.
The team found that the absence of the function of a protein called NLRP3 can result in a four-fold increase in a tumour’s response to a therapeutic cancer vaccine. If this finding proves consistent, it may be a key to making cancer vaccines a realistic treatment option.
Doctor Jonathan Serody, a study author, explains, "This finding suggests an unexpected role for NLRP3 in vaccine development and gives us a potentially pharmacologic target to increase vaccine efficacy."
The research team was headed by co-leaders of the UNC Lineberger Immunology Program: Doctor Serody, an expert in tumour immunology, and Doctor Jenny Ting, a pioneer in understanding the NLR family of proteins.
The team discovered that deleting the NLRP3 proteins reduced the supply of a tumour-associated cell called myeloid-derived suppressors, making them five times less effective in reaching the site of tumour growth. Researchers working with Serody had previously shown that these myeloid cells are critically important as they allow the tumour to evade a beneficial immune response. This finding is the first to link immature myeloid cells, NLRP3, and the response to cancer vaccines.
Serody says, "We had originally thought inactivating the NLRP3 protein would decrease the immune system's ability to respond to cancer because NLRP3 is important in alerting immune cells to changes in the environment the immune response to cancer. Instead what we found was that by inactivating these proteins, the tumour vaccine was made more effective because fewer myeloid-derived suppressor cells were available to promote tumour growth and reduce the efficacy of the vaccine."
"A vaccine is not like a pill that can be manufactured in bulk," Serody explains. "And, it's not like developing a vaccine against a virus such as polio or smallpox. Cancer cells look a lot like regular cells, so it is hard to trick the body into thinking cancer cells are 'foreign.' Our hope is that our findings and future work in this area will enable us to develop more effective vaccines against many types of cancer. "
MEDICA.de; Source: University of North Carolina School of Medicine