Fig 2.

Role of HSPG sulfation on baculovirus binding and transduction. (A) Quantification of cell surface-bound baculovirus on EA.hy926 and HepG2 cells treated with NaClO₃ (0 to 75 mM). Baculovirus (MOI, 400) was allowed to bind to the surface of NaClO₃-treated cells (1 h). The bound virus was stained with mouse anti-gp64 and anti-mouse Alexa 488-conjugated secondary antibody and imaged with confocal microscopy (60× magnification). Image analysis was performed as described in Materials and Methods. (B) HepG2 cells treated with different concentrations of NaClO₃ (0 to 75 mM) and transduced with baculovirus (MOI of 200) for 48 h. The virus-mediated transgene (EGFP) expression percentages were analyzed by FACS. (C) HepG2 and 293T cells transduced with baculoviruses (MOI, 500) pretreated with basic and differentially 2-O-, 6-O-, and N-desulfated heparins (2 mg/ml). The percentage of EGFP-positive cells was analyzed 48 h later by FACS. In all experiments, EGFP/WPRE-bearing baculovirus was used. Mean fluorescence values and standard deviations are shown.