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1.
PLoS One ; 17(1): e0262657, 2022.
Article in English | MEDLINE | ID: covidwho-1639087

ABSTRACT

BACKGROUND: Tests for SARS-CoV-2 immunity are needed to help assess responses to vaccination, which can be heterogeneous and may wane over time. The plaque reduction neutralization test (PRNT) is considered the gold standard for measuring serum neutralizing antibodies but requires high level biosafety, live viral cultures and days to complete. We hypothesized that competitive enzyme linked immunoassays (ELISAs) based on SARS-CoV-2 spike protein's receptor binding domain (RBD) attachment to its host receptor, the angiotensin converting enzyme 2 receptor (ACE2r), would correlate with PRNT, given the central role of RBD-ACE2r interactions in infection and published studies to date, and enable evaluation of vaccine responses. METHODS AND RESULTS: Configuration and development of a competitive ELISA with plate-bound RBD and soluble biotinylated ACE2r was accomplished using pairs of pre/post vaccine serum. When the competitive ELISA was used to evaluate N = 32 samples from COVID-19 patients previously tested by PRNT, excellent correlation in IC50 results were observed (rs = .83, p < 0.0001). When the competitive ELISA was used to evaluate N = 42 vaccinated individuals and an additional N = 13 unvaccinated recovered COVID-19 patients, significant differences in RBD-ACE2r inhibitory activity were associated with prior history of COVID-19 and type of vaccine received. In longitudinal analyses pre and up to 200 days post vaccine, surrogate neutralizing activity increased markedly after primary and booster vaccine doses, but fell substantially, up to <12% maximal levels within 6 months. CONCLUSIONS: A competitive ELISA based on inhibition of RBD-ACE2r attachment correlates well with PRNT, quantifies significantly higher activity among vaccine recipients with prior COVID (vs. those without), and highlights marked declines in surrogate neutralizing activity over a 6 month period post vaccination. The findings raise concern about the duration of vaccine responses and potential need for booster shots.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Vaccines, Synthetic/immunology , /immunology , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/immunology , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Vaccines, Synthetic/administration & dosage , /administration & dosage
2.
Front Immunol ; 12: 771011, 2021.
Article in English | MEDLINE | ID: covidwho-1639016

ABSTRACT

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is an ongoing pandemic. Detection and vaccination are essential for disease control, but they are distinct and complex operations that require significant improvements. Here, we developed an integrated detection and vaccination system to greatly simplify these efforts. We constructed recombinant baculoviruses to separately display the nucleocapsid (N) and spike (S) proteins of SARS-CoV-2. Insect cells infected by the recombinant baculoviruses were used to generate a cell-based system to accurately detect patient serum. Notably, although well-recognized by our newly developed detection system in which S-displaying insect cells acted as antigen, anti-S antibodies from many patients were barely detectable by Western blot, evidencing that COVID-19 patients primarily produce conformation-dependent anti-S antibodies. Furthermore, the same baculovirus constructs can display N (N-Bac) or S (S-Bac) on the baculovirus envelope and serve as vector vaccines. Animal experiments show that S-Bac or N-Bac immunization in mice elicited a strong and specific antibody response, and S-Bac in particular stimulated effective neutralizing antibodies without the need for adjuvant. Our integrated system maintains antigen conformation and membrane structure to facilitate serum detection and antibody stimulation. Thus, compared with currently available technologies, our system represents a simplified and efficient platform for better SARS-CoV-2 detection and vaccination.


Subject(s)
Baculoviridae/immunology , COVID-19 Vaccines/immunology , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Aged, 80 and over , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Baculoviridae/genetics , COVID-19/immunology , COVID-19/prevention & control , Cell Line , Cell Surface Display Techniques , Coronavirus Nucleocapsid Proteins/genetics , Enzyme-Linked Immunosorbent Assay , Female , HEK293 Cells , Humans , Male , Mice , Mice, Inbred BALB C , Middle Aged , Phosphoproteins/genetics , Phosphoproteins/immunology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/genetics , Spodoptera , Vaccination , Young Adult
3.
J Clin Virol ; 146: 105057, 2022 01.
Article in English | MEDLINE | ID: covidwho-1638778

