<i>Candida albicans</i>Phospholipomannan Is Sensed through Toll‐Like Receptors

Candida albicans is a common, harmless yeast in the human digestive tract that also causes severe systemic fungal infection in hospitalized patients. Its cell-wall surface displays a unique glycolipid called phospholipomannan (PLM). The ability of PLM to stimulate tumor necrosis factor (TNF)-α production by J774 mouse cells correlates with the activation of nuclear factor (NF)-κB. We examined the involvement of Toll-like receptors (TLRs) in PLM-dependent stimulation. Compared with wild-type cells, which produced large amounts of TNF-α after incubation with PLM, the deletion of the TLR4 and TLR6 genes led to a limited alteration of the PLM-induced response. Deletion of the TLR2 gene completely abolished the cell response. Surface expression of PLM is a phylogenic trait of C. albicans , and the recognition of PLM by TLRs, together with the unique pathogenic potential of C. albicans , suggests that this molecule may be a member of the pathogenassociated molecular pattern family.