Expression of a soluble form of LFA-1 and demonstration of its binding activity with ICAM-1.
The interaction between lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) is of importance in a number of cellular events, including antigen-specific T cell activation and emigration of leukocytes into sites of inflammation. We describe here the first use of a recombinant soluble form of human LFA-1 (sLFA-1) for the measurement of the binding between LFA-1 and ICAM-1. sLFA-1 has been successfully expressed and purified. The expressed sLFA-1 was shown to be functionally active by their binding to ICAM-1. Binding of sLFA-1 to ICAM-1 was observed by receptor binding assay. Both monomeric (soluble ICAM-1 or the first two domains of ICAM-1) and dimeric ICAM-1 (IgG chimera of each ICAM-1 fragment) showed inhibitory activity on assay with IC50 values of 400 nM and 40 nM, respectively. These results suggest that the soluble constructs would be useful tools for molecular analysis of ICAM-1/LFA-1 interaction as well as in screening for ICAM-1/LFA-1 antagonists.
New Product Research Laboratories III, Daiichi Pharmaceutical, Tokyo, Japan.
Y
Y
Tominaga
Y
Y
Kita
T
T
Uchiyama
K
K
Sato
K
K
Sato
T
T
Takashi
T
T
Horiuchi
D018821:CD18 Antigens / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility
D018821:CD18 Antigens; D018076:DNA, Complementary; D016169:Lymphocyte Function-Associated Antigen-1; D010446:Peptide Fragments; D011994:Recombinant Proteins; D018799:Intercellular Adhesion Molecule-1