ABSTRACT

It is well-known that the Coronavirus Disease 2019, which is caused by the beta-coronavirus severe acute respiratory syndrome (SARS-CoV-2), emerged in December 2019 followed by an outbreak first reported in Wuhan, China. Thus far, vaccination appears to be the only way to bring the pandemic to an end. In the present study, immunogenicity data was evaluated using LIAISON® SARS-CoV-2 TrimericS IgG assay (DiaSorin S.p.A) among a sample of 52 vaccinated healthcare workers, five of whom were previously infected with SARS-CoV-2 and 47 who were seronegative, over a time span of ≤90 days following the second dose of the BNT162b2 mRNA vaccine. The test detects antibodies against the Trimeric complex (S1, S2 and receptor binding domain). The overall mean value of the serum levels of IgG antibodies to SARS-CoV-2 30 days following the second dose of the vaccine was 1,901.8 binding arbitrary unit (BAU)/ml, after 60 days the mean value declined to 1,244.9 BAU/ml. The antibody levels then reached a plateau, as confirmed by the antibody test carried out 90 days following the second dose, which revealed a mean value of 1,032.4 BAU/ml (P<0.0001). A higher level was observed at all three times in male subjects compared with female subjects, and in younger male participants compared with female participants, although these differences did not reach a statistically significant level. Similarly, no significant difference was found in antibody values at different times according to age. After the second dose of the vaccine, two subjects were infected with SARS-CoV-2, and an increase in antibody values in the third assay was observed in both individuals.


Subject(s)
COVID-19 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , Female , Humans , Male , Preliminary Data , SARS-CoV-2 , Vaccines, Synthetic
4.
J Transl Med ; 20(1): 22, 2022 01 08.
Article in English | MEDLINE | ID: covidwho-1637829

ABSTRACT

BACKGROUND: COVID-19 vaccines have demonstrated effectiveness in reducing SARS-CoV-2 mild and severe outcomes. In vaccinated subjects with SARS-CoV-2 history, RBD-specific IgG and pseudovirus neutralization titers were rapidly recalled by a single BTN162b2 vaccine dose to higher levels than those in naïve recipients after the second dose, irrespective of waning immunity. In this study, we inspected the long-term kinetic and neutralizing responses of S-specific IgG induced by two administrations of BTN162b2 vaccine in infection-naïve subjects and in subjects previously infected with SARS-CoV-2. METHODS: Twenty-six naïve and 9 previously SARS-CoV-2 infected subjects during the second wave of the pandemic in Italy were enrolled for this study. The two groups had comparable demographic and clinical characteristics. By means of ELISA and pseudotyped-neutralization assays, we investigated the kinetics of developed IgG-RBD and their neutralizing activity against both the ancestral D614G and the SARS-CoV-2 variants of concern emerged later, respectively. The Wilcoxon matched pair signed rank test and the Kruskal-Wallis test with Dunn's correction for multiple comparison were applied when needed. RESULTS: Although after 15 weeks from vaccination IgG-RBD dropped in all participants, naïve subjects experienced a more dramatic decline than those with previous SARS-CoV-2 infection. Neutralizing antibodies remained higher in subjects with SARS-CoV-2 history and conferred broad-spectrum protection. CONCLUSIONS: These data suggest that hybrid immunity to SARS-CoV-2 has a relevant impact on the development of IgG-RBD upon vaccination. However, the rapid decay of vaccination-elicited antibodies highlights that the administration of a third dose is expected to boost the response and acquire high levels of cross-neutralizing antibodies.


Subject(s)
COVID-19 , Volatile Organic Compounds , Antibodies, Neutralizing , Antibodies, Viral , Antibody Formation , COVID-19 Vaccines , Humans , SARS-CoV-2 , Vaccination
5.
Eur J Med Res ; 27(1): 6, 2022 Jan 13.
Article in English | MEDLINE | ID: covidwho-1635980

ABSTRACT

SARS-CoV-2, a novel coronavirus, is the agent responsible for the COVID-19 pandemic and is a major public health concern nowadays. The rapid and global spread of this coronavirus leads to an increase in hospitalizations and thousands of deaths in many countries. To date, great efforts have been made worldwide for the efficient management of this crisis, but there is still no effective and specific treatment for COVID-19. The primary therapies to treat the disease are antivirals, anti-inflammatories and respiratory therapy. In addition, antibody therapies currently have been a many active and essential part of SARS-CoV-2 infection treatment. Ongoing trials are proposed different therapeutic options including various drugs, convalescent plasma therapy, monoclonal antibodies, immunoglobulin therapy, and cell therapy. The present study summarized current evidence of these therapeutic approaches to assess their efficacy and safety for COVID-19 treatment. We tried to provide comprehensive information about the available potential therapeutic approaches against COVID-19 to support researchers and physicians in any current and future progress in treating COVID-19 patients.


