A possible mechanism in the recruitment of eosinophils and Th2 cells through CD163(+) M2 macrophages in the lesional skin of eosinophilic cellulitis.

BACKGROUND

M2 macrophages play a critical role in the recruitment of T helper 2 (Th2) regulatory T cells (Treg).

OBJECTIVES

To study the role of M2 macrophages and Treg cells in eosinophilic celulitis.

MATERIAL AND

METHODS

We employed immunohistochemical staining for CD163( )and CD206 (macrophages) as well as FoxP3 (Treg), in lesional skin of four cases of eosinophilic cellulitis.

RESULTS

CD163(+) CD206(+) M2 macrophages, which were previously reported to produce CCL17 to induce Th2 cells and Treg cells, were predominantly infiltrating the subcutaneous tissues and interstitial area of the dermis. M2 macrophages derived from PBMC showed significantly increased expression of CCL11, CCL17, CCL24 and CCL26 mRNA and production of CCL17 and CCL24, when stimulated by IL-4 or IL- 13. In addition, CCL17-producing cells and CCL24-producing cells were prominent in the lesional skin of EC.

CONCLUSION

Our study sheds light on one of the possible immunological mechanisms of eosinophilic cellulitis.