Insertion of a retroviral LTR expression cassette into the first intron of LMO2. (A) The AAV-LMO2 vector consists of a single retroviral LTR-GFP cassette and 1.4 kb of upstream and 1.4 kb of downstream intron sequences. The LTR-GFP cassette was flanked by loxP (▵) and loxP511 (▴) sites, and the entire assembly was cloned between AAV-ITRs. The restriction enzyme sites (D, DraIII; B, BglII) and the expected band sizes on cassette integration along with probes used in Southern blot hybridization are indicated. (B) Jurkat cells were transduced with scAAV-GFP or AAV-LMO2 at the indicated MOI, and GFP expression was periodically monitored by FACS analysis. (C) BglII-digested DNA (left) or DraIII-digested DNA (right) was probed with GFP (top) or LMO2 (bottom) intron sequences in a Southern blot analysis.