N-linked carbohydrate on human leukocyte antigen-C and recognition by natural killer cell inhibitory receptors.
The possible role of carbohydrate in the interaction of HLA-C with a human inhibitory natural Killer cell Immunoglobulin-like Receptor with two Ig domains, KIR2DL1, was investigated. Transfectants of 721.221 (a class I MHC-negative human B cell line) expressing only HLA-Cw4 or -Cw6 or their respective non-glycosylated mutants (N86Q, S88A) were made. The binding of a KIR2DL1-Ig fusion protein to the non-glycosylated mutant HLA-Cw4- or -Cw6-expressing cells was markedly decreased compared to the wild type-expressing cells. The ability to induce an inhibitory signal in the NK tumor line YTS transfected with KIR2DL1 was also impaired in the nonglycosylated mutant expressing cells. Furthermore, in a second functional assay, mutant HLA-Cw4 and -Cw6 molecules had impaired ability to induce signal transduction in BW cells expressing a KIR2DL1-CD3 zeta chain chimeric protein. Thus, the deletion of the N-linked glycosylation signal in HLA-Cw4 and -Cw6 greatly reduced recognition by KIR2DL1. Alternative interpretations of the data are discussed.
Pubmed ID: 11163076 RIS Download
Amino Acid Substitution | Animals | Antigens, CD | Asparagine | COS Cells | Carbohydrate Conformation | Carbohydrate Metabolism | Carbohydrates | Cell Line, Transformed | Cytotoxicity Tests, Immunologic | Cytotoxicity, Immunologic | Glutamine | Glycosylation | HLA-C Antigens | Humans | Immunoglobulins | Killer Cells, Natural | Lectins, C-Type | Membrane Glycoproteins | Mice | NK Cell Lectin-Like Receptor Subfamily D | Protein Binding | Receptors, Immunologic | Receptors, KIR | Receptors, KIR2DL1 | Receptors, Natural Killer Cell | Recombinant Fusion Proteins | Signal Transduction | Swainsonine | Transfection | Tumor Cells, Cultured