Induction of interferons (IFNs) and tumor necrosis factor (TNF) in mice by a novel glycolipid trehalose 2,3,6'-trimycolate from Rhodococcus aurantiacus (Gordona aurantiaca).

The immunomodifying activity of a novel mycoloyl glycolipid, trehalose 2,3,6'-trimycolate (GaGM), from a unique psychrophilic acid-fast bacterium, Rhodococcus aurantiacus, was examined. ICR mice were primed intravenously (i.v.) or intraperitoneally (i.p.) with liposomes containing GaGM (300 micrograms/mouse), and were administered LPS dissolved in saline (25 micrograms/mouse, i.v.) 2 weeks later. Two hours after injection of LPS, interferons (IFNs) and tumor necrosis factor (TNF) were induced significantly in mice sera. The increase in activities of IFNs and TNF was approximately paralleled with granuloma formation in spleen of mice primed with GaGM. However, IFNs and TNF were not induced either in mice primed with GaGM but not elicited with LPS, or in those primed with GaGM and elicited by GaGM. Both activities induced were lower in mice primed with trehalose mono- or dimycolate from R. aurantiacus (GaTMM, GaTDM) or TDM from Nocardia rubra than in GaGM-primed mice. Time course study showed that the maximum activity of each interferon (alpha, beta, or gamma) was observed at different stages after LPS administration; IFN-alpha, IFN-beta, and IFN-gamma appeared 3, 2, and 6 hours most abundantly after LPS administration, respectively.