Subject(s)
COVID-19/drug therapy , COVID-19/therapy , Immunization, Passive , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing , Antiviral Agents/therapeutic use , Clinical Trials as Topic , Dietary Supplements , Humans , Immunization, Passive/methods , Immunoglobulins, Intravenous/therapeutic use , Pandemics , SARS-CoV-2 , Treatment Outcome
6.
Oxid Med Cell Longev ; 2022: 5397733, 2022.
Article in English | MEDLINE | ID: covidwho-1635531

ABSTRACT

The infection of coronavirus disease (COVID-19) seriously threatens human life. It is urgent to generate effective and safe specific antibodies (Abs) against the pathogenic elements of COVID-19. Mice were immunized with SARS-CoV-2 spike protein antigens: S ectodomain-1 (CoV, in short) mixed in Alum adjuvant for 2 times and boosted with CoV weekly for 6 times. A portion of mice were treated with Maotai liquor (MTL, in short) or/and heat stress (HS) together with CoV boosting. We observed that the anti-CoV Ab was successfully induced in mice that received the CoV/Alum immunization for 2 times. However, upon boosting with CoV, the CoV Ab production diminished progressively; spleen CoV Ab-producing plasma cell counts reduced, in which substantial CoV-specific Ab-producing plasma cells (sPC) were apoptotic. Apparent oxidative stress signs were observed in sPCs; the results were reproduced by exposing sPCs to CoV in the culture. The presence of MTL or/and HS prevented the CoV-induced oxidative stress in sPCs and promoted and stabilized the CoV Ab production in mice in re-exposure to CoV. In summary, CoV/Alum immunization can successfully induce CoV Ab production in mice that declines upon reexposure to CoV. Concurrent administration of MTL/HS stabilizes and promotes the CoV Ab production in mice.


Subject(s)
Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , Apoptosis , COVID-19/immunology , Plasma Cells/immunology , SARS-CoV-2/physiology , Superoxide Dismutase-1/physiology , Adjuvants, Immunologic , Alcoholic Beverages , Alum Compounds , Angiotensin-Converting Enzyme 2/physiology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/enzymology , COVID-19 Vaccines/immunology , Heat-Shock Response , Immunization, Secondary , Immunogenicity, Vaccine , Janus Kinase 2/physiology , Male , Mice , Mice, Inbred C57BL , Oxidative Stress , Plasma Cells/drug effects , Plasma Cells/pathology , Reactive Oxygen Species/metabolism , STAT1 Transcription Factor/physiology , Signal Transduction , Specific Pathogen-Free Organisms , Spike Glycoprotein, Coronavirus/immunology , Vaccination
7.
Cell Rep ; 38(2): 110235, 2022 01 11.
Article in English | MEDLINE | ID: covidwho-1634873

ABSTRACT

We have analyzed BNT162b2 vaccine-induced immune responses in naive subjects and individuals recovered from coronavirus disease 2019 (COVID-19), both soon after (14 days) and later after (almost 8 months) vaccination. Plasma spike (S)-specific immunoglobulins peak after one vaccine shot in individuals recovered from COVID-19, while a second dose is needed in naive subjects, although the latter group shows reduced levels all along the analyzed period. Despite how the neutralization capacity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mirrors this behavior early after vaccination, both groups show comparable neutralizing antibodies and S-specific B cell levels late post-vaccination. When studying cellular responses, naive individuals exhibit higher SARS-CoV-2-specific cytokine production, CD4+ T cell activation, and proliferation than do individuals recovered from COVID-19, with patent inverse correlations between humoral and cellular variables early post-vaccination. However, almost 8 months post-vaccination, SARS-CoV-2-specific responses are comparable between both groups. Our data indicate that a previous history of COVID-19 differentially determines the functional T and B cell-mediated responses to BNT162b2 vaccination over time.


