Fig. 1.
Infection with low passage HCMV strains provides maximum protection against NK cell attack. (a) HFs infected with high passage strain AD169 show significant protection from NK cell lysis, compared with uninfected targets or targets infected with an AD169 UL40 deletion mutant. Cells infected with strain Toledo or other low passage isolates (not shown) were completely resistant to NK cell attack. (b) The ability to induce complete resistance to NK cell lysis could be restored by inserting the strain Toledo ULb′ sequence into high passage strain Towne to produce recombinant Tx4 (kindly provided by E. Mocarski). Modified from Tomasec et al. (2005).
