Expression of Ag2/PRA constructs in the CL-7 cell line as determined by RT-PCR. The pVR1012-based plasmids of Ag2/PRA(1-18), Ag2/PRA(19-194), and Ag2/PRA(1-194) and, as a control, pVR1012 alone were transfected into CL-7 cells. Total RNA was isolated at day 3 after transfection, and Ag2/PRA mRNA expression was assayed by RT-PCR. The PCR products were visualized on a 2% agarose gel.