Immune activation induced by β-glucans. β-glucans can act on a variety of membrane receptors found on the immune cells. It may act singly or in combine with other ligands. Various signaling pathway are activated and their respective simplified downstream signaling molecules are shown. The reactors cells include monocytes, macrophages, dendritic cells, natural killer cells and neutrophils. Their corresponding surface receptors are listed. The immunomodulatory functions induced by β-glucans involve both innate and adaptive immune response. β-glucans also enhance opsonic and non-opsonic phagocytosis and trigger a cascade of cytokines release, such as tumor necrosis factor(TNF)-α and various types of interleukins (ILs).