MYCOPLASMA-FERMENTANS GLYCOLIPID TRIGGERS INFLAMMATORY RESPONSE IN RAT ASTROCYTES

Mycoplasma fermentans glycolipid (MfGL-II) is a major lipid in the mem branes of this AIDS-associated mycoplasma and constituting up to 20% o f the total phospholipids of this organism. It was recently shown that MfGL-II, mainly through its phosphocholine moiety, is responsible for the attachment of M. fermentans to host cells. We now show that MfGL- II is also associated with the secretion of inflammatory mediators by cells of the central nervous system. Stimulation of primary rat astroc ytes by MfGL-II caused activation of protein kinase C, secretion of ni tric oxide (NO) and prostaglandin E-2, and augmented glucose utilizati on and lactate formation in a dose-dependent manner. In an attempt to define the minimal structural requirements for MfGL-II activity, the t wo O-acylated fatty acids in the molecule were removed. Deacylation pr onouncedly reduced the stimulatory activity of the glycolipid, suggest ing that the fatty acyl residues are essential. Incubation of MfGL-II with polyclonal anti-MfGL-II antiserum or with monoclonal anti-phospho choline antibody diminished NO release, whereas incubation of MfGL-II with normal rabbit serum had no effect. It is, therefore, likely that the terminal phosphocholine moiety plays an important role in MfGL-IIs stimulation of glial cells. (C) 1998 Elsevier Science B.V. All rights reserved.