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Lenk R, Kleindienst W, Szabó GT, Baiersdörfer M, Boros G, Keller JM, Mahiny AJ, Vlatkovic I. Understanding the impact of in vitro transcription byproducts and contaminants. Front Mol Biosci 2024; 11:1426129. [PMID: 39050733 PMCID: PMC11266732 DOI: 10.3389/fmolb.2024.1426129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Accepted: 06/14/2024] [Indexed: 07/27/2024] Open
Abstract
The success of messenger (m)RNA-based vaccines against SARS-CoV-2 during the COVID-19 pandemic has led to rapid growth and innovation in the field of mRNA-based therapeutics. However, mRNA production, whether in small amounts for research or large-scale GMP-grade for biopharmaceutics, is still based on the In Vitro Transcription (IVT) reaction developed in the early 1980s. The IVT reaction exploits phage RNA polymerase to catalyze the formation of an engineered mRNA that depends on a linearized DNA template, nucleotide building blocks, as well as pH, temperature, and reaction time. But depending on the IVT conditions and subsequent purification steps, diverse byproducts such as dsRNA, abortive RNAs and RNA:DNA hybrids might form. Unwanted byproducts, if not removed, could be formulated together with the full-length mRNA and cause an immune response in cells by activating host pattern recognition receptors. In this review, we summarize the potential types of IVT byproducts, their known biological activity, and how they can impact the efficacy and safety of mRNA therapeutics. In addition, we briefly overview non-nucleotide-based contaminants such as RNases, endotoxin and metal ions that, when present in the IVT reaction, can also influence the activity of mRNA-based drugs. We further discuss current approaches aimed at adjusting the IVT reaction conditions or improving mRNA purification to achieve optimal performance for medical applications.
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He W, Zhang X, Zou Y, Li J, Wang C, He Y, Jin Q, Ye J. Effective Synthesis of High-Integrity mRNA Using In Vitro Transcription. Molecules 2024; 29:2461. [PMID: 38893337 PMCID: PMC11173937 DOI: 10.3390/molecules29112461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/12/2024] [Accepted: 05/14/2024] [Indexed: 06/21/2024] Open
Abstract
mRNA vaccines are entering a period of rapid development. However, their synthesis is still plagued by challenges related to mRNA impurities and fragments (incomplete mRNA). Most impurities of mRNA products transcribed in vitro are mRNA fragments. Only full-length mRNA transcripts containing both a 5'-cap and a 3'-poly(A) structure are viable for in vivo expression. Therefore, RNA fragments are the primary product-related impurities that significantly hinder mRNA efficacy and must be effectively controlled; these species are believed to originate from either mRNA hydrolysis or premature transcriptional termination. In the manufacturing of commercial mRNA vaccines, T7 RNA polymerase-catalyzed in vitro transcription (IVT) synthesis is a well-established method for synthesizing long RNA transcripts. This study identified a pivotal domain on the T7 RNA polymerase that is associated with erroneous mRNA release. By leveraging the advantageous properties of a T7 RNA polymerase mutant and precisely optimized IVT process parameters, we successfully achieved an mRNA integrity exceeding 91%, thereby further unlocking the immense potential of mRNA therapeutics.
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Affiliation(s)
- Wei He
- College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China;
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Xinya Zhang
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Yangxiaoyu Zou
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Ji Li
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Chong Wang
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Yucai He
- School of Pharmacy, Changzhou University, Changzhou 213164, China
| | - Qiuheng Jin
- Vazyme Biotech Co., Ltd., Nanjing 210037, China; (X.Z.); (Y.Z.); (J.L.); (C.W.)
