When studying rare subsets of the immune system, getting enough cells to be able to run an experiment is a constant restriction. In the Radford lab, we have two approaches to allow us to harvest larger numbers of rare dendritic cells. Dendritic cells crawl through tissues and travel via blood to sample the micro-environment. They are alerted into action by foreign micro-organisms such as bacteria, protozoa and fungi as well as mutant cells, such as cancer cells. The dendritic cell can engulf microbes or defective cells, and break down large complicated proteins into small bite sized peptides, which are easier for other cells of the immune system to recognise and respond to. With the help of genetically modified mice, we can graft human stem cells into mouse pups and grow up dendritic cells, which respond to other human cells as self-self, there is no species cross-reactivity. Stem cells may also be grown in plastic dishes, and the maturation of cells is directed towards making dendritic cells with the help of a cocktail of chemicals. With the use of these two methods we can obtain larger numbers of dendritic cells than what we can collect out of 500ml of healthy donor blood. These cells are then used for cancer studies whereby we can feed the dendritic cells cancer cells, or components of, and learn more about the pathways involved in cancer recognition and destruction. We hope that by learning more about the immune pathways, we can hone in on reagents that may allow broad cancer type, non-person specific cancer therapy, primarily focusing on solid tumours such as prostate cancer, breast cancer and melanoma.