Subject(s)
/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Vaccines, Synthetic/immunology , /immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , B-Lymphocytes/immunology , B-Lymphocytes/virology , COVID-19/virology , Chlorocebus aethiops , Humans , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/virology , Lymphocyte Activation/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vero Cells
8.
Ann Intern Med ; 175(1): JC5, 2022 01.
Article in English | MEDLINE | ID: covidwho-1634464

ABSTRACT

SOURCE CITATION: O'Brien MP, Forleo-Neto E, Musser BJ, et al. Subcutaneous REGEN-COV antibody combination to prevent Covid-19. N Engl J Med. 2021;385:1184-95. 34347950.


Subject(s)
COVID-19 , Antibodies, Monoclonal, Humanized , Antibodies, Neutralizing , Drug Combinations , Humans , SARS-CoV-2
9.
Ital J Pediatr ; 48(1): 7, 2022 Jan 12.
Article in English | MEDLINE | ID: covidwho-1634416

ABSTRACT

The fast diffusion of the SARS-CoV-2 pandemic have called for an equally rapid evolution of the therapeutic options.The Human recombinant monoclonal antibodies (mAbs) have recently been approved by the Food and Drug Administration (FDA) and by the Italian Medicines Agency (AIFA) in subjects aged ≥12 with SARS-CoV-2 infection and specific risk factors.Currently the indications are specific for the use of two different mAbs combination: Bamlanivimab+Etesevimab (produced by Eli Lilly) and Casirivimab+Imdevimab (produced by Regeneron).These drugs have shown favorable effects in adult patients in the initial phase of infection, whereas to date few data are available on their use in children.AIFA criteria derived from the existing literature which reports an increased risk of severe COVID-19 in children with comorbidities. However, the studies analyzing the determinants for progression to severe disease are mainly monocentric, with limited numbers and reporting mostly generic risk categories.Thus, the Italian Society of Pediatrics invited its affiliated Scientific Societies to produce a Consensus document based on the revision of the criteria proposed by AIFA in light of the most recent literature and experts' agreement.This Consensus tries to detail which patients actually have the risk to develop severe disease, analyzing the most common comorbidities in children, in order to detail the indications for mAbs administration and to guide the clinicians in identifying eligible patients.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Patient Selection , Adolescent , Age Factors , COVID-19/complications , Child , Consensus , Drug Combinations , Humans , Italy , Risk Factors , Societies, Medical
10.
PLoS One ; 17(1): e0262169, 2022.
Article in English | MEDLINE | ID: covidwho-1633137

ABSTRACT

Current SARS-CoV-2 serological assays generate discrepant results, and the longitudinal characteristics of antibodies targeting various antigens after asymptomatic to mild COVID-19 are yet to be established. This longitudinal cohort study including 1965 healthcare workers, of which 381 participants exhibited antibodies against the SARS-CoV-2 spike antigen at study inclusion, reveal that these antibodies remain detectable in most participants, 96%, at least four months post infection, despite having had no or mild symptoms. Virus neutralization capacity was confirmed by microneutralization assay in 91% of study participants at least four months post infection. Contrary to antibodies targeting the spike protein, antibodies against the nucleocapsid protein were only detected in 80% of previously anti-nucleocapsid IgG positive healthcare workers. Both anti-spike and anti-nucleocapsid IgG levels were significantly higher in previously hospitalized COVID-19 patients four months post infection than in healthcare workers four months post infection (p = 2*10-23 and 2*10-13 respectively). Although the magnitude of humoral response was associated with disease severity, our findings support a durable and functional humoral response after SARS-CoV-2 infection even after no or mild symptoms. We further demonstrate differences in antibody kinetics depending on the antigen, arguing against the use of the nucleocapsid protein as target antigen in population-based SARS-CoV-2 serological surveys.


