Lotje D De Witte, MD, PhD Email Lotje De Witte
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- Position
- ASSISTANT PROFESSOR | Psychiatry
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- Language
- English
Dr. de Witte is a psychiatrist with a background in preclinical research in the fields of virology and immunology. She studied Medicine at the University of Amsterdam, the Netherlands and performed a Ph.D. at the department of cell biology and immunology at the VU medical center in Amsterdam and a postdoc at the department of virology at the Erasmus MC, Rotterdam, the Netherlands, where she was extensively trained in the concepts and techniques involved in immunology, cell biology and virology. She investigated the role of Langerhans cells and other myeloid cell types in viral infections. She set up various cellular models in the lab, including the isolation of primary Langerhans cells. Dr. de Witte graduated cum laude for her Ph.D. and her research projects have been published in high impact journals including Nature Medicine, the Journal of Clinical Investigation, PLOS pathogens and PNAS.
After graduating cum laude for her M.D., Dr.de Witte decided to specialize in psychiatry. She was not only attracted to this field from a clinical point of view but also devoted to use her experience in immunology to start to unravel how the immune system plays a role in psychotic disorders. In parallel to her residencies in psychiatry, she therefore started her own research group at the Brain Center Rudolf Magnus in Utrecht, the Netherlands. She investigated the prevalence and role of neuronal auto-antibodies and neurotropic pathogens in psychotic disorders. In addition, she set up several human microglia models, including the isolation of these cells from post-mortem brain tissue, generating them from induced pluripotent stems cells and monocytes. This has resulted in a novel and distinctive research line studying the phenotype and function of microglia in psychotic disorders.
Education and Training
2008 PhD, Department of Molecular Celbiology & Immunology, VU Medical Center
Amsterdam, The Netherlands
2010 MD, School of Medicine, VU Medical Center
Amsterdam, The Netherlands
2008-2010 Postdoc, Department of Virology, Erasmus MC
Rotterdam, The Netherlands
2011-2016 Residency Psychiatry, UMC Utrecht
Utrecht, The Netherlands
2011-2017 Postdoc Translational Neuroscience,
Utrecht, The Netherlands
2016-2017 Psychiatrist Department of Psychiatry, University Medical Center
Utrecht, The Netherlands
2017-present Assistant Professor, Department of Psychiatry, Icahn School of Medicine at Mount Sinai,
New York, USA
Language
English
The role of the immune system in psychiatric disorders
An association between the immune system and psychiatric disorders, such as schizophrenia, bipolar disorder and autism, is becoming more and more evident. Targeting the immune system is therefore one of the major focuses for finding novel drug targets. However, it is still largely unknown how immune processes are involved in these diseases at the molecular level.
Microglia
Microglia cells are the resident immune cells of the brain. From animal studies it is known that microglia are not only involved in initiating and controlling inflammation in the central nervous system (CNS), but that they are also crucial for neurodevelopment and neuronal functioning in adulthood. In her lab, Dr. de Witte studies whether one of these functions is affected in psychiatric disorders. She has set up several human microglia models, including the isolation of these cells from post-mortem brain tissue, generating them from induced pluripotent stems cells and monocytes. Using these models she compares microglia from patients and controls at the phenotypic and functional level. In addition, she studies whether specific genetic risk factors for neurodevelopmental disorders alter microglia functioning.
Auto-antibodies
Antibodies that bind to synaptic proteins can cause autoimmune encephalitis and this can lead to prominent psychiatric symptoms. A clear example is anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, which is caused by auto-antibodies to one of the subunits of the NMDA receptor. Dr. de Witte studies whether subgroups of patients with psychiatric disorders may have an underlying autoimmune disease caused by neuronal auto-antibodies. Her studies on blood samples of patients with schizophrenia or bipolar disorders indicate that the presence of these auto-antibodies is very rare. She is now involved in validating these findings in cerebrospinal fluid.
Physicians and scientists on the faculty of the Icahn School of Medicine at Mount Sinai often interact with pharmaceutical, device and biotechnology companies to improve patient care, develop new therapies and achieve scientific breakthroughs. In order to promote an ethical and transparent environment for conducting research, providing clinical care and teaching, Mount Sinai requires that salaried faculty inform the School of their relationships with such companies.
Below are financial relationships with industry reported by Dr. De Witte during 2019 and/or 2020. Please note that this information may differ from information posted on corporate sites due to timing or classification differences.
Employment:
- GGZ Noord Holland Noord, the Netherlands
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