HIV-2 Envs MCN and MCR mediate MLV-B and MLV-NB restriction in HeLa/CD4 cells, and the restriction is rescued by different retroviral Envs. VSV-G, MCN, MCR and Ampho MLV Envs were pseudotyped onto MLV-B and MLV-NB cores, and viral titres were normalised on NP2/CD4/CXCR4 cells to 10% GFP +ve infection. (a) MCN and MCR pseudotyped MLV-B and MLV-NB viral vectors showed a restricted infection of HeLa/CD4 cells when compared to NP/CD4/CXCR4 cells, while Ampho pseudotyped vectors were relatively unrestricted. (b) Fold restriction is defined as the ratio of transduction of the non- restricted NP2/CD4/CXCR4 cells to the restricted HeLa/CD4 cell line for MLV-B and -NB viral cores. (c) MCN Env pseudotyped HIV-2 CA (RodA delta Env GFP) is not restricted on HeLa/CD4 cells while MCR is. (d) Fold restriction of HIV-2 CA RodA infectivity data in Figure 1c. (e) MLV-B pseudotyped with RD114 Env is restricted in HeLa/CD4 cells, GALV and HIV-1 Envs are not restricted. MLV-NB pseudotyped with RD114, GALV and HIV-1 Envs are not restricted in HeLa/CD4 cells. (f) Fold Restriction for the MLV-B and MLV-NB cored viral vectors in Figure 1e. Data represent the average of three or more independent experiments +/- S.E.M.