Specific anti-SARS-CoV-2 S1 IgY-scFv is a promising tool for recognition of the virus

Preparation of Bispecific IgY-scFvs Inhibition Adherences of Enterotoxigenic Escherichia coli (K88 and F18) to Porcine IPEC-J2 Cell

Enterotoxigenic Escherichia coli (ETEC) strains are significant contributors to postweaning diarrhea in piglets. Of the ETEC causing diarrhea, K88 and F18 accounted for 92.7%. Despite the prevalence of ETEC K88 and F18, there is currently no effective vaccine available due to the diversity of these strains. This study presents an innovative approach by isolating chicken-derived single-chain variable fragment antibodies (scFvs) specific to K88 and F18 fimbrial antigens from chickens immunized against these ETEC virulence factors. These scFvs effectively inhibited adhesion of K88 and F18 to porcine intestinal epithelial cells (IPEC-J2), with the inhibitory effect demonstrating a dose-dependent increase. Furthermore, a bispecific scFv was designed and expressed in Pichia pastoris. This engineered construct displayed remarkable potency; at a concentration of 25.08 μg, it significantly reduced the adhesion rate of ETEC strains to IPEC-J2 cells by 72.10% and 69.11% when challenged with either K88 or F18 alone. Even in the presence of both antigens, the adhesion rate was notably decreased by 57.92%. By targeting and impeding the initial adhesion step of ETEC pathogenesis, this antibody-based intervention holds promise as a potential alternative to antibiotics, thereby mitigating the risks associated with antibiotic resistance and residual drug contamination in livestock production. Overall, this study lays the groundwork for the development of innovative treatments against ETEC infections in piglets.

Development of a potent recombinant scFv antibody against the SARS-CoV-2 by in-depth bioinformatics study: Paving the way for vaccine/diagnostics development

BACKGROUND

The SARS-CoV-2 has led to a worldwide disaster. Thus, developing prophylactics/therapeutics is required to overcome this public health issue. Among these, producing the anti-SARS-CoV-2 single-chain variable fragment (scFv) antibodies has attracted a significant attention. Accordingly, this study aims to address this question: Is it possible to bioinformatics-based design of a potent anti-SARS-CoV-2 scFv as an alternative to current production approaches?

METHOD

Using the complexed SARS-CoV-2 spike-antibodies, two sets analyses were performed: (1) B-cell epitopes (BCEs) prediction in the spike receptor-binding domain (RBD) region as a parameter for antibody screening; (2) the computational analysis of antibodies variable domains (VH/VL). Based on these primary screenings, and docking/binding affinity rating, one antibody was selected. The protein-protein interactions (PPIs) among the selected antibody-epitope complex were predicted and its epitope conservancy was also evaluated. Thereafter, some elements were added to the final scFv: (1) the PelB signal peptide; (2) a GSGGGGS linker to connect the VH-VL. Finally, this scFv was analyzed/optimized using various web servers.

RESULTS

Among the antibody library, only one met the various criteria for being an efficient scFv candidate. Moreover, no interaction was predicted between its paratope and RBD hot-spot residues of SARS-CoV-2 variants-of-Concern (VOCs).

CONCLUSIONS

Herein, a step-by-step bioinformatics platform has been introduced to bypass some barriers of traditional antibody production approaches. Based on existing literature, the current study is one of the pioneer works in the field of bioinformatics-based scFv production. This scFv may be a good candidate for diagnostics/therapeutics design against the SARS-CoV-2 as an emerging aggressive pathogen.

Antibody mimetics: The next generation antibody engineering, a retrospective and prospective analysis

Antibody mimetics represent the fourth generation of antibody engineering, following polyclonal antibodies, monoclonal antibodies, and genetically engineered antibody fragments. Despite cumulative studies highlighting the advantages of antibody mimetics, including enhanced recognition properties, superior affinity, stability, penetrability, and cost-effectiveness, a comprehensive review of this evolving field is notably absent. In this study, spanning 1986-2023 and analyzing 24,318 publications, we undertake a retrospective and prospective analysis to elucidate the evolution roadmap of antibody mimetics, providing insights into the current landscape, global contributions, and future trajectories. Concurrently, our aim is to establish standardized terminology and delineate the research scope within the realm of antibody mimetics. These endeavors not only chart the trajectory and scope of antibody mimetics research but also underscore its potential to revolutionize medicine, technology, and science.

RBD-specific single-chain antibody protects against acute lung injury in mice

As SARS-CoV-2 variants continue spreading globally, the discovery of broad spectrum therapeutically active antibodies with retaining good protective activity is a global priority. It was reported that infection with SARS-CoV-2 could cause acute lung injury (ALI) in clinical investigations. Therefore, we discovered that anti-RBD scFv is effective against SARS-CoV-2-induced ALI. To begin, we utilized the receptor binding domain (RBD) of spike glycoprotein as a target to produce single-chain antibodies (scFvs) through an intensive phage display technology. The binding affinity and inhibitory effect of the scFvs were evaluated via ELISA and flow cytometry. Moreover, anti-RBD scFv No.35 significantly prevented ALI caused by LPS and SARS-CoV-2 spike RBD protein in mouse model. Thus, the anti-RBD scFv will aid the development of potential antibody treatments and reduce the inflammatory response of SARS-CoV-2.

