Spike Protein IgG Antibody Immune Response Following SARS-CoV-2 Vaccination and Individual Factors Related to Its Level

Background: Bursa of Fabricius is the acknowledged central humoral immune organ. The bursal-derived peptides play the important roles on the immature B cell development and antibody production. Objective: Here we explored the functions of the new isolated bursal hexapeptide and pentapeptide on the humoral, cellular immune response and antigen presentation to Avian Influenza Virus (AIV) vaccine in mice immunization. Methods: The bursa extract samples were purified following RP HPLC method, and were analyzed with MS/MS to identify the amino acid sequences. Mice were twice subcutaneously injected with AIV inactivated vaccine plus with two new isolated bursal peptides at three dosages, respectively. On two weeks after the second immunization, sera samples were collected from the immunized mice to measure AIV-specific IgG antibody levels and HI antibody titers. Also, on 7th day after the second immunization, lymphocytes were isolated from the immunized mice to detect T cell subtype and lymphocyte viabilities, and the expressions of co-stimulatory molecule on dendritic cells in the immunized mice. Results: Two new bursal hexapeptide and pentapeptide with amino acid sequences KGNRVY and MPPTH were isolated, respectively. Our investigation proved the strong regulatory roles of bursal hexapeptide on AIV-specific IgG levels and HI antibody titers, and lymphocyte viabilities, and the significant increased T cells subpopulation and expressions of MHCII molecule on dendritic cells in the immunized mice. Moreover, our findings verified the significantly enhanced AIV-specific IgG antibody and HI titers, and the strong increased T cell subpopulation and expressions of CD40 molecule on dendritic cells in the mice immunized with AIV vaccine and bursal pentapeptide. Conclusion: We isolated and identified two new hexapeptide and pentapeptide from bursa, and proved that these two bursal peptides effectively induced the AIV-specific antibody, T cell and antigen presentation immune responses, which provided an experimental basis for the further clinical application of the bursal derived active peptide on the vaccine improvement.

Download Full-text

Longitudinal analysis of antibody decay in convalescent COVID-19 patients

Scientific Reports ◽

10.1038/s41598-021-96171-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Weiming Xia ◽

Mingfei Li ◽

Ying Wang ◽

Lewis E. Kazis ◽

Kim Berlo ◽

...

Keyword(s):

Immune Response ◽

Reduction Rate ◽

Mixed Linear Model ◽

Decay Rates ◽

Primary Study ◽

Igg Antibody ◽

Blood Samples ◽

Response Capacity ◽

Index Level ◽

Abbott Architect

AbstractDetermining the sustainability of antibodies targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for predicting immune response against the Coronavirus disease 2019 (COVID-19). To quantify the antibody decay rates among the varying levels of anti-nucleocapsid (anti-N) Immunoglobulin G (IgG) in convalescent COVID-19 patients and estimate the length of time they maintained SARS-CoV-2 specific antibodies, we have collected longitudinal blood samples from 943 patients over the course of seven months after their initial detection of SARS-CoV-2 virus by RT-PCR. Anti-N IgG levels were then quantified in these blood samples. The primary study outcome was the comparison of antibody decay rates from convalescent patients with high or low initial levels of antibodies using a mixed linear model. Additional measures include the length of time that patients maintain sustainable levels of anti-N IgG. Antibody quantification of blood samples donated by the same subject multiple times shows a gradual decrease of IgG levels to the cutoff index level of 1.4 signal/cut-off (S/C) on the Abbott Architect SARS-CoV-2 IgG test. In addition, this study shows that antibody reduction rate is dependent on initial IgG levels, and patients with initial IgG levels above 3 S/C show a significant 1.68-fold faster reduction rate compared to those with initial IgG levels below 3 S/C. For a majority of the donors naturally occurring anti-N antibodies were detected above the threshold for only four months after infection with SARS-CoV-2. This study is clinically important for the prediction of immune response capacity in COVID-19 patients.

Download Full-text

SARS-CoV-2 RNA and antibodies in tear fluid

BMJ Open Ophthalmology ◽

10.1136/bmjophth-2021-000733 ◽

2021 ◽

Vol 6 (1) ◽

pp. e000733

Author(s):

Astrid Muyldermans ◽

Maria Bjerke ◽

Thomas Demuyser ◽

Deborah De Geyter ◽

Ingrid Wybo ◽

...

