Fungicidal activity of human monocyte-derived multinucleated giant cells induced in vitro by Paracoccidioides brasiliensis antigen

Abstract

Multinucleated giant cells (MGC) are characteristic cells in granulomatous disorders such as paracoccidioidomycosis (PCM) and also are formed in vitro from peripheral blood mononuclear cells by several stimuli. In this study, the authors investigated in vitro formation of MGC derived from monocytes of healthy individuals, stimulated with Paracoccidioides brasiliensis antigen (PbAg), compared with other stimuli such as IFN-gamma and supernatant of Con-A-stimulated peripheral blood mononuclear cells (CM-ConA). Besides, the fungicidal activity of monocytes and monocyte-derived MGC challenged with P. brasiliensis were compared, at a ratio of one fungus per 50 monocytes. Results demonstrated that PbAg, IFN-gamma, and CM-ConA stimuli were able to induce MGC generation, with fusion indices significantly higher than control cultures. Striking results were observed when MGC induced by PbAg and IFN-gamma presented higher fungicidal activity than monocytes, submitted to the same stimuli, showing a better capacity of these cells to kill P. brasiliensis. In summary, the results suggest that PbAg is able to induce MGC generation, and these cells presented higher fungicidal activity against P. brasiliensis than monocytes.

Granulocyte macrophage colony-stimulating factor enhances the modulatory effect of cytokines on monocyte-derived multinucleated giant cell formation and fungicidal activity against Paracoccidioides brasiliensis

“…The fungicidal activity of MGC stimulated with PbAg plus IFN-γ or PbAg plus IFN-γ and GM-CSF was significantly higher than the activity of MGC induced by TNF-α, IL-10 and TGF-β 1 . These results confirm our previous study demonstrating that IFN-γ and PbAg promote MGC formation and also the fungicidal activity of these cells (Nascimento et al 2008).…”

“…Preparation of antigen -PbAg was prepared from Pb18 cultured on GPY agar at 35ºC for five days as described previously (Nascimento et al 2008). The fungal growth from three randomly selected tubes (about 300 mg, wet weight) was collected by gently scraping the surface.…”

“…The fusion rate of monocytes was determined by counting the number of stained nuclei within MGC (defined as cells with 3 or more nuclei per cell) and the total number of nuclei within a given field under a microscope at 200X magnification (Nascimento et al 2008). The FI was calculated according to the following formula: FI (%) = (number of nuclei within MGC/total number of nuclei counted) x 100.…”

“…106(6): 735-741, September 2011 Multinucleated giant cells (MGC) are a common feature of granulomatous lesions induced by intracellular pathogens such as fungi and mycobacterium. MGC are also formed in vitro from peripheral blood mononuclear cells (PBMC) by stimulation with cytokines and lectins (Okamoto et al 2004, Nascimento et al 2008. Considerable evidence suggests that MGC are formed by the fusion of cells in the mononuclear phagocyte lineage, particularly monocytes from human blood (Enelow et al 1992a, Anderson 2000.…”

“…Considerable evidence suggests that MGC are formed by the fusion of cells in the mononuclear phagocyte lineage, particularly monocytes from human blood (Enelow et al 1992a, Anderson 2000. The phenomenon of adherent macrophage fusion in both human and experimental animals is enhanced in vitro by the addition of cytokines (McInnes & Rennick 1988, Chensue et al 1992, specific antibodies (Orentas et al 1992), mitogens (Hassan et al 1989) and conditioned medium (Mizuno et al 2001, Nascimento et al 2008. Interferon-gamma (IFN-γ) is essential for MGC generation by promoting cell clustering and cell-to-cell adhesion (Most et al 1990, Fais et al 1994.…”