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2.
Microorganisms ; 10(6)2022 Jun 10.
Article in English | MEDLINE | ID: covidwho-1884281

ABSTRACT

The severity of coronavirus disease 2019 (COVID-19) may be influenced by pre-existing immune responses against endemic coronaviruses, but conflicting data have been reported. We studied 148 patients who were hospitalised because of a confirmed diagnosis of COVID-19, classified mild in 58, moderate in 44, and severe in 46. The controls were 27 healthy subjects. At admission, blood samples were collected for the measurement of biomarkers of disease severity and levels of the IgG against the receptor-binding domain (RBD) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and pre-existing coronaviruses OC43, HKU1, NL63 and 229E. Higher levels of IgG antibodies against the RBD of pre-existing coronavirus (with the highest significance for anti-HKU1 IgG, p = 0.01) were found in patients with mild disease, compared with those with moderate or severe disease. Multivariable logistic regression confirmed the association of high levels of antibodies to pre-existing coronavirus with mild disease and showed their associations with low levels of the complement activation marker SC5b-9 (p range = 0.007-0.05). High levels of anti-NL63 antibodies were associated with low levels of the coagulation activation marker D-dimer (p = 0.04), while high levels of IgG against 229E were associated with low levels of the endothelial activation marker von Willebrand factor (p = 0.05). Anti-SARS-CoV-2-neutralising activity of plasma positively correlated with anti-SARS-CoV-2 IgG (r = 0.53, p = 0.04) and with anti-HKU1 IgG (r = 0.51, p = 0.05). In hospitalised patients with COVID-19, high levels of antibodies to pre-existing coronaviruses are associated with mild disease, suggesting that their measurement could be useful in predicting the severity of the disease.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-337046

ABSTRACT

Infection by SARS-CoV-2 leads to diverse symptoms, which can persist for months. While antiviral antibodies are protective, those targeting interferons and other immune factors are associated with adverse COVID-19 outcomes. Instead, we discovered that antibodies against specific chemokines are omnipresent after COVID-19, associated with favorable disease, and predictive of lack of long COVID symptoms at one year post infection. Anti-chemokine antibodies are present also in HIV-1 and autoimmune disorders, but they target different chemokines than those in COVID-19. Finally, monoclonal antibodies derived from COVID-19 convalescents that bind to the chemokine N-loop impair cell migration. Given the role of chemokines in orchestrating immune cell trafficking, naturally arising anti-chemokine antibodies associated with favorable COVID 19 may be beneficial by modulating the inflammatory response and thus bear therapeutic potential.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-315452

ABSTRACT

BNT162b2 vaccine was introduced in Italy on 27th December 2020 and healthcare workers were rapidly vaccinated. In this study, we demonstrated that one vaccine dose was sufficient for eliciting a sustained humoral and cell-mediated response in SARS-CoV-2 experienced healthcare workers but had a lower effect in SARS-CoV-2 naïve subjects. However, 98% naïve subjects developed both neutralizing antibodies and Spike-specific T-cells after the second dose. Moreover, the antibody and T-cell responses were effective against viral variants since a partial reduction in antibody response was observed only against the South-African variant in SARS-CoV-2 naïve individuals, while the T-cell response was less affected.

5.
Nat Immunol ; 23(2): 275-286, 2022 02.
Article in English | MEDLINE | ID: covidwho-1661973

ABSTRACT

The humoral arm of innate immunity includes diverse molecules with antibody-like functions, some of which serve as disease severity biomarkers in coronavirus disease 2019 (COVID-19). The present study was designed to conduct a systematic investigation of the interaction of human humoral fluid-phase pattern recognition molecules (PRMs) with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of 12 PRMs tested, the long pentraxin 3 (PTX3) and mannose-binding lectin (MBL) bound the viral nucleocapsid and spike proteins, respectively. MBL bound trimeric spike protein, including that of variants of concern (VoC), in a glycan-dependent manner and inhibited SARS-CoV-2 in three in vitro models. Moreover, after binding to spike protein, MBL activated the lectin pathway of complement activation. Based on retention of glycosylation sites and modeling, MBL was predicted to recognize the Omicron VoC. Genetic polymorphisms at the MBL2 locus were associated with disease severity. These results suggest that selected humoral fluid-phase PRMs can play an important role in resistance to, and pathogenesis of, COVID-19, a finding with translational implications.