Subject(s)
COVID-19/pathology , Immunity, Humoral , Adult , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Asymptomatic Infections/epidemiology , COVID-19/immunology , COVID-19/virology , Female , Health Personnel , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Longitudinal Studies , Male , Middle Aged , Nucleocapsid/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Severity of Illness Index , Spike Glycoprotein, Coronavirus/immunology
11.
Blood Cancer J ; 12(1): 8, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1630561

ABSTRACT

Understanding antibody-based SARS-CoV-2 immunity in hematologic malignancy (HM) patients following infection is crucial to inform vaccination strategies for this highly vulnerable population. This cross-sectional study documents the anti-SARS-CoV-2 humoral response and serum neutralizing activity in 189 HM patients recovering from a PCR-confirmed infection. The overall seroconversion rate was 85.7%, with the lowest values in patients with lymphoid malignancies or undergoing chemotherapy. Therapy-naive patients in the "watch and wait" status were more likely to seroconvert and display increased anti-s IgG titers. Enhanced serum neutralizing activity was observed in the following SARS-CoV-2-infected HM patient groups: (i) males; (ii) severe COVID-19; and (iii) "watch and wait" or "complete/partial response". The geometric mean (GeoMean) ID50 neutralization titers in patients analyzed before or after 6 months post-infection were 299.1 and 306.3, respectively, indicating that >50% of the patients in either group had a neutralization titer sufficient to provide 50% protection from symptomatic COVID-19. Altogether, our findings suggest that therapy-naive HM patients mount a far more robust immune response to SARS-CoV-2 infection vs. patients receiving anti-cancer treatment, raising the important question as to whether HM patients should be vaccinated before therapy and/or receive vaccine formats capable of better recapitulating the natural infection.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antineoplastic Agents/administration & dosage , COVID-19/immunology , Hematologic Neoplasms , Immunity, Humoral , SARS-CoV-2/immunology , Aged , Female , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/immunology , Humans , Male , Middle Aged
13.
Lancet Infect Dis ; 21(10): 1383-1394, 2021 10.
Article in English | MEDLINE | ID: covidwho-1621119

ABSTRACT

BACKGROUND: Given the scale of the ongoing COVID-19 pandemic, the development of vaccines based on different platforms is essential, particularly in light of emerging viral variants, the absence of information on vaccine-induced immune durability, and potential paediatric use. We aimed to assess the safety and immunogenicity of an MF59-adjuvanted subunit vaccine for COVID-19 based on recombinant SARS-CoV-2 spike glycoprotein stabilised in a pre-fusion conformation by a novel molecular clamp (spike glycoprotein-clamp [sclamp]). METHODS: We did a phase 1, double-blind, placebo-controlled, block-randomised trial of the sclamp subunit vaccine in a single clinical trial site in Brisbane, QLD, Australia. Healthy adults (aged ≥18 to ≤55 years) who had tested negative for SARS-CoV-2, reported no close contact with anyone with active or previous SARS-CoV-2 infection, and tested negative for pre-existing SARS-CoV-2 immunity were included. Participants were randomly assigned to one of five treatment groups and received two doses via intramuscular injection 28 days apart of either placebo, sclamp vaccine at 5 µg, 15 µg, or 45 µg, or one dose of sclamp vaccine at 45 µg followed by placebo. Participants and study personnel, except the dose administration personnel, were masked to treatment. The primary safety endpoints included solicited local and systemic adverse events in the 7 days after each dose and unsolicited adverse events up to 12 months after dosing. Here, data are reported up until day 57. Primary immunogenicity endpoints were antigen-specific IgG ELISA and SARS-CoV-2 microneutralisation assays assessed at 28 days after each dose. The study is ongoing and registered with ClinicalTrials.gov, NCT04495933. FINDINGS: Between June 23, 2020, and Aug 17, 2020, of 314 healthy volunteers screened, 120 were randomly assigned (n=24 per group), and 114 (95%) completed the study up to day 57 (mean age 32·5 years [SD 10·4], 65 [54%] male, 55 [46%] female). Severe solicited reactions were infrequent and occurred at similar rates in participants receiving placebo (two [8%] of 24) and the SARS-CoV-2 sclamp vaccine at any dose (three [3%] of 96). Both solicited reactions and unsolicited adverse events occurred at a similar frequency in participants receiving placebo and the SARS-CoV-2 sclamp vaccine. Solicited reactions occurred in 19 (79%) of 24 participants receiving placebo and 86 (90%) of 96 receiving the SARS-CoV-2 sclamp vaccine at any dose. Unsolicited adverse events occurred in seven (29%) of 24 participants receiving placebo and 35 (36%) of 96 participants receiving the SARS-CoV-2 sclamp vaccine at any dose. Vaccination with SARS-CoV-2 sclamp elicited a similar antigen-specific response irrespective of dose: 4 weeks after the initial dose (day 29) with 5 µg dose (geometric mean titre [GMT] 6400, 95% CI 3683-11 122), with 15 µg dose (7492, 4959-11 319), and the two 45 µg dose cohorts (8770, 5526-13 920 in the two-dose 45 µg cohort; 8793, 5570-13 881 in the single-dose 45 µg cohort); 4 weeks after the second dose (day 57) with two 5 µg doses (102 400, 64 857-161 676), with two 15 µg doses (74 725, 51 300-108 847), with two 45 µg doses (79 586, 55 430-114 268), only a single 45 µg dose (4795, 2858-8043). At day 57, 67 (99%) of 68 participants who received two doses of sclamp vaccine at any concentration produced a neutralising immune response, compared with six (25%) of 24 who received a single 45 µg dose and none of 22 who received placebo. Participants receiving two doses of sclamp vaccine elicited similar neutralisation titres, irrespective of dose: two 5 µg doses (GMT 228, 95% CI 146-356), two 15 µg doses (230, 170-312), and two 45 µg doses (239, 187-307). INTERPRETATION: This first-in-human trial shows that a subunit vaccine comprising mammalian cell culture-derived, MF59-adjuvanted, molecular clamp-stabilised recombinant spike protein elicits strong immune responses with a promising safety profile. However, the glycoprotein 41 peptide present in the clamp created HIV diagnostic assay interference, a possible barrier to widespread use highlighting the criticality of potential non-spike directed immunogenicity during vaccine development. Studies are ongoing with alternative molecular clamp trimerisation domains to ameliorate this response. FUNDING: Coalition for Epidemic Preparedness Innovations, National Health and Medical Research Council, Queensland Government, and further philanthropic sources listed in the acknowledgments.


