Cross-reactivity of antibodies from non-hospitalized COVID-19 positive individuals against the native and B.1.351 SARS-CoV-2 spike proteins

AbstractSARS-CoV-2 variants of concern (VOCs) have emerged worldwide, with implications on the spread of the pandemic. Characterizing the cross-reactivity of antibodies against these VOCs is necessary to understand the humoral response of non-hospitalized individuals previously infected with SARS-CoV-2, a population that remains understudied. Thirty-two SARS-CoV-2-positive (PCR-confirmed) and non-hospitalized Canadian adults were enrolled 14–21 days post-diagnosis in 2020, before the emergence of the B.1.351 (also known as Beta), B.1.617.2 (Delta) and P.1 (Gamma) VOCs. Sera were collected 4 and 16 weeks post-diagnosis. Antibody levels and pseudo-neutralization of the ectodomain of SARS-CoV-2 spike protein/human ACE-2 receptor interaction were analyzed with native, B.1.351, B.1.617.2 and P.1 variant spike proteins. Despite a lower response observed for the variant spike proteins, we report evidence of a sustained humoral response against native, B.1.351, B.1.617.2 and P.1 variant spike proteins among non-hospitalized Canadian adults. Furthermore, this response inhibited the interaction between the spike proteins from the different VOCs and ACE-2 receptor for ≥ 16 weeks post-diagnosis, except for individuals aged 18–49 years who showed no inhibition of the interaction between B.1.617.1 or B.1.617.2 spike and ACE-2. Interestingly, the affinity (KD) measured between the spike proteins (native, B.1.351, B.1.617.2 and P.1) and antibodies elicited in sera of infected and vaccinated (BNT162b2 and ChAdOx1 nCoV-19) individuals was invariant. Relative to sera from vaccine-naïve (and previously infected) individuals, sera from vaccinated individuals had higher antibody levels (as measured with label-free SPR) and more efficiently inhibited the spike–ACE-2 interactions, even among individuals aged 18–49 years, showing the effectiveness of vaccination.

Download Full-text

Potent binding of 2019 novel coronavirus spike protein by a SARS coronavirus-specific human monoclonal antibody

10.1101/2020.01.28.923011 ◽

2020 ◽

Cited By ~ 13

Author(s):

Xiaolong Tian ◽

Cheng Li ◽

Ailing Huang ◽

Shuai Xia ◽

Sicong Lu ◽

...

Keyword(s):

Monoclonal Antibody ◽

Binding Site ◽

Neutralizing Antibodies ◽

Rapid Development ◽

Antiviral Treatment ◽

Human Monoclonal Antibody ◽

Cross Reactivity ◽

Spike Protein ◽

The Cross ◽

Novel Coronavirus

ABSTRACTThe newly identified 2019 novel coronavirus (2019-nCoV) has caused more than 800 laboratory-confirmed human infections, including 25 deaths, posing a serious threat to human health. Currently, however, there is no specific antiviral treatment or vaccine. Considering the relatively high identity of receptor binding domain (RBD) in 2019-nCoV and SARS-CoV, it is urgent to assess the cross-reactivity of anti-SARS-CoV antibodies with 2019-nCoV spike protein, which could have important implications for rapid development of vaccines and therapeutic antibodies against 2019-nCoV. Here, we report for the first time that a SARS-CoV-specific human monoclonal antibody, CR3022, could bind potently with 2019-nCoV RBD (KD of 6.3 nM). The epitope of CR3022 does not overlap with the ACE2 binding site within 2019-nCoV RBD. Therefore, CR3022 has the potential to be developed as candidate therapeutics, alone or in combination with other neutralizing antibodies, for the prevention and treatment of 2019-nCoV infections. Interestingly, some of the most potent SARS-CoV-specific neutralizing antibodies (e.g., m396, CR3014) that target the ACE2 binding site of SARS-CoV failed to bind 2019-nCoV spike protein, indicating that the difference in the RBD of SARS-CoV and 2019-nCoV has a critical impact for the cross-reactivity of neutralizing antibodies, and that it is still necessary to develop novel monoclonal antibodies that could bind specifically to 2019-nCoV RBD.

Download Full-text

A Cross-Reactive Mouse Monoclonal Antibody against Rhinovirus Mediates Phagocytosis In Vitro

Proceedings ◽

10.3390/proceedings2020050132 ◽

2020 ◽

Vol 50 (1) ◽

pp. 132

Author(s):

Mohammad Amin Behzadi ◽

James Duehr ◽

Angela Choi ◽

Michael Schotsaert ◽

Adolfo García-Sastre ◽

...

