title: A comprehensive analysis of the binding of anti-KIR antibodies to activating KIRs.
abstract: Analysis of killer cell immunoglobulin-like receptor (KIR) expression has been notoriously difficult because of the cross-reactivity of available antibodies, in particular between activating and inhibitory isoforms. We undertook a comprehensive study of available anti-KIR antibodies binding to activating KIRs (a-KIRs). Using cell lines stably transfected with a-KIRs (KIR2DS1-S5 and KIR3DS1), we confirmed documented binding specificities. In addition, we show that clones HPMA4 and 143211-previously assumed to be specific for KIR2DS1/L1 and KIR2DL1, respectively-bind KIR2DS5 and KIR2DS3 (HPMA4), and KIR2DS5 (143211). Other antibodies with previously undocumented binding were JJC11.6 (recognizing KIR2DS3) and 5.133 (recognizing all a-KIRs except KIR2DS1 and KIR2DS3). The novel KIR2DS5 reactivities were confirmed by blocking with soluble KIR-Fc fusion proteins, and by reverse transcriptase-PCR analysis of sorted primary natural killer cells. In conclusion, we show formerly undocumented binding properties of anti-KIR antibodies. These cross-reactivities should be taken into account when analyzing KIR expression.
authors.affiliation: Immunotherapy Laboratory, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Czaja
authors.affiliation: Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, Villigen, Switzerland.
authors.forename: A-S
authors.initials: AS
authors.lastname: Borer
authors.affiliation: Immunotherapy Laboratory, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Schmied
authors.affiliation: Immunotherapy Laboratory, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Terszowski
authors.affiliation: Immunotherapy Laboratory, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Stern
authors.affiliation: Immunotherapy Laboratory, Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Gonzalez
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism*; D000918:Antibody Specificity; D002460:Cell Line; D003429:Cross Reactions; D006801:Humans; D007694:Killer Cells, Natural; D054340:Receptors, KIR / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D054349:Receptors, KIR3DS1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; C496212:KIR2DS1 protein, human; C433932:KIR2DS2 protein, human; C541358:KIR2DS3 protein, human; C473953:KIR2DS4 protein, human; C531595:KIR2DS5 protein, human; D054340:Receptors, KIR; D054349:Receptors, KIR3DS1; D011993:Recombinant Fusion Proteins