Subject(s)
Adjuvants, Immunologic/pharmacology , COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Squalene/immunology , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Australia , Female , Healthy Volunteers , Humans , Male , Pandemics/prevention & control , Polysorbates , Vaccination/adverse effects , Young Adult
14.
PLoS One ; 17(1): e0262311, 2022.
Article in English | MEDLINE | ID: covidwho-1622358

ABSTRACT

In the fight against SARS-COV-2, the development of serological assays based on different antigenic domains represent a versatile tool to get a comprehensive picture of the immune response or differentiate infection from vaccination beyond simple diagnosis. Here we use a combination of the Nucleoprotein (NP), the Spike 1 (S1) and Spike 2 (S2) subunits, and the receptor binding domain (RBD) and N-terminal domain (NTD) of the Spike antigens from the CoViDiag® multiplex IgG assay, to follow the immune response to SARS-CoV-2 infection over a long time period and depending on disease severity. Using a panel of 209 sera collected from 61 patients up to eight months after infection, we observed that most patients develop an immune response against multiple viral epitope, but anti-S2 antibodies seemed to last longer. For all the tested IgGs, we have found higher responses for hospitalized patients than for non-hospitalized ones. Moreover the combination of the five different IgG responses increased the correlation to the neutralizing antibody titers than if considered individually. Multiplex immunoassays have the potential to improve diagnostic performances, especially for ancient infection or mild form of the disease presenting weaker antibody responses. Also the combined detection of anti-NP and anti-Spike-derived domains can be useful to differentiate vaccination from viral infection and accurately assess the antibody potential to neutralize the virus.


Subject(s)
COVID-19/immunology , Immunity/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Female , Humans , Immunoassay/methods , Male , Middle Aged , Spike Glycoprotein, Coronavirus/immunology
15.
Sci Rep ; 12(1): 696, 2022 01 13.
Article in English | MEDLINE | ID: covidwho-1621270

