Priming The Immune System To Attack Cancer
Immunotherapies, such as checkpoint inhibitor drugs, have made worlds of difference for the treatment of cancer. Most clinicians and scientists understand these drugs to act on what’s known as the adaptive immune system, the T cells and B cells that respond to specific threats to the body.
New research from an international team co-led by George Hajishengallis of the University of Pennsylvania School of Dental Medicine suggests that the innate immune system, which responds more generally to bodily invaders, may be an important yet overlooked component of immunotherapy’s success.
Their work, published in the journal Cell, found that “training” the innate immune system with β-glucan, a compound derived from fungus, inspired the production of innate immune cells, specifically neutrophils, that were primed to prevent or attack tumors in an animal model.
“The focus in immunotherapy is placed on adaptive immunity, like checkpoint inhibitors inhibit the interaction between cancer cells and T cells,” says Hajishengallis, a co-senior author on the work. “The innate immune cells, or myeloid cells, have not been considered so important. Yet our work suggests the myeloid cells can play a critical role in regulating tumor behavior.”
The current study builds on earlier work published in Cell by Hajishengallis and a multi-institutional team of collaborators, which showed that trained immunity, elicited through exposure to exposure to the fungus-derived compound β-glucan, could improve immune recovery after chemotherapy in a mouse model.
In that previous study, the researchers also showed that the “memory” of the innate immune system was held within the bone marrow, in hematopoetic stem cells that serve as precursors of myeloid cells, such as neutrophils, monocytes, and macrophages.