Antiviral Drugs and Vaccines for Omicron Variant: A Focused Review

The Omicron variant of concern (VOC) replaced the delta variant rapidly and became the predominant strain due to more mutations in spike protein and receptor-binding domain (RBD) enhancing its infectivity and binding affinity. The severity of the illness is less than that of the delta variant. Omicron is nonsusceptible to REGEN-COV™ and bamlanivimab with etesevimab. Drugs that are effective against the Omicron variant are oral antiviral drugs such as Paxlovid (nirmatrelvir/ritonavir), remdesivir, sotrovimab, and molnupiravir. The potency of sotrovimab is reduced to 3-fold against Omicron, and 8-fold reduction in potency with sotrovimab is found in a particular variant of Omicron with a R346K substitution in spike protein. There are neither clinical trials comparing the efficacy of these 4 therapies with each other nor any data on a combination of two or more therapies. The current recommendation for mild-moderate, nonhospitalized patients who are at a high risk of disease progression is to use Paxlovid as the first-line option. If Paxlovid is not available or cannot be administered due to drug interactions, then the next best choice is sotrovimab. The third choice is remdesivir if sotrovimab is also not available and molnupiravir is to be given if the other three options are not available or cannot be administered. For prevention, 2130 (cilgavimab) in combination with COV2-2196 (tixagevimab) has been effective against BA.2 only. LY-CoV1404 (bebtelovimab) is recently authorized as it is effective against all sublineages of the Omicron variant. Regarding vaccine efficacy (VE), the 3-dose VE with mRNA vaccines at 14-60 days was found to be 71.6%, and after 60 days, it is 47.4%. There is a 34-38-fold reduction of neutralizing activity with prebooster sera and a 19-fold reduction with booster sera for the Omicron variant. This probably explains the reason for worldwide breakthrough infections with the Omicron variant with waning immunity. The neutralizing antibody response against Omicron elicited by the bivalent vaccine is superior to that of the ancestral Wuhan strain, without any safety concerns. For future advances, the ribosome display technology can be applied for the generation of human single-chain fragment variable (scFv) antibodies from B cells of recovered patients against Omicron and other Coronavirus variants as they are easier and faster to produce and have high affinity and high specificity.

Novel extraction technologies and potential applications of egg yolk proteins

The high nutritional value and diverse functional properties of egg yolk proteins have led to its widespread use in the fields of food, medicine, and cosmetics. Various extraction methods have been reported to obtain the proteins from egg yolk, however, their utilization is limited due to the relatively low extraction efficiency and/or toxic solvents involved. Several simpler and greener technologies, especially physical fields (ultrasound), have been successfully developed to improve the extraction efficiency. The egg yolk proteins may exert multiple biological activities, enabling them to be a promising tool in improve human health and wellbeing, such as anti-obesity, anti-atherosclerosis, anti-osteoporosis, diagnosis and therapy for SARS-CoV-2 infections. This article summarizes the novel extraction technologies and latest applications of the egg yolk proteins in the recent 5 years, which should stimulate their utilization as health-promoting functional ingredients in foods and other commercial products.

1Progress, applications, challenges and prospects of protein purification technology

Protein is one of the most important biological macromolecules in life, which plays a vital role in cell growth, development, movement, heredity, reproduction and other life activities. High quality isolation and purification is an essential step in the study of the structure and function of target proteins. Therefore, the development of protein purification technologies has great theoretical and practical significance in exploring the laws of life activities and guiding production practice. Up to now, there is no forthcoming method to extract any proteins from a complex system, and the field of protein purification still faces significant opportunities and challenges. Conventional protein purification generally includes three steps: pretreatment, rough fractionation, and fine fractionation. Each of the steps will significantly affect the purity, yield and the activity of target proteins. The present review focuses on the principle and process of protein purification, recent advances, and the applications of these technologies in the life and health industry as well as their far-reaching impact, so as to promote the research of protein structure and function, drug development and precision medicine, and bring new insights to researchers in related fields.

Trends in industrialization and commercialization of IgY technology

IgY technology refers to the strategic production process involved in generating avian immunoglobulin (IgY) against target antigens in a much more cost-effective manner with broad applications in the fields of diagnostics, prophylaxis, and therapeutics for both human and veterinary medicine. Over the past decade, promising progress in this research area has been evident from the steep increase in the number of registered manufacturing companies involved in the production of IgY products, the number of patents, and the notable number of clinical trials underway. Hence, it is crucial to conduct a prospective analysis of the commercialization and marketing potential of IgY-based commercial products for large-scale applications. This review revealed that the number of IgY patent applications increased steeply after 2010, with the highest of 77 patents filed in 2021. In addition, 73 industries are reportedly involved in marketing IgY products, out of which 27 were promoting biotherapeutics for human and veterinary medicine and 46 were in the diagnostic field. IgY antibodies are being used as primary and secondary antibodies, with approximately 3729 and 846 products, respectively. Biotherapeutic product consumption has notably increased as a food supplement and as a topical application in human and veterinary medicine, which are under different clinical phases of development to reach the market with around 80 and 56 products, respectively. In contrast, the number of IgY products as parenteral administrations and licensed drugs is not well developed given the lack of technical standards established for IgY registration and industrialization, as well as the restriction of the nature of polyclonal antibodies. However, recent ongoing research on functional IgY fragments indicates a promising area for IgY applications in the near future. Therefore, retrospective analysis with speculations is mandatory for IgY technology maturation toward industrialization and commercialization.