An experimental model for study of sialoglycoproteins of human immunodeficiency virus 1 epitope structures

Sialic acid (SA) molecules located terminally on retrovirus glycoproteins (gps) play a key role in virus-cell interactions. The specificity of sialylation of Human immunodeficiency virus 1 (HIV-1) gps has not yet been studied. Looking for a convenient and reproducible experimental virus-cell model for studying the problem mentioned above we compared viral sialoglycoprotein (Sgp) patterns in H9/HTLV III B cells chronically infected with laboratory-adapted HIV-1LAI and MT-2 cells acutely infected with the same virus. Cytosols (CSs) and supernatant concentrates (SNs) from these cells and cell cultures, respectively, following N-acetyl-D-[U-14C]-mannosamine ([14C]NAcMan) labeling were subjected to preparative isoelectrofocusing and the obtained fractions were assayed for 14C-incorporation, reverse transcriptase (RT) activity and protein content. Sgp patterns in CSs from the two types of infection were similar. Highly sialylated peaks clustered mainly in the acidic region where the highest 14C-incorporation, RT activity and protein content were found. The 14C-incorporation was higher in CS than in SN. Analysis of CS from MT-2 cells infected with HIV-1 for the markers described above seems to be the experimental approach and model of choice for clinical isolates of HIV-1.