Presence of CXCR3-positive cells and IFN-gamma-producing cells in human periapical granulomas.

In an attempt to understand further the balance between the types of helper T (Th) cells in human apical periodontitis, we examined the difference in the expression of the chemokine receptor and cytokine in samples obtained from human subjects by means of immunohistochemical methods. Chemokine receptor CXCR3-positive cells and IFN-gamma-producing cells were found to be present in human periapical granulomas, whereas chemokine receptor CCR3-positive cells and IL-4-producing cells could not be detected. By contrast, no factor expression was observed in a clinically healthy periodontal ligament serving as a negative control. Our findings suggest that Th1 cells may play an important role in the pathological process of local inflammation such as apical periodontitis.