title: Engineering of a novel anti-CD40L domain antibody for treatment of autoimmune diseases.
abstract: CD40-CD40L interactions play a critical role in regulating immune responses. Blockade of CD40L by Abs, such as the anti-CD40L Ab 5c8, demonstrated positive clinical effects in patients with autoimmune diseases; however, incidents of thromboembolism (TE) precluded further development of these molecules. In this study, we examined the role of the Fc domain interaction with FcγRs in modulating platelet activation and potential for TE. Our results show that the interaction of the 5c8 wild-type IgG1 Fc domain with FcγRs is responsible for platelet activation, as measured by induction of PAC-1 and CD62P. A version of 5c8 with a mutated IgG1 tail was identified that showed minimal FcγR binding and platelet activation while maintaining full binding to CD40L. To address whether Fc effector function is required for immunosuppression, a potent Ab fragment, termed a "domain Ab" (dAb), against murine CD40L was identified and fused to a murine IgG1 Fc domain containing a D265A mutation that lacks Fc effector function. In vitro, this dAb-Fc demonstrated comparable potency to the benchmark mAb MR-1 in inhibiting B cell and dendritic cell activation. Furthermore, the anti-CD40L dAb-Fc exhibited a notable efficacy comparable to MR-1 in various preclinical models, such as keyhole limpet hemocyanin-induced Ab responses, alloantigen-induced T cell proliferation, "heart-to-ear" transplantation, and NZB × NZW F1 spontaneous lupus. Thus, our data show that immunosuppression and TE can be uncoupled and that a CD40L dAb with an inert Fc tail is expected to be efficacious for treating autoimmune diseases, with reduced risk for TE.
authors.affiliation: Department of Discovery Biology, Bristol Myers Squibb, Princeton, NJ 08543;
authors.forename: Jenny H
authors.initials: JH
authors.lastname: Xie
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Yamniuk
authors.forename: Virna
authors.initials: V
authors.lastname: Borowski
authors.forename: Robert
authors.initials: R
authors.lastname: Kuhn
authors.forename: Vojkan
authors.initials: V
authors.lastname: Susulic
authors.forename: Sandra
authors.initials: S
authors.lastname: Rex-Rabe
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Yang
authors.forename: Xiadi
authors.initials: X
authors.lastname: Zhou
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kathleen
authors.initials: K
authors.lastname: Gillooly
authors.forename: Ruth
authors.initials: R
authors.lastname: Brosius
authors.forename: Rathna
authors.initials: R
authors.lastname: Ravishankar
authors.forename: Kimberly
authors.initials: K
authors.lastname: Waggie
authors.forename: Kathy
authors.initials: K
authors.lastname: Mink
authors.forename: Laura
authors.initials: L
authors.lastname: Price
authors.forename: Robert
authors.initials: R
authors.lastname: Rehfuss
authors.forename: James
authors.initials: J
authors.lastname: Tamura
authors.forename: Yongmi
authors.initials: Y
authors.lastname: An
authors.forename: Lin
authors.initials: L
authors.lastname: Cheng
authors.forename: Bozena
authors.initials: B
authors.lastname: Abramczyk
authors.forename: Olga
authors.initials: O
authors.lastname: Ignatovich
authors.forename: Philip
authors.initials: P
authors.lastname: Drew
authors.forename: Steven
authors.initials: S
authors.lastname: Grant
authors.forename: James W
authors.initials: JW
authors.lastname: Bryson
authors.forename: Suzanne
authors.initials: S
authors.lastname: Suchard
authors.forename: Luisa
authors.initials: L
authors.lastname: Salter-Cid
authors.forename: Steven
authors.initials: S
authors.lastname: Nadler
authors.forename: Anish
authors.initials: A
authors.lastname: Suri
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000009:adverse effects; D001327:Autoimmune Diseases / Q000276:immunology*; D023201:CD40 Ligand / Q000276:immunology*; D004195:Disease Models, Animal; D057809:HEK293 Cells; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D051379:Mice; D015539:Platelet Activation / Q000187:drug effects* / Q000276:immunology; D017452:Receptors, IgG / Q000276:immunology; D061905:Single-Domain Antibodies / Q000276:immunology / Q000494:pharmacology*; D020349:Surface Plasmon Resonance; D013923:Thromboembolism / Q000209:etiology / Q000517:prevention & control; D014162:Transfection
chemical_list: D000911:Antibodies, Monoclonal; D017452:Receptors, IgG; D061905:Single-Domain Antibodies; D023201:CD40 Ligand