Keyword(s):

Recombinant Dna ◽

Specific Binding ◽

Humoral Response ◽

Cross Reactivity ◽

Capsid Proteins ◽

Escape Mutant ◽

Study Results ◽

The Cross ◽

Different Strains

Human rhinoviruses (RVs) are the main cause of the common cold worldwide. To date, more than 160 serotypes of the virus have been recognized. These viruses are categorized into three major groups: A, B, and C. There are currently no approved vaccines available to prevent infection with RVs. We designed a mouse immunization strategy that aimed to elicit a humoral response against conserved regions of capsid proteins of RV-A viruses. To this end, recombinant DNA plasmids expressing the capsid proteins (VP1-4) and two proteases (2A and 3C) of RV1A, 16, 49, 68, and 71 were engineered. Mice were sequentially vaccinated with these DNA plasmids at three-week intervals. After a final boost with purified whole virus using the RV15 strain, mice spleens were extracted and cells expressing monoclonal antibodies (mAbs) were generated by hybridoma fusion. A total of 98 mAbs with reactivity to different strains of RV-A were isolated. After isotyping, 22 mAbs expressing an IgG Fc-domain were selected for further expansion and purification. Three mAbs showed cross-reactivity against multiple strains of RV-A viruses by ELISA, including 1A, 1B, 15, 16, and 49. Additional mAbs had strain-specific binding patterns, with a surprising number of mAbs showing reactivity to RV15, the strain used for the final vaccination. Using a microneutralization assay, we found that the RV15-specific mAbs, but not the cross-reactive mAbs, were highly neutralizing. Additional testing in a flow cytometry-based antibody-dependent cellular phagocytosis (ADCP) assay revealed a high degree of ADCP activity for one of the cross-reactive mAbs. Epitope mapping of the neutralizing mAbs via escape mutant viruses revealed binding sites with a shared epitope on VP1 of RV15. The epitope of the ADCP-active, non-neutralizing mAb was determined by the microarray analysis of cyclic constrained peptides generated from the VP1 capsid protein. This study identified a cross-reactive mAb that mediates phagocytosis. These findings could be used toward the development of vaccines against RV. The full study results have since been published (https://doi.org/10.1038/s41598-020-66600-x).

Download Full-text

Sensitivity in Detection of Antibodies to Nucleocapsid and Spike Proteins of Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Coronavirus Disease 2019

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa273 ◽

2020 ◽

Vol 222 (2) ◽

pp. 206-213 ◽

Cited By ~ 52

Author(s):

Peter D Burbelo ◽

Francis X Riedo ◽

Chihiro Morishima ◽

Stephen Rawlings ◽

Davey Smith ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Nucleocapsid Protein ◽

Spike Protein ◽

Heat Inactivation ◽

Cross Sectional ◽

Quantitative Measurements ◽

Initial Symptoms ◽

Antibody Levels ◽

Immunocompetent Patients ◽

Spike Proteins

Abstract Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related disease and death. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response. Methods Quantitative measurements of plasma or serum antibodies to the nucleocapsid and spike proteins were analyzed using luciferase immunoprecipitation system assays in 100 cross-sectional or longitudinal samples from patients with SARS-CoV-2 infection. A subset of samples was tested both with and without heat inactivation. Results At >14 days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, whereas antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from 6 patients with COVID-19 showed anti-nucleocapsid and spike protein antibodies appearing between days 8 and 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2, compared with immunocompetent patients. Conclusions Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples with a luciferase immunoprecipitation system assay is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

Download Full-text

Characterization of a Pan-Immunoglobulin Assay Quantifying Antibodies Directed against the Receptor Binding Domain of the SARS-CoV-2 S1-Subunit of the Spike Protein: A Population-Based Study

Journal of Clinical Medicine ◽

10.3390/jcm9123989 ◽

2020 ◽

Vol 9 (12) ◽

pp. 3989

Author(s):

Anna Schaffner ◽

Lorenz Risch ◽

Stefanie Aeschbacher ◽

Corina Risch ◽

Myriam C. Weber ◽

...

