Petter Höglund

I am a research group leader at the Department of Medicine Huddinge (MedH), where my group studies how immune tolerance develops and how failures of this process may cause autoimmunity and transfusion complications.

I also have a long-standing interest in natural killer (NK) cells and how these cells are functionally educated. My group also studies platelet function in healthy individuals and in patients with metabolic disorders and cancer, especially diabetes and leukemia.

I defended my PhD thesis at Karolinska Institutet in 1993 at the Department of Tumor Biology and completed by medical training at the Karolinska University Hospital in 1996. I performed a three-year postdoctoral training period in Strasbourg, France, where I worked with Diane Mathis and Christophe Benoist to define early immunological events in autoimmune diabetes.

After my return to Sweden in 1999, I established my research group at the Department of Microbiology Tumor Biology and Cell Biology (MTC), where I became assistant professor in 2003. in 2011, I was recruited to MedH as a professor of immunology.

I obtained my specialist degree in Clincal Immunology and Transfusion Medicine in 2016 and became senior consultant at the Karolinska University Hospital in 2022.

Since December 2019, I am the head of department at MedH.

Immunological tolerance protects self from immune attack while at the same time maintains a broad capacity to attack foreign invaders. When tolerance fails, autoimmunity may occur. At the clinical immunology hospital laboratory, we diagnose autoantibodies in many conditions, including in children with neutropenia. Autoimmune neutropenia (AIN) in children follows a defined track with the appearance of autoantibodies against Fc-gamma receptor IIb (CD16) wthin a the first year of life, followed by deep neutropenia with infectious complications. We are interested in why anti-CD16 antibodies develop and what underlies their synchronous apperance across individuals. In our reserach as a diagnostic lab, we perform method development studies to perfect antibody detection and study links between autoantibodies and clinical disease history. In the reserach laboratory, we ask if antibody development links to anti-viral immunity and how the immune system recognizes and kills neutrophils in the presence of antibodies. 

Platelet transfusion refractoriness (PTR) is a clinically important situation where patients fail to respond to platelet transfusions with the expected rise in platelet counts. The condition can be fatal in cases of uncontrolled bleeding and can also delay diagnostic and therapeutic procedures. about a third of all PTR cases are caused by immunological rejection of transfused platelets, primarily by antibodies against HLA formed eariler in life, often in pregnancy. We are interested in how HLA antibodies trigger platelet clerance and try to develop an alternative transfusion product based on stripping of HLA from platelets before transfusion. Our preclinical work on HLA-stripping, including an experimental transfusion model, provides a foundation for clinical translation.

Platelets are not only low in numbers in patients with leukemia, they are also unexpectedly poor in function. We study the reasons for this using flow cytometry to quantify platelet activation in respons to various platelet agonists and to enumerate platelet subsets with increased capacity to promote blood coagulation. By comparing platelets of healthy people to platelets in leukemia using a microfluidic setup, we intend to probe specific signaling defects underlying poor platelet functionality. conversely, we are interested in studying platelet hypoerreactivity in metabolic disorders, such as diabetes and obesity.

NK cells (natural killer cells) are a type of lymphocyte that is considered part of the non-adaptive immune system and can recognize and kill virus-infected cells and cancer cells. When the immune system recovers after a stem cell transplantation, NK cells can contribute to important anti-cancer effects in patients with leukaemia - a reaction called Graft-versus-Leukaemia (GvL). One of my research aims is to understand the molecular mechanisms that govern the formation of NK cells in the body. We are particularly interested in how NK cell are “educated” in vivo, how they learn to distinguish self from non self and which mechanisms that regulate the responsiveness of NK cells.

Over the years, my reserach has been supported by grants from the Swedish Cancer Society, The Swedish Research Council, Radiumhemmets Research Funds, CIMED, Ragnar Söderberg Foundation, Human Frontier Science Program, Marianne and Marcus Wallenberg Foundation, Regions Stockholm ALF program and Karolinska Institutet.