Oral delivery of bioencapsulated coagulation factor IX prevents inhibitor formation and fatal anaphylaxis in hemophilia B mice.
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 beta-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 microg recombinant F.IX/kg), and controlled inhibitor formation and anaphylaxis long-term, up to 7 months (approximately 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.
Verma
Dheeraj
D
Department of Molecular Biology and Microbiology, College of Medicine, University of Central Florida, Orlando, FL 32816-2364, USA.
Moghimi
Babak
B
LoDuca
Paul A
PA
Singh
Harminder D
HD
Hoffman
Brad E
BE
Herzog
Roland W
RW
Daniell
Henry
H
D000284:Administration, Oral; D000707:Anaphylaxis / Q000401:mortality / Q000517:prevention & control*; D000818:Animals; D002736:Chloroplasts / Q000378:metabolism; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D005164:Factor IX / Q000008:administration & dosage* / Q000037:antagonists & inhibitors / Q000737:chemistry; D005822:Genetic Vectors; D002836:Hemophilia B / Q000097:blood* / Q000150:complications; D007073:Immunoglobulin E / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008957:Models, Genetic; D014026:Nicotiana / Q000235:genetics
D007073:Immunoglobulin E; D005164:Factor IX