Dr. Brenner completed his postdoctoral training in 1981 and joined the Clinical Research Centre of Northwick Park Hospital in London, England as a MRC Clinical Scientist and Honorary Senior Registrar. He also began lecturing in Haematology at the Royal Free Hospital and Hospital for Sick Children, also in London.

Dr. Brenner joined the faculty at the University of Tennessee in Memphis as a Professor in the Departments of Pediatrics and Medicine in 1990. He also became the Director of the Bone Marrow Transplant Division of the St. Jude Children's Research Hospital that same year. He later directed the Cell and Gene Therapy Program at St. Jude's from 1994 until 1997, when he assumed his current positions at the Baylor College of Medicine.

Dr. Brenner's research focuses on gene transfer to stem cells and to effector cells of the immune system. His research group was one of the first to use gene transfer in human subjects, establishing the feasibility of tracking human stem cells and their progeny in subjects with cancer. Dr. Brenner also develops tumor vaccines for pediatric and hematological malignancies, using genetic modification with retroviral and adenoviral vectors.