β1 integrin coreceptor function is dependent on postreceptor events. No transduction could be observed in suspension (Susp) K562 cells, even after pretreatment with divalent ions (1 mM Mn2+, 1 mM Mg2+) and high-affinity conformation-stabilizing β1 integrin antibodies (N29, 21C8). In contrast, transduction of spontaneously adherent (Adh) and PMA-differentiated K562 cells by recombinant parvovirus B19-Luc vectors was increased by pretreatment with high-affinity conformation-stabilizing β1 integrin antibodies (N29, 21C8) and decreased with inhibitory (P4C10) β1 integrin antibodies. Transduction without antibody treatment (Control) was set at 1 for comparison. Firefly luciferase activity was detected in cell extracts 24 hours after infection. Data are representative of 3 independent experiments; error bars represent SD.