Keyword(s):

Immune Response ◽

Humoral Immune Response ◽

Spike Protein ◽

Tear Fluid ◽

Local Response ◽

Schirmer Test ◽

Humoral Immune ◽

Non Invasive ◽

Reverse Transcription Pcr ◽

Ocular Symptoms

Background/aimsSARS-CoV-2 is highly contagious. More evidence concerning extrapulmonary transmission routes such as the eyes is urgently needed. Although the humoral immune response is important in the viral containment, the local response in tears has not yet been studied. The aim of our study was twofold: to assess the prevalence of both SARS-CoV-2 RNA and antibodies in tear fluid.MethodsIn a first series, nasopharyngeal sampling and tear sampling by Schirmer test strips were performed in 26 acutely ill patients with COVID-19 to assess the presence of SARS-CoV-2 RNA by reverse transcription PCR. In a second series, IgG and IgA responses to SARS-CoV-2 spike protein in serum and tear fluid of convalescent individuals (n=22) were compared with control individuals (n=15) by ELISA.ResultsSARS-CoV-2 RNA was detected in tears of 7/26 (26.9%) patients with COVID-19. None of them had ocular symptoms. Convalescent individuals displayed a significant higher ratio of IgG (p<0.0001) and IgA (p=0.0068) in tears compared with control individuals. A sensitivity of 77.3% and specificity of 93.3% was observed for IgG, and 59.1% and 100% for IgA.ConclusionsOur results demonstrate the presence of SARS-CoV-2 RNA and a local IgG and IgA immune response in tear fluid. These data confirm the possibility of SARS-CoV-2 transmission through tear fluid and the importance of the eye as a first defence against SARS-CoV-2, indicating the potential of tears as a non-invasive surrogate for serum in monitoring the host immune response.

Download Full-text

Immunological imprinting of the antibody response in COVID-19 patients

Nature Communications ◽

10.1038/s41467-021-23977-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Teresa Aydillo ◽

Alexander Rombauts ◽

Daniel Stadlbauer ◽

Sadaf Aslam ◽

Gabriela Abelenda-Alonso ◽

...

Keyword(s):

Immune Response ◽

Severe Acute Respiratory Syndrome ◽

Antibody Response ◽

Humoral Immune Response ◽

Nucleocapsid Protein ◽

Spike Protein ◽

Ongoing Research ◽

Variable Regions ◽

Humoral Immune ◽

Human Coronaviruses

AbstractIn addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), humans are also susceptible to six other coronaviruses, for which consecutive exposures to antigenically related and divergent seasonal coronaviruses are frequent. Despite the prevalence of COVID-19 pandemic and ongoing research, the nature of the antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here we longitudinally profile the early humoral immune response against SARS-CoV-2 in hospitalized coronavirus disease 2019 (COVID-19) patients and quantify levels of pre-existing immunity to OC43, HKU1 and 229E seasonal coronaviruses, and find a strong back-boosting effect to conserved but not variable regions of OC43 and HKU1 betacoronaviruses spike protein. However, such antibody memory boost to human coronaviruses negatively correlates with the induction of IgG and IgM against SARS-CoV-2 spike and nucleocapsid protein. Our findings thus provide evidence of immunological imprinting by previous seasonal coronavirus infections that can potentially modulate the antibody profile to SARS-CoV-2 infection.

Download Full-text

SARS-CoV-2 in severe COVID-19 induces a TGF-β-dominated chronic immune response that does not target itself

Nature Communications ◽

10.1038/s41467-021-22210-3 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Marta Ferreira-Gomes ◽

Andrey Kruglov ◽

Pawel Durek ◽

Frederik Heinrich ◽

Caroline Tizian ◽

...

Keyword(s):

Gene Expression ◽

Immune Response ◽

Immune Reaction ◽

Adaptive Immune Response ◽

Gene Expression Signature ◽

Spike Protein ◽

Single Cell Level ◽

Cell Level ◽

Adaptive Immune

AbstractThe pathogenesis of severe COVID-19 reflects an inefficient immune reaction to SARS-CoV-2. Here we analyze, at the single cell level, plasmablasts egressed into the blood to study the dynamics of adaptive immune response in COVID-19 patients requiring intensive care. Before seroconversion in response to SARS-CoV-2 spike protein, peripheral plasmablasts display a type 1 interferon-induced gene expression signature; however, following seroconversion, plasmablasts lose this signature, express instead gene signatures induced by IL-21 and TGF-β, and produce mostly IgG1 and IgA1. In the sustained immune reaction from COVID-19 patients, plasmablasts shift to the expression of IgA2, thereby reflecting an instruction by TGF-β. Despite their continued presence in the blood, plasmablasts are not found in the lungs of deceased COVID-19 patients, nor does patient IgA2 binds to the dominant antigens of SARS-CoV-2. Our results thus suggest that, in severe COVID-19, SARS-CoV-2 triggers a chronic immune reaction that is instructed by TGF-β, and is distracted from itself.

