ANTI-INTEGRIN (LFA-1, VLA-4, AND MAC-1) ANTIBODY TREATMENT AND ACUTE CARDIAC GRAFT-REJECTION IN THE RAT

Cell adhesion molecules mediate interactions with other cells and extr acellular matrix, control cell infiltration in sites of inflammation, and regulate cell activation. Previous studies have shown that treatme nt of rat cardiac transplant recipients with a combination of antibodi es against the T-cell integrins LFA-1 and VLA-4 gave a modest prolonga tion of graft survival. Current experiments were designed to examine t he effect of blocking Mac-1, an important monocyte adhesion receptor a nd mediator of monocyte migration, together with anti-LFA-l and anti-V LA-4 antibodies on cardiac graft survival and on the graft rejection p attern. The anti-Mac-1, CD11b-specific antibody OX-42 did not affect g raft survival time although it did decrease the graft infiltration by rounded, ED-2-positive macrophages.