title: Variation in the ordered structure of complexes between CD154 and anti-CD154 monoclonal antibodies.
abstract: The cell surface co-stimulatory protein CD154 (CD40L) is a target for monoclonal antibody (mAb) inhibitors of T-cell mediated immune diseases. This protein, like most other members of the TNF ligand family, forms homotrimeric complexes on the cell surface and in solution, with a three-fold axis of symmetry. We find that several different anti-CD154 monoclonal antibodies form distinctive complexes with soluble CD154. These soluble complexes have been analyzed using size exclusion chromatography, static and dynamic light scattering, and electron microscopy and shown to consist of caged structures of various geometries. The cell surface complexes have been analyzed by confocal microscopy and, depending on the mAb, remain as small, separate complexes or form large aggregates. The formation of these complexes in solution is likely to have an impact on measures of affinity, while the cell surface complexes could affect binding potency and provoke other biological effects.
authors.affiliation: Biogen Inc., Cambridge, MA 02142, USA.
authors.forename: Janine L
authors.initials: JL
authors.lastname: Ferrant
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Wilson
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Benjamin
authors.forename: Donna M
authors.initials: DM
authors.lastname: Hess
authors.forename: Yen-Ming
authors.initials: YM
authors.lastname: Hsu
authors.forename: Michael
authors.initials: M
authors.lastname: Karpusas
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Roux
authors.forename: Frederick R
authors.initials: FR
authors.lastname: Taylor
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000936:Antigen-Antibody Complex / Q000737:chemistry*; D023201:CD40 Ligand / Q000737:chemistry*; D006801:Humans; D019169:Jurkat Cells; D008854:Microscopy, Electron
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D023201:CD40 Ligand