scholarly journals Immunologic testing for SARS-CoV-2 infection from the antigen perspective

2020 ◽  
pp. JCM.02160-20
Author(s):  
Dandan Li ◽  
Jinming Li
Keyword(s):  
Cross Reactivity ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Serological Testing ◽  
S Protein ◽  
N Protein ◽  
Viral Loads ◽  
Improved Performance ◽  
Human Coronaviruses ◽  
Novel Coronavirus

Coronavirus disease 2019 (COVID-19) caused by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally as a severe pandemic. SARS-CoV-2 infection stimulates antigen-specific antibody responses. Multiple serologic tests have been developed for SARS-CoV-2. However, which antigens are most suitable for serological testing remains poorly understood. Specifically, which antigens have the highest sensitivity and specificity for serological testing and which have the least cross-reactivity with other coronaviruses are currently unknown. Previous studies have shown that the S1 domain of the spike (S) protein has very low cross-reactivity between epidemic coronaviruses and common human coronaviruses, whereas the S2 domain of the S protein, and the nucleocapsid protein (N protein) show low-level cross-reactivity. Therefore, S1 is considered more specific than the native homotrimer of the S protein, and the receptor-binding domain as an antigen to test patient antibodies is more sensitive than the native N protein. In addition, an increasing number of studies have used multi-antigen protein arrays to screen serum from convalescent patients with COVID-19. Antigen combinations demonstrated improved performance as compared to each individual antigen. For rapid antigen detection, the sensitivity of the test is higher in the first week of onset of the disease with high viral loads. Highly sensitive and specific immunological diagnostic methods for antibodies or those that directly detect viral antigens in clinical samples would be beneficial for the rapid and accurate diagnosis of SARS-CoV-2 infection.

scholarly journals Cross-reactive antibodies after SARS-CoV-2 infection and vaccination

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marloes Grobben ◽  
Karlijn van der Straten ◽  
Philip JM Brouwer ◽  
Mitch Brinkkemper ◽  
Pauline Maisonnasse ◽  
...  
Keyword(s):  
Fold Increase ◽  
Cross Reactivity ◽  
S Protein ◽  
Healthy Donors ◽  
Main Target ◽  
Human Coronaviruses ◽  
Novel Coronavirus ◽  
S Proteins

Current SARS-CoV-2 vaccines are losing efficacy against emerging variants and may not protect against future novel coronavirus outbreaks, emphasizing the need for more broadly protective vaccines. To inform the development of a pan-coronavirus vaccine, we investigated the presence and specificity of cross-reactive antibodies against the spike (S) proteins of human coronaviruses (hCoV) after SARS-CoV-2 infection and vaccination. We found an 11- to 123-fold increase in antibodies binding to SARS-CoV and MERS-CoV as well as a 2- to 4-fold difference in antibodies binding to seasonal hCoVs in COVID-19 convalescent sera compared to pre-pandemic healthy donors, with the S2 subdomain of the S protein being the main target for cross-reactivity. In addition, we detected cross-reactive antibodies to all hCoV S proteins after SARS-CoV-2 vaccination in macaques and humans, with higher responses for hCoV more closely related to SARS-CoV-2. These findings support the feasibility of and provide guidance for development of a pan-coronavirus vaccine.

scholarly journals Immune response dynamics in COVID-19 patients to SARS-CoV-2 and other human coronaviruses

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254367
Author(s):  
Resmi Ravindran ◽  
Cindy McReynolds ◽  
Jun Yang ◽  
Bruce D. Hammock ◽  
Aamer Ikram ◽  
...  
Keyword(s):  
Serological Test ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Response Dynamics ◽  
S Protein ◽  
Infected People ◽  
N Protein ◽  
Patient Health ◽  
Antibody Titers ◽  
Human Coronaviruses

