Figure 3.

Measurements of cytokine mRNA levels with the RNAse protection assay. The assays were performed on RNA extracts from SP samples of individual experimental mCTLA4‐Hg1 tg and non‐tg mice at the 13th week after infection with Du5H (G6T2) or sham inoculation with PBS. The number of mice studied in each group is indicated over the top of the corresponding column. Selected film exposures yielding similar overall signal intensities between experiments were scanned with a densitometer (PhosphorImager) to obtain absorbance values for cytokines and L32 transcripts. Quantification of cytokine mRNA levels was done by normalization to those of the L32 housekeeping gene. The values for infected non‐tg, infected tg and uninfected tg mice were converted to percentage of values obtained in uninfected non‐tg mice. The mean indexes (± SEM) from all experiments are shown.