Dr. Gregson developed an interest in host-pathogen interactions and translational research while working overseas during during residency and fellowship. After completing his residency training in Internal Medicine at Harbor-UCLA, Dr. Gregson pursued Infectious Diseases training at the University of Maryland. While at the University of Maryland's Center for Vaccine Development he trained as a clinical vaccinologist, running a domestic phase 1 malaria vaccine trial and serving as a co-investigator on two separate phase 1b malaria vaccine trials in Bandiagara, Mali. Dr. Gregson also completed a study to test the hypothesis that antimalarial treatment enhances the spread of drug resistance through the induction and selection of gametocytes carrying resistance-conferring mutations in Bancoumana, Mali. After completion of his Vaccinology Fellowship Dr. Gregson worked with PATH's Malaria Vaccine Initiative (MVI) as the Chief Scientific and Technical Consultant for the RTS, S Malaria Vaccine Project.
His current research focuses on the cellular immune response to infection and allorejection following solid organ transplantation. Ongoing projects include investigations into the role of both regulatory and effector lymphocyte populations in the development and progression of chronic lung allograft rejection (BOS), predominately utilizing flow cytometry. The role of common infectious complications following lung transplantation in the development and progression of chronic lung allograft rejection is examined in combination with the lung allograft immune milieu utilizing novel statistical approaches. Additionally, examination of the selective pressure in the development of and outcomes for various hospital related infections at UCLA is underway with collaborators from Harbor-UCLA.
Dr. Gregson is an inpatient consultant on the Liver, Small Bowel and Pancreas Transplant Program, the Stem Cell Transplant Program, the Heart & Lung Transplant & Cardiac Assist Device Program and the General Infectious Diseases Teaching Service.