Nicholas Kuhn

Fibroblasts play critical roles in regulating cellular relationships during tissue homeostasis, immunity, and tumor biology at multiple sites. However, tools to perturb fibroblasts at just one site in vivo are limited, restricting our understanding of how these cellular relationships emerge on a local level. I developed an in vivo gene editing tool in fibroblasts and applied it within multiple mouse tumor models to investigate how locally restricted fibroblast perturbations affect the tumor microenvironment (TME). By knocking out various surface receptors on cancer-associated fibroblasts (CAFs), we uncover that TGFBR2 signaling loss uniquely induces the emergence of an alternative CAF cell state that is distinct from previously described fibroblast states and is associated with worse survival in human PDAC patients. Further bioinformatic analysis and combinatorial gene knockouts in CAFs identified heterotypic cell interactions between CAFs and neutrophils in the TME; and uncovered that this alternative Tgfbr2-KO CAF cell state is dependent on TNFR1 and canonical WNT signaling. Together, a fast, affordable, and modular engineering method in CAFs is demonstrated, allowing discovery of alternative CAF identities and their effects in the TME. The in vivo fibroblast gene editing method was further developed to generate targeted gene knockins in CAFs, allowing in vivo screening of multiple perturbations at once, as well as proximity labeling of extracellular matrix (ECM) proteins. These technological advances will serve as the central tools in my lab to systematically decode and engineer fibroblast cell states to manipulate the cellular and ECM components of the TME for the development of more effective therapeutic interventions.

Nicholas Kuhn received his PhD in Cancer Biology at Memorial Sloan Kettering Cancer Center, New York, in the lab of Renier Brentjens, developing novel chimeric antigen receptor T cell modalities that engage the endogenous immune system for collaborative antitumor immune responses. Now, he is a postdoctoral fellow, supported by a Cancer Research Institute Postdoctoral fellowship, in Matthew Krummel’s lab in the Department of Pathology at the University of California, San Francisco, developing in vivo gene engineering tools of cancer-associated fibroblasts to identify and reprogram their roles within the tumor microenvironment.