Mycoplasma penetrans infection of Molt-3 lymphocytes induces changes in the lipid composition of host cells.

The AIDS-associated Mycoplasma penetrans is capable of inducing its own uptake by non-phagocytic cells. The ability of M. penetrans to both adhere to and invade Molt-3 lymphocytes was markedly increased in the presence of polyethylene glycol 8000 (PEG). The effect of PEG was more pronounced in the more alkaline pH range, where the binding kinetics were much faster and almost unaffected by temperature (4-37 degrees C). Incubation of [14C]oleic-acid-labelled Molt-3 cells with viable M. penetrans resulted in a substantial release of radioactive fatty acids, whereas treating the host cells with heat-inactivated mycoplasmas, isolated M. penetrans membrane preparations, or M. penetrans growth medium, had no effect. Total lipid analysis of Molt-3 lymphocytes infected by M. penetrans revealed an augmented level of the neutral lipid fraction that was associated with a decrease in the relative amounts of polar lipids, mainly a decrease in the amount of phosphatidylserine and diphosphatidylglycerol. Analysis of the neutral lipid fraction in the infected Molt-3 cells revealed a fivefold increase in the relative amount of diacylglycerol and a marked increase in the free fatty acid (FFA) fraction. The profile of the FFAs released was dominated by a relatively high concentration of the polyunsaturated fatty acid docosahexaenoic acid. The release of lipid intermediates suggests that the degradation of Molt-3 cell phospholipids induced by M. penetrans may initiate a signal transmission cascade in the host cell.