A synthetic second messenger; has mucosal adjuvant properties in vitro and in vivo by the mucosal route; enriches the population of MHC class I and II, CD80, CD86, CD40, and CD54 positive dendritic cells derived from murine bone marrow; stimulates macrophages at 200 ng/ml; intranasal immunization with β-gal increases IgG titers up to 2-fold and induces a Th1/Th2 response