Subject(s)
COVID-19/immunology , Immunity, Humoral , Receptors, Pattern Recognition/immunology , SARS-CoV-2/immunology , Animals , C-Reactive Protein/immunology , C-Reactive Protein/metabolism , COVID-19/metabolism , COVID-19/virology , Case-Control Studies , Chlorocebus aethiops , Complement Activation , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus Nucleocapsid Proteins/immunology , Coronavirus Nucleocapsid Proteins/metabolism , Female , Glycosylation , HEK293 Cells , Host-Pathogen Interactions , Humans , Male , Mannose-Binding Lectin/genetics , Mannose-Binding Lectin/immunology , Mannose-Binding Lectin/metabolism , Phosphoproteins/genetics , Phosphoproteins/immunology , Phosphoproteins/metabolism , Polymorphism, Genetic , Protein Binding , Receptors, Pattern Recognition/genetics , Receptors, Pattern Recognition/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Serum Amyloid P-Component/immunology , Serum Amyloid P-Component/metabolism , Signal Transduction , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells
6.
iScience ; 25(2): 103743, 2022 Feb 18.
Article in English | MEDLINE | ID: covidwho-1611783

ABSTRACT

Information concerning the longevity of immunity to SARS-CoV-2 following natural infection may have considerable implications for durability of immunity induced by vaccines. Here, we monitored the SARS-CoV-2 specific immune response in COVID-19 patients followed up to 15 months after symptoms onset. Following a peak at day 15-28 postinfection, the IgG antibody response and plasma neutralizing titers gradually decreased over time but stabilized after 6 months. Compared to G614, plasma neutralizing titers were more than 8-fold lower against variants Beta, Gamma, and Delta. SARS-CoV-2-specific memory B and T cells persisted in the majority of patients up to 15 months although a significant decrease in specific T cells, but not B cells, was observed between 6 and 15 months. Antiviral specific immunity, especially memory B cells in COVID-19 convalescent patients, is long-lasting, but some variants of concern may at least partially escape the neutralizing activity of plasma antibodies.

7.
Clin Microbiol Infect ; 28(2): 301.e1-301.e8, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1474453

ABSTRACT

OBJECTIVES: To assess the humoral and cell-mediated response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) elicited by the mRNA BNT162b2 vaccine in SARS-CoV-2-experienced and -naive subjects against a reference strain and SARS-CoV-2 variants. METHODS: The humoral response (including neutralizing antibodies) and T-cell-mediated response elicited by BNT162b2 vaccine in 145 healthcare workers (both naive and positive for previous SARS-CoV-2 infection) were evaluated. In a subset of subjects, the effect of SARS-CoV-2 variants on antibody level and cell-mediated response was also investigated. RESULTS: Overall, 125/127 naive subjects (98.4%) developed both neutralizing antibodies and specific T cells after the second dose of vaccine. Moreover, the antibody and T-cell responses were effective against viral variants since SARS-CoV-2 NT Abs were still detectable in 55/68 (80.9%) and 25/29 (86.2%) naive subjects when sera were challenged against ß and δ variants, respectively. T-cell response was less affected, with no significant difference in the frequency of responders (p 0.369). Of note, two doses of vaccine were able to elicit sustained neutralizing antibody activity against all the SARS-CoV-2 variants tested in SARS-CoV-2-experienced subjects. CONCLUSIONS: BNT162b2 vaccine elicited a sustained humoral and cell-mediated response in immunocompetent subjects after two-dose administration of the vaccine, and the response seemed to be less affected by SARS-CoV-2 variants, the only exceptions being the ß and δ variants. Increased immunogenicity, also against SARS-CoV-2 variant strains, was observed in SARS-CoV-2-experienced subjects. These results suggest that triple exposure to SARS-CoV-2 antigens might be proposed as valuable strategy for vaccination campaigns.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19 Vaccines , Health Personnel , Humans , Vaccination , Vaccines, Synthetic
9.
Nature ; 593(7859): 424-428, 2021 05.
Article in English | MEDLINE | ID: covidwho-1152859

