Hidde Ploegh Senior Investigator, Program in Cellular and Molecular MedicineBoston Children's HospitalBiosketch Hidde Ploegh is a biochemist whose area of interest is the immune system. He is known for his analysis of the pathways involved in antigen presentation by products of the Major histocompatibility Complex (MHC). Ploegh was born in the Netherlands and came to Boston to perform the experimental part of his Ph.D. work under the supervision of Jack Strominger at Harvard university in 1977. He returned to Europe in 1980, and after having held positions in Germany (1980-1984) and the Netherlands (1984-1992) he joined the faculty of MIT as full professor in 1992. In 1997 he became the incumbent of the Mallinckrodt Professorship in Immunopathology at Harvard Medical School and taught both undergraduate and graduate immunology as the director of the graduate program in immunology. He was recruited back to MIT in 2005. After spending more than 10 years at the MIT's Whitehead Institute for Biomedical Research, he joined the Program in Cellular and Molecular Medicine at the Boston Children’s Hospital. Ploegh is a correspondent of the Royal Dutch Academy of Sciences, a member of EMBO, a fellow of the American Academy of Arts and Sciences and a member of the National Academy of Sciences Research Interests Hidde Ploegh’s laboratory is interested in the biochemistry of immune recognition, and in mechanisms by which pathogens avoid being seen by the immune system. His earlier work centered on the analysis of the biochemical pathways involved in antigen processing and presentation by the products of the Major Histocompatibility Complex (MHC), which led to studies into glycoprotein biosynthesis and trafficking more generally. The discovery that human cytomegalovirus exploits an unusual mechanism to dispose of Class I MHC products, critical for recognition by cytotoxic T cells of virus-infected cells, led to observations that illuminated new aspects of glycoprotein quality control. Ploegh has applied chemistry to develop activity-based probes to study proteasomal proteolysis and more specifically the role of ubiquitin-specific proteases, also in the context of herpesvirus infections. More recently Ploegh has combined the generation of camelid-derived antibody fragments with a protein engineering approach, based on the use of bacterial sortases in conjunction with peptide chemistry. This combination is being developed to enable the visualization, by non-invasive means, of anti-tumor and anti-virus immune responses using positron emission tomography.