Departmental Papers (Dental)

Document Type

Journal Article

Date of this Version

4-13-2010

Publication Source

Proc Natl Acad Sci U S A

Volume

107

Issue

15

Start Page

7101

Last Page

7106

DOI

10.1073/pnas.0912181107

Abstract

To address complications of pathogenic antibody or life-threatening anaphylactic reactions in protein replacement therapy for patients with hemophilia or other inherited protein deficiencies, we have developed a prophylactic protocol using a murine hemophilia B model. Oral delivery of coagulation factor IX fused with cholera toxin β-subunit (with or without a furin cleavage site; CTB-FFIX or CTB-FIX), expressed in chloroplasts (up to 3.8% soluble protein or 0.4 mg/g leaf tissue), bioencapsulated in plant cells, effectively blocked formation of inhibitory antibodies (undetectable or up to 100-fold less than controls). Moreover, this treatment eliminated fatal anaphylactic reactions that occurred after four to six exposures to intravenous F.IX. Whereas only 20–25% of control animals survived after six to eight F.IX doses, 90–93% of F.IX-fed mice survived 12 injections without signs of allergy or anaphylaxis. Immunostaining confirmed delivery of F.IX to Peyer's patches in the ileum. Within 2–5 h, feeding of CTB-FFIX additionally resulted in systemic delivery of F.IX antigen. This high-responder strain of hemophilia B mice represents a new animal model to study anaphylactic reactions. The protocol was effective over a range of oral antigen doses (equivalent to 5–80 μg recombinant F.IX/kg), and controlled inhibitor formation and anaphylaxis long-term, up to 7 months (∼40% life span of this mouse strain). Oral antigen administration caused a deviant immune response that suppressed formation of IgE and inhibitory antibodies. This cost-effective and efficient approach of antigen delivery to the gut should be applicable to several genetic diseases that are prone to pathogenic antibody responses during treatment.

Copyright/Permission Statement

© [2010] National Academy of Sciences

Keywords

allergy, chloroplast, genetic disorders, oral tolerance, plant-made therapeutics

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Dentistry Commons

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Date Posted: 01 March 2022

This document has been peer reviewed.