FIG. 7.

IFN-γ treatment, or introduction of CIITA, reduced the expression of endogenous collagen α₂(I) transcripts in 2fTGH cells. (A) Total RNA was isolated from 2fTGH cells with or without IFN-γ treatment for 24 (lane 2) or 48 h (lane 3), or cells were transiently transfected with empty vector (lane 4) or CIITA (lane 5). Total RNAs were subjected to amplification by RT-PCR with primers specific for the collagen α₂(I) gene. GAPDH was used as a control. (B) The experiment depicted in lanes 1 to 5 is the same as that depicted in panel A, except that G3A cells were used. Additionally, both transient (lanes 4 and 5) and stably transfected (lanes 6 and 7) cells were analyzed. (C and D) Total RNAs (1.5 μg), prepared in a manner similar to that described for panels A and B, were reverse transcribed, and an aliquot of each sample was subjected to amplification by hot-PCR with the collagen-specific primers in the presence of [α-³²P]dCTP. PCR samples were electrophoresed in nondenatured polyacrylamide gel, autoradiographed, and quantitated using the NIH Image software (lower graphs). GAPDH was used as a control (second row of the upper panel).