Involvement of β-glucan receptors on the antitumor activity of β-glucans

β-glucans consisting of β-(1,3)-linked glucose as the main chain (hereafter simply called “β-glucan”) are suggested to have the potential for many beneficial effects on health. Among known beneficial effects, the most notable effect of β-glucan would be the antitumor effect. The antitumor effect of β-glucan has been known since the mid-twentieth century. In current cancer treatments where immune checkpoint inhibitors are attracting attention, it is expected that the combined administration of β-glucan will exhibit a greater therapeutic effect. The antitumor effect of β-glucan is believed to be closely linked to the receptors that recognize β-glucan. On the other hand, it has been clarified that there are many receptors for the recognition of β-glucan, in addition to CR3 (complement receptor 3) and dectin-1 (dendritic cell-associated C-type lectin-1), the well-known β-glucan receptors. This review focused on various β-glucan receptors reported previously and discusses the molecular mechanisms through which β-glucans exhibit antitumor effect