Comparison of MuHV-4 cell binding and infection in the presence of heparin.

<p>A. EGFP-expressing wild-type or gp150⁻ virions were incubated with different heparin concentrations, then used to infect GAG⁺ and GAG⁻ CHO cells. Infection was assayed 18h later by flow cytometry of viral eGFP expression, counting the %eGFP⁺ cells in a gate where uninfected cells (no virus) were <0.2% eGFP⁺. Each point represents 10,000 cells. The bars show infection levels without heparin. nil = no virus. Equivalent data were obtained in a repeat experiment. B. gM-eGFP⁺ versions of the same viruses were incubated with GAG⁺ and GAG⁻ CHO cells, with or without added heparin (2h, 37°C), then washed x3 in PBS and assayed for eGFP uptake by flow cytometry. Again, the bars show eGFP uptake without heparin, and nil = no virus. Equivalent data were obtained in a repeat experiment. The minor increases in gp150⁻ binding to and infection of GAG⁻ CHO cells at low heparin dose were quite variable between experiments; the reductions, particularly in wild-type MuHV-4 infection of and binding to GAG⁺ CHO cells, were not.