Abstract
Molecularly cloned radiation leukaemia viruses (RadLVs) isolated from the BL/VL3 radiation-induced thymoma have been used in assays to compare the binding specificity of the BL/VL3 cell line for different retroviruses. BL/VL3 cells bound well to two of three thymotropic, leukaemogenic viruses produced by this cell line. BL/VL3 did not bind to a cloned fibrotropic, non-leukaemogenic RadLV. BL/VL3 appears to have receptor specificity for only some of the leukaemogenic RadLVs, and this appears to be related to differences in the viral env sequence.