Keyword(s):

Receptor Binding ◽

Clinical Characteristics ◽

Protein A ◽

Population Based ◽

Cross Reactivity ◽

Binding Domain ◽

Spike Protein ◽

Receptor Binding Domain ◽

Population Based Study ◽

Antibody Levels

Pan-immunoglobulin assays can simultaneously detect IgG, IgM and IgA directed against the receptor binding domain (RBD) of the S1 subunit of the spike protein (S) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 S1-RBD Ig). In this work, we aim to evaluate a quantitative SARS-CoV-2 S1-RBD Ig electrochemiluminescence immunoassay (ECLIA) regarding analytical, diagnostic, operational and clinical characteristics. Our work takes the form of a population-based study in the principality of Liechtenstein, including 125 cases with clinically well-described and laboratory confirmed SARS-CoV-2 infection and 1159 individuals without evidence of coronavirus disease 2019 (COVID-19). SARS-CoV-2 cases were tested for antibodies in sera taken with a median of 48 days (interquartile range, IQR, 43–52) and 139 days (IQR, 129–144) after symptom onset. Sera were also tested with other assays targeting antibodies against non-RBD-S1 and -S1/S2 epitopes. Sensitivity was 97.6% (95% confidence interval, CI, 93.2–99.1), whereas specificity was 99.8% (95% CI, 99.4–99.9). Antibody levels linearly decreased from hospitalized patients to symptomatic outpatients and SARS-CoV-2 infection without symptoms (p < 0.001). Among cases with SARS-CoV-2 infection, smokers had lower antibody levels than non-smokers (p = 0.04), and patients with fever had higher antibody levels than patients without fever (p = 0.001). Pan-SARS-CoV-2 S1-RBD Ig in SARS-CoV-2 infection cases significantly increased from first to second follow-up (p < 0.001). A substantial proportion of individuals without evidence of past SARS-CoV-2 infection displayed non-S1-RBD antibody reactivities (248/1159, i.e., 21.4%, 95% CI, 19.1–23.4). In conclusion, a quantitative SARS-CoV-2 S1-RBD Ig assay offers favorable and sustained assay characteristics allowing the determination of quantitative associations between clinical characteristics (e.g., disease severity, smoking or fever) and antibody levels. The assay could also help to identify individuals with antibodies of non-S1-RBD specificity with potential clinical cross-reactivity to SARS-CoV-2.

Download Full-text

Serological surveillance of SARS-CoV-2: trends and humoral response in a cohort of public health workers

10.1101/2020.10.21.20216689 ◽

2020 ◽

Author(s):

Ross J Harris ◽

Heather J Whitaker ◽

Nick J Andrews ◽

Felicity Aiano ◽

Zahin Amin-Chowdhury ◽

...

Keyword(s):

Half Life ◽

Healthcare Workers ◽

Health Workers ◽

Natural Infection ◽

Humoral Response ◽

Spike Protein ◽

Positive Test ◽

Public Health Workers ◽

Serological Surveillance ◽

Antibody Levels

AbstractBackgroundThere is considerable debate about the rate of antibody waning after SARS-CoV-2 infection, raising questions around long-term immunity following both natural infection and vaccination. We undertook prospective serosurveillance in a large cohort of healthy adults from the start of the epidemic in England.MethodsThe serosurveillance cohort included office and laboratory-based staff and healthcare workers in 4 sites in England, who were tested monthly for SARS-CoV-2 spike protein and nucleoprotein IgG between 23rd March and 20th August 2020. Antibody levels from 21 days after a positive test were modelled using mixed effects regression models.FindingsIn total, 2247 individuals were recruited and 2014 (90%) had 3-5 monthly antibody tests. Overall, 272 (12.1%) of individuals had at least one positive/equivocal spike protein IgG result, with the highest proportion in a hospital site (22%), 14% in London and 2.1% in a rural area. Results were similar for nucleoprotein IgG. Following a positive result, 39/587 (6.6%) tested negative for nucleoprotein IgG and 52/515 (10.1%) for spike protein IgG. Nucleoprotein IgG declined by 6.4% per week (95% CI, 5.5-7.4%; half-life, 75 [95% CI, 66-89] days) and spike protein IgG by 5.8% (95% CI, 5.1-6.6%; half-life, 83 [95% CI, 73-96] days).ConclusionsOver the study period SARS-CoV-2 seropositivity was 8-10% overall and up to 21% in clinical healthcare workers. In seropositive individuals, nucleoprotein and spike protein IgG antibodies declined with time after infection and 50% are predicted to fall below the positive test threshold after 6 months.FundingPHE

Download Full-text

Induction of Th1/Th2-Balanced Protection Against SARS-CoV-2 Through Mucosal Delivery of An Adenovirus Vaccine Expressing an Engineered Spike Protein

10.21203/rs.3.rs-134494/v1 ◽

2021 ◽

Author(s):

Nai-Hsiang Chung ◽

Ying-Chin Chen ◽

Shiu-Ju Yang ◽

Yu-Ching Lin ◽

Horng-Yunn Dou ◽

...

