FIG. 8.

Soluble heparin decreases titers of HTLV-1 pseudotyped viruses in CD4⁺ T cells. HTLV-1 or VSV-G pseudotyped virus particles were generated as described in Materials and Methods. The virus preparations were incubated in RPMI containing 0, 10, or 25 μg/ml of soluble heparin for 30 min. SupT1 cells were resuspended at 2 × 10⁵/ml in RPMI, and then 0.5 ml of cells was mixed with an equal volume of the pseudotyped virus in the presence or absence of heparin, as indicated. The cells were transduced by spinoculation and then harvested 4 days later, and the viral titers were determined as described in Materials and Methods.