43 kDa Glycoprotein (gp43) from Paracoccidioides brasiliensis Induced IL-17A and PGE2 Production by Human Polymorphonuclear Neutrophils: Involvement of TLR2 and TLR4.

Taiane Priscila Gardizani,Rosana Puccia,Luciane Alarcão Dias-Melicio,Ângela Maria Victoriano De Campos Soares,Amanda Manoel Della Coletta,Ana Paula Moreira Serezani,Graziela Gorete Romagnoli

doi:10.1155/2019/1790908

Abstract

The glycoprotein gp43 is the major antigenic/diagnostic component of Paracoccidioides brasiliensis, one of the etiologic agents of paracoccidioidomycosis (PCM). Gp43 has protective roles in mice, but due to adhesive properties, this glycoprotein has also been associated with immune evasion mechanisms. The present study evaluated gp43 interaction in vitro with Toll-like receptors 2 and 4 (TLR2 and TLR4) present in polymorphonuclear neutrophils (PMNs) from healthy human individuals and the consequent modulation of the immune response through the expression and release of cytokines and eicosanoids. PMNs were incubated in the absence or presence of monoclonal antibodies anti-TLR2 and anti-TLR4 (individually or in combination) before gp43 stimulation. Then, PMNs were analyzed for the expression of both surface receptors and the detection of intracytoplasmic IL-17A and IL-4 using flow cytometry, while the production of PGE2, LTB4, IL-6, IL-10, IL-12, IFN-γ, and TNF-α was evaluated in the supernatants by enzyme-linked immunosorbent assay (ELISA). Our results showed that gp43 increased TLR2 and TLR4 expression by PMNs and induced PGE2 and IL-17A via TLR4 and TLR2, respectively. Thus, our data suggest that gp43 from P. brasiliensis might modulate host susceptibility to the fungal infection by affecting PGE2 and IL-17A production.

Highlights

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease prevalent in Latin America
polymorphonuclear neutrophils (PMNs) were analyzed for the expression of both surface receptors and the detection of intracytoplasmic IL-17A and IL-4 using flow cytometry, while the production of prostaglandin E2 (PGE2), leukotriene B4 (LTB4), IL-6, IL-10, IL-12, IFN-γ, and TNF-α was evaluated in the supernatants by enzyme-linked immunosorbent assay (ELISA)
We blocked TLR2 or TLR4 using a monoclonal antibody prior gp43 stimulation, and we observed that the percentage of TLR2+ and TLR4+ cells remained similar to nonstimulated control cells (Figure 1(a) and 1(b))

Summary

Introduction

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease prevalent in Latin America. P. brasiliensis exhibits in the cytoplasm, and along the cell wall, a 43-kDa glycoprotein (gp43) that is considered the main fungal antigen. It is secreted by the fungus and frequently found in the serum of PCM patients [8,9,10]. Inhibition of gp expression in genetically modified P. brasiliensis resulted in a less severe infection in experimentally infected mice due to diminishing adherence of the fungi to host cell proteins, increased yeast cell phagocytosis, and consequent production and action of proteases responsible for inhibiting fungal tissue diffusion [18]. The present study assessed whether gp is recognized by TLR2 and TLR4 on the surface of human PMNs, modulating the production of immunomodulatory cytokines and eicosanoids

Methods

Results

Conclusion