S100 induced regulation of the immune system in auto-inflammatory diseases
Pediatric and Adolescent Medicine
Final Report Abstract
The research project initially focused on whether persistent secretion of S100 alarmins in autoinflammatory diseases such as Familial Mediterranean Fever (FMF) and PAPA syndrome (Pyogenic Arthritis, Pyoderma Gangrenosum, and Acne) leads to a pathological reprogramming of the innate immune system and the role of specific signaling pathways like PI3K/AKT/GSK-3ß or IL-10/STAT3/BCL-3 in this process. The aim was to apply these findings to other diseases characterized by uncontrolled activation of the innate immune system. In experiments with ER-HoxB8 monocytes/macrophages carrying typical mutations for FMF (V726A) or PAPA syndrome (PSTPIP1 knockout), tolerance development was investigated after repeated stimulation with lipopolysaccharide (LPS). No significant differences in tolerance development were observed among the different cell lines. The attempt to breed homozygous mice to validate the in vitro results in vivo was unsuccessful due to high mortality rates. However, no differences in tolerance development were noted between cells with FMF or PSTPIP1 mutations. Significant differences in cell morphology and adhesion were observed. V726A cells showed increased adhesion, while Pyrin and PSTPIP1 knockout cells exhibited reduced adhesion. Morphology was analyzed using spinning-disc microscopy, revealing a reduction in circularity in V726A cells. Differences in cell migration were also observed: Pyrin knockout cells showed reduced spontaneous migration speed but increased movement linearity. The cell lines were further characterized by immunophenotyping, identifying differentiation patterns that correlated with phenotypic differences. In conclusion, we could show that mutations in the Pyrin inflammasome affect cytoskeletonmediated effector functions of phagocytes. These mechanisms were further investigated through transcriptome analysis, revealing significant differences in gene expression, particularly in cytoskeleton-dependent clusters. Validation of these findings is ongoing through qPCR and Western blot analyses.