COVID-19 serological test must have high sensitivity as well as specificity to rule out cross-reactivity with common coronaviruses (HCoVs). We have developed a quantitative multiplex test, measuring antibodies against spike (S) proteins of SARS-CoV-2, SARS-CoV, MERS-CoV, and common human coronavirus strains (229E, NL63, OC43, HKU1), and nucleocapsid (N) protein of SARS-CoV viruses. Receptor binding domain of S protein of SARS-CoV-2 (S-RBD), and N protein, demonstrated sensitivity (94% and 92.5%, respectively) in COVID-19 patients (n = 53), with 98% specificity in non-COVID-19 respiratory-disease (n = 98), and healthy-controls (n = 129). Anti S-RBD and N antibodies appeared five to ten days post-onset of symptoms, peaking at approximately four weeks. The appearance of IgG and IgM coincided while IgG subtypes, IgG1 and IgG3 appeared soon after the total IgG; IgG2 and IgG4 remained undetectable. Several inflammatory cytokines/chemokines were found to be elevated in many COVID-19 patients (e.g., Eotaxin, Gro-α, CXCL-10 (IP-10), RANTES (CCL5), IL-2Rα, MCP-1, and SCGF-b); CXCL-10 was elevated in all. In contrast to antibody titers, levels of CXCL-10 decreased with the improvement in patient health suggesting it as a candidate for disease resolution. Importantly, anti-N antibodies appear before S-RBD and differentiate between vaccinated and infected people—current vaccines (and several in the pipeline) are S protein-based.

scholarly journals Impact of the Nucleic Acid Extraction Method and the RT-qPCR Assay on SARS-CoV-2 Detection in Low-Viral Samples

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2247
Author(s):  
Magdalena Komiazyk ◽  
Jarosław Walory ◽  
Aleksandra Kozinska ◽  
Izabela Wasko ◽  
Anna Baraniak
Keyword(s):  
Rna Extraction ◽  
Extraction Methods ◽  
Etiologic Agent ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Acid Extraction ◽  
Upper Respiratory Tract ◽  
Viral Loads ◽  
Upper Respiratory ◽  
Novel Coronavirus

COVID-19 was initially reported in China at the end of 2019 and soon thereafter, in March 2020, the WHO declared it a pandemic. Until October 2021, over 240 million COVID-19 cases were recorded, with 4.9 mln deaths. In order to stop the spread of this disease, it is crucial to monitor and detect any infected person. The etiologic agent of COVID-19 is a novel coronavirus called SARS-CoV-2. The gold standard for the detection of the virus is the RT-qPCR method. This study evaluated two RNA extraction methods and four commercial RT-qPCR assays routinely used in diagnostic laboratories for detecting SARS-CoV-2 in human specimens from the upper respiratory tract. We analyzed a panel of 70 clinical samples with varying RNA loads. Our study demonstrated the significant impact of the diagnostic methods selected by the laboratory on the SARS-CoV-2 detection in clinical specimens with low viral loads.

scholarly journals Cross-reactive antibodies after SARS-CoV-2 infection and vaccination

2021 ◽  
Author(s):  
Marloes Grobben ◽  
Karlijn van der Straten ◽  
Philip J.M. Brouwer ◽  
Mitch Brinkkemper ◽  
Pauline Maisonnasse ◽  
...  
Keyword(s):  
Fold Increase ◽  
Cross Reactivity ◽  
S Protein ◽  
Healthy Donors ◽  
Main Target ◽  
Protein Immunization ◽  
Human Coronaviruses ◽  
Novel Coronavirus ◽  
S Proteins

Current SARS-CoV-2 vaccines are losing efficacy against emerging variants and may not protect against future novel coronavirus outbreaks, emphasizing the need for more broadly protective vaccines. To inform the development of a pan-coronavirus vaccine, we investigated the presence and specificity of cross-reactive antibodies against the spike (S) proteins of human coronaviruses (hCoV) after SARS-CoV-2 infection and vaccination. We found an 11 to 123-fold increase in antibodies binding to SARS-CoV and MERS-CoV as well as a 2 to 4-fold difference in antibodies binding to seasonal hCoVs in COVID-19 convalescent sera compared to pre-pandemic healthy donors, with the S2 subdomain of the S protein being the main target for cross-reactivity. In addition, we detected cross-reactive antibodies to all hCoV S proteins after SARS-CoV-2 S protein immunization in macaques, with higher responses for hCoV more closely related to SARS-CoV-2. These findings support the feasibility of and provide guidance for development of a pan-coronavirus vaccine.

