Beta-1,2-mannotriose (Man3) (Man3)

Beta-1,2-mannotriose is a trisaccharide consisting of three mannose units joined by beta-1,2-glycosidic bonds. It serves as a critical antigenic determinant within the phospholipomannan complex on the cell surface of Candida albicans (Johnson et al., 2012). This glycan is distinct from the more common alpha-linked mannans and is recognized as a foreign molecular pattern by the human immune system. The monoclonal antibody C3.1 (mAb C3.1) specifically binds to this mannotriose epitope, demonstrating the target's importance in fungal recognition (Han & Cutler, 1995). In the context of disease, beta-1,2-mannotriose facilitates the adhesion of Candida to host epithelial and endothelial cells, contributing to fungal virulence. It also plays a role in modulating host cytokine production, which can influence the overall immune response to infection (Faille et al., 1992). Therapeutic strategies targeting this molecule include the development of synthetic glycovaccines designed to induce protective antibody titers. Additionally, passive administration of antibodies like mAb C3.1 has shown efficacy in reducing fungal burden in experimental models of candidiasis. Because beta-1,2-linkages are rare in human glycobiology, this molecule represents a highly specific target for antifungal immunotherapy.

Other names

Beta-1,2-mannotrioseβ-1,2-mannotrioseBeta-1,2-linked mannotriosePhospholipomannan trisaccharide epitopeBeta-D-Manp-(1→2)-beta-D-Manp-(1→2)-D-Manpβ-1,2-mannotriose – recognized by mAb C3.1

The mechanism involves the binding of monoclonal antibodies (such as mAb C3.1) to the beta-1,2-mannotriose epitope on the fungal cell wall, which facilitates opsonophagocytosis by host immune cells and inhibits the fungus's ability to adhere to host tissues (Han & Cutler, 1995). Additionally, synthetic vaccines targeting this epitope aim to stimulate the production of endogenous IgG antibodies that provide long-term protection against Candida species (Johnson et al., 2012).