Stem cells reside in a specialized microenvironment called the stem cell niche. The stem cell niche has been extensively studied as a site that regulates stem cell function. However, immunological attributes of the niche have been largely unexplored.

Dr. Fujisaki hypothesizes that the blood stem cell niche is, like the testis and the placenta, an immune suppressive environment—termed the “immune privileged” site—where immune activities are suppressed to shield the stem cells from immune attack. He predicts that this protective property for stem cells may further shield malignant cells from the immune system, leading to therapeutic resistance of cancer.

Dr. Fujisaki was recruited in 2012 to P&S, where he is also a principal investigator and director of in vivo imaging at the Columbia Center for Translational Immunology. He has published a Nature paper based on his hypothesis.