PHASE 1 CLINICAL TRIALS OF A Q-GRIFFITHSIN NASAL SPRAY FOR SARS-CoV-2 PROPHYLAXIS

Background: The currently approved vaccines do not induce sterilizing immunity against SAR-CoV-2 infection, and immunity wanes over time. A robust broad spectrum topical prophylaxis strategy could protect vulnerable populations in the face of continuous evolution of SARS-CoV-2. The algal antiviral lectin Griffithsin (GRFT), and an engineered oxidation-resistant variant Q-GRFT have robust entry inhibitory activity against SARS-CoV variants of concern, in addition to other respiratory viruses with pandemic potential. We designed a nasal spray to deliver Q-GRFT to the upper respiratory tract mucosa for on-demand use as a broad-spectrum prophylactic. Two clinical trials (Phase 1a and 1b) were conducted to assess safety, tolerability, and pharmacokinetics of Q-GRFT nasal spray in healthy adults. Method(s): Healthy adult volunteers were enrolled in a Phase 1a double blinded, randomized study to receive a single dose of either intranasal Q-GRFT (3.0 mg, 2 sprays per nostril) or placebo at 2:1 ratio. Following a safety review, the Phase 1b study was initiated. Eleven volunteers in Group 1 received 3.0 mg dose once daily, for 7 days. After a safety review, 11 volunteers in Group 2 received a total of 6.0 mg Q-GRFT (3.0 mg twice daily for 7 days). Topical Q-GRFT concentrations were measured by ELISA in collected nasal and nasopharyngeal fluids. Drug levels in plasma were assayed to determine systemic exposure. Viral microneutralization cytopathic effect (CPE) assays were performed against SARS-CoV-2 Omicron BA-5 and MERS-CoV. Result(s): Eighteen adults (24-54 years;Males 58.3%, Females 41.7%;12 Q-GRFT, 6 Placebo), and 22 adults (aged 23-59 years;Males 52.4%, Females 47.6%) were enrolled in Phase 1a and 1b, respectively. In Phase 1a, a single dose of Q-GRFT maintained quantifiable levels in nasal passages and nasopharynx for up to 24 hours. Similarly, Q-GRFT was quantifiable in nasal and nasopharyngeal regions in the Phase 1b study. No dose accumulation effect or systemic exposure was observed. Nasal and nasopharyngeal swab eluates inhibited SARS-CoV-2 Omicron BA.5 and MERS-CoV in CPE assays. Q-GRFT did not modify olfactory sensation. No severe adverse events were reported. Thus, the nasal spray was deemed safe. Conclusion(s): Intranasal Q-GRFT was safe and enhanced mucosal SARSCoV-2 inhibitory activity in human volunteers. The results support further development of Q-GRFT as a broad-spectrum prophylactic against coronaviruses to curb ongoing infections, and for future pandemic preparedness.

An approach to rapid distributed manufacturing of broad spectrum anti-viral griffithsin using cell-free systems to mitigate pandemics.

This study describes the cell-free biomanufacturing of a broad-spectrum antiviral protein, griffithsin (GRFT) such that it can be produced in microgram quantities with consistent purity and potency in less than 24 h. We demonstrate GRFT production using two independent cell-free systems, one plant and one microbial. Griffithsin purity and quality were verified using standard regulatory metrics. Efficacy was demonstrated in vitro against SARS-CoV-2 and HIV-1 and was nearly identical to that of GRFT expressed in vivo. The proposed production process is efficient and can be readily scaled up and deployed wherever a viral pathogen might emerge. The current emergence of viral variants of SARS-CoV-2 has resulted in frequent updating of existing vaccines and loss of efficacy for front-line monoclonal antibody therapies. Proteins such as GRFT with its efficacious and broad virus neutralizing capability provide a compelling pandemic mitigation strategy to promptly suppress viral emergence at the source of an outbreak.