ABSTRACT

Despite encouraging preclinical data, therapies to reduce ARDS mortality remains a globally unmet need, including during the COVID-19 pandemic. We previously identified extracellular nicotinamide phosphoribosyltransferase (eNAMPT) as a novel damage-associated molecular pattern protein (DAMP) via TLR4 ligation which regulates inflammatory cascade activation. eNAMPT is tightly linked to human ARDS by biomarker and genotyping studies in ARDS subjects. We now hypothesize that an eNAMPT-neutralizing mAb will significantly reduce the severity of ARDS lung inflammatory lung injury in diverse preclinical rat and porcine models. Sprague Dawley rats received eNAMPT mAb intravenously following exposure to intratracheal lipopolysaccharide (LPS) or to a traumatic blast (125 kPa) but prior to initiation of ventilator-induced lung injury (VILI) (4 h). Yucatan minipigs received intravenous eNAMPT mAb 2 h after initiation of septic shock and VILI (12 h). Each rat/porcine ARDS/VILI model was strongly associated with evidence of severe inflammatory lung injury with NFkB pathway activation and marked dysregulation of the Akt/mTORC2 signaling pathway. eNAMPT neutralization dramatically reduced inflammatory indices and the severity of lung injury in each rat/porcine ARDS/VILI model (~ 50% reduction) including reduction in serum lactate, and plasma levels of eNAMPT, IL-6, TNFα and Ang-2. The eNAMPT mAb further rectified NFkB pathway activation and preserved the Akt/mTORC2 signaling pathway. These results strongly support targeting the eNAMPT/TLR4 inflammatory pathway as a potential ARDS strategy to reduce inflammatory lung injury and ARDS mortality.


Subject(s)
Acute Chest Syndrome/metabolism , Mechanistic Target of Rapamycin Complex 2/metabolism , NF-kappa B/metabolism , Nicotinamide Phosphoribosyltransferase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/physiology , Animals , Antibodies, Neutralizing/metabolism , Biomarkers/metabolism , COVID-19/metabolism , Disease Models, Animal , Inflammation/metabolism , Lipopolysaccharides/metabolism , Lung/metabolism , Male , Rats , Rats, Sprague-Dawley , SARS-CoV-2/pathogenicity , Swine
16.
Sci Rep ; 12(1): 692, 2022 01 13.
Article in English | MEDLINE | ID: covidwho-1621265

ABSTRACT

The receptor binding domain (RBD) of the Spike protein from SARS-CoV-2 is a promising candidate to develop effective COVID-19 vaccines since it can induce potent neutralizing antibodies. We have previously reported the highly efficient production of RBD in Pichia pastoris, which is structurally similar to the same protein produced in mammalian HEK-293T cells. In this work we designed an RBD multimer with the purpose of increasing its immunogenicity. We produced multimeric particles by a transpeptidation reaction between RBD expressed in P. pastoris and Lumazine Synthase from Brucella abortus (BLS), which is a highly immunogenic and very stable decameric 170 kDa protein. Such particles were used to vaccinate mice with two doses 30 days apart. When the particles ratio of RBD to BLS units was high (6-7 RBD molecules per BLS decamer in average), the humoral immune response was significantly higher than that elicited by RBD alone or by RBD-BLS particles with a lower RBD to BLS ratio (1-2 RBD molecules per BLS decamer). Remarkably, multimeric particles with a high number of RBD copies elicited a high titer of neutralizing IgGs. These results indicate that multimeric particles composed of RBD covalent coupled to BLS possess an advantageous architecture for antigen presentation to the immune system, and therefore enhancing RBD immunogenicity. Thus, multimeric RBD-BLS particles are promising candidates for a protein-based vaccine.


Subject(s)
COVID-19/immunology , Immunity, Humoral/immunology , Protein Binding/immunology , Protein Domains/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Formation/immunology , COVID-19 Vaccines/immunology , Cell Line , Female , HEK293 Cells , Humans , Immunoglobulin G/immunology , Mice , Mice, Inbred BALB C
17.
PLoS Comput Biol ; 17(12): e1009675, 2021 12.
Article in English | MEDLINE | ID: covidwho-1619980

ABSTRACT

Identifying the epitope of an antibody is a key step in understanding its function and its potential as a therapeutic. Sequence-based clonal clustering can identify antibodies with similar epitope complementarity, however, antibodies from markedly different lineages but with similar structures can engage the same epitope. We describe a novel computational method for epitope profiling based on structural modelling and clustering. Using the method, we demonstrate that sequence dissimilar but functionally similar antibodies can be found across the Coronavirus Antibody Database, with high accuracy (92% of antibodies in multiple-occupancy structural clusters bind to consistent domains). Our approach functionally links antibodies with distinct genetic lineages, species origins, and coronavirus specificities. This indicates greater convergence exists in the immune responses to coronaviruses than is suggested by sequence-based approaches. Our results show that applying structural analytics to large class-specific antibody databases will enable high confidence structure-function relationships to be drawn, yielding new opportunities to identify functional convergence hitherto missed by sequence-only analysis.


