Fig 2.

Two alleles of sooty mangabey CD4 support SIVsmm Env-mediated entry via CCR5 in vitro. Target 293T cells were transfected with human CD4 (huCD4) or each of two sooty mangabey alleles of CD4 (smCD4 2.1 and smCD4 4.3), with or without sooty mangabey CCR5 (smCCR5). Cells were then infected with luciferase-expressing pseudotype virions carrying Env glycoproteins from two subtype 1 SIVsmm-infected SM, using equal amounts of each virus based on infectivity in U87/CD4/CCR5 cells (10⁶ RLU of each virus). FFv Envs were derived from an infected animal with a CCR5^wt/wt genotype, and FNp Envs were derived from an infected animal with a CCR5^Δ/Δ genotype. Virions lacking envelope glycoprotein served as negative controls. Infection was measured by relative light units (RLU) in cell lysates at 3 days postinfection (n = 3; values are means ± standard deviations [SD]).