Agaricus bisporus mannose-binding protein stimulates the innate immune cells

Abstract

Purpose: A lectin-like protein from the mushroom Agaricus bisporus has been shown to slightly increase the proliferation of RAW 264.7 cells. Following its identification as a mannose-binding lectin, henceforth called A. bisporus mannose-binding protein (Abmb), the protein is hypothesized to stimulate the innate immune cells response. The present work was aimed to substantiate that hypothesis. Furthermore, this study complements Abmb exploration as a potential agent for anti-breast cancer, which its treatment is hampered with compromised immunity of patient receiving chemotherapy. Method: Abmb’s effect on the phagocytic activity of the macrophage was measured with FACS. Nitric oxide production was checked using Griess test while expression of the cytokines in the RAW 264.7 cells was analysed at gene and protein level using PCR and FACS, respectively. Abmb’s effect on the expression of surface markers of the human immune cells in the peripheral blood mononuclear cells was checked with specific antibodies for targeted cluster differentiation and analysed using FACS. Result: Abmb increased the phagocytic activity of the macrophage and NO production. Abmb increased the expression of cytokines i.e. tumour necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10. With the peripheral blood mononuclear cells, Abmb activated dendritic and Natural Killer cells, but not the B- or T-cells. Conclusion: Abmb increased the activity of the macrophage cells and activated the immune cells that are related to the innate immune system, particularly the cellular immunity.

Keywords: breast cancer, cellular immunity, innate immune system, lectin; macrophage, mannose-binding protein