Working at the interface of biophysics and immunology with strategic applications of the S-RBD from SARS-CoV-2

TOMAS GRAU , R; PLOPER D.; NAVARRO S.; ÁVILA C.; STAGNETTO A.; GONZÁLEZ LIZÁRRAGA M.F.; SOCÍAS B.; CAZORLA S.; MALDONADO GALDEANO C.; PERDIGÓN G.; APICHELA S.; ARGAÑARÁZ M. ; ZAMPINI R.; VELEZ E.; CHAVES S.; VERA PINGITORE E.; LLAPUR C.; APFELBAUM G.; AGUILAR LÓPEZ M.; AZNAR P.; FLORES I.; TOLEDO R.; COSTA D.; CHEHÍN R.

Digital

Simposio; BIOFÍSICA EN TIEMPOS DE COVID-19. SOCIEDAD ARGENTINA DE BIOFÍSICA; 2020

Sociedad Argentina de Biofísica

COVID-19, the pandemic caused by the SARS-CoV-2 virus, threatens to collapsehealthcare systems around the world. Therefore, the search for strategies capable ofcounteracting the effects of this disease is crucial. Taking into account that the receptorbinding domain (S-RBD), located in the glycoprotein S of the virus surface is crucial forits pathogenesis, and its region is a critical target for neutralizing antibodies, we set outto express and purify the recombinant S-RBD protein from SARS-CoV-2 and use it for thedevelopment of local diagnostic methods and research purposes. To obtain the S-RBDprotein, we generated a stable cell line by transducing HEK293T cells using a lentivirussystem. The correct transduction and expression were assessed by animmunofluorescence. S-RBD was purified by FPLC by affinity purification for itsubsequent use in: i) the development of an ELISA test ii) immunization of a llama toobtain nanoantibodies and iii) studying the potential effect of SARS-CoV-2 inneurodegenerative diseases. The continuous production of S-RBD protein was used forthe development of a reproducible, low cost, sensitive and robust serological test thatcorrelates with neutralizing antibodies. We found that 25% of patients tested withdetectable IgG anti-RBD have a high enough antibody titer (above 1/1000) to beconsidered as plasma donors. In llama, the titers obtained were above 1/80000, suitableto continue the project to purify nanoantibodies. The continuous production of S-RBDprotein also ensure enough reagent to study how SARS-CoV-2 might affectneurodegeneration from a biochemical and cell biology perspective.