Efficacy of affinity resin containing Galanthus nivalis agglutinin against SARS-CoV-2

A recent study posted to the bioRxiv* preprint server demonstrated the efficacy of the Galanthus nivalis agglutinin (GNA)-incorporated affinity resin against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants.

Background

The coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been persistent for more than two years. SARS-CoV-2 infections have resulted in over 511 million cases and 6.2 million deaths globally as of May 2022. The pandemic has been marked by the emergence of a series of SARS-CoV-2 variants with mutations in the spike (S) protein, boosting the virulence and infectiousness and hampering the effectiveness of COVID-19 monoclonal antibodies and vaccines.

Resistance to COVID-19 vaccination and restrictions in currently available treatments necessitate continued research and development, particularly for patients with severe SARS-CoV-2 infections. 

Existing reports show that the Aethlon Hemopurifier® device harboring an affinity resin comprising GNA, a plant lectin, attaches to alpha 1,3 mannose units in enveloped viruses. Further, previous studies depicted that the Aethlon Hemopurifier® extracorporeal equipment containing the GNA affinity resin linked and eradicated SARS-CoV-2 from the blood in vivo. 

About the study

In the present study, the investigators hypothesized that the GNA affinity resin would have comparable binding to the main SARS-CoV-2 variants producing clinical illness during the previous two years since the SARS-CoV-2 mutations should not impact mannosylation inside the viral envelope. Known titers of seven clinically significant SARS-CoV-2 variants were seeded in medium and processed over three columns harboring 1gm of GNA affinity resin, and percent binding was determined. Additionally, the percent decline in viral concentrations was contrasted against a control lot.

Seven SARS-CoV-2 variants (Delta B.1.672 and AY.1 variants, Omicron, Lambda, United Kingdom (UK), Brazil, and South Africa) were propagated on cultured human airway epithelial 3 (Calu-3) cells and Vero E6 cells (CRL-1586). Supernatants from cell cultures were collected, purified by centrifugation, fractionated, and kept at -80°C until used.

Each column received a total of 1gm of affinity resin. Four columns were produced for each SARS-CoV-2 variant examined (three with affinity resin and one without resin control). The resin was rinsed initially with 10 ml and then 5 ml phosphate-buffered saline (PBS). The existence of viable viruses was determined by utilizing a plaque assay on the viral concentration of each challenge solution and the samples acquired after three passages.

 The resin effectiveness was determined by the number of viable organisms in suspension following crossings over the resin bed. Viral capture efficiency was calculated by comparing the captured live virus concentrations to the column control.

Results

The study results showed that the GNA affinity resin in the Aethlon Hemopurifier device could engage with the seven SARS-CoV-2 variants analyzed with viral capture efficiency varying from 53.2% to 89.9%. The resin columns eliminated more than 70% of the SARS-COV-2 load in a single cycle for four out of the seven SARS-CoV-2 variants. The highest binding was found for the SARS-CoV-2 Brazilian P.1 and contemporary Omicron variants, whereas the lowest adherence was found for the Delta AY.1 variant. 

During the South African SARS-CoV-2 variant analysis, among the three test samples, sample 2's 5-mL challenge aliquot went through the column with almost half the time relative to samples 1 and 3. While there were no visible air pockets in the resin bed, it was likely that some of the challenge suspension was channeled, possibly explaining why sample 2 had a lower virus capture efficiency.

Each column received a total viral challenge of about 5x 10⁴ plaque-forming units (PFU) in vitro. Prior assessments depicted that the ratio of PFUs/ml to viral RNA copies/ml was about 1:3400, indicating a viral challenge of nearly 1.7x 10⁸. The investigators calculated that 1gm of GNA affinity resin would remove 90,440,000 viral copies using the most cautious data point of 53.2% viral eradication. They stated that the GNA affinity resin in the Hemopurifier might offer an alternate strategy for regulating the coagulopathic and immune response to COVID-19. This was by eliminating micro ribonucleic acid (microRNA)-containing exosomes linked with acute lung damage and coagulopathy.

Conclusions

On the whole, the study findings demonstrated that a column harboring a GNA affinity resin could attach all the main SARS-CoV-2 mutants inducing clinical illness. According to extrapolation, an adult Aethlon Hemopurifier® would exhibit more than enough binding ability to adhere to SARS-CoV-2 loads seen in adult severe COVID-19 patients.

This technique will most likely continue to work against potential SARS-CoV-2 variants that alter COVID-19 vaccination and treatment efficacy. The authors also mentioned that the Aethlon Hemopurifier incorporating this affinity resin is underway in critically sick and severe SARS-CoV-2-infected patients.

*Important notice

bioRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Written by

Shanet Susan Alex

Shanet Susan Alex, a medical writer, based in Kerala, India, is a Doctor of Pharmacy graduate from Kerala University of Health Sciences. Her academic background is in clinical pharmacy and research, and she is passionate about medical writing. Shanet has published papers in the International Journal of Medical Science and Current Research (IJMSCR), the International Journal of Pharmacy (IJP), and the International Journal of Medical Science and Applied Research (IJMSAR). Apart from work, she enjoys listening to music and watching movies.