Changes in lipid composition of human peripheral blood lymphocytes infected by HIV

The possible differences in lipid composition between human immunodeficiency virus- (HIV) infected and uninfected PHA-activated human peripheral blood mononuclear cells (PBMC) have been studied. The total fatty acid composition was similar, except for the proportion of arachidonic acid, that was slightly higher in infected than in noninfected cells. No significant differences were obtained in the incorporation of radiolabeled stearic or oleic acids in the different lipid classes. The staining of cells with Nile Red showed similar amounts of intracytoplasmic lipid droplets. On the contrary, the CH/PL ratio, the major factor in determining cell membrane fluidity, was clearly higher in infected than in uninfected cells (0.60 and 0.36, respectively). This fact is discussed in relation with the known high CH/PL ratio (0.95) of the lipid envelope of HIV.