The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) has caused global panic in 2003, and the risk of SARS-CoV outbreak still exists. However, no specific antiviral drug or vaccine is available; thus, the development of therapeutic antibodies against SARS-CoV is needed. In this study, a nanobody phage-displayed library was constructed from peripheral blood mononuclear cells of alpacas immunized with the recombinant receptor-binding domain (RBD) of SARS-CoV. Four positive clones were selected after four rounds of bio-panning and subjected to recombinant expression in E. coli . Further biological identification demonstrated that one of the nanobodies, S14, showed high affinity to SARS-CoV RBD and potent neutralization activity at the picomole level against SARS-CoV pseudovirus. A competitive inhibition assay showed that S14 blocked the binding of SARS-CoV RBD to either soluble or cell-expressed angiotensin-converting enzyme 2 (ACE2). In summary, we developed a novel nanobody targeting SARS-CoV RBD, which might be useful for the development of therapeutics against SARS.
【저자키워드】 neutralizing antibody, nanobody, Receptor-binding domain (RBD), severe acute respiratory syndrome coronavirus (SARS-CoV), 【초록키워드】 ACE2, Vaccine, coronavirus, antibody, SARS-CoV, Therapeutics, risk, severe acute respiratory syndrome Coronavirus, angiotensin-converting enzyme 2, antiviral drug, Peripheral blood, pseudovirus, outbreak, RBD, therapeutic, Peripheral blood mononuclear cells, nanobodies, expression, binding, Angiotensin-converting enzyme, angiotensin, Panic, therapeutic antibodies, mononuclear cell, acute respiratory syndrome, E. coli, acute respiratory syndrome coronavirus, enzyme, domain, high affinity, neutralization activity, positive, clone, SARS-CoV RBD, immunized, competitive inhibition, SARS-CoV pseudovirus, selected, blocked, caused, demonstrated, against SARS-CoV, 【제목키워드】 SARS-CoV, characterization, Generation, Against,