Improving the use of probiotics in immune mediated diseases
Thursday 16 April 2009
Project
Recent intervention studies with probiotic bacteria in immune mediated diseases have provided different and sometimes contradictory results. This is probably due to poor strain selection. We hypothesize that each immune mediated disease to be influenced needs a strain with specific characteristics, fit for the specific immunological background of the disease.
In this project, we characterize the immune modulationg capacities of several probiotic strains. PBMC isolated from healty volunteers are cocultured with several strains. Subsequently, mRNA of transcription factors T-bet, GATA3, RORyT and FOXP3 is isolated to quantify the induction of Th1, Th2, Th17 and Treg cells.
The bacteria most potent to induce a T helper subset will be used for further analysis of the induced subsets. For this purpose we FACS analyse the cells for specific cytokines, and use proliferation assays to see if the subsets are induced from naive cells or from expanding memory cells.
Our special focus is on the induction of regulatory T cells, as these cells appear to be the master regulators of immune homeostasis. The suppressive capacities of Tregs induced by bacteria is characterized with suppression assays. The effect of bacteria on existing Tregs will also be tested.
When immunologically different bacteria are selected, we will test if PBMC from children with immune mediated diseases as atopic dermatitis, colitis ulcerosa and juvenile arthritis can be ‘skewed’ in a Th1, Th2 or Th17 direction by bacteria. Of course, the induction of Tregs and their suppressive capacity will again be a focus of interest.
With the results of this project, we can improve strain selection and the use of probiotics in immune mediated diseases.
Techniques
Cell culture of T cells and different types of DC, FACS, Elisa, luminex, gel electrophoresis, confocal microscopy, immunohistochemistry, in vivo animal studies
Duration
6 or 9 months
Contact
Dr. Mark Klein, 088 75 555 55 (pager 4118), mklein01@umcutrecht.nl