XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:59-1

Poster (Painel)

59-1

Comparison between monocytes effector mechanisms against Paracoccidioides brasiliensis and Paracoccidioides lutzii.

Authors:

Guilherme Augusto Biondo (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho) ; Ana Paula Bordon-graciani (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho) ; Cibele Ferrari (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho) ; Raquel Cordeiro Theodoro (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho) ; Eduardo Bagagli (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho) ; Ângela Maria Victoriano de Câmpos Soares (UNESP - Universidade Estadual Paulista - Julio de Mesquita Filho)

Abstract

Introduction: Paracoccidioides brasiliensis (Pb) is a thermodimorphic fungus that causes paracoccidioidomycosis, a systemic disease endemic in Latin America. Pb isolates exhibit extensive genetic variability, as well as a possible correlation between genotype distribution and geographical isolation, drug resistance and virulence. In our laboratory we have investigated the role of Pb strain virulence in inducting antifungal mechanisms of human phagocytes. The results have clearly demonstrated that low virulent strain is more susceptible to killing by monocytes before and mainly after activation with cytokines such as TNF-α and GM-CSF. Pb01 isolate, which belongs to Paracoccidioides lutzii, the most divergent species of Paracoccidioides genus, tends to inducing different responses of the host. There are no studies on interaction between this new specie and phagocytic cells. Objective: Then, the purpose of this study was to compare human monocytes antifungal activities against P. lutzii with those presented for high (Pb18) and low (Pb265) virulent strain of P. brasiliensis. Methodology: Peripheral blood monocytes obtained from 10 healthy donors were activated or not with IFN-γ, TNF-α or GM-CSF by 18h and further challenged with Pb18, Pb265 and P. lutzii for 4h. After, cultures were evaluated for fungicidal activity, H2O2 release and TNF-α and IL-10 production by ELISA. Results: Killing and H2O2 production, mainly after cytokines cells activation was significantly higher for Pb265 in relation to Pb18. Fungicidal activity and H2O2 release after challenge with P. lutzii was similar to that detected for Pb18. However, after challenge with the P. lutzii, we observed a decrease in the levels of TNF-α and increased in IL-10 when compared with Pb18 and Pb265. Conclusion: Although very divergent in other aspects, such as morphology and coding sequences, as already documented, these preliminary results suggest that Pb01 isolate induces human monocytes to present a similar response to that detected for Pb18, a high virulent strain which belongs to S1 group from P. brasiliensis species complex.

Keyword: Paracoccidioides brasiliensis, Paracoccidioides lutzii, monocytes effector mechanisms

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