Leukocyte-associated Ig-like receptor-1 functions as an inhibitory receptor on cytotoxic T cells.
Leukocyte associated Ig-like receptor-1 (LAIR-1) is a surface molecule expressed on human mononuclear leukocytes that functions as an inhibitory receptor on human NK cells. In addition to NK cells, LAIR-1 is expressed on T cells, B cells, macrophages, and dendritic cells. Most cells express two biochemically distinct forms of LAIR-1, which we now show are likely alternative splice variants of the same gene. Cross-linking of LAIR-1 on human T cell clones results in inhibition of cytotoxicity only in T cell clones that lack CD28 and are able to spontaneously lyse certain targets in vitro. Moreover, the cytolytic activity of freshly isolated T cells, which is thought to be mainly due to "effector" T cells, can be inhibited by anti-LAIR-1 mAb. Thus, LAIR-1 functions as an inhibitory receptor not only on NK cells, but also on human T cells. This indicates that LAIR-1 provides a mechanism of regulation of effector T cells and may play a role in the inhibition of unwanted bystander responses mediated by Ag-specific T cells.
Meyaard
L
L
Department of Immunobiology, DNAX Research Institute of Molecular and Cellular Biology, Palo Alto, CA 94304, USA. l.meyaard@lab.azu.nl
Hurenkamp
J
J
Clevers
H
H
Lanier
L L
LL
Phillips
J H
JH
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D018106:CD28 Antigens / Q000276:immunology; D002999:Clone Cells; D003602:Cytotoxicity, Immunologic; D006801:Humans; D019169:Jurkat Cells; D007694:Killer Cells, Natural / Q000276:immunology*; D008969:Molecular Sequence Data; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology*; D017386:Sequence Homology, Amino Acid; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D018106:CD28 Antigens; D011971:Receptors, Immunologic; C108073:leukocyte-associated immunoglobulin-like receptor 1