Download Full-text

Bioinformatics Analysis of Allele Frequencies and Expression Patterns of ACE2, TMPRSS2 and FURIN in Different Populations and Susceptibility to SARS-CoV-2

Genes ◽

10.3390/genes12071041 ◽

2021 ◽

Vol 12 (7) ◽

pp. 1041

Author(s):

Mohammad Tarek ◽

Hana Abdelzaher ◽

Firas Kobeissy ◽

Hassan A. N. El-Fawal ◽

Mohammed M. Salama ◽

...

Keyword(s):

Immune Response ◽

Genetic Factors ◽

Bioinformatics Analysis ◽

Expression Patterns ◽

Spike Protein ◽

Target Cells ◽

Health Crisis ◽

Expression Levels ◽

Different Populations ◽

Shed Light

The virus responsible for the COVID-19 global health crisis, SARS-CoV-2, has been shown to utilize the ACE2 protein as an entry point to its target cells. The virus has been shown to rely on the actions of TMPRSS2 (a serine protease), as well as FURIN (a peptidase), for the critical priming of its spike protein. It has been postulated that variations in the sequence and expression of SARS-CoV-2’s receptor (ACE2) and the two priming proteases (TMPRSS2 and FURIN) may be critical in contributing to SARS-CoV-2 infectivity. This study aims to examine the different expression levels of FURIN in various tissues and age ranges in light of ACE2 and TMPRSS2 expression levels using the LungMAP database. Furthermore, we retrieved expression quantitative trait loci (eQTLs) of the three genes and their annotation. We analyzed the frequency of the retrieved variants in data from various populations and compared it to the Egyptian population. We highlight FURIN’s potential interplay with the immune response to SARS-CoV-2 and showcase a myriad of variants of the three genes that are differentially expressed across populations. Our findings provide insights into potential genetic factors that impact SARS-CoV-2 infectivity in different populations and shed light on the varying expression patterns of FURIN.

Download Full-text

Seropositivity to Nucleoprotein to detect SARS-CoV-2 infections: a tool to detect breakthrough infections after COVID-19 vaccination

10.1101/2021.10.05.21264555 ◽

2021 ◽

Author(s):

Lotus Leonie van den Hoogen ◽

Gaby Smits ◽

Cheyenne CE van Hagen ◽

Denise Wong ◽

Eric RA Vos ◽

...

Keyword(s):

Immune Response ◽

Primary Infection ◽

Spike Protein ◽

Multiplex Immunoassay ◽

Specific Immunoglobulin ◽

Vaccination History ◽

Specific Igg ◽

Exposure History ◽

Asymptomatic Individuals ◽

Roll Out

Background With COVID-19 vaccine roll-out ongoing in many countries globally, monitoring of breakthrough infections is of great importance. Antibodies persist in the blood after a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Since COVID-19 vaccines induce immune response to the Spike protein of the virus, which is the main serosurveillance target to date, alternative targets should be explored to distinguish infection from vaccination. Methods Multiplex immunoassay data from 1,513 SARS-CoV-2 RT-qPCR-tested individuals (352 positive and 1,161 negative) with a primary infection and no vaccination history were used to determine the accuracy of Nucleoprotein-specific immunoglobulin G (IgG) in detecting past SARS-CoV-2 infection. We also described Spike S1 and Nucleoprotein-specific IgG responses in 230 COVID-19 vaccinated individuals (Pfizer/BioNTech). Results The sensitivity of Nucleoprotein seropositivity was 85% (95% confidence interval: 80-90%) for mild COVID-19 in the first two months following symptom onset. Sensitivity was lower in asymptomatic individuals (67%, 50-81%). Participants who had experienced a SARS-CoV-2 infection up to 11 months preceding vaccination, as assessed by Spike S1 seropositivity or RT-qPCR, produced 2.7-fold higher median levels of IgG to Spike S1 ≥14 days after the first dose as compared to those unexposed to SARS-CoV-2 at ≥7 days after the second dose (p=0.011). Nucleoprotein-specific IgG concentrations were not affected by vaccination in naïve participants. Conclusions Serological responses to Nucleoprotein may prove helpful in identifying SARS-CoV-2 infections after vaccination. Furthermore, it can help interpret IgG to Spike S1 after COVID-19 vaccination as particularly high responses shortly after vaccination could be explained by prior exposure history.

Download Full-text

COVID19 vaccine type and humoral immune response in patients receiving dialysis

10.1101/2021.08.02.21261516 ◽

2021 ◽

Author(s):

Pablo Garcia ◽

Shuchi Anand ◽

Jialin Han ◽

Maria Montez-Rath ◽

Sumi Sun ◽

...

