Teun Guichelaar is an immunologist with expertise in experimental immunology concerning aging of the immune system, immune regulation, and circadian rhythm of the immune system. His studies aim to better understand how aging-related deterioration and disturbances of the day-night rhythm may impact natural and vaccine-induced immunity to respiratory viral infections, such as influenza, COVID-19, and RSV. Current studies by his research team focus on the mechanisms of regulation of T-cell activation and on the induction of antibodies to respiratory viruses such as Respiratory Syncytial Virus (RSV).

At older age, our immune system often reacts differently to infectious diseases and vaccines. This notion fuels our efforts on new research that aims to gain better understanding of how aging may impact our immune system. Such understanding is needed to find ways to improve immunity against infectious diseases for those who become highly susceptible at old age



Teun Guichelaar obtained his MSc in Cell and Molecular Biology at Wageningen University (The Netherlands), while gaining a major interest in virology and immunology. He obtained his PhD at the University of Utrecht in The Netherlands, where he studied regulation of inflammation by T cells in the autoimmune disease rheumatoid arthritis. After obtaining his PhD, he continued his research on immune regulation at the University Medical Center Utrecht. As post doc, he studied immune suppression by FOXP3+ regulatory T cells in immunotherapy of cancer. Since 2011, Guichelaar and his research team study effects of aging on immune regulation and immunity to respiratory viruses, at the National Institute for Public Health and The Environment (RIVM) in The Netherlands.


  • Immunology
  • Aging
  • Circadian rhythm of the immune system


E-mail: info@rivm.nl 

Key publications

Regulatory KIR+ RA+ T cells accumulate with age and are highly activated during viral respiratory disease . Pieren DKJ, Smits NAM, Hoeboer J, Kandiah V, Postel RJ, Mariman R, van Beek J, van Baarle D, de Wit J, Guichelaar T (Aging Cell, 2021) 

Compromised DNA Repair Promotes the Accumulation of Regulatory T Cells With an Aging-Related Phenotype and Responsiveness. Pieren DKJ, Smits NAM, Imholz S, Nagarajah B, van Oostrom CT, Brandt RMC, Vermeij WP (work package), Dollé MET, Guichelaar T (Frontiers in Aging, 2021) 

Disruption of circadian rhythm by alternating light-dark cycles aggravates atherosclerosis development in APOE*3-Leiden.CETP mice - Schilperoort M, van den Berg R, Bosmans LA, van Os BW, Dollé MET, Smits NAM, Guichelaar T, van Baarle D, Koemans L, Berbée JFP,  Deboer T, Meijer JH, Kooijman S (Journal of Pineal Research, 2020) 

Response kinetics reveal novel features of ageing in murine T cells. Pieren DKJ, Smits NAM, van de Garde MDB, Guichelaar T (Scientific Reports, 2019) 

Impaired immune response to vaccination against infection with human respiratory syncytial virus at advanced age.  Guichelaar T, Hoeboer J, Widjojoatmodjo MN, Reemers SS, van Els CA, Otten R, van Remmerden Y, Boes J, Luytjes W (Journal of Virology, 2014)