Comparison of results of cotransduction of ALL (Nalm-6, ALL 1) and AML (ML-1, AML 1) leukemia cells with the separate pHR-CD80 and pHR-GM-CSF vectors and results with the bicistronic pHR-GM/CD vector.

(A) Frequency of CD80⁺ nontransduced (mock-transduced [M]) cells, cells transduced with pHR-GM-CSF and pHR-CD80 at a multiplicity of infection (MOI) of 1 for each (G+C), and cells transduced with the pHR-GM/CD vector at an MOI of 1. (B) Relative fluorescence of cells in the CD80⁺ gate. (C) GM-CSF expression measured as picograms per 10⁶ cells per 24 hours.