John W. Semple obtained his PhD in Immunology from Queen’s University at Kingston and was a Diabetes Canada Fellow at the Banting and Best Department of Medical Research in the C.H. Best Institute, University of Toronto. He joined St. Michael’s Hospital in Toronto in 1990 and became Head of the Toronto Platelet Immunobiology Group and a Professor of Pharmacology and Medicine at the University of Toronto. In 2016, Professor Semple was recruited to Lund from St. Michael’s Hospital and the University of Toronto. His research program is related to adverse responses in Transfusion Medicine.

            His laboratory has a long history of studying the pathogenesis of immune thrombocytopenia (ITP), an autoimmune disease where platelets are targeted by anti-platelet autoantibodies and T cells. In 1991, his pioneering work first described the T helper/IL-2 hyperactivity responsible for anti-platelet autoantibody production in patients with ITP.  This observation has now been confirmed by many other labs all over the world and over 200 papers have been published in this area. He went on to also first demonstrate (1996) that the T cell hyperactivity was associated with a Th1 cytokine phenotype and has since then generated a relevant animal model of ITP (2010) that demonstrates both antibody- and T cell-mediated thrombocytopenia.

       A second research interest of his laboratory is to elucidate the pathogenic mechanisms responsible for Transfusion Related Acute Lung Injury (TRALI), the leading killer of transfused patients worldwide. His laboratory has identified several key areas of the recipient immune system that significantly affect TRALI reactions.  These include 1) monocyte activation that initiates the TRALI reaction via MIP-2 expression, 2) osteopontin release that propagates recipient pulmonary neutrophil recruitment during TRALI and 3) the ability of the T regulatory (Treg) cell/Dendritic Cell axis to suppress these reactions via IL-10 secretion.    

            In 2006, his laboratory was one of the first to describe the expression and function of Toll-like Receptors (TLR) on platelets that critically linked them with the innate immune system and he has had an interest in platelet-immune interactions ever since. 

       Professor Semple is the recipient of many awards and a member of several organizations, including the American and European Societies of Hematology and has delivered over 250 presentations at local, national and international meetings. He is currently the Scientific Secretary of the International Society of Blood Transfusion and sits on the editorial board of the journals Haematologica and Transfusion.  He has served as a reviewer for numerous journals and granting agencies and has published more than 200 papers in the area of platelet immunology and TRALI.