title: Inhibition of CD28-mediated natural cytotoxicity by KIR2DL2 does not require p56(lck) in the NK cell line YT-Indy.
abstract: CD28 functions as a cytotoxicity activation receptor in the NK cell line YT-Indy. To analyze the requirement of p56(lck) kinase in the function of killer inhibitory receptors, we transfected the p56(lck) negative YT-Indy cell line with the cl43 gene encoding for KIR2DL2. Pervanadate treatment revealed KIR2DL2 phosphorylation in YT-Indy-cl43, as well as SHP1/SHP2 recruitment. YT-Indy-cl43 cells were inhibited in their ability to lyse target cells expressing HLA-Cw3, a ligand for KIR2DL2. This inhibition was blocked by anti-KIR2DL2 or anti-HLA class I mAb. CD28 crosslinking on YT-Indy-cl43 enhanced tyrosine phosphorylation of PLC-gamma1. The simultaneous ligation of KIR2DL2 with mAb resulted in a decrease in CD28-induced tyrosine phosphorylation of PLC-gamma1 confirming that dephosphorylation of this protein is involved in the KIR2DL2-induced inhibition of CD28-mediated cytotoxicity. As YT-Indy-cl43 did not express detectable levels of p56(lck), these results indicate that this kinase is not required for transmitting the negative signals generated by KIR2DL2 ligation.
authors.affiliation: Faculty of Medicine, Department of Immunology, Reina Sofía Hospital, University of Córdoba, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Tarazona
authors.forename: Francisco
authors.initials: F
authors.lastname: Borrego
authors.forename: Maria D
authors.initials: MD
authors.lastname: Galiani
authors.forename: Enrique
authors.initials: E
authors.lastname: Aguado
authors.forename: Jose
authors.initials: J
authors.lastname: Peña
authors.forename: John E
authors.initials: JE
authors.lastname: Coligan
authors.forename: Rafael
authors.initials: R
authors.lastname: Solana
mesh_terms: D018106:CD28 Antigens / Q000276:immunology / Q000378:metabolism*; D003602:Cytotoxicity, Immunologic; D006801:Humans; D019169:Jurkat Cells; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D008024:Ligands; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000276:immunology / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism*; D054340:Receptors, KIR; D054343:Receptors, KIR2DL2; D015398:Signal Transduction / Q000276:immunology
chemical_list: D018106:CD28 Antigens; C515077:KIR2DL2 protein, human; D008024:Ligands; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054343:Receptors, KIR2DL2; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck)