Anti-Kd mAbs elicits CD154-independent cardiac and skin allograft rejection. a. Rejection of BALB/c heart grafts by B6 recipients treated with anti-CD154 and anti-Kd mAbs (N = 4) ( closed square) compared to B6 recipients treated with anti-CD154 alone (N = 15) (closed triangle) or untreated recipients (N = 4) (open circle). b. Rejection of BALB/c skin grafts by B6 recipients treated with anti-Kd mAbs plus anti-CD154/DST (N = 20) (closed triangle) in comparison to long-term graft survival of BALB/c grafts by B6 recipients treated with anti-CD154/DST (N = 11) (open diamond) and rejecting untreated B6 recipients of BALB/c grafts (N = 9) (closed square). Acceptance of BALB/c grafts by B6 recipients treated with anti-CD154/DST and denatured anti-Kd mAbs (N = 5) (closed circle), or mouse IgG isotype control (N = 4) (asterisk), and C3H grafts by B/6 recipients treated with anti-Kd mAbs and anti-CD154/DST (N = 4) (half closed downward triangle). c. The transfer of serum from pre-sensitized mice (200 μl/mouse; day −2, 0 and 2 post-transplantation; Pre-Sen), but not from naïve mice, prevented BALB/c skin graft acceptance in B6 mice treated with anti-CD154/DST (N=4/group).