scholarly journals Review on Diagnostic Methods for SARS-CoV-2

Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Chandrashekhar Chauriya ◽  
Mahesh Sahu ◽  
Anuj Kumar Singh ◽  
Amita Verma
Keyword(s):  
Disease Control ◽  
Diagnostic Methods ◽  
World Health ◽  
Diagnostic Strategy ◽  
Serological Testing ◽  
Rt Pcr ◽  
Number Of Patients ◽  
Control And Prevention ◽  
Antigen Tests ◽  
Novel Coronavirus

Background: In December 2019, a large number of patients with a novel coronavirus were identified in Wuhan, China. The novel coronavirus (COVID-19) is highly contagious and increasing the rate of mortality day by day. The World Health Organization declared COVID-19 as a worldwide pandemic on March 11, 2020. Early diagnosis, of SARS-CoV-2, can restrict the COVID-19 pandemic. Objective: We aim to study the currently available diagnostic methods for COVID-19. Methods: World Health Organisation portal, Centre for Disease control and prevention portal, Indian Council of Medical Research portal, Chinese Centre for Disease Control and prevention portal, Science Direct, Google Scholar, Research Gate, etc. were searched for obtaining data. Results: Rapid diagnosis and prompt treatment can reduce the number of prospective cases. The diagnostic strategy encompasses the screening of virus with nucleic acid amplification test (NAAT) such as real-time reverse-transcription polymerase chain reaction (RT-PCR) assays. Serological testing is a diagnostic procedure used for identifying the presence of an immune responses. Radiological findings in individuals with COVID-19 were characterised by multiple areas of consolidation in chest. Rapid antigen tests are in- vitro diagnostics have been designed to give results within 10–20 min. Conclusion: Rapid, simple, and safe diagnosis of COVID-19 has a great impact on deciding clinical and epidemiological factors. RT-PCR results often require 5 to 6 hours. Diagnosis of by serological testing is not suitable but they are important epidemiologically. At present, the best radiological strategy remains undefined. Rapid antigen tests have limitations on sensitivity.

scholarly journals Monoclonal antibodies for the S2 subunit of spike of SARS-CoV-1 cross-react with the newly-emerged SARS-CoV-2

2020 ◽  
Vol 25 (28) ◽  
Author(s):  
Zhiqiang Zheng ◽  
Vanessa Marthe Monteil ◽  
Sebastian Maurer-Stroh ◽  
Chow Wenn Yew ◽  
Carol Leong ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Common Cold ◽  
Sandwich Elisa ◽  
Cell Receptor ◽  
Cross Reactivity ◽  
S Protein ◽  
Mammalian Cell Lines ◽  
Infected Cells ◽  
The Cross ◽  
Novel Coronavirus

Background A novel coronavirus, SARS-CoV-2, which emerged at the end of 2019 and causes COVID-19, has resulted in worldwide human infections. While genetically distinct, SARS-CoV-1, the aetiological agent responsible for an outbreak of severe acute respiratory syndrome (SARS) in 2002–2003, utilises the same host cell receptor as SARS-CoV-2 for entry: angiotensin-converting enzyme 2 (ACE2). Parts of the SARS-CoV-1 spike glycoprotein (S protein), which interacts with ACE2, appear conserved in SARS-CoV-2. Aim The cross-reactivity with SARS-CoV-2 of monoclonal antibodies (mAbs) previously generated against the S protein of SARS-CoV-1 was assessed. Methods The SARS-CoV-2 S protein sequence was aligned to those of SARS-CoV-1, Middle East respiratory syndrome (MERS) and common-cold coronaviruses. Abilities of mAbs generated against SARS-CoV-1 S protein to bind SARS-CoV-2 or its S protein were tested with SARS-CoV-2 infected cells as well as cells expressing either the full length protein or a fragment of its S2 subunit. Quantitative ELISA was also performed to compare binding of mAbs to recombinant S protein. Results An immunogenic domain in the S2 subunit of SARS-CoV-1 S protein is highly conserved in SARS-CoV-2 but not in MERS and human common-cold coronaviruses. Four murine mAbs raised against this immunogenic fragment could recognise SARS-CoV-2 S protein expressed in mammalian cell lines. In particular, mAb 1A9 was demonstrated to detect S protein in SARS-CoV-2-infected cells and is suitable for use in a sandwich ELISA format. Conclusion The cross-reactive mAbs may serve as useful tools for SARS-CoV-2 research and for the development of diagnostic assays for COVID-19.