Keyword(s):

Cellular Response ◽

Body Weight Loss ◽

Humoral Response ◽

Protein S ◽

Spike Protein ◽

Th2 Cells ◽

Neutralizing Activity ◽

Viral Loads ◽

Mucosal Delivery ◽

Antibody Levels

Abstract We developed a series of recombinant human type 5 adenoviruses that express the full-length or membrane-truncated spike protein (S) of SARS-CoV-2 (AdCoV2-S or AdCoV2-SdTM, respectively). We tested the immunoprotective efficacy against SARS-CoV-2 via intranasal (i.n.) or subcutaneous (s.c.) immunization in a rodent model following two-dose immunizations. Mucosal delivery of adenovirus (Ad) vaccines could induce anti-SARS-CoV-2 IgG and IgA in the serum and in the mucosal, respectively as indicated by vaginal wash (vw). Serum anti-SARS-CoV-2 IgG but not IgA was induced in the vw by s.c. injection of AdCoV2-S. Intranasal administration of AdCoV2-S was able to induce higher anti-SARS-CoV-2 antibody levels than s.c. injection. Immunization with AdCoV2-SdTM induced a lower antibody response than AdCoV2-S. In addition, the degree of neutralization of clinically isolated SARS-CoV-2 in the serum correlated with the above anti-SARS-CoV-2 responses; the most potent neutralizing activity was observed in the AdCoV2-S i.n. group, and less viral neutralizing activity was observed in response to AdCoV2-S s.c. and AdCoV2dTM i.n. Novelty, S-specific IgG1 which represented Th2-mediated humoral response was dominantly induced in Ad i.n.-immunized serum in contrast to more IgG2a which represented Th1-mediated cellular response found in Ad s.c.-immunized serum. The activation of S-specific IFN-ɣ and IL-4 in Th1 and Th2 cells, respectively, was observed in the AdCoV2s i.n. and s.c. groups, indicating the Th1/Th2-balenced immunity was activated. During the protection study, two doses of i.n. AdCoV2-S or i.n. AdCoV2-SdTM significantly prevented body weight loss and reduced pulmonary viral loads in hamsters. A significant reduction in inflammation in the lungs was observed in AdCoV-S-immunized hamsters following a SARS-CoV-2 challenge. It correlated to Th1 cytokine but no inflammatory cytokines secretions found in i.n. AdCoV-immunized respiratory tract. These results indicate that intranasal delivery of AdCoV2-S vaccines is safe and potent at preventing SARS-CoV-2 infections.

Download Full-text

Serologic cross-reactivity of SARS-CoV-2 with endemic and seasonal Betacoronaviruses

10.1101/2020.06.22.20137695 ◽

2020 ◽

Cited By ~ 11

Author(s):

Jennifer Hicks ◽

Carleen Klumpp-Thomas ◽

Heather Kalish ◽

Anandakumar Shunmugavel ◽

Jennifer Mehalko ◽

...

Keyword(s):

Recombinant Proteins ◽

Humoral Immunity ◽

Sequence Homology ◽

Viral Genome ◽

Cross Reactivity ◽

Serum Antibodies ◽

The Cross ◽

Immunosorbent Assays ◽

Spike Proteins

ABSTRACTIn order to properly understand the spread of SARS-CoV-2 infection and development of humoral immunity, researchers have evaluated the presence of serum antibodies of people worldwide experiencing the pandemic. These studies rely on the use of recombinant proteins from the viral genome in order to identify serum antibodies that recognize SARS-CoV-2 epitopes. Here, we discuss the cross-reactivity potential of SARS-CoV-2 antibodies with the full spike proteins of four other Betacoronaviruses that cause disease in humans, MERS-CoV, SARS-CoV, HCoV-OC43, and HCoV-HKU1. Using enzyme-linked immunosorbent assays (ELISAs), we detected the potential cross-reactivity of antibodies against SARS-CoV-2 towards the four other coronaviruses, with the strongest cross-recognition between SARS-CoV-2 and SARS /MERS-CoV antibodies, as expected based on sequence homology of their respective spike proteins. Further analysis of cross-reactivity could provide informative data that could lead to intelligently designed pan-coronavirus therapeutics or vaccines.

