Critical amino acids in the lymphocyte function-associated antigen-1 I domain mediate intercellular adhesion molecule 3 binding and immune function.
J Exp Med
; 183(3): 1247-52, 1996 Mar 01.
Article
em En
| MEDLINE
| ID: mdl-8642267
ABSTRACT
We have identified amino acid residues within the evolutionarily conserved I domain of the alpha-chain (CD11a) of the leukocyte integrin leukocyte function-associated antigen (LFA) 1 that are critical for intercellular adhesion molecule (ICAM) 3 (CD50) binding. ICAM-3, a ligand of LFA-1, is thought to mediate intercellular adhesion essential for the initiation of immune responses. Using a panel of human/murine I domain chimeras and point mutants, we observed that the Ile-Lys-Gly-Asn motif, located in the NH2-terminal part of the CD11a I domain, is required for ICAM-3 but not ICAM-1 binding. These findings demonstrate that the I domain of CD11a contains distinct functional subdomains for ligand specific binding. An aspartic acid located at position 137, which is essential to ICAM-1/LFA-1 interactions (Edwards, C.P., M. Champe, T. Gonzalez, M.E. Wessinger, S.A. Spencer, L.G. Presta, P.W. Berman, and S.C. Bodary. 1995. J. Biol. Chem. 27012635-12640), was also critical for ICAM-3 binding, whereas Ser at position 139 did not effect ICAM-1 or ICAM-3 binding. A synthetic peptide containing the Ile-Lys-Gly-Asn motif inhibited ICAM-3-dependent adhesion and proliferation of T cells at micromolar concentrations, suggesting that this peptide interferes with immune recognition. These observations underscore the importance of ICAM-3 in leukocyte function, and may lead to development of a new category of immunosuppressive agents.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Antígenos de Diferenciação
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Antígenos CD
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Moléculas de Adesão Celular
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Adesão Celular
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Antígeno-1 Associado à Função Linfocitária
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
1996
Tipo de documento:
Article