Electromobility shift assay (EMSA) of nuclear extracts from CD4+ T cells (preincubated with anti-CD4 mAbs or stimulated with PMA/ionomycin) for AP-1 (a) and NF-κB (b). One representative phosphoimage of three independent experiments is shown (upper panels). Quantification of the bands of all three experiments is shown below (means ± SEM). All three anti-CD4 mAbs slightly decreased the AP-1 activity, and RIB5/2 induced a profound, significant increase of NF-κB activity. *P ≤ 0.05 in comparison with the isotype control, #P ≤ 0.05 in comparison with W3/25, §P ≤ 0.05 in comparison with OX35, &P ≤ 0.05 in comparison with RIB5/2.