title: Mechanistic insight into pertussis toxin and lectin signaling using T cells engineered to express a CD8α/CD3ζ chimeric receptor.
abstract: Mammalian cell-surface receptors typically display N- or O-linked glycans added post-translationally. Plant lectins such as phytohemagluttinin (PHA) can activate the T cell receptor (TCR) and other cell-surface receptors by binding to glycans and initiating receptor cross-linking. Pathogenic microorganisms such as Bordetella pertussis also express proteins with lectin-like activities. Similar to plant lectins, pertussis toxin (PTx) can activate the TCR and bind to a variety of glycans. However, whether the lectin-like activity of PTx is responsible for its ability to activate TCR signaling has not been formally proven. Here we examined the ability of PTx and a panel of lectins to activate the TCR or a CD8α/CD3ζ chimeric receptor (termed CD8ζ). We demonstrate that CD8ζ rescues PTx-induced signaling events lacking in TCR null cells. This result indicates that CD8ζ can substitute for TCR and supports the hypothesis that PTxB (functioning as a lectin) stimulates signaling via receptor cross-linking rather than by binding to a specific epitope on the TCR. Moreover, PTx is able to activate signaling by binding either N-linked or O-linked glycan-modified receptors as the TCR displays N-linked glycans while CD8ζ displays O-linked glycans. Finally, studies with a diverse panel of lectins indicate that the signaling activity of the lectins does not always correlate with the biochemical reports of ligand preferences. Comparison of lectin signaling through TCR or CD8ζ allows us to better define the structural and functional properties of lectin-glycan interactions using a biologically based signaling readout.
authors.affiliation: Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA.
authors.forename: Olivia D
authors.initials: OD
authors.lastname: Schneider
authors.forename: Scott H
authors.initials: SH
authors.lastname: Millen
authors.forename: Alison A
authors.initials: AA
authors.lastname: Weiss
authors.forename: William E
authors.initials: WE
authors.lastname: Miller
mesh_terms: D017252:CD3 Complex / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D016827:CD8 Antigens / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D005818:Genetic Engineering; D006801:Humans; D019169:Jurkat Cells; D037342:Pertussis Toxin / Q000737:chemistry* / Q000276:immunology; D037121:Plant Lectins / Q000737:chemistry* / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000737:chemistry* / Q000276:immunology
chemical_list: D017252:CD3 Complex; D016827:CD8 Antigens; D037121:Plant Lectins; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D037342:Pertussis Toxin