Impaired regulation of Toll-like receptor-2 mediated T helper type 1 responses in NOD2/CARD15 deficient Crohn*s disease patients

NOD2 is an intracellular receptor for the bacterial product MDP. Mutations in
the CARD15 gene, coding for NOD2, lead to in increased risk for developing
Crohn's disease, however, the mechanism responsible for this is not fully
understood yet. Recently, it has been shown in mice, that simultaneous
activation of NOD2 and Toll-like Receptor (TLR) 2 lead to a less strong immune
response that TLR2 activation alone.

Hypothesis: In Crohn's disease patients with CARD15/NOD2 deficiencies, NOD2
signaling is altered, leading to a loss of the inhibition of TLR2-mediated
immune responses.

Aim:
With this study we would like to prove that also in humans, NOD2 signaling
inhibits the TLR2-mediated immune response.

Procedure:
-Drawing of 50 ml venous blood in heparinized tubes
-Isolation of monocytes with densit gradients
-Culture and stimualtion of the cells
-Harvesting of supernatants, isolation of nuclear extracts
-Measuring cytokine production, NF-kB activation with ELISAs, measuring mRNA
levels with qPCR

Drawing of blood can lead to a bruise and in some cases some tenderness. No
other risks are involved in this study. For the study, blood is only drawn
once, therefore, the burden for the patients can be scaled as *minimal*.