title: High affinity soluble ILT2 receptor: a potent inhibitor of CD8(+) T cell activation.
abstract: Using directed mutagenesis and phage display on a soluble fragment of the human immunoglobulin super-family receptor ILT2 (synonyms: LIR1, MIR7, CD85j), we have selected a range of mutants with binding affinities enhanced by up to 168,000-fold towards the conserved region of major histocompatibility complex (MHC) class I molecules. Produced in a dimeric form, either by chemical cross-linking with bivalent polyethylene glycol (PEG) derivatives or as a genetic fusion with human IgG Fc-fragment, the mutants exhibited a further increase in ligand-binding strength due to the avidity effect, with resident half-times (t(1/2)) on the surface of MHC I-positive cells of many hours. The novel compounds antagonized the interaction of CD8 co-receptor with MHC I in vitro without affecting the peptide-specific binding of T-cell receptors (TCRs). In both cytokine-release assays and cell-killing experiments the engineered receptors inhibited the activation of CD8(+) cytotoxic T lymphocytes (CTLs) in the presence of their target cells, with subnanomolar potency and in a dose-dependent manner. As a selective inhibitor of CD8(+) CTL responses, the engineered high affinity ILT2 receptor presents a new tool for studying the activation mechanism of different subsets of CTLs and could have potential for the development of novel autoimmunity therapies.
authors.affiliation: Immunocore Limited, 57c Milton Park, Abingdon, Oxon, OX14 4RX, UK.
authors.forename: Ruth K
authors.initials: RK
authors.lastname: Moysey
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Samantha J
authors.initials: SJ
authors.lastname: Paston
authors.forename: Emma E
authors.initials: EE
authors.lastname: Baston
authors.forename: Malkit S
authors.initials: MS
authors.lastname: Sami
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Cameron
authors.forename: Jessie
authors.initials: J
authors.lastname: Gavarret
authors.forename: Penio
authors.initials: P
authors.lastname: Todorov
authors.forename: Annelise
authors.initials: A
authors.lastname: Vuidepot
authors.forename: Steven M
authors.initials: SM
authors.lastname: Dunn
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Pumphrey
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Adams
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Dennis
authors.forename: Deborah H
authors.initials: DH
authors.lastname: Sutton
authors.forename: Andy D
authors.initials: AD
authors.lastname: Johnson
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Brewer
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ashfield
authors.forename: Nikolai M
authors.initials: NM
authors.lastname: Lissin
authors.forename: Bent K
authors.initials: BK
authors.lastname: Jakobsen
mesh_terms: D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D015551:Autoimmunity; D001681:Biological Assay; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000235:genetics / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007136:Immunoglobulins / Q000276:immunology / Q000378:metabolism; D007155:Immunologic Factors / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D007700:Kinetics; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D058990:Molecular Targeted Therapy; D016297:Mutagenesis, Site-Directed; D019151:Peptide Library; D011092:Polyethylene Glycols; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D011971:Receptors, Immunologic / Q000737:chemistry / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D007136:Immunoglobulins; D007155:Immunologic Factors; C105299:LILRB1 protein, human; D000075362:Leukocyte Immunoglobulin-like Receptor B1; D019151:Peptide Library; D011971:Receptors, Immunologic; D011993:Recombinant Fusion Proteins; D011092:Polyethylene Glycols