Fig 1.

rCD8a expression correlates linearly with rVEGF production in rVICD8 myoblasts. (A) The coding sequences for rat VEGF164 (rVEGF164) and truncated rat CD8a (tr. rCD8a) were linked through an Internal Ribosomal Entry Site (IRES) sequence in a bicistronic retroviral construct (pAMFG-rVICD8). : retroviral packaging signal; LTR: long terminal repeats. (B) Schematic representation showing co-expression of both genes at a fixed ratio from the bicistronic mRNA, so that the amount of VEGF secreted (red molecules) is correlated to that of tr.rCD8a retained on the cell surface (green molecules), which can be quantified by staining with an anti-rCD8a antibody (CD8-Ab). (C) The production of rVEGF (in ng/106 cells/day) was measured by ELISA in supernatants of 12 individual myoblast clones isolated from the primary transduced rVICD8 population (n = 3–5). (D) Correlation between the expression of rCD8a, quantified by FACS, and the amount of secreted rVEGF, quantified by ELISA, in the 12 clonal populations analyzed. MFI: mean fluorescence intensity.