Isolation and Culture of Primary Human Cells

293T and MAGI cells were maintained as previously described [45 (link)]. Primary human monocytes and CD4⁺ T cells were isolated from peripheral blood buffy coats by positive selection using CD14 or CD4 beads (Miltenyi Biotec, San Diego, CA), as previously described [46 (link)], and maintained in RPMI medium with 10 % FCS and penicillin/streptomycin. CD14⁺ monocytes were matured to macrophages using 5 ng/mL human GM-CSF for 7 days (Miltenyi Biotec). CD4⁺ T cells were activated with 5 µg/mL phytohemagglutinin (Sigma-Aldrich) and 20 units/mL IL2 (Miltenyi Biotec) for 1 day, then 20 units/mL IL2 alone for 5 days.