zymosan

An insoluble beta-1,3-glucan polysaccharide derived from, and structural component of, yeast cell walls, with potential immunostimulating activity. Upon administration, zymosan targets, binds to and activates certain Toll-like receptors, primarily TLR type 2 (TLR-2), on leukocytes and dectin-1 on macrophages. Activation of TLR2 and dectin-1 stimulates the release of pro-inflammatory mediators, and enhances innate immune responses.