Leonardo V. Riella, M.D., Ph.D. is the Harold and Ellen Danser Endowed Chair in Transplantation at Harvard Medical School, Medical Director of Kidney Transplantation at Massachusetts General Hospital, and a global leader in transplant immunology and xenotransplantation. His research focuses on immune regulation, biomarker discovery, and therapeutic innovation to improve long-term transplant outcomes.

Dr. Riella led the world’s first successful kidney xenotransplantation from a genetically engineered pig into a living human with end-stage kidney disease (NEJM 2025). He now directs the first FDA-approved xenotransplantation study and applies multi-omics technologies to optimize graft survival and immune monitoring (Nat Med in press). In parallel, his lab is advancing kidney bioengineering using human stem cells to create vascularized nephron units.

His research has uncovered key immune regulatory pathways, including Notch, PD-1/PD-L1, and the innate checkpoint Siglec-E (Sci Transl Med 2025) and developed a novel IL-2 mutein that expands regulatory T cells without stimulating effectors (JCI 2024). His group also created CRISPR-based diagnostics for rejection and infection, and identified MMP3 and CCL18 as biomarkers in human face transplantation.

Dr. Riella founded and leads the international TANGO consortium, which has generated the largest cohorts on recurrent glomerular diseases after transplantation, informing new clinical guidelines and enabling exploratory studies on post-transplant immune disease pathogenesis. As Medical Director at MGH, he implemented equity initiatives that doubled transplant rates among underserved populations and introduced AI-driven tools and remote interventions to improve transplant readiness.

Author of over 200 publications, he has secured >$25M in research funding and serves as Section Editor for the American Journal of Transplantation. He has mentored over 35 trainees and co-directs NIH-funded transplant education programs. Dr. Riella was recognized with the 2024 AST Basic Science Investigator Award for his transformative scientific contributions.