Expression of mammalian proteins for diagnostics and therapeutics: a review

The Potential of Single-Chain Variable Fragment Antibody: Role in Future Therapeutic and Diagnostic Biologics

The advancement of genetic engineering has revolutionized the field of immunology by allowing the utilization of intrinsic antibody structures. One of the biologics that are being produced by recombinant antibody technology is single-chain fragments variable (scFv). Genes of variable regions, the heavy and light chains that are genetically linked into a single transcript by a short flexible linker peptide, are used to generate this fragment from cellular and synthetic libraries. The specificity and affinity of these molecules are comparable to those of parental antibodies. Fusion with marker proteins and other potent molecules improves their stability, circulation half-life, activity, and efficient purification. Besides, this review comprises construction protocols, therapeutics, and diagnostic applications of scFv, as well as related challenges. Nonetheless, there are still issues with efficacy, stability, safety, intracellular administration, and production costs that need to be addressed.

Protein-imprinted polymers: How far have "plastic antibodies" come?

Antibodies are highly selective and sensitive, making them the gold standard for recognition affinity tools. However, their production cost is high and their downstream processing is time-consuming. Molecularly imprinted polymers (MIPs) are tailor-made by incorporating specific molecular recognition sites in their structure, thus translating into receptor-like activity mode of action. The interest in molecular imprinting technology, applied to biomacromolecules, has increased in the past decade. MIPs, produced using biomolecules as templates, commonly referred to as "plastic antibodies" or "artificial receptors", have been considered as suitable cheaper and easy to produce alternatives to antibodies. Research on MIPs, designed to recognize proteins or peptides is particularly important, with potential contributions towards biomedical applications, namely biosensors and targeted drug delivery systems. This mini review will cover recent advances on (bio)molecular imprinting technology, where proteins or peptides are targeted or mimicked for sensing and therapeutic applications. Polymerization methods are reviewed elsewhere, being out of the scope of this review. Template selection and immobilization approaches, monomers and applications will be discussed, highlighting possible drawbacks and gaps in research.

Recombinant Porcine Interferon-α Decreases Pseudorabies Virus Infection

Interferon (IFN) is a cell-secreted cytokine possessing biological activities including antiviral functioning, immune regulation, and others. Interferon-alpha (IFN-α) mainly derives from plasmacytoid dendritic cells, which activate natural killer cells and regulate immune responses. IFN-α responds to the primary antiviral mechanism in the innate immune system, which can effectively cure acute infectious diseases. Pseudorabies (PR) is an acute infectious disease caused by pseudorabies virus (PRV). The clinical symptoms of PRV are as follows: reproductive dysfunction among pregnant sows and high mortality rates among piglets. These pose a severe threat to the swine industry. Related studies show that IFN-α has broad applications in preventing and treating viral diseases. Therefore, a PRV mouse model using artificial infection was established in this study to explore the pathogenic effect of IFN-α on PRV. We designed a sequence with IFN-α4 (M28623, Genbank) and cloned it on the lentiviral vector. CHO-K1 cells were infected and identified using WB and RT-PCR; a CHO-K1 cell line with a stable expression of the recombinant protein PoIFN-α was successfully constructed. H&E staining and virus titer detection were used to investigate the recombinant protein PoIFN-α's effect on PR in BALB/c mice. The results show that the PoIFN-α has a preventive and therapeutic impact on PR. In conclusion, the recombinant protein can alleviate symptoms and reduce the replication of PRV in vivo.

Molecular Farming Strategy for the Rapid Production of Protein-Based Reagents for Use in Infectious Disease Diagnostics

Recombinant proteins are a major breakthrough in biomedical research with a wide range of applications from diagnostics to therapeutics. Strategic construct design, consistent expression platforms, and suitable upstream and downstream techniques are key considerations to produce commercially viable recombinant proteins. The recombinant antigenic protein production for use either as a diagnostic reagent or subunit vaccine formulation is usually carried out in prokaryotic or eukaryotic expression platforms. Microbial and mammalian systems dominate the biopharmaceutical industry for such applications. However, there is no universal expression system that can meet all the requirements for different types of proteins. The adoptability of any expression system is likely based on the quality and quantity of the proteins that can be produced from it. The huge demand of recombinant proteins for different applications requires an inexpensive production platform for rapid development. The molecular farming scientific community has been promoting the plant system for nearly 3 decades as a cost-effective alternative to produce high-quality proteins for research, diagnostic, and therapeutic applications. Here, we discuss how plant biotechnology could offer solutions for the rapid and scalable production of protein antigens as low-cost diagnostic reagents for use in functional assays.

Application of CRISPR-Cas9 genome editing technology in various fields: A review

CRISPR-Cas9 has emerged as a revolutionary tool that enables precise and efficient modifications of the genetic material. This review provides a comprehensive overview of CRISPR-Cas9 technology and its applications in genome editing. We begin by describing the fundamental principles of CRISPR-Cas9 technology, explaining how the system utilizes a single guide RNA (sgRNA) to direct the Cas9 nuclease to specific DNA sequences in the genome, resulting in targeted double-stranded breaks. In this review, we provide in-depth explorations of CRISPR-Cas9 technology and its applications in agriculture, medicine, environmental sciences, fisheries, nanotechnology, bioinformatics, and biotechnology. We also highlight its potential, ongoing research, and the ethical considerations and controversies surrounding its use. This review might contribute to the understanding of CRISPR-Cas9 technology and its implications in various fields, paving the way for future developments and responsible applications of this transformative technology.

Recombinant vaccines in 2022: a perspective from the cell factory

The last big outbreaks of Ebola fever in Africa, the thousands of avian influenza outbreaks across Europe, Asia, North America and Africa, the emergence of monkeypox virus in Europe and specially the COVID-19 pandemics have globally stressed the need for efficient, cost-effective vaccines against infectious diseases. Ideally, they should be based on transversal technologies of wide applicability. In this context, and pushed by the above-mentioned epidemiological needs, new and highly sophisticated DNA-or RNA-based vaccination strategies have been recently developed and applied at large-scale. Being very promising and effective, they still need to be assessed regarding the level of conferred long-term protection. Despite these fast-developing approaches, subunit vaccines, based on recombinant proteins obtained by conventional genetic engineering, still show a wide spectrum of interesting potentialities and an important margin for further development. In the 80's, the first vaccination attempts with recombinant vaccines consisted in single structural proteins from viral pathogens, administered as soluble plain versions. In contrast, more complex formulations of recombinant antigens with particular geometries are progressively generated and explored in an attempt to mimic the multifaceted set of stimuli offered to the immune system by replicating pathogens. The diversity of recombinant antimicrobial vaccines and vaccine prototypes is revised here considering the cell factory types, through relevant examples of prototypes under development as well as already approved products.