Dendritic cells and pattern of cytokines in paracoccidioidomycosis skin lesions

We demonstrated and quantified by immunohistochemistry epidermal Langerhans cells, CD34+ dermal dendrocytes (DDs), and cells expressing TNFalpha, interferon-gamma (IFNgamma), IL-5, and IL-10 in skin lesions of paracoccidioidomycosis (PCM). Sixty-one biopsies were classified in three groups according to the pattern of tissue response: Group 1, well-organized granuloma; Group 2, poorly organized granuloma; and Group 3, both kinds of granuloma. Langerhans cells had short and irregular dendrites in all groups and were decreased in number in Groups 1 and 2. CD34+ DDs did not differ in number from the control group. Group 1 was characterized by many cells expressing IFNgamma. Groups 2 and 3 exhibited large numbers of cells expressing IL-5 and IL-10. The data obtained suggest that well-organized granulomas reflect a better cellular immune response, and the large number of cells expressing IL-5 and IL-10 in Group 2 indicate an ineffective response in PCM skin lesions. Both kinds of granuloma in the same cutaneous lesion probably represent an intermediate response between the anergic and hyperergic poles. Group 3 also showed higher numbers of cells expressing TNFalpha when compared with the control group. Some cells expressing TNFalpha were dendritic and localized around the granuloma similar to the factor XIIIa+ DD localization that we previously described.