ABSTRACT
Several endemic corona viruses (eCoVs) have been reported to be the most common etiologic agents for the seasonal common cold and also cause pneumonia. These eCoVs share extensive sequence homology with SARS-CoV-2, and immune responses to eCoVs can cross-react with SARS-CoV-2 antigens. Based on such cross-reactivity of antigens among eCoVs, the IgG antibodies against the spike protein (SP) of severe acute respiratory syndrome coronavirus (SARS-CoV) were isolated from pig serum using magnetic beads immobilized with SARS-CoV SP and a protein-A column. The selectivity of the isolated antibodies was tested using different types of antigens, such as SARS-CoV-2 nucleoprotein (NP), influenza A virus (Beijing type), influenza B virus (Tokio and Florida types), human hepatitis B virus surface antigen (HBsAg), and bovine serum albumin (BSA). From the selectivity test, the anti-SP antibodies isolated from pig serum had sufficient selectivity to other kinds of viral antigens, and the apparent binding constant of the isolated antibodies was approximately 1.5 × 10-8 M from the surface plasmon resonance (SPR) measurements. Finally, the isolated anti-SP antibodies were applied to the immunoassay of SP using competitive immunoassay configuration. The feasibility of the detection as well as the quantitative analysis of the SARS-CoV viral culture fluid was determined using four viral culture samples, namely, SARS-CoV, SARS-CoV-2, MERS-CoV, and CoV-229E.
ABSTRACT
Anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) nucleoprotein (NP) antibodies were isolated from pig sera using human SARS-CoV-2 NP-immobilized magnetic beads. The binding properties of the isolated antibodies against SARS-CoV-2 NP were tested via flow cytometry using SARS-CoV-2 NP-immobilized magnetic beads. A competitive immunoassay was developed for detecting SARS-CoV-2 NP as well as SARS-CoV-2 in the culture fluid using magnetic beads with immobilized anti-SARS-CoV-2 NP antibodies. Selectivity tests were carried out during the competitive immunoassay for SARS-CoV, MERS-CoV, and CoV strain 229E in the culture fluid.
ABSTRACT
Anti-coronavirusdisease-2019 (COVID-19; anti-severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2)) antibodies against nucleoprotein (NP) were purified from pig sera. Following the separation of the antibody fraction using a protein-A column, the final yield of the purified antibodies against SARS-CoV-2 NPs was estimated to be 0.26 ± 0.05 % (absolute amount of 143.4 ± 25.2 ng, n=5) from 1 mL of pig sera. The binding activities of the isolated antibodies were confirmed using immunoassay and immunostaining. Based on the specific binding activity to NPs, a quantitative assay was performed using a surface plasmon resonance (SPR) biosensor. From the doseresponse curve, the binding constant (Kd) was calculated to be 185 pM and the limit of detection was estimated to be 1.02 pM. The SPR biosensor with the isolated antibodies against SARS-CoV-2 NPs was applied for the detection of SARS-CoV-2, MERS-CoV, and CoV strain 229E in culture fluid.
ABSTRACT
Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 not yet has established its treatment, but convalescent plasma has been expected to increase survival rates as in the case with other emerging viral infections. We describe two cases of COVID-19 treated with convalescent plasma infusion. Both patients presented severe pneumonia with acute respiratory distress syndrome and showed a favorable outcome after the use of convalescent plasma in addition to systemic corticosteroid. To our knowledge, this is the first report of the use of convalescent plasma therapy for COVID-19 in Korea.
Subject(s)
Betacoronavirus , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Aged , COVID-19 , Female , Humans , Immunization, Passive , Male , Pandemics , Republic of Korea , Respiratory Distress Syndrome/therapy , SARS-CoV-2 , COVID-19 SerotherapyABSTRACT
Convalescent plasma therapy has been used to achieve passive immunization against diverse infectious agents by administering pathogen-specific antibodies. Coronavirus disease 19 (COVID-19), which originated in Wuhan, China, has recently become a major concern all over the world. There are no specific treatment recommendations for COVID-19 because of the lack of knowledge and evidence about this virus. Convalescent plasma therapy can be used as an empirical and investigational treatment for COVID-19, and so we briefly describe the main issues related to convalescent plasma therapy from the perspective of transfusion medicine.