Immunohistochemistry evaluation of the immune response and metaloproteinasis in cutaneous lesions of chromoblastomycosis

Abstract

The Chromoblastomycosis is a chronic fungal infection that affects the skin and subcutaneous tissue. The host defense mechanisms in chromoblastomycosis have not been thoroughly investigated. It is described a predominance of cellular immune response, phagocytosis mediated by macrophage, without however having frequent death of the fungi. There is also participation of Langerhans cells (LC) and Factor XIIIa + dendrocytes and cellular immune response mediated by CD4 + T cells producing Th1 cytokine profile in controlling infection by F. pedrosoi. The severe form is characterized by production of IL10 and TNF-alpha, which coupled with low production of IFN-gamma and results in a depressed cellular immune response and disease severity. Patients can exhibit high IFN-gamma and low levels of IL-10. M2 macrophages are described as immunomodulators and are related to chronicity of some diseases.The LC dendritic cells are currently described by the specific expression of Langerin. Recent studies, however, have found a new population of Langerin + cells in the dermis that could not be related to LC. This subset has not been well studied in human dermis. The ability to bind to wall elements of various fungi led some authors to consider how important is Langerin receptor for these pathogens. The IL17 seems pivotal role in protective immunity against fungi. In this project we intend to contribute to the study of the characterization of skin tissue response in chromoblastomycosis, verifying the presence of M2 macrophages, matrix metalloproteinases, elements of the extracellular matrix, cytokine profile of Th17 cells. Specifically: Check by immunohistochemistry the expression of arginase 1, CD206, that are M2 macrophage markers .Check the expression of metalloproteinases MMP 2 and 9, laminin, fibronectin and collagen IV.Demonstrate the presence of cells with expression of IL17, IL22 and IL23. To demonstrate the expression of Langerin and comparing with previous data on the expression of CD1a + Langerhans cells. We will study 30 skin biopsies selected from the files of Dermatopathology Laboratory, Division of Clinical Dermatology, Hospital das Clinicas, University of São Paulo School of Medicine, from patients with clinical and pathological diagnosis of chromoblastomycosis. Ten normal skin fragments will constitute the control group. Histopathological examination of the lesions will be done by staining with hematoxylin-eosin. The search will be performed by immunohistochemistry using specific antibodies and streptavidin-biotin system or polymers. The reaction protocols to be used are already standardized in Lab of the Department of Pathology of Transmitted Diseases, FMUSP, where the work will be developed. Furthermore, we intend to use confocal microscopy to study the matrix-metalloproteinases 2 and 9 (AU)