title: A novel method for detection of IFN-lambda 3 binding to cells for quantifying IFN-lambda receptor expression.
abstract: Type III interferons (IFN-lambdas) are important antiviral cytokines that also modulate immune responses acting through a unique IFN-λR1/IL-10R2 heterodimeric receptor. Conflicting data has been reported for which cells express the IFN-λR1 subunit and directly respond to IFN-λs. In this study we developed a novel method to measure IFN-λ3 binding to IFN-λR1/IL-10R2 on the surface of cells and relate this to a functional readout of interferon stimulated gene (ISG) activity in various cell lines. We show that Huh7.5 hepatoma cells bind IFN-λ3 at the highest levels with the lowest Kd(app), translating to the highest induction of various ISGs. Raji and Jurkat cell lines, representing B and T cells, respectively, moderately bind IFN-λ3 and have lower ISG responses. U937 cells, representing monocytes, did not bind IFN-λ3 well and therefore, did not have any ISG induction. Importantly, knockdown of IFNLR1 in Huh7.5 cells decreased our binding signal proportionally and reduced ISG induction by up to 93%. IFN-λ3 responsiveness increased over time with maximal ISG responses seen at 24h for all but one gene. These data confirm our new IFN-λ3 binding assay can be used to quantify IFN-λ receptor surface expression on a variety of cell types and reflects IFN-λ3 responsiveness.
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: santer@ualberta.ca.
authors.forename: Deanna M
authors.initials: DM
authors.lastname: Santer
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Gillian E S
authors.initials: GES
authors.lastname: Minty
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Adil
authors.initials: A
authors.lastname: Mohamed
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Lesley
authors.initials: L
authors.lastname: Baldwin
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Bhat
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Joyce
authors.affiliation: Division of Clinical Microbiology, University Hospital Basel, Basel, Switzerland; Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Egli
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: D Lorne J
authors.initials: DLJ
authors.lastname: Tyrrell
authors.affiliation: Li Ka Shing Institute of Virology and Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada. Electronic address: mhoughto@ualberta.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: Houghton
mesh_terms: D001665:Binding Sites; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D006801:Humans; D007372:Interferons; D007378:Interleukins / Q000032:analysis* / Q000276:immunology; D017471:Receptors, Interferon / Q000235:genetics* / Q000276:immunology; D000095022:Interferon Lambda
chemical_list: D007372:Interferons; D007378:Interleukins; D017471:Receptors, Interferon; C000624353:interferon-lambda, human; D000095022:Interferon Lambda
keywords: Binding assay; Flow cytometry; Interferon-lambda; Interferon-lambda receptor; Interferon-stimulated genes