IMMUNOSUPPRESSION BY ANTI-ICAM-1 AND ANTI-LFA-1 MONOCLONAL-ANTIBODIESOF FREE AND VASCULARIZED SKIN ALLOGRAFT-REJECTION

Immunosuppression by anti-adhesion molecule antibody of free or vascul arized skin allograft rejection was investigated in rats. Lewis (LEW, RT1(1)) rats were used as donors and Fisher (F344, RT(lv1)) rats as th e recipients. When F344 rats were treated intraperitoneally (i.p.) wit h anti-intercellular adhesion molecule-1 (ICAM-1) mAb (1A29) (3 mg/kg/ day) and anti-leukocyte function-associated antigen-1 (LFA-1) mAb (WT. 1) (3 mg/kg/day) one day prior to grafting and daily after grafting fo r nine days, free skin graft survival was prolonged only slightly comp ared with that in control rats which were injected i.p. with a daily d ose of 6 mg/kg of anti-TNP mAbs (H1-6-2) one day prior to grafting and daily after grafting for nine days. (Mean survival time [MST] of the free skin graft was 11.2 +/- 0.6 days in the control group and 13.4 +/ - 0.3 days in the 1A29 + WT-1 treated group [p < 0.01], respectively.) On the other hand, the vascularized graft survival was prolonged sign ificantly in anti-ICAM-1/LFA-1 mAbs-treated F344 rats as compared with that in control rats. (The mean vascularized graft survival time was 14.2 +/- 0.7 days in the control group and 21.5 +/- 1.9 days in 1A29 WT-1 treated group [p < 0.002].) Our results suggest that interaction with ICAM-1 and LFA-1 is more important in the rejection of vasculari zed skin allografts than that of free skin allografts.