Expression of SOCS-1 is suppressed following pre-TCR signaling.

Neonatal RAG2^−/− mice were injected intraperitoneally with anti-CD3ε mAb. Injections were given 36 or 72 hours prior to harvest to obtain CD25^Low or ISP and DP thymocytes, respectively. CD25⁺ thymocytes were obtained from untreated RAG2^−/− mice. The cDNAs were prepared from total RNA and analyzed by RT-PCR for expression of β-actin, SOCS-1, TCRα (germline transcripts), and CD45 mRNA. As control (H₂O), RT-PCR reactions lacking template were amplified simultaneously.