Fig 2.

Receptor usage of KoRV-A and KoRV-J. (A) Host ranges of KoRV subgroups. lacZ pseudotypes were inoculated into the indicated cells, and titers of the viruses were determined in a LacZ assay. Data were obtained from three independent experiments, and the values are expressed as means ± 1 standard deviation (SD). N.D., not detected. (B) Interference assay of KoRV subgroups. lacZ pseudotypes were inoculated onto naive HEK293T cells and HEK293T cells chronically infected with FeLV-B strain Gardner-Arnstein, and titers of the viruses were determined in a LacZ assay. Data were obtained from three independent experiments, and the values are expressed as means ± 1 SD. (C) Infectivity of KoRV subgroups in MDTF cells expressing human Pit-1 (MDTF/hPit1) and human THTR1 (MDTF/hTHTR1). cDNAs of human Pit1 and THTR1 were cloned into a RetroQDsRed monomer vector (Clontech) to produce pRetro-hTHTR-DsRed. The resultant plasmid was transfected into MDTF cells, selected by puromycin, and subjected to a lacZ pseudotype infection assay. lacZ pseudotypes were inoculated onto MDTF/hPit1, MDTF/hTHTR1, and MDTF cells transfected with an empty expression vector (MDTF/RED) and HEK293T cells. Titers of the viruses were determined in a LacZ assay. Data were obtained from three independent experiments, and the values are expressed as means ± 1 SD.