However, these cells were also identified in normal mucosa. In fact, healthy oral and nasal mucosae are in permanent contact with foreign bodies and microorganisms, maintaining baseline immune surveillance even in the absence of clinical signs of inflammation. Expression of NOS2 varied greatly. Despite the lack of a significant difference, nasal lesions tended selleckchem to express more NOS2. An inverse correlation was observed between the expression of NOS2 and the presence of parasites. Similar results have been reported for cutaneous lesions (14). In addition, nitric oxide – the product of NOS2 – has been associated with tissue destruction

(25) and may contribute to the formation of the extensive lesions generally observed in ATL mucosa as well as in other infections (18). Low expression of NOS2 has been previously observed in healthy tissues (26). Neutrophils were detected in all groups studied, but their number was significantly higher in ATL lesions. Studies have demonstrated higher parasite burdens in mice depleted of neutrophils and infected with Leishmania spp. (27,28).

Moreover, the importance of the formation of neutrophil extracellular traps during in vitro infection with Leishmania spp., and the presence of these cells in human lesions, has been demonstrated (15,29). Langerhans cells are normally found above the basal layer of the skin (30), oral mucosa (31) and nasal mucosa (32). We observed a similar GDC-0941 molecular weight distribution of these cells in the epithelium and a small number in the lamina propria of all tissues analysed. However, Modlin et al. (16) and Martinez-Arendes et al. (8) did not detect Langerhans cells in nasal mucosal leishmaniasis lesions. These apparently contradictory findings

may have various explanations, ranging from differences in the type of lesion and biopsy site to the source of the antibody used. C59 mw Cutaneous lymphocyte-associated antigen (CLA+) cells were frequently found inside vessels and adhered to the endothelium. The importance of CLA during migration and its location in the skin and mucosa has been demonstrated (23,33). CD62E and CLA showed a similar distribution and variable intensity in mucosal ATL, similar to cutaneous ATL (14). In our study, the number of CLA+ cells was twice as high in nasal ATL lesions when compared to C–N. This finding agrees with the description of an intense inflammatory process characterized by continuous cell migration producing the maintenance or constant increase in the local immune response. In contrast, a similar expression of CLA was observed in ATL and healthy oral mucosa. It might be explained by the particular conditions of microtrauma and constant exposure to infectious agents of supposedly healthy oral mucosa. As an aggravating factor, oral lesions are generally highly painful, a fact impairing adequate cleaning. In addition, the mouth can be considered a contaminated site.