Abstract: β-glucans show multiple biological activities and function such as immunomodulation, anti-tumor, anti-microbial infection. As non-specific immunomodulators, β-glucans activate immune cells, promote cytokine production, activate complement system, and stimulate antibody production, therefore it play an important role in immune system, The study is to give general review on molecular mechanism of β-glucans for enhanced immune system. Research on molecular level from recent years showed that polysaccharides as immunomodulators combine with receptors on surface of macrophages, neutrophilic granulocyte, and lymphocytes, affecting information transfer which therefore further affect gene expression and function of these immune cells. Roles of lymphocytes are related to cellular cAMP and cGMP levels and its ratio. β-glucans affect cAMP and cGMP levels and ratio and therefore modulate cellular activities. -glucans induce NO production of immune cells and have synergism action with interferons. In addition, βglucans affect secretion of prostaglandin of lymphocytes and modulate immune function. Elucidation of immune modulation mechanism of β-glucans will be helpful for development of new types of immune enhancers. 

Key words: β-Glucans; immune enhancement; mode of action