Fig. 4.

The calpain inhibitor Z-LL-H blocks AID of lck. BK bulk CTLs were activated by IVT-pulsed APCs for 4 h in the absence (control) or presence of Z-LL-H at the indicated concentrations. (A) Effect Z-LL-H on the AID of lck, ZAP-70, or ζ-chain tested by immunoblotting with the relevant Abs. (B) Intensities of lck, ZAP-70, or ζ-chain-specific bands expressed as percentage expression relative to band intensities in samples of unstimulated CTLs. Shown are the means ± SD of five experiments performed with lck-specific Abs and one representative of two experiments performed with ZAP-70- and ζ-chain-specific Abs.