ABSTRACT

Neutralizing antibodies that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein are among the most promising approaches against COVID-191,2. A bispecific IgG1-like molecule (CoV-X2) has been developed on the basis of C121 and C135, two antibodies derived from donors who had recovered from COVID-193. Here we show that CoV-X2 simultaneously binds two independent sites on the RBD and, unlike its parental antibodies, prevents detectable spike binding to the cellular receptor of the virus, angiotensin-converting enzyme 2 (ACE2). Furthermore, CoV-X2 neutralizes wild-type SARS-CoV-2 and its variants of concern, as well as escape mutants generated by the parental monoclonal antibodies. We also found that in a mouse model of SARS-CoV-2 infection with lung inflammation, CoV-X2 protects mice from disease and suppresses viral escape. Thus, the simultaneous targeting of non-overlapping RBD epitopes by IgG-like bispecific antibodies is feasible and effective, and combines the advantages of antibody cocktails with those of single-molecule approaches.


Subject(s)
Antibodies, Bispecific/immunology , Antibodies, Neutralizing/immunology , COVID-19/immunology , COVID-19/virology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Bispecific/therapeutic use , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/therapeutic use , Body Weight , COVID-19/drug therapy , COVID-19/prevention & control , Dependovirus/genetics , Disease Models, Animal , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Female , Humans , Immune Evasion/genetics , Mice , Mice, Inbred C57BL , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
10.
Nat Commun ; 12(1): 1577, 2021 03 11.
Article in English | MEDLINE | ID: covidwho-1132068

ABSTRACT

COVID-19 is a severe acute respiratory disease caused by SARS-CoV-2, a new recently emerged sarbecovirus. This virus uses the human ACE2 enzyme as receptor for cell entry, recognizing it with the receptor binding domain (RBD) of the S1 subunit of the viral spike protein. We present the use of phage display to select anti-SARS-CoV-2 spike antibodies from the human naïve antibody gene libraries HAL9/10 and subsequent identification of 309 unique fully human antibodies against S1. 17 antibodies are binding to the RBD, showing inhibition of spike binding to cells expressing ACE2 as scFv-Fc and neutralize active SARS-CoV-2 virus infection of VeroE6 cells. The antibody STE73-2E9 is showing neutralization of active SARS-CoV-2 as IgG and is binding to the ACE2-RBD interface. Thus, universal libraries from healthy human donors offer the advantage that antibodies can be generated quickly and independent from the availability of material from recovering patients in a pandemic situation.


Subject(s)
Angiotensin-Converting Enzyme 2/immunology , Antibodies, Neutralizing/genetics , Antibodies, Viral/genetics , COVID-19/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Angiotensin-Converting Enzyme 2/chemistry , Animals , Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/isolation & purification , Antibody Affinity , COVID-19/epidemiology , Cell Line , Chlorocebus aethiops , Gene Library , Healthy Volunteers , Host Microbial Interactions/immunology , Humans , Immunoglobulin G/genetics , Immunoglobulin G/isolation & purification , Models, Molecular , Mutation , Neutralization Tests , Pandemics , Peptide Library , Protein Interaction Domains and Motifs , Recombinant Proteins/genetics , Recombinant Proteins/immunology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Vero Cells
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