title: Copy number and nucleotide variation of the LILR family of myelomonocytic cell activating and inhibitory receptors.
abstract: Leukocyte immunoglobulin-like receptors (LILR) are cell surface molecules that regulate the activities of myelomonocytic cells through the balance of inhibitory and activation signals. LILR genes are located within the leukocyte receptor complex (LRC) on chromosome 19q13.4 adjacent to KIR genes, which are subject to allelic and copy number variation (CNV). LILRB3 (ILT5) and LILRA6 (ILT8) are highly polymorphic receptors with similar extracellular domains. LILRB3 contains inhibitory ITIM motifs and LILRA6 is coupled to an adaptor with activating ITAM motifs. We analysed the sequences of the extracellular immunoglobulin domain-encoding regions of LILRB3 and LILRA6 in 20 individuals, and determined the copy number of these receptors, in addition to those of other members of the LILR family. We found 41 polymorphic sites within the extracellular domains of LILRB3 and LILRA6. Twenty-four of these sites were common to both receptors. LILRA6, but not LILRB3, exhibited CNV. In 20 out of 48 human cell lines from the International Histocompatibility Working Group, LILRA6 was deleted or duplicated. The only other LILR gene exhibiting genomic aberration was LILRA3, in this case due to a partial deletion.
authors.affiliation: Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
authors.forename: María R
authors.initials: MR
authors.lastname: López-Álvarez
authors.forename: Des C
authors.initials: DC
authors.lastname: Jones
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: James A
authors.initials: JA
authors.lastname: Traherne
authors.forename: John
authors.initials: J
authors.lastname: Trowsdale
mesh_terms: D000483:Alleles; D020816:Amino Acid Motifs; D015703:Antigens, CD / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D002460:Cell Line; D002888:Chromosomes, Human, Pair 19; D056915:DNA Copy Number Variations; D020440:Gene Duplication; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D011110:Polymorphism, Genetic; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000235:genetics* / Q000276:immunology; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D015398:Signal Transduction
chemical_list: D015703:Antigens, CD; C530062:LILRA3 protein, human; C586909:LILRA6 protein, human; C527699:LILRB3 protein, human; D011971:Receptors, Immunologic