Yeast-derived Beta-(1-3),(1-6)-D-glucan Induces Up-regulation of CD86 on Dectin-1-positive Human B-Lymphoma Cell Lines

Background: The knowledge of direct effects of beta-glucans on tumor cells is limited. This study evaluated the impact of a soluble yeast-derived beta-(1-3),(1-6)-D-glucan, containing a fraction of aggregated sugar polymers, on viability, proliferation and expression of CD86 of the human B-cell lymphoma cell lines Daudi and Raji. Materials and Methods: Proliferation of carboxyfluorescein diacetate succinimidyl ester (CFSE)-stained cell lines was determined by measuring depletion of the dye and cell death was quantified by staining with propidium iodide, both by flow cytometry. Surface expression of CD86 and the beta-glucan receptors dectin-1 and complement receptor 3 (CR3) was assessed by flow cytometry. Results: Exposure to the carbohydrate increased the expression of CD86 on both dectin-1(+)CR3(-) cell lines, whereas proliferation and viability of the cells were not affected. Conclusion: Yeast-derived beta-glucan lacks cytotoxic effects towards B-lymphoma cells but up-regulation of CD86 suggests maturation of the cells via dectin-1 by the carbohydrate.