Johanna Joyce

Johanna Joyce, PhD is a Professor of Oncology and Ludwig Cancer Research Chair at the University of Lausanne. She is one of the foremost authorities on how the tumor microenvironment, particularly stromal and myeloid components, drives immunotherapy resistance. Her laboratory has made seminal contributions to understanding TGF-beta-mediated immune exclusion, demonstrating that TGF-beta secreted by cancer-associated fibroblasts (CAFs) and tumor cells creates a physical and functional barrier to T cell infiltration in desmoplastic tumors. Her work in pancreatic, breast, and brain cancers elucidated how stromal TGF-beta signaling promotes fibroblast activation, collagen deposition, and the formation of a dense extracellular matrix that physically excludes cytotoxic T lymphocytes from reaching cancer cells. She demonstrated that combined TGF-beta receptor inhibition with PD-L1 blockade synergistically converts immune-excluded tumors to a T cell-inflamed phenotype and achieves tumor regression in preclinical models. Dr. Joyce also pioneered single-cell RNA-seq approaches to characterize intra-tumoral macrophage and fibroblast heterogeneity, identifying specific immunosuppressive subpopulations as therapeutic targets.