Subject(s)
Antigens, Viral/chemistry , COVID-19/immunology , COVID-19/virology , Epitopes, B-Lymphocyte/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/immunology , Amino Acid Sequence , Animals , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/genetics , Antibodies, Viral/chemistry , Antibodies, Viral/genetics , Antibodies, Viral/metabolism , Antibody Specificity , Antigen-Antibody Complex/chemistry , Antigen-Antibody Complex/genetics , Antigen-Antibody Reactions/genetics , Antigen-Antibody Reactions/immunology , Computational Biology , Coronavirus/chemistry , Coronavirus/genetics , Coronavirus/immunology , Databases, Chemical , Epitope Mapping , Epitopes, B-Lymphocyte/genetics , Humans , Mice , Models, Molecular , Pandemics , SARS-CoV-2/genetics , Single-Domain Antibodies/immunology
19.
Nat Commun ; 13(1): 21, 2022 01 10.
Article in English | MEDLINE | ID: covidwho-1616983

ABSTRACT

While the seroprevalence of SARS-CoV-2 in healthy people does not differ significantly among age groups, those aged 65 years or older exhibit strikingly higher COVID-19 mortality compared to younger individuals. To further understand differing COVID-19 manifestations in patients of different ages, three age groups of ferrets are infected with SARS-CoV-2. Although SARS-CoV-2 is isolated from all ferrets regardless of age, aged ferrets (≥3 years old) show higher viral loads, longer nasal virus shedding, and more severe lung inflammatory cell infiltration, and clinical symptoms compared to juvenile (≤6 months) and young adult (1-2 years) groups. Furthermore, direct contact ferrets co-housed with the virus-infected aged group shed more virus than direct-contact ferrets co-housed with virus-infected juvenile or young adult ferrets. Transcriptome analysis of aged ferret lungs reveals strong enrichment of gene sets related to type I interferon, activated T cells, and M1 macrophage responses, mimicking the gene expression profile of severe COVID-19 patients. Thus, SARS-CoV-2-infected aged ferrets highly recapitulate COVID-19 patients with severe symptoms and are useful for understanding age-associated infection, transmission, and pathogenesis of SARS-CoV-2.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Disease Models, Animal , SARS-CoV-2/immunology , Virus Shedding/immunology , Age Factors , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , COVID-19/genetics , COVID-19/transmission , Chlorocebus aethiops , Female , Ferrets , Gene Expression Profiling/methods , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Vero Cells , Virulence
20.
Nat Commun ; 13(1): 153, 2022 01 10.
Article in English | MEDLINE | ID: covidwho-1616980

ABSTRACT

Anti-viral immunity continuously declines over time after SARS-CoV-2 infection. Here, we characterize the dynamics of anti-viral immunity during long-term follow-up and after BNT162b2 mRNA-vaccination in convalescents after asymptomatic or mild SARS-CoV-2 infection. Virus-specific and virus-neutralizing antibody titers rapidly declined in convalescents over 9 months after infection, whereas virus-specific cytokine-producing polyfunctional T cells persisted, among which IL-2-producing T cells correlated with virus-neutralizing antibody titers. Among convalescents, 5% of individuals failed to mount long-lasting immunity after infection and showed a delayed response to vaccination compared to 1% of naïve vaccinees, but successfully responded to prime/boost vaccination. During the follow-up period, 8% of convalescents showed a selective increase in virus-neutralizing antibody titers without accompanying increased frequencies of circulating SARS-CoV-2-specific T cells. The same convalescents, however, responded to vaccination with simultaneous increase in antibody and T cell immunity revealing the strength of mRNA-vaccination to increase virus-specific immunity in convalescents.


Subject(s)
/immunology , COVID-19/immunology , Convalescence , Nucleocapsid/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Cytokines/immunology , Cytokines/metabolism , Flow Cytometry/methods , Follow-Up Studies , Humans , Immunoglobulin G/immunology , Interleukin-2/immunology , Interleukin-2/metabolism , Kinetics , SARS-CoV-2/physiology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , T-Lymphocytes/virology , Time Factors , Vaccination/methods
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