Figure 4. Effect of cyclosporin A and Ca²⁺ ionophore on the expression of fast MHCIIa mRNA.

Cell cultures were grown for 28 days without any treatment (lane 1) or from day 14 of the culture onwards for a further 14 days in the presence of cyclosporin A (500 ng ml⁻¹) (lane 2) or the Ca²⁺ ionophore A23187 (4 × 10⁻⁷m) (lane 3) or cyclosporin A and Ca²⁺ ionophore (lane 4). Total RNA (10 mg) was isolated from control and treated cultures at the time points indicated, hybridized with an in vitro transcribed ³²P-labelled antisense RNA probe, protecting a 360 bp fragment of MHCIIa mRNA, and an in vitro transcribed ³²P-labelled antisense probe, protecting a 250 bp fragment of the β-actin mRNA. The protected fragments were separated on an 8 m urea-5 % polyacrylamide gel and visualized by autoradiography.