scholarly journals COVID-19 coronavirus vaccine design using reverse vaccinology and machine learning

2020 ◽  
Author(s):  
Edison Ong ◽  
Mei U Wong ◽  
Anthony Huffman ◽  
Yongqun He
Keyword(s):  
Machine Learning ◽  
Vaccine Development ◽  
Reverse Vaccinology ◽  
T Cell Epitopes ◽  
Mhc I ◽  
S Protein ◽  
N Protein ◽  
Mhc Ii ◽  
Human Coronaviruses ◽  
New Strategies

AbstractTo ultimately combat the emerging COVID-19 pandemic, it is desired to develop an effective and safe vaccine against this highly contagious disease caused by the SARS-CoV-2 coronavirus. Our literature and clinical trial survey showed that the whole virus, as well as the spike (S) protein, nucleocapsid (N) protein, and membrane protein, have been tested for vaccine development against SARS and MERS. We further used the Vaxign reverse vaccinology tool and the newly developed Vaxign-ML machine learning tool to predict COVID-19 vaccine candidates. The N protein was found to be conserved in the more pathogenic strains (SARS/MERS/COVID-19), but not in the other human coronaviruses that mostly cause mild symptoms. By investigating the entire proteome of SARS-CoV-2, six proteins, including the S protein and five non-structural proteins (nsp3, 3CL-pro, and nsp8-10) were predicted to be adhesins, which are crucial to the viral adhering and host invasion. The S, nsp3, and nsp8 proteins were also predicted by Vaxign-ML to induce high protective antigenicity. Besides the commonly used S protein, the nsp3 protein has not been tested in any coronavirus vaccine studies and was selected for further investigation. The nsp3 was found to be more conserved among SARS-CoV-2, SARS-CoV, and MERS-CoV than among 15 coronaviruses infecting human and other animals. The protein was also predicted to contain promiscuous MHC-I and MHC-II T-cell epitopes, and linear B-cell epitopes localized in specific locations and functional domains of the protein. Our predicted vaccine targets provide new strategies for effective and safe COVID-19 vaccine development.

scholarly journals Antibody Response against the SARS-CoV-2 Nucleocapsid Protein and Its Subdomains—Identification of Pre-Immunization Status by Human Coronaviruses with Multipanel Nucleocapsid Fragment Immunoblotting

COVID ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 105-114
Author(s):  
Sahra Pajenda ◽  
Sebastian Kapps ◽  
Thomas Reiter ◽  
Raimundo Freire ◽  
Veronique A. J. Smits ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Posterior Part ◽  
Rapid Identification ◽  
Diagnostic Methods ◽  
Serum Samples ◽  
N Protein ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Global Pandemic ◽  
Human Coronaviruses

A novel beta coronavirus that emerged in late December 2019 triggered a global pandemic. Diagnostic methods for rapid identification of infected individuals were established in new biotechnological approaches. Vaccine production and application to individuals and measurement of SARS-CoV-2 antibodies also began. Serum samples from 240 health care workers were collected at three-month intervals over nine months. Indirect SARS-CoV-2 nucleocapsid IgG ELISA tests were used to identify humoral immune responses. All seropositive individuals and those with borderline ELISA values were tested with a specifically generated multipanel nucleocapsid fragment immunoblot. Of the 240 individuals, 24 showed seroconversion in ELISA after experiencing COVID-19. All of them showed a positive reaction against the full-length nucleocapsid protein in the immunoblot. The highest reactivity was seen either against fragment N(100–300) or in a minority against the posterior part N(200–419). In general, the staining pattern of COVID-19 patients showed four phenotypes. In contrast, three individuals classified as borderline by ELISA reacted exclusively with fragments N(1–220) and N(100–300) containing the octamer amino acid sequence FYYLGTGP, which is identical in human coronaviruses sharing this sequence with SARS-CoV-2. These represent a unique and thus fifth phenotype. This work suggests the existence of distinct phenotypic patterns of IgG production towards N-protein subdomains.

