Mice treated with a leumedin or antibody to Mac-1 to inhibit leukocyte sequestration survive endotoxin challenge

Endotoxin challenge causes metabolic dysfunction mediated by TNF, and sequestration of leukocytes. NPC 15669, N-carboxy-L-leucine, N-[2,7-dimethylfluoren-9-yl)methyl] ester, inhibits leukocyte recruitment into inflammatory lesions in animals, and inhibits endotoxin-induced neutropenia and lymphopenia in mice. This study was carried out to determine whether the ability of NPC 15669 to inhibit leukocyte sequestration is sufficient to promote survival after endotoxin challenge. To inhibit leukocyte sequestration directly, mice were treated with anti-CD11a (LFA-1) or anti-CD11b (Mac-1) before endotoxin challenge. Anti-CD11b partly inhibited neutropenia and lymphopenia in response to challenge with LP5, but anti-CD11a had little effect on leukopenia