Dhaenens Maarten

Maarten Dhaenens














phone: ++32 9 264 83 56
fax: ++32 9 220 66 88


 "A mass spectrometry journey through medical and molecular biology"


Throughout the course of my PhD, the research focus has greatly shifted. The initial objective was reached when the discovered aberrant protein expression patterns in HLAB27 transgenic rat dendritic cells were confirmed with both videomicroscopy and flow cytometry: the dendritic cells from this animal model for Spondyloarthritis exert an endoplasmic reticulum stress due to HLAB27 misfolding, resulting in downregulated cytoskeletal dynamics. This latter deficiency results in lower motility and changed morphology, as well as a less efficient immunological synapse formation with T-cells. The overall downregulation of surface MHCII expression and increased apoptotic sensitivity of the tolerigenic CD4- dendritic cells are most probably also entwined with the deficient cytoskeleton.
An iTRAQ analysis on Chronic Lymphocytic Leukemia B-cells, which was initially set up to optimize the protocol of this new proteomics approach, led to the rediscovery of a histone clipping event that was first described over 35 years ago. In the light of current knowledge, this old proteolytical event could have far-reaching effects on hematopoiesis, through its interaction with the Polycomb Group of epigenetic modifiers. We have now unmasked this so-called “H2A-specific protease”. The obvious parallel between H2A clipping and the recently described histone H3 clipping in embryonic stem cells has inspired us to start the study of this model as well and to summarize all previous reports on histone clipping in a review.
More recently, we have set out to validate a new iTRAQ-based approach to identify and quantify posttranslational modifications. Validation of this approach for parallel expressional and posttranslational analysis is ongoing. Finally, the LabFBT proteomics platform has been used in collaboration with several different labs to tackle diverse biological and technical challenges such as the analysis of protein binders in historical paints, the search for mechanisms that can explain recrudescence of infection in pigs following stress, the pathogenicity of a mould that causes world-wide decline in amphibian populations, identification of di- and tripeptides with ACE inhibitory characteristics,…