Chloroplast transformation for bioencapsulation and oral delivery using the immunoglobulin G fragment crystallizable (Fc) domain

• Published in: Scientific reports Vol. 13; no. 1; p. 18916
• Main Authors: LaManna, Lisa, Chou, Chih-Hsuan, Lei, Hanqin, Barton, Elisabeth R, Maliga, Pal
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 02.11.2023; Nature Publishing Group UK; Nature Portfolio
• Subjects: Animals; Chloroplasts; Chloroplasts - genetics; Chloroplasts - metabolism; Confocal microscopy; Digestive system; Drug delivery; Enzyme-linked immunosorbent assay; Epithelium; Fc receptors; Fusion protein; Genetic transformation; Immunoglobulin G; Immunoglobulin G - genetics; Immunoglobulin G - metabolism; Immunoglobulins; Insulin; Leaves; Mice; Myostatin; Nicotiana - genetics; Nicotiana tabacum; Oral administration; Plant cells; Plants, Genetically Modified - genetics; Plants, Genetically Modified - metabolism; Proteins; Small intestine
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-45698-9

Proinsulin Like Growth Factor I (prolGF-I) and myostatin (Mstn) regulate muscle regeneration and mass when intravenously delivered. We tested if chloroplast bioencapsulated forms of these proteins may serve as a non-invasive means of drug delivery through the digestive system. We created tobacco (Nicotiana tabacum) plants carrying GFP-Fc1, proIGF-I-Fc1, and Mstn-Fc1 fusion genes, in which fusion with the immunoglobulin G Fc domain improved both protein stability and absorption in the small intestine. No transplastomic plants were obtained with the Mstn-Fc1 gene, suggesting that the protein is toxic to plant cells. proIGF-I-Fc1 protein levels were too low to enable in vivo testing. However, GFP-Fc1 accumulated at a high level, enabling evaluation of chloroplast-made Fc fusion proteins for oral delivery. Tobacco leaves were lyophilized for testing in a mouse system. We report that the orally administered GFP-Fc1 fusion protein (5.45 µg/g GFP-Fc1) has been taken up by the intestinal epithelium cells, evidenced by confocal microscopy. GFP-Fc1 subsequently entered the circulation where it was detected by ELISA. Data reported here confirm that chloroplast expression and oral administration of lyophilized leaves is a potential delivery system of therapeutic proteins fused with Fc1, with the advantage that the proteins may be stored at room temperature.