scholarly journals Cross-reactive neutralization of SARS-CoV-2 by serum antibodies from recovered SARS patients and immunized animals

2020 ◽  
Author(s):  
Yuanmei Zhu ◽  
Danwei Yu ◽  
Yang Han ◽  
Hongxia Yan ◽  
Huihui Chong ◽  
...  
Keyword(s):  
Public Health ◽  
Receptor Binding ◽  
Cross Reactivity ◽  
Social Stability ◽  
Receptor Binding Domain ◽  
Serum Antibodies ◽  
Serum Samples ◽  
S Protein ◽  
Palm Civet ◽  
Novel Coronavirus

AbstractThe current COVID-19 pandemic, caused by a novel coronavirus SARS-CoV-2, poses serious threats to public health and social stability, calling for urgent need for vaccines and therapeutics. SARS-CoV-2 is genetically close to SARS-CoV, thus it is important to define the between antigenic cross-reactivity and neutralization. In this study, we firstly analyzed 20 convalescent serum samples collected from SARS-CoV infected individuals during the 2003 SARS outbreak. All patient sera reacted strongly with the S1 subunit and receptor-binding domain (RBD) of SARS-CoV, cross-reacted with the S ectodomain, S1, RBD, and S2 proteins of SARS-CoV-2, and neutralized both SARS-CoV and SARS-CoV-2 S protein-driven infections. Multiple panels of antisera from mice and rabbits immunized with a full-length S and RBD immunogens of SARS-CoV were also characterized, verifying the cross-reactive neutralization against SARS-CoV-2. Interestingly, we found that a palm civet SARS-CoV-derived RBD elicited more potent cross-neutralizing responses in immunized animals than the RBD from a human SARS-CoV strain, informing a strategy to develop a universe vaccine against emerging CoVs.SummarySerum antibodies from SARS-CoV infected patients and immunized animals cross-neutralize SARS-CoV-2 suggests strategies for universe vaccines against emerging CoVs.

scholarly journals Systematic evaluation of SARS-CoV-2 spike protein derived peptides for diagnosis of COVID-19 patients

2020 ◽  
Author(s):  
Yang Li ◽  
Danyun Lai ◽  
Qing Lei ◽  
Zhaowei Xu ◽  
Hongyan Hou ◽  
...  
Keyword(s):  
Serological Test ◽  
Protein S ◽  
Cross Reactivity ◽  
Spike Protein ◽  
Systematic Evaluation ◽  
Peptide Microarray ◽  
Serological Tests ◽  
S Protein ◽  
Asymptomatic Patients ◽  
Human Coronaviruses

Serological test plays an essential role in monitoring and combating COVID-19 pandemic. Recombinant spike protein (S protein), especially S1 protein is one of the major reagents for serological tests. However, the high cost in production of S protein, and the possible cross-reactivity with other human coronaviruses poses unneglectable challenges. Taking advantage of a peptide microarray of full spike protein coverage, we analyzed 2,434 sera from 858 COVID-19 patients, sera from 63 asymptomatic patients and 610 controls collected from multiple clinical centers. Based on the results of the peptide microarray, we identified several S protein derived 12-mer peptides that have high diagnosis performance. Particularly, for monitoring IgG response, one peptide (aa 1148-1159 or S2-78) has a comparable sensitivity (95.5%, 95% CI 93.7-96.9%) and specificity (96.7%, 95% CI 94.8-98.0%) to that of S1 protein for detection of both COVID-19 patients and asymptomatic infections. Furthermore, the performance of S2-78 IgG for diagnosis was successfully validated by ELISA with an independent sample cohort. By combining S2-78/ S1 with other peptides, a two-step strategy was proposed to ensure both the sensitivity and specificity of S protein based serological assay. The peptide/s identified in this study could be applied independently or in combination with S1 protein for accurate, affordable, and accessible COVID-19 diagnosis.

Sign in / Sign up

Export Citation Format

Share Document