Geert Wiegertjes graduated at the Aquaculture & Fisheries Group (AFI) of Wageningen University in 1988, to take up his teaching and research position at the Cell Biology & Immunology Group in 1990. He got his PhD on Immunogenetics of Disease Resistance in Fish in 1995. He has long-term experience with funding by the Netherlands organisation for scientific research (NWO) and by the European Community (Marie Curie) and organises the annual Fish Immunology Workshop since 1998. His research activities focus on aquatic animal health in general and on immunity to fish parasites in particular.
Studies on infections with trypanosomes have brought much understanding of host-parasite interactions. Antigenic variation (African trypanosomes) as well as intracellular hiding have become schoolbook examples of parasite adaptations to the host. Studies on trypanosome infections of fish allow us to evaluate evolutionary routes to adaption. Infections of common carp (Cyprinus carpio) with the extracellular protozoan parasite Trypanoplasma borreli provide an excellent example of how adaptation and homeostasis are essential elements of the host-pathogen relationship. On the one hand, host-derived nitric oxide interferes with clearance of IgM from the parasite surface and thus can be considered a protective immune reaction of the host. On the other hand, it is essential that the host limits the risks associated with the production of nitric oxide, preventing suppressive effects on lymphocyte proliferation.
Study on viruses
As sub-coordinator of the large integrated project ‘IMAQUANIM’ (EU-FP6; 22 partners) we have studied the immune response of carp to Spring Viraemia of Carp (SVC) virus. Gene expression studies identified 4 days post-infection as a crucial moment in the immune response of carp to the virus, with a potentially important role for the cytokine interleukin-12 (IL-12). These findings have formed the basis for a Veni grant (NWO) for Maria Forlenza and a Marie Curie grant for Alberto Falco on the development of DNA vaccination protocols against viral infections of carp. The studies on innate immune responses to viruses are also continued by the research project of Joeri Kint on Infectious Bronchitis Virus of chicken.
The work of my PhD student Carla Ribeiro on receptors of carp macrophages has helped form a basis for further studies on immunomodulation by β glucans. As sub-coordinator of the Marie Curie International Training Network ‘NEMO’ (EU-FP7; 9 partners, 16 young scientists), which has as scientific aim to establish optimal protocols for the use of ß-glucans (components of fungal cell walls) in the strategic improvement of animal health, we are studying the role of several TOLL-like and scavenger receptors including TLR1 and TLR2 (Inge Fink), TLR4 and TLR20 (Danilo Pietretti) and C-type lectin receptors (Anders Østergaard).
Post Doc and PhD projects
- PhD Inge Fink: Comparative molecular characterization of TOLL-like receptors activated by ß-glucans
- PhD Danielo Pietretti: Comparative molecular characterization of TOLL-like receptors activated by ß-glucans
- PhD Joeri Kint: Unraveling the anti-viral response and entry of avian viruses in avian cells and cell lines
- PhD Carmen Embregts: Oral vaccination of carp against KHV and SVCV and investigation of protective B- and T-cell immune responses