Download Full-text

Addressing anti-syncytin antibody levels, and fertility and breastfeeding concerns, following BNT162B2 COVID-19 mRNA vaccination

10.1101/2021.05.23.21257686 ◽

2021 ◽

Author(s):

Citra Nurfarah Mattar ◽

Winston Koh ◽

Yiqi Seow ◽

Shawn Hoon ◽

Aparna VENKATESH ◽

...

Keyword(s):

Breast Milk ◽

Humoral Response ◽

Cross Reactivity ◽

Neutralising Antibodies ◽

Post Vaccination ◽

History Of ◽

Observational Cohort ◽

Front Line Workers ◽

Antibody Levels ◽

Breast Fed

Objective: To determine whether antibodies against the SARS-CoV-2 spike protein following BNT162B2 (Pfizer-BioNTech) COVID-19 mRNA vaccination cross-react with human syncytin-1 protein, and if BNT162B2 mRNA enters breast milk. Methods: In this observational cohort study of female front-line workers with no history of COVID-19 infection, we amplified BNT162B2 mRNA in plasma and breast milk and assayed anti-SARS-CoV-2 neutralising antibodies and anti-human syncytin-1 binding antibodies in plasma, at early (1-4 days) and late (4-7 weeks) time points following first-dose vaccination. Results: Fifteen consented participants (mean age 40.4 years, various ethnicities) who received at least one dose of BNT162B2, including five breast-feeding women and two women who were inadvertently vaccinated in early pregnancy, were recruited. BNT162B2 mRNA, detected by amplifying part of the spike-encoding region, was detected in plasma 1-4 days following the first dose (n=13), but not 4-5 weeks later (n=2), nor was the mRNA isolated from aqueous or lipid breast milk fractions collected 0-7 days post-vaccination (n=5). Vaccine recipients demonstrated strong SARS-CoV-2 neutralising activity by at least four weeks after the first dose (n=15), including the two pregnant women. None had placental anti-syncytin-1 binding antibodies at either time-point following vaccination. Conclusions: BNT162B2-vaccinated women did not transmit vaccine mRNA to breast milk, and did not produce a concurrent humoral response to syncytin-1, suggesting that cross-reactivity to syncytin-1 on the developing trophoblast, or other adverse effects in the breast-fed infant from vaccine mRNA ingestion, are unlikely.

Download Full-text

mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant

10.1101/2021.12.14.21267755 ◽

2021 ◽

Author(s):

Wilfredo F Garcia-Beltran ◽

Kerri J. St Denis ◽

Angelique Hoelzemer ◽

Evan C. Lam ◽

Adam D. Nitido ◽

...

Keyword(s):

Humoral Immunity ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Cross Reactivity ◽

Antibody Responses ◽

Spike Protein ◽

Wild Type ◽

The Cross ◽

Potent Neutralization

Recent surveillance has revealed the emergence of the SARS-CoV-2 Omicron variant (BA.1/B.1.1.529) harboring up to 36 mutations in spike protein, the target of vaccine-induced neutralizing antibodies. Given its potential to escape vaccine-induced humoral immunity, we measured neutralization potency of sera from 88 mRNA-1273, 111 BNT162b, and 40 Ad26.COV2.S vaccine recipients against wild type, Delta, and Omicron SARS-CoV-2 pseudoviruses. We included individuals that were vaccinated recently (<3 months), distantly (6-12 months), or recently boosted, and accounted for prior SARS-CoV-2 infection. Remarkably, neutralization of Omicron was undetectable in most vaccinated individuals. However, individuals boosted with mRNA vaccines exhibited potent neutralization of Omicron only 4-6-fold lower than wild type, suggesting that boosters enhance the cross-reactivity of neutralizing antibody responses. In addition, we find Omicron pseudovirus is significantly more infectious than any other variant tested. Overall, this study highlights the importance of boosters to broaden neutralizing antibody responses against highly divergent SARS-CoV-2 variants.

Download Full-text