The serious acute respiratory syndrome covid 2 is the etiological agent of the covid induced disease 19 that emerged in china in late 2019 and caused a global pandemic. SARS-CoV-2 belongs to the subgenus Sarbecovirus together with SARS-CoV that emerged in 2002 causing eight thousand infections with a lethality of 10 percent.
Both viruses crossed species barriers from an animal’s reservoir and may cause a life-threatening respiratory illness in humans. Currently, no approved targeting therapeutics are available for coronavirus.
Monoclonal antibodies targeting vulnerable sites on viral surface proteins are rising in recognition as a promising class of drug against infectious diseases and have shown therapeutic efficacy for several viruses.
Covid-19 neutralizing antibodies primarily aim at the trimeric spike glycoproteins on the viral surface that mediate entry into host cells. The S protein has 2 functional subunits that, medicate cell attachment and fusion of the viral and cellular membrane. Potent-neutralizing antibodies often aim at the receptor interaction site in S1 disabling receptor interactions.
The spike protein of SARS-CoV-2 and SARS-CoV are 75 percent identical by main amino acid sequence are structurally very similar and generally bind the human angiotensin-converting enzyme protein as host receptor through their domain.
Receptor interaction is known to trigger irreversible conformational changes in coronavirus spike protein enabling membrane fusion. To identify SARS-CoV-2 neutralizing antibodies, ELISA reactivity was assessed of antibodies-containing supernatants of a collection of 51 SARS-S hybridoma’s drive from immunized transgenic H2L2 mice that encode chimeric immunoglobulins with human variable HL, VL and constant regions of rat origin.
The human monoclonal gamma globulin spike 47D11 binds to cells expressing the full-length spike protein of SARS-CoV-2. The 47D11 antibody was found to potentially inhibit infection of veroE6 cells with SARS-S and SARS2-S pseudotyped VSV with IC values. Authentic infection of veroE6 cells with SARS-CoV and SARS-CoV-2 was neutralized within values.
Using ELISA 47D11 bound was used to aim the S1 receptor binding domain of SARS-CoV and SARS2-s 47D11 bound the S1 of both viruses with similar affinities as shown by the ELISA-based half maximal effective concentration value. The ELISA-based binding affinity of 47D11 for the spike ectodomain of SARS-CoV was higher relative to that of SARS-CoV-2, despite equimolar binding coating.
This is the first report on a monoclonal antibody that neutralizes SARS-CoV-2 47D11 binds a conserved epitope on the spike receptor binding domain explaining its ability to cross-neutralize SARS-CoV and SARS-CoV-2 using a mechanism that is independent of receptor binding inhibition.
We at GeNext Genomics have developed SARS-CoV-2 recombinant proteins such as the monoclonal gamma globulin spike, Spike-S1, RBD, and more. While the world is fighting the deadly pandemic, we stand forefront to provide high-quality biologics for effective research and development of solutions.
Our expert scientists and technicians at work have developed their efforts into proteins and several humanized monoclonal antibody which can be used for animal immunization, antibody development, and more.