The Candida albicans phospholipomannan induces in vitro production of tumour necrosis factor-alpha from human and murine macrophages.

We have previously identified a Candida albicans 14,000-18,000 MW antigen reacting with anti-beta-1,2-linked oligomannosides antibodies as being a phospholipomannan (PLM). Because of the structural similarities between the C. albicans PLM and lipophosphoglycans from various microbial pathogens known to be potent tumour necrosis factor-alpha (TNF-alpha) inducers, we investigated the PLM ability to induce TNF-alpha. Incubation of human monocytic cells THP-1 with PLM led to dose-dependent production of TNF-alpha that was significantly increased by prestimulation of the cells with interferon-gamma (IFN-gamma). Production of TNF-alpha by macrophages under PLM stimulation was confirmed by using macrophages elicited from the mouse peritoneal cavity. In all investigated conditions, PLM-induced TNF-alpha production differed significantly in both kinetics and dose dependence from lipopolysaccharide (LPS) induction used as control. It appears, therefore, that the C. albicans PLM shares functional homologies with microbial lipophosphoglycans identified as pathogenicity factors, although prestimulation of the target cells was required for the PLM-derived opportunistic pathogen to trigger the cytokine network.