Figure3: hS100A7 and hS100A15 function through distinct classes of receptors.
A) Frozen sections of inflamed lesional psoriasis were stained for hS100A7 (green) and hS100A15 (red) showing differential upregulation of both S100 proteins. Nuclei were stained with DAPI (blue). Bar size: 50 μm. B) Recombinant hS100A7, hS100A15 were injected intraperitoneally into C57/BL6 wild-type mice alone or premixed in combination. After four hours, cells attracted into the peritoneal fluid were counted and analyzed by flow cytometry using the granulocyte marker Gr-1. (mean value + s.d. from six mice, * P ≤ 0.05). C) hS100A7 mediates leukocyte chemotaxis through RAGE (receptor of advanced glycated end products). This atypical chemotaxis receptor is pertussis toxin-insensitive, which helps distinguish ligand activity through classical chemokine receptors. hS100A15 chemotactic activity is Gi-protein-dependent, however the receptor has to be specified.