XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:65-2

Oral / Poster

65-2	Recognition of TLR2 heterodimers by ArtinM accountsfor its modulatory effect in experimental paracoccidioidomycosis
Authors:	Vania Sammartino Mariano (FMRP-USP - Faculdade de Medicina de Ribeirão Preto) ; Igor Correia Almeida (UTEP - University of Texas at El Paso) ; Maria Cristina Roque Barreira (FMRP-USP - Faculdade de Medicina de Ribeirão Preto)

Abstract

ArtinM (AM), a D-mannose-binding lectin from jackfruit seeds induces interleukin (IL)-12 production by macrophages and T helper 1 immunity that confers resistance against Leishmania major and Paracoccidioides brasiliensis murine infections. It is known that in in fungal infections, TLR4 and TLR2 are implicated in the cell signaling for induction of IL-12 production. Interaction of AM with macrophages from TLR2 and TLR4 knockout mice showed that only TLR2 is implicated in the protection conferred by ArtinM against experimental paracoccidioidomycosis (PCM). To better understand the mechanisms responsible for the AM immunomodulatory effect in PCM, we have evaluated the interaction of AM with TLR2 heterodimers (TLR2/1 and TLR2/6) and TLR4 by using HEK293 adherent cells.The cells were transiently cotransfected with combinations of plasmids of TLR (TLR2/1 or TLR2/6 or TLR4), co-receptors/ accessory molecules (CD36, CD14, MD-2) plus ELAM-1-firefly luciferase and β-actin Renilla luciferase. After 24 hours, the cells were stimulated for4 hwith different concentrations of AM or with known TLR agonists (P3C, FSL-1 or LPS), as positive controls. After cell lyses, the luciferase activity was measured by using the Dual-Luciferase Reporter Assay System. Luciferase activity was expressed as the ratio of NF-kB dependent firefly luciferase activity to constitutively expressed Renilla luciferase activity. NF-kB activation was induced by the TLR specific ligands, as well as by AM (0.1µM and 1.0µM) in cells expressing TLR2/1 and TLR2/6. No activation was determined by similar AM concentrations in cells expressing TLR4.Beyond TLR2, the co-receptor CD36 was shown to be important in the process, because in its absence concentrations 10 times higher of ArtinM were required to induce NF-kB activation. Further studies are necessary to clarify the role of the glycosylated co-receptors/accessory molecules of TLR on the signaling triggered by AM. ਀䘀椀渀愀渀挀椀愀氀猀甀瀀瀀漀爀琀㨀䘀䄀倀䔀匀倀Ⰰ 䌀䄀倀䔀匀Ⰰ 䌀一倀焀⸀

Keyword: ArtinM, TLR2, paracoccidioidomycosis

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