Hypaque

Ogusuku, S.1: Baida, H.2; Duarte, A. J. S.3; Mendes-Giannini, M. J. S.4; Benard, G.5; Romano, C. C.6

1Faculdade de Medicina da USP - Dermatologie; 2Faculdade de Medicina da Universidade de São Paulo - Dermatologia; 3FM - USP - Dermatologia e Imunodeficiências; 4UNESP - Departamento de Analises Clinicas, Faculdade de Ciencias Farmaceuticas; 5USP - Laboratório de Alergia e Imunologia Clínica e Experimental, Faculdade de Medicina , São Paulo, SP, Brazil; 6USP Dermatologia

Introduction: Paracoccidioidomycosis (PCM) is a mycosis that evolves with variable degrees of cellular immune immunosuppresston, according to the severity of the clinical presentation. The mechanism of cellular immunity seems to be crucial for the control and recovery of the disease. In this context, the dendritic cells present an important role, constituting a family of antigen presenting cells with capacity to interact with T and B lymphocytes and to modulate heir reactivities. In this study, we evaluate the in vitro phagocytosis of the dendritic cells (DC) of healthy individuals and patients with PCM challenged with Paracoccidioides brasilienitis. Methods: Suspension of mononuclear cells was obtained through gradient of Ficoll-hypaque density from peripheral blood, washed for 2 times in RPMI 1640 and centrifugated in another density gradient of Percoll for the obtention of monocytes enriched suspension. The cells were cultivated in 6 wells plates for 7 days in the presence of GM-CSF and IL-4. On day 7, we analyzed the differentiation of monocytes into dendritic cells verifying the expression of the following surface markers: CD11c, CD14, CD86 and HLA-DR by flow cytometry. Moreover, the cellular morphology by microscopy was also verified. The dendritic cells (DC) were incubated with P. brasiliensix marked with FITC for a period of 1h and 24h in eppendorf tubes, protected of the light. The analysis of phagocytosis was also carried out by flow cytometry. Results: Healthy individuals DC of stimulates with the fungus demonstrated 59.7% of phagocytosis when the cells were kept for 1h and 54.2% in the 24h of incubation. On the other hand, DC of individuals with active PCM showed a drastic reduction or absence of phagocytosis in the same periods (1,5% for 1 hour and 5,2% for 24h). We did not observe differences between controls and patients (37,13% versus 44,71%) for dextran phagocytosis index. Conclusion: These data suggest a deficiency of recognition and phagocytosis in DC of the individuals with PCM front to fungus, suggesting a possible mechanism of alteration in the innate immune response. However, it will be necessary to investigate and to characterize the recognition receptors, cytokines and costimulatory molecules in this response. Financial support: FAPESP 03/10597-2, 03/06515-0; LIM56 HC

Copyright Instituto de Medicina Tropical de Sao Paulo Oct 2005
Provided by ProQuest Information and Learning Company. All rights Reserved