Impact of T cell–cancer cell contact on healthy T cells. Highly purified T cells from healthy donors were cocultured with B cells from CLL patients or from their HLA-matched healthy donors at a 2:1 (T/B cell) ratio for 48 hours. (A) Decrease in 65-kDa NF-κB and increase in 41-kDa Arp3 in healthy CD4 cells after contact with allogeneic CLL cells (C1 and C2) and healthy B cells (H). (B) Decrease in 190-kDa Rho-GAP and increase in 41-kDa Arp3 in healthy CD8 cells after contact with CLL cells (C1 and C2) and healthy allogeneic B cells (H). (C) Impact of CLL cell contact on cytoskeletal protein expression in allogeneic healthy T cells, confirmed by ICAM1 or LFA1 blocking. Highly purified CD4 or CD8 cells from healthy donors were cocultured with B cells from CLL patients (C1 and C2) or healthy donors (H) with or without blockade of the LFA1 or ICAM1 interaction. Expression of 190-kDa Rho-GAP in healthy CD8 cells was increased after blockade of the ICAM1 during CLL cell–T cell contact, and expression of 41-kDa Arp3 in CD4 T cells and 25-kDa CDC42 in healthy CD8 cells was decreased after blockade of the LFA1 or ICAM1. –, protein expression in nonblocked cells; +, protein expression in blocked cells. Protein expressions were normalized by GAPDH expression level and are shown as protein bands and densitometric intensity of each band. The figure is representative of 3 different experiments performed with 6 different patients with CLL and 6 different healthy donors showing a similar pattern (P < 0.05).