Anti-coronaviral Activity of Plant and Seaweed Secondary Metabolites: A Review

Background: Coronavirus Disease 2019 (COVID-19), one of the greatest challenges facing humanity, continues to affect millions of people worldwide. Vaccines approved and authorized for use are effective against COVID-19, but viral variants of concern may emerge in the near future. The discovery of novel antiviral agents will help humanity overcome COVID-19 and aid in any future viral pandemics. Objective(s): This review aimed to evaluate evidence from the plant-and seaweed-derived secondary com-pound-based interventions for viral diseases caused by coronaviruses. Method(s): A comprehensive search of several databases, including Cochrane Library, Web of Science and PubMed was conducted to identify available studies evaluating the outcomes of plant-and seaweed secondary metabolites in viral diseases such as Severe Acute Respiratory Syndrome, Middle East Respiratory Syndrome and COVID-19. Result(s): The volume of existing reports is irrefutable evidence that some plant-and seaweed-derived secondary compounds (e.g., mannose-specific lectins, griffithsin, cyanovirin-N, gallate, curcumin, luteo-lin, quercetin and betulinic acid) possess a potential antiviral ability against coronaviruses, including SARS-CoV-2. Conclusion(s): Plant and seaweed secondary metabolites with antiviral activity show their activity in different metabolic pathways. Besides reducing and preventing the metabolic damage caused by proinflamma-tory cytokines and oxidative stress, several plants and seaweed secondary metabolites can also be effective in improving some clinical indexes specific to COVID-19. Despite their effectiveness in preclinical studies, plant and seaweed-derived secondary compounds need more pharmacokinetic studies and safety measures concerning their mitogenic and allergenic properties.Copyright © 2022 Bentham Science Publishers.

Potential of algae-derived bioactive molecules for cure of SARS-CoV-2

The exploration for various effective antiviral agents is pressing issue regarding the histrionic circumstances of the global COVID pandemic, a blowout of SARS-CoV-2 virus disease. Actual antiviral remedies are not existing at present and the agreed remedy available for COVID somewhat has not been well recognized yet. In these circumstances, there is a need of more consideration which should be given to the exploration for all possible antiviral agents existing in nature. Though, the algae (marine/fresh water) are one of the richest reservoirs of bioactive complexes yet they are sporadically been studied as antiviral agents. In past, the bioactive compounds of algal origin have demonstrated remarkable in vitro antiviral activity against the HIV and HCV. The present article recapitulates the antiviral possessions of algae or their extracts that have been studied in several in vitro/in vivo animal system-based studies, with the aim that the vast algal diversity should get the due attentions related to the deterrence of SARS-CoV-2.

American Society for Microbiology (ASM) Microbe-2022 Annual Meeting Washington, DC - June 9-13, 2022 Abstrcats

Two years after the COVID-19 public health emergency began, the 2022 annual American Society for Microbiology (ASM) Microbe Conference returned to in-person attendance. ASM is one of the largest scientific professional societies with approximately 30,000 scientists and health practitioners. Its mission is to promote and advance the microbial sciences. This meeting comprised plenary sessions, scientific s and presentations across 9 scientific tracks exploring topics in microbiology including infectious pathogens like SARS-CoV-2, antimicrobial resistance, the role of microbes in climate change, agriculture and food microbiology, clinical infections and vaccines, and synthetic and applied microbiology. This report highlights a selection of presentations about treatment updates provided during the conference.

Integrated autolysis, DNA hydrolysis and precipitation enables an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral and clinical-stage anti-COVID-19 candidate.

Across the biomanufacturing industry, innovations are needed to improve efficiency and flexibility, especially in the face of challenges such as the COVID-19 pandemic. Here we report an improved bioprocess for Q-Griffithsin, a broad-spectrum antiviral currently in clinical trials for COVID-19. Q-Griffithsin is produced at high titer in E. coli and purified to anticipated clinical grade without conventional chromatography or the need for any fixed downstream equipment. The process is thus both low-cost and highly flexible, facilitating low sales prices and agile modifications of production capacity, two key features for pandemic response. The simplicity of this process is enabled by a novel unit operation that integrates cellular autolysis, autohydrolysis of nucleic acids, and contaminant precipitation, giving essentially complete removal of host cell DNA as well as reducing host cell proteins and endotoxin by 3.6 and 2.4 log10 units, respectively. This unit operation can be performed rapidly and in the fermentation vessel, such that Q-GRFT is obtained with 100% yield and > 99.9% purity immediately after fermentation and requires only a flow-through membrane chromatography step for further contaminant removal. Using this operation or variations of it may enable improved bioprocesses for a range of other high-value proteins in E. coli.

