dr. CA (Christine) Jansen

dr. CA (Christine) Jansen

Universitair docent

I am a veterinary immunologist. My research focuses on understanding the interaction between pathogens and the innate (early) immune system in veterinary species such as chickens and pigs. On one hand we investigate how pathogens influence the innate immune system and on the other hand how the innate immune system can be modulated to enhance immune mediated protection.

One of my favorite subjects is the natural killer (NK) cell, an important player of the innate immune system. NK cells play a crucial role in the early defense against viral infections by direct killing of infected cells. In addition, NK cells are important for the induction of subsequent adaptive immune responses

In contrast to mammalian NK cells, knowledge on non-mammalian NK cells is limited. This is mainly due to the lack of NK-cell specific reagents. In the past years I characterized new markers for chicken NK cells and developed functional assays which we use to study the NK-cell response upon viral infection in chickens.

The NK-cell research is divided in several subprojects.

(1) Study basic NK-cell biology in the chicken, as not much is known on these non-mammalian cells. So far, we have identified different populations of chicken NK cells, and are currently characterizing these populations in more detail (with respect to development, function, migration).

(2) Characterize the function of NK cells during viral infections. Studies on the NK-cell response during avian influenza infections resulted in the novel finding that chicken NK-cell activation is diminished upon infection with highly pathogenic H5N1 viruses. Low pathogenicity H9N2 avian influenza virus as well as infectious bronchitis virus showed enhanced activation of lung NK cells. How these different viruses induce NK cell activation in not clear yet and one of the subjects of our ongoing research.

In another project we investigated the NK cell response during an infection with the oncogenic herpesvirus MDV and were able to show for the first time that NK cell can be infected by this virus.  Understanding the contribution of NK cells during MDV-induced immune suppression NK cells in in MDV-infected and vaccinated chickens will provide us with important insights and could facilitate the development of novel MDV vaccines.

(3) Investigate the effect of feed intervention strategies and changes in microbiome on the function of intestinal NK cells.  In parallel the effect of nutritional interventions on NK cell mediated resistance to infections with intestinal pathogens such as Salmonella is studied.

(4) NK cell targeting in vitro and in vivo to increase their activity and study their contribution to immune mediated resistance.