Schematic representation of the different chimeric CD18 constructs. B110H, the N-terminal 110 amino acids of human CD18 were replaced with bovine CD18; B200H, the N-terminal 200 amino acids of human CD18 were replaced with bovine CD18; B400H, the N-terminal 400 amino acids of human CD18 were replaced with bovine CD18; B600H, the N-terminal 600 amino acids of human CD18 were replaced with bovine CD18; B700H, the entire extracellular domain of human CD18 was replaced with bovine CD18; H110B, the N-terminal 110 amino acids of bovine CD18 were replaced with human CD18; H200B, the N-terminal 200 amino acids of bovine CD18 were replaced with human CD18; H400B, the N-terminal 400 amino acids of bovine CD18 were replaced with human CD18; H500B, the N-terminal 500 amino acids of bovine CD18 were replaced with human CD18; H600B, the N-terminal 600 amino acids of bovine CD18 were replaced with human CD18. The figure also shows schematic depiction of the BoCD18 and HuCD18. aa, amino acids.