Porcine deltacoronavirus infection is inhibited by Griffithsin in cell culture.

Porcine deltacoronavirus (PDCoV) is an emerging porcine enteric coronavirus that causes severe diarrhea in piglets and results in serious economic losses. There are no effective vaccines and antiviral drugs to prevent and treat PDCoV infection currently. Griffithsin (GRFT) is a lectin with potent antiviral activity against enveloped viruses because of its ability to specifically bind N-linked high-mannose oligosaccharides. GRFT has been reported to possess antiviral activity against severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and porcine epidemic diarrhea virus (PEDV). Here, we first confirmed the antiviral activity of GRFT against PDCoV in vitro. The infected cells (%) and virus titers were significantly decreased at concentration 1 µg/mL or above of GRFT. Time-course experiments revealed that GRFT inhibits PDCoV infection at the adsorption and penetration step. GRFT binding to PDCoV spike (S) protein on the surface wraps the virus and blocks its entry. The outstanding antiviral potency indicates that GRFT has the potential value as a candidate drug for the prevention and treatment of PDCoV infection.

Potential role of marine species-derived bioactive agents in the management of SARS-CoV-2 infection.

COVID-19, caused by the SARS-CoV-2 outbreak, has resulted in a massive global health crisis. Bioactive molecules extracted or synthesized using starting material obtained from marine species, including griffithsin, plitidepsin and fingolimod are in clinical trials to evaluate their anti-SARS-CoV-2 and anti-HIV efficacies. The current review highlights the anti-SARS-CoV-2 potential of marine-derived phytochemicals explored using in silico, in vitro and in vivo models. The current literature suggests that these molecules have the potential to bind with various key drug targets of SARS-CoV-2. In addition, many of these agents have anti-inflammatory and immunomodulatory potentials and thus could play a role in the attenuation of COVID-19 complications. Overall, these agents may play a role in the management of COVID-19, but further preclinical and clinical studies are still required to establish their role in the mitigation of the current viral pandemic.

The Need for Ocular Protection for Health Care Workers During SARS-CoV-2 Outbreak and a Hypothesis for a Potential Personal Protective Equipment.

SARS-CoV-2 is a coronavirus with high infectivity and has caused dramatic pressure on health systems all over the world. Appropriate personal protection for medical staffs is critical. For ocular protection, there is ongoing hot debate and concern for potential ocular transmission of SARS-CoV-2. Ocular manifestations and positive detection of viral RNA in ocular samples were only reported in very small number of patients infected with SARS-CoV-2. However, health care workers need to face patients more closely and have higher risk of aerosol contamination. Thus, appropriate ocular protection for medical workers is still recommended by organizations such as WHO and American Academy of Ophthalmology. Although eye goggles provide excellent protection and are mandatory for medical practitioners with high risk of exposure, they are not ideal for common clinical practice, because they can disturb vision due to extensive formation of water droplets and frequently cause moderate to severe discomfort after longtime wearing, which have been reported to interfere with working status. For the majority of medical workers who don't deal with high risk patients, they are not advised to wear goggles in daily practice. However, they also face the risk of infection due to the presence of asymptomatic carriers. Especially in situations with high risk of ocular exposure, such as close physical examination, eye surgery, dental clinics and surgery, ocular protection may be needed. Griffithsin has been shown to directly bind to spike proteins and has anti-viral activity against a broad spectrum of viruses, including coronavirus. Griffithsin is found to inhibit the entry of SARS-CoV at relatively low concentration and is stable and non-toxic. SARS-CoV-2 and SARS-CoV share the same entry receptors and their spike proteins are similar in conformation. We hypothesize that contact lenses containing nanoparticles loaded with griffithsin may provide sufficient ocular protection for medical staffs without high risk of exposure during the outbreak period of SARS-CoV-2. If proven effective, griffithsin-loaded contact lens can be considered as a supplementary ocular protective equipment for medical workers who can tolerate well. The daily disposable contact lens should be applied as needed and refrain from extended wearing in order to reduce potential side effects.

