Dr. Holland received his M.D. from the Johns Hopkins University School of Medicine in 1983, where he stayed as a resident in internal medicine, assistant chief of service in medicine, and fellow in infectious diseases. He came to the National Institutes of Health in 1989 as a National Research Council fellow in the Laboratory of Molecular Microbiology, working on transcriptional regulation of HIV.
In 1991, Dr. Holland joined the Laboratory of Host Defenses, shifting his research to the host side, with a focus on phagocyte defects and their associated infections. His work centered on the pathogenesis and management of chronic granulomatous disease, as well as other congenital immune defects affecting phagocytes, including those predisposing to mycobacterial diseases. In 2004, he became chief of LCID.