Regulatory T cells in cutaneous lesions of patients with Paracoccidioidomycosis.

Paracoccidioidomycosis (PCM) is a systemic mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis, with high incidence in Brazil and very significant in Latin America. The disease is clinically classified as acute, subacute or chronic where the primary lesion initiates in the lungs and can spread to other organs such as the skin and mucous membranes. The lesions are characterized by granulomatous formation, organized according to the type of pattern of host immune response. We demonstrated and quantified by immunohistochemistry the expression of Foxp3, CD25, TGF-beta and IL-10 in thirty cutaneous lesions with different presentation of granulomatous response. Cells expressing Foxp3 and CD25 were increased in lesions with compact granulomas. The expression of TGF-beta and IL-10 was similar in all PCM lesions. As previous studies, our data suggest the correlation of Treg cells with the chronicity of the disease and the participation in suppressing mechanism as a possible source of IL-10. TGF-β and IL-10, two important suppressor cytokines, are expressed in great amounts in the lesions but our results do not allow correlating with the differences in the granulomatous response.