Keyword(s):

Immune Response ◽

Antibody Index ◽

Igg Antibody ◽

Post Vaccination ◽

Humoral Immune ◽

Vaccination Response ◽

Vaccine Type ◽

Igg Index ◽

Impaired Immune Response ◽

Index Value

Background Patients on dialysis vaccinated with the attenuated adenovirus SARS-CoV-2 vaccine might mount an impaired response to vaccination. Methods We evaluated the humoral vaccination response among 2,099 fully vaccinated patients receiving dialysis. We used commercially available assays (Siemens) to assess prevalence of no response or diminished response to COVID-19 vaccination by vaccine type. We defined no seroconversion as lack of change from negative to positive in total RBD Ig antibody, no detectable response on semiquantitative RBD IgG antibody (index value <1) as no RBD IgG response, and a semiquantitative RBD IgG index value <10 as diminished RBD IgG response Results Of the 2,099 fully vaccinated patients on dialysis, the proportion receiving the mRNA1273, BNT162b2, and Ad26.COV2.S were 62% (n=1316), 20% (n=416) and 18% (n=367), respectively. A third (33.3%) of patients receiving the attenuated adenovirus Ad26.COV2.S vaccine failed to seroconvert and an additional 36% had no detectable or diminished IgG response even 28-60 days post vaccination. Conclusions One in three fully vaccinated patients receiving dialysis had evidence of an impaired immune response to the attenuated adenovirus Ad26.COV2.S vaccine.

Download Full-text

Long-term persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific and neutralizing antibodies in recovered COVID-19 patients

10.21203/rs.3.rs-1073046/v1 ◽

2021 ◽

Author(s):

Jira Chansaenroj ◽

Ritthideach Yorsaeng ◽

Nasamon Wanlapakorn ◽

Chintana Chirathaworn ◽

Natthinee Sudhinaraset ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Symptom Onset ◽

Neutralizing Antibodies ◽

Serum Antibody ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Spike Protein ◽

Immunological Study ◽

Igg Antibody ◽

Vaccine Schedule

Abstract Understanding antibody responses after natural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can guide the coronavirus disease 2019 (COVID-19) vaccine schedule. This study aimed to assess the dynamics of SARS-CoV-2 antibodies, including anti-spike protein 1 (S1) immunoglobulin (Ig)G, anti-receptor-binding domain (RBD) total Ig, anti-S1 IgA, and neutralizing antibody against wild-type SARS-CoV-2 in a cohort of patients who were previously infected with SARS-CoV-2. Between March and May 2020, 531 individuals with virologically confirmed cases of SARS-CoV-2 infection were enrolled in our immunological study. The neutralizing titers against SARS-CoV-2 were detected in 95.2%, 86.7%, 85.0%, and 85.4% of recovered COVID-19 patients at 3, 6, 9, and 12 months after symptom onset, respectively. The seropositivity rate of anti-S1 IgG, anti-RBD total Ig, anti-S1 IgA, and neutralizing titers remained at 68.6%, 89.6%, 77.1%, and 85.4%, respectively, at 12 months after symptom onset. The half-life of neutralizing titers was estimated at 100.7 days (95% confidence interval = 44.5 – 327.4 days, R2 = 0.106). These results support that the decline in serum antibody levels over time depends on the symptom severity, and the individuals with high IgG antibody titers experienced a significantly longer persistence of SARS-CoV-2-specific antibody responses than those with lower titers.

Download Full-text

Crucial Mutations of Spike Protein on SARS-CoV-2 Evolved to Variant Strains Escaping Neutralization of Convalescent Plasmas and RBD-Specific Monoclonal Antibodies

Frontiers in Immunology ◽

10.3389/fimmu.2021.693775 ◽

2021 ◽

Vol 12 ◽

Author(s):

Chengchao Ding ◽

Jun He ◽

Xiangyu Zhang ◽

Chengcheng Jiang ◽

Yong Sun ◽

...

Keyword(s):

Immune Response ◽

Monoclonal Antibodies ◽

Humoral Immune Response ◽

Immune Escape ◽

Spike Protein ◽

Single Amino Acid ◽

Humoral Immune ◽

Cross Neutralization ◽

Altered Sensitivity ◽

Single Amino Acid Mutation

Small number of SARS-CoV-2 epidemic lineages did not efficiently exhibit a neutralization profile, while single amino acid mutation in the spike protein has not been confirmed in altering viral antigenicity resulting in immune escape. To identify crucial mutations in spike protein that escape humoral immune response, we evaluated the cross-neutralization of convalescent plasmas and RBD-specific monoclonal antibodies (mAbs) against various spike protein-based pseudoviruses. Three of 24 SARS-CoV-2 pseudoviruses containing different mutations in spike protein, including D614G, A475V, and E484Q, consistently showed an altered sensitivity to neutralization by convalescent plasmas. A475V and E484Q mutants are highly resistant to neutralization by mAb B38 and 2-4, suggesting that some crucial mutations in spike protein might evolve SARS-CoV-2 variants capable of escaping humoral immune response.

Download Full-text