Background: Talaromyces marneffei (T. marneffei ) is a thermally dimorphic fungus endemic to Southeast Asia that causes human systemic infection. Our earlier immunohistochemical studies revealed that the organisms were markedly labeled with the CD86 antigen in cutaneous lesions brought on by infection. However, the relationship between T. marneffei and the CD86 co-stimulatory molecule is still unknown.
Objective: To explore the association between CD86 Protein and Talaromyces marneffei organisms in vitro and discuss the potential mechanisms.
Methods: We created the CD86-EGFP fusion protein in THP-1 macrophages and co-cultured T. marneffei conidia with it. We used confocal fluorescence microscopy to view in vitro dynamics. The link between CD86 Protein and Talaromyces marneffei organisms in vitro was discovered using immunoelectron microscopy, indirect immunofluorescence test, and immunohistochemistry assay.
Results: T. marneffei cells received soluble CD86-EGFP from THP-1 macrophages detected by confocal fluorescent microscopy. Both the indirect immunofluorescence assay and the immunohistochemical assay showed that T. marneffei conidia were stained by the CD86 marker. Immunoelectron microscopy showed that characteristic colloidal gold particles were observed in T. marneffei organisms when co-cultured with THP-1 macrophages.
Conclusion: T. marneffei organisms have the ability to capture CD86 proteins from macrophages in vitro.
Keywords: Talaromyces marneffei , macrophage, CD86, confocal microscopy, immunoelectron microscopy, immunohistochemistry