Man-Specific, GalNAc/T/Tn-Specific and Neu5Ac-Specific Seaweed Lectins as Glycan Probes for the SARS-CoV-2 (COVID-19) Coronavirus.

Seaweed lectins, especially high-mannose-specific lectins from red algae, have been identified as potential antiviral agents that are capable of blocking the replication of various enveloped viruses like influenza virus, herpes virus, and HIV-1 in vitro. Their antiviral activity depends on the recognition of glycoprotein receptors on the surface of sensitive host cells-in particular, hemagglutinin for influenza virus or gp120 for HIV-1, which in turn triggers fusion events, allowing the entry of the viral genome into the cells and its subsequent replication. The diversity of glycans present on the S-glycoproteins forming the spikes covering the SARS-CoV-2 envelope, essentially complex type N-glycans and high-mannose type N-glycans, suggests that high-mannose-specific seaweed lectins are particularly well adapted as glycan probes for coronaviruses. This review presents a detailed study of the carbohydrate-binding specificity of high-mannose-specific seaweed lectins, demonstrating their potential to be used as specific glycan probes for coronaviruses, as well as the biomedical interest for both the detection and immobilization of SARS-CoV-2 to avoid shedding of the virus into the environment. The use of these seaweed lectins as replication blockers for SARS-CoV-2 is also discussed.

Griffithsin Inhibits Nipah Virus Entry and Fusion and Can Protect Syrian Golden Hamsters From Lethal Nipah Virus Challenge.

Nipah virus (NiV) is a highly pathogenic zoonotic paramyxovirus that causes fatal encephalitis and respiratory disease in humans. There is currently no approved therapeutic for human use against NiV infection. Griffithsin (GRFT) is high-mannose oligosaccharide binding lectin that has shown in vivo broad-spectrum activity against viruses, including severe acute respiratory syndrome coronavirus, human immunodeficiency virus 1, hepatitis C virus, and Japanese encephalitis virus. In this study, we evaluated the in vitro antiviral activities of GRFT and its synthetic trimeric tandemer (3mG) against NiV and other viruses from 4 virus families. The 3mG had comparatively greater potency than GRFT against NiV due to its enhanced ability to block NiV glycoprotein-induced syncytia formation. Our initial in vivo prophylactic evaluation of an oxidation-resistant GRFT (Q-GRFT) showed significant protection against lethal NiV challenge in Syrian golden hamsters. Our results warrant further development of Q-GRFT and 3mG as potential NiV therapeutics.

Low-Cost, Large-Scale Production of the Anti-viral Lectin Griffithsin.

Griffithsin, a broad-spectrum antiviral lectin, has potential to prevent and treat numerous viruses including HIV, HCV, HSV, SARS-CoV, and SARS-CoV-2. For these indications, the annual demand for Griffithsin could reach billions of doses and affordability is paramount. We report the lab-scale validation of a bioprocess that supports production volumes of >20 tons per year at a cost of goods sold below $3,500/kg. Recombinant expression in engineered E. coli enables Griffithsin titers ∼2.5 g/L. A single rapid precipitation step provides > 90% yield with 2-, 3-, and 4-log reductions in host cell proteins, endotoxin, and nucleic acids, respectively. Two polishing chromatography steps remove residual contaminants leading to pure, active Griffithsin. Compared to a conventional one this process shows lower costs and improved economies of scale. These results support the potential of biologics in very large-scale, cost-sensitive applications such as antivirals, and highlight the importance of bioprocess innovations in enabling these applications.