title: Antigen-Specific Binding of Multivalent Soluble Antigen Arrays Induces Receptor Clustering and Impedes B Cell Receptor Mediated Signaling.
abstract: A pressing need exists for autoimmune disease therapies that act in an antigen-specific manner while avoiding global immunosuppression. Multivalent soluble antigen arrays (SAgAPLP:LABL), designed to induce tolerance to a specific multiple sclerosis autoantigen, consist of a flexible hyaluronic acid (HA) polymer backbone cografted with multiple copies of autoantigen peptide (PLP) and cell adhesion inhibitor peptide (LABL). Previous in vivo studies revealed copresentation of both signals on HA was necessary for therapeutic efficacy. To elucidate therapeutic cellular mechanisms, in vitro studies were performed in a model B cell system to evaluate binding and specificity. Compared to HA and HA arrays containing only grafted PLP or LABL, SAgAPLP:LABL displaying both PLP and LABL exhibited greatly enhanced B cell binding. Furthermore, the binding avidity of SAgAPLP:LABL was primarily driven by the PLP antigen, determined via flow cytometry competitive dissociation studies. Fluorescence microscopy showed SAgAPLP:LABL induced mature receptor clustering that was faster than other HA arrays with only one type of grafted peptide. SAgAPLP:LABL molecules also reduced and inhibited IgM-stimulated signaling as discerned by a calcium flux assay. The molecular mechanisms of enhanced antigen-specific binding, mature receptor clustering, and dampened signaling observed in B cells may contribute to SAgAPLP:LABL therapeutic efficacy.
authors.affiliation: Bioengineering Graduate Program, University of Kansas , 1520 West 15th Street, Lawrence, Kansas 66045, United States.
authors.forename: Brittany L
authors.initials: BL
authors.lastname: Hartwell
authors.affiliation: Immunology Core Laboratory of the Kansas Vaccine Institute, University of Kansas 2030 Becker Drive, Lawrence, Kansas 66047, United States.|Department of Pharmaceutical Chemistry, University of Kansas 2095 Constant Avenue, Lawrence, Kansas 66047, United States.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Martinez-Becerra
authors.affiliation: Department of Pharmaceutical Chemistry, University of Kansas 2095 Constant Avenue, Lawrence, Kansas 66047, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: Microscopy and Analytical Imaging Laboratory, University of Kansas 1200 Sunnyside Avenue, Lawrence, Kansas 66045, United States.
authors.forename: Heather
authors.initials: H
authors.lastname: Shinogle
authors.affiliation: Department of Chemical and Petroleum Engineering, University of Kansas 1530 West 15th Street, Lawrence, Kansas 66045, United States.
authors.forename: Michelle
authors.initials: M
authors.lastname: Sarnowski
authors.affiliation: Microscopy and Analytical Imaging Laboratory, University of Kansas 1200 Sunnyside Avenue, Lawrence, Kansas 66045, United States.
authors.forename: David S
authors.initials: DS
authors.lastname: Moore
authors.affiliation: Bioengineering Graduate Program, University of Kansas , 1520 West 15th Street, Lawrence, Kansas 66045, United States.|Department of Pharmaceutical Chemistry, University of Kansas 2095 Constant Avenue, Lawrence, Kansas 66047, United States.|Department of Chemical and Petroleum Engineering, University of Kansas 1530 West 15th Street, Lawrence, Kansas 66045, United States.
authors.forename: Cory
authors.initials: C
authors.lastname: Berkland
mesh_terms: D001324:Autoantigens / Q000737:chemistry / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology*; D009103:Multiple Sclerosis / Q000276:immunology; D040081:Protein Array Analysis; D015398:Signal Transduction
chemical_list: D001324:Autoantigens; D016169:Lymphocyte Function-Associated Antigen-1; D006820:Hyaluronic Acid