Expression of K^b on transduced cells.

(A) Expression of K^b on the surface of VSV-Kb–transduced NIH3T3 cells. The 5 × 10⁵ NIH3T3 cells were transduced overnight at an MOI of 5 with VSV-Kb (solid line) and examined for K^b expression by cell surface staining and flow cytometry 48 hours later. Mock-transduced cells (dashed line) were used as a control. (B) Expression of K^b on the surface of VSV-Kb (solid line) or mock-transduced (dashed line) B10.AKM BM. Expression of K^b was analyzed following cell surface staining by flow cytometry. (C) Expression of K^b on the surface of BM hematopoietic progenitor cells. Following transduction, B10.AKM BM cells were stained with antibodies specific for the lineage markers indicated in “Materials and methods,” Sca-1 and K^b. The cells were then analyzed by flow cytometry to examine expression of K^b. Shown are cells gated on the Lin⁻Sca-1⁺ fraction, which is approximately 3% of total BM after 5 days in culture. Thirty-six percent of Lin⁻Sca-1⁺ cells express K^bfollowing infection of 5-FU–treated BM with VSV-Kb (solid line). Mock-transduced controls (dashed line) are shown for comparison purposes. Shown is a representative experiment.