| | - Jianren Ye
- College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China;
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Božič K, Sedlar A, Kralj Š, Černigoj U, Štrancar A, Sekirnik R. Selective hydrophobic interaction chromatography for high purity of supercoiled DNA plasmids. Biotechnol Bioeng 2024; 121:1739-1749. [PMID: 38351874 DOI: 10.1002/bit.28667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 01/05/2024] [Accepted: 01/21/2024] [Indexed: 02/20/2024]
Abstract
High purity of plasmid DNA (pDNA), particularly in supercoiled isoform (SC), is used for various biopharmaceutical applications, such as a transfecting agent for production of gene therapy viral vectors, for pDNA vaccines, or as a precursor for linearized form that serves as a template for mRNA synthesis. In clinical manufacturing, pDNA is commonly extracted from Escherichia coli cells with alkaline lysis followed by anion exchange chromatography or tangential flow filtration as a capture step for pDNA. Both methods remove a high degree of host cell contaminants but are unable to generically discriminate between SC and open-circular (OC) pDNA isoforms, as well as other DNA impurities, such as genomic DNA (gDNA). Hydrophobic interaction chromatography (HIC) is commonly used as polishing purification for pDNA. We developed HIC-based polishing purification methodology that is highly selective for enrichment of SC pDNA. It is generic with respect to plasmid size, scalable, and GMP compatible. The technique uses ammonium sulfate, a kosmotropic salt, at a concentration selective for SC pDNA binding to a butyl monolith column, while OC pDNA and gDNA are removed in flow-through. The approach is validated on multiple adeno-associated virus- and mRNA-encoding plasmids ranging from 3 to 12 kbp. We show good scalability to at least 300 mg of >95% SC pDNA, thus paving the way to increase the quality of genomic medicines that utilize pDNA as a key raw material.
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Affiliation(s)
- Klemen Božič
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
| | - Ajda Sedlar
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
| | - Špela Kralj
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
| | - Urh Černigoj
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
| | - Aleš Štrancar
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
| | - Rok Sekirnik
- Sartorius BIA Separations d.o.o., Ajdovščina, Slovenia
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Altern SH, Kocot AJ, LeBarre JP, Boi C, Phillips MW, Roush DJ, Menegatti S, Cramer SM. Mechanistic model-based characterization of size-exclusion-mixed-mode resins for removal of monoclonal antibody fragments. J Chromatogr A 2024; 1718:464717. [PMID: 38354506 DOI: 10.1016/j.chroma.2024.464717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 01/22/2024] [Accepted: 02/03/2024] [Indexed: 02/16/2024]
Abstract
Although antibody fragments are a critical impurity to remove from process streams, few platformable purification techniques have been developed to this end. In this work, a novel size-exclusion-mixed-mode (SEMM) resin was characterized with respect to its efficacy in mAb fragment removal. Inverse size-exclusion chromatography showed that the silica-based resin had a narrow pore size distribution and a median pore radius of roughly 6.2 nm. Model-based characterization was carried out with Chromatography Analysis and Design Toolkit (CADET), using the general rate model and the multicomponent Langmuir isotherm. Model parameters were obtained from fitting breakthrough curves, performed at multiple residence times, for a mixture of mAb, aggregates, and an array of fragments (varying in size). Accurate fits were obtained to the frontal chromatographic data across a range of residence times. Model validation was then performed with a scaled-up column, altering residence time and feed composition from the calibration run. Accurate predictions were obtained, thereby illustrating the model's interpolative and extrapolative capabilities. Additionally, the SEMM resin achieved 90% mAb yield, 37% aggregate removal, 29% [Formula: see text] removal, 54% Fab/Fc removal, 100% Fc fragments removal, and a productivity of 72.3 g mAbL×h. Model predictions for these statistics were all within 5%. Simulated batch uptake experiments showed that resin penetration depth was directly related to protein size, with the exception of the aggregate species, and that separation was governed by differential pore diffusion rates. Additional simulations were performed to characterize the dependence of fragment removal on column dimension, load density, and feed composition. Fragment removal was found to be highly dependent on column load density, where optimal purification was achieved below 100 mg protein/mL column. Furthermore, fragment removal was dependent on column volume (constant load mass), but agnostic to whether column length or diameter was changed. Lastly, the dependence on feed composition was shown to be complex. While fragment removal was inversely related to fragment mass fraction in the feed, the extent depended on fragment size. Overall, the results from this study illustrated the efficacy of the SEMM resin in fragment and aggregate removal and elucidated relationships with key operational parameters through model-based characterization.
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Affiliation(s)
- Scott H Altern
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Andrew J Kocot
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Jacob P LeBarre
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Cristiana Boi
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA; Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC, USA; Department of Civil, Chemical, Environmental, and Materials Engineering, University of Bologna, Bologna, Italy
| | - Michael W Phillips
- Downstream Research and Development, EMD Millipore Corporation, Burlington, MA, USA
| | - David J Roush
- Process Research and Development, Merck & Co., Inc., Rahway, NJ, USA
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA; Biomanufacturing Training and Education Center (BTEC), North Carolina State University, Raleigh, NC, USA; North Carolina Viral Vector Initiative in Research and Learning (NC-VVIRAL), North Carolina State University, Raleigh, NC, USA
| | - Steven M Cramer
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.
