Fli-1 pre-T LBL can be transplanted to secondary recipients, is not due to retroviral insertion site and is oligoclonal.
A. Spleen cells from a mouse with Fli-1 leukaemia were injected into 4 sublethally irradiated recipients, which subsequently developed disease around 3 weeks post-transplant. Three additional transplants into 11 unirradiated mice gave similar results. Single cell suspensions from spleen and liver were analysed for CD4, CD8 and TCRβ expression by flow cytometry. Data representative of 4 independent transplants. B. Southern blot of total thymocyte (thy) genomic DNA from mice transplanted with Fli-1 transduced bone marrow showing multiple different retroviral integration sites in Fli-1 leukaemia. EcoRI digested DNA was probed with a DIG-labelled IRES-GFP fragment. Lane 1: λ Hind III marker, 2–6: primary Fli-1 thymi as indicated, 7: secondary from Fli-1 #622, 8: mouse #625 Radiation-Induced Thymic Lymphoma (RITL). Data representative of three independent experiments. C. TCRβ VDJ rearrangement as assessed by PCR showing normal VDJ rearrangement in MigR1 control mice (7 bands: Vβ-Jβ2.1–2.8) and oligoclonal rearrangement in Fli-1 mice (1–4 bands). Lanes 1 & 24: Marker, 2–23: MigR1 control (Mig) or primary and secondary (2°) Fli-1 thymocytes (Thy) or spleen cells (Spl) as indicated. 23: Fli-1 #627 is TCRβ−.