Preclinical studies for plant-based oral enzyme replacement therapy (Oral-ERT) in Pompe disease knockout mice with transgenic tobacco seeds expressing human GAA (tobrhGAA)

Frank Martiniuk, Adra Mack, Justin Martiniuk, Shoreh Miller, Gregory O. Voronin, David Reimer, Nancy Rossi, Leslie Sheppard Bird, Sussan Saleh, Ruby Gupta, Mariel Nigro, Peter Meinke, Schoser B, Feng Wu, Angelo Kambitsis, John Arvanitopoulos, Elena Arvanitopoulos, Kam-Meng Tchou-Wong
2021 · doi:10.1101/2021.11.11.468227
preprint OA: closed
📄 Open PDF View at publisher

Abstract

ABSTRACT Genetic deficiency of acid α -glucosidase (GAA) results in glycogen storage disease type II (GSDII) or Pompe disease (PD) encompassing at least four clinical subtypes of varying severity (infantile; childhood, juvenile and late onset). Our objective is to develop an innovative and affordable approach for enzyme replacement therapy (ERT) via oral administration (Oral-ERT) to maintain a sustained, therapeutic level of enzyme on a daily basis to improve efficacy of treatment and quality of life for people living with Pompe disease. A consensus at a 2019 US Acid Maltase Deficiency (AMDA) conference suggested that a multi-pronged approach including gene therapy, diet, exercise, etc. must be evaluated for a successful treatment of Pompe disease. Tobacco seeds contain the metabolic machinery that is more compatible with mammalian glycosylation-phosphorylation and processing. Previously, we have shown that a lysate from transgenic tobacco seeds expressing human GAA (tobrhGAA) was enzymatically active and can correct enzyme deficiency in cultured PD cells and in adult lymphocytes of Pompe patients and in vivo in disease-relevant tissues in GAA knockout (KO) mice when administered IP. We have extended these pre-clinical studies in PD knockout (KO) mice with ground tobrhGAA seeds that supports proof-of-concept for Oral-ERT for future clinical trials. Briefly in GAA KO mice, Oral-ERT with ground tobrhGAA seeds showed significant reversal of fore-limb and hind-limb muscle weakness, increased motor coordination/balance/strength and mobility, improved spontaneous learning, increased GAA baseline activity in tissues, reduced glycogen in tissues and negible serum titers to GAA. Pharmacokinetics showed maximum serum GAA concentration (Cs) at 8-10 hr and peak urine excretion at 10-12 hr. The tobrhGAA was taken up in PD fibroblast, lymphoid and myoblast cells. Enzyme kinetics compared favorably or superior to placental hGAA, plus alglucosidase alfa or other rhGAAs for K m , V max , pH optima, thermal heat stability and IC 50 for inhibitors. The tobrhGAA in seeds was extremely stable stored for 15 years at room temperature. NGS-genome sequencing of the tobrhGAA and wild-type plants and RNA expression profiles was performed and will be posted on our website. Thus, Oral-ERT with ground tobrhGAA seeds is an innovative approach that overcomes some of the challenges of alglucosidase alfa-ERT and provides a more effective, safe and significantly less expensive treatment.

My notes (saved in your browser only)

Citation neighborhood (no data yet)

We don't have any in-corpus citations linked to this paper yet. The paper's references may be in our DB but unresolved to ``paper_id`` (resolution happens at ingest when the cited DOI matches a row we already have). Run the cross-source citation reconcile pass to retry.

References (100)

Source provenance

crossref
last seen: 2026-07-08T06:45:35.395371+00:00
europepmc
last seen: 2026-05-19T01:45:01.086888+00:00
unpaywall
last seen: 2026-07-09T06:39:34.564547+00:00