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Coll De Peña A, Vaduva M, Li NS, Shah S, Ben Frej M, Tripathi A. Enzymatic isolation and microfluidic electrophoresis analysis of residual dsRNA impurities in mRNA vaccines and therapeutics. Analyst 2024; 149:1509-1517. [PMID: 38265070 DOI: 10.1039/d3an02157b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
The versatility, rapid development, and ease of production scalability of mRNA therapeutics have placed them at the forefront of biopharmaceutical research. However, despite their vast potential to treat diseases, their novelty comes with unsolved analytical challenges. A key challenge in ensuring sample purity has been monitoring residual, immunostimulatory dsRNA impurities generated during the in vitro transcription of mRNA. Here, we present a method that combines an enzyme, S1 nuclease, to identify and isolate dsRNA from an mRNA sample with a microfluidic electrophoresis analytical platform to characterize the impurity. After the method was developed and optimized, it was tested with clinically relevant, pseudouridine-modified 700 and 1800 bp dsRNA and 818-4451 nt mRNA samples. While the treatment impacted the magnitude of the fluorescent signal used to analyze the samples due to the interference of the buffer with the labeling of the sample, this signal loss was mitigated by 8.8× via treatment optimization. In addition, despite the mRNA concentration being up to 400× greater than that of the dsRNA, under every condition, there was a complete disappearance of the main mRNA peak. While the mRNA peak was digested, the dsRNA fragments remained physically unaffected by the treatment, with no change to their migration time. Using these samples, we detected 0.25% dsRNA impurities in mRNA samples using 15 μL with an analytical runtime of 1 min per sample after digestion and were able to predict their size within 8% of the expected length. The short runtime, sample consumption, and high throughput compatibility make it suitable to support the purity assessment of mRNA during purification and downstream.
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Affiliation(s)
- Adriana Coll De Peña
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA.
| | - Matei Vaduva
- Department of Molecular Biology, Cell Biology, and Biochemistry, Division of Biology and Medicine, Brown University, Providence, RI, USA
| | - Nina S Li
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA.
| | | | | | - Anubhav Tripathi
- Center for Biomedical Engineering, School of Engineering, Brown University, Providence, RI, USA.
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Hu C, Bai Y, Liu J, Wang Y, He Q, Zhang X, Cheng F, Xu M, Mao Q, Liang Z. Research progress on the quality control of mRNA vaccines. Expert Rev Vaccines 2024; 23:570-583. [PMID: 38733272 DOI: 10.1080/14760584.2024.2354251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Abstract
INTRODUCTION The mRNA vaccine technologies have progressed rapidly in recent years. The COVID-19 pandemic has accelerated the application of mRNA vaccines, with research and development and clinical trials underway for many vaccines. Application of the quality by design (QbD) framework to mRNA vaccine development and establishing standardized quality control protocols for mRNA vaccines are essential for the continued development of high-quality mRNA vaccines. AREAS COVERED mRNA vaccines include linear mRNA, self-amplifying mRNA, and circular RNA vaccines. This article summarizes the progress of research on quality control of these three types of vaccines and presents associated challenges and considerations. EXPERT OPINION Although there has been rapid progress in research on linear mRNA vaccines, their degradation patterns remain unclear. In addition, standardized assays for key impurities, such as residual dsRNA and T7 RNA polymerase, are still lacking. For self-amplifying mRNA vaccines, a key focus should be control of stability in vivo and in vitro. For circular RNA vaccines, standardized assays, and reference standards for determining degree of circularization should be established and optimized.
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Affiliation(s)
- Chaoying Hu
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Yu Bai
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- Changping Laboratory, Beijing, China
| | - Jianyang Liu
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
| | - Yiping Wang
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Qian He
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Xuanxuan Zhang
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Feiran Cheng
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Miao Xu
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Qunying Mao
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
| | - Zhenglun Liang
- Institute of Biological Products, Division of Hepatitis and Enterovirus Vaccines, National Institutes for Food and Drug Control, Beijing, China
- National Institutes for Food and Drug Control, Key Laboratory of Research on Quality and Standardization of Biotech Products, Beijing, China
- National Institutes for Food and Drug Control, Evaluation of Biological Products, Beijing, China
- State Key Laboratory of Drug Regulatory Science, Institute of Biological Products, National Institutes for Food and Drug Control, Beijing, China
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