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1.
Nat Commun ; 12(1): 1715, 2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33731724

RESUMEN

The coronavirus spike glycoprotein, located on the virion surface, is the key mediator of cell entry and the focus for development of protective antibodies and vaccines. Structural studies show exposed sites on the spike trimer that might be targeted by antibodies with cross-species specificity. Here we isolated two human monoclonal antibodies from immunized humanized mice that display a remarkable cross-reactivity against distinct spike proteins of betacoronaviruses including SARS-CoV, SARS-CoV-2, MERS-CoV and the endemic human coronavirus HCoV-OC43. Both cross-reactive antibodies target the stem helix in the spike S2 fusion subunit which, in the prefusion conformation of trimeric spike, forms a surface exposed membrane-proximal helical bundle. Both antibodies block MERS-CoV infection in cells and provide protection to mice from lethal MERS-CoV challenge in prophylactic and/or therapeutic models. Our work highlights an immunogenic and vulnerable site on the betacoronavirus spike protein enabling elicitation of antibodies with unusual binding breadth.


Asunto(s)
Anticuerpos Monoclonales Humanizados/inmunología , Betacoronavirus/inmunología , Epítopos/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Animales , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/uso terapéutico , Anticuerpos Antivirales/inmunología , Betacoronavirus/clasificación , Camelus , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/virología , Reacciones Cruzadas , Epítopos/química , Epítopos/genética , Humanos , Ratones , Conformación Proteica , Subunidades de Proteína , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética
2.
BMC Vet Res ; 17(1): 128, 2021 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-33757494

RESUMEN

BACKGROUND: Morbilliviruses are categorized under the family of Paramyxoviridae and have been associated with severe diseases, such as Peste des petits ruminants, canine distemper and measles with evidence of high morbidity and/or could cause major economic loss in production of livestock animals, such as goats and sheep. Feline morbillivirus (FeMV) is one of the members of Morbilliviruses that has been speculated to cause chronic kidney disease in cats even though a definite relationship is still unclear. To date, FeMV has been detected in several continents, such as Asia (Japan, China, Thailand, Malaysia), Europe (Italy, German, Turkey), Africa (South Africa), and South and North America (Brazil, Unites States). This study aims to develop a TaqMan real-time RT-PCR (qRT-PCR) assay targeting the N gene of FeMV in clinical samples to detect early phase of FeMV infection. RESULTS: A specific assay was developed, since no amplification was observed in viral strains from the same family of Paramyxoviridae, such as canine distemper virus (CDV), Newcastle disease virus (NDV), and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 × 104 copies/µL with Cq value of 34.32 ± 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34-0.53% and 1.38-2.03%, respectively. In addition, the clinical sample evaluation using this assay showed a higher detection rate, with 25 (35.2%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR. CONCLUSIONS: The TaqMan-based real-time RT-PCR assay targeting the N gene described in this study is more sensitive, specific, rapid, and reproducible compared to the conventional RT-PCR assay targeting the N gene, which could be used to detect early infection in cats.


Asunto(s)
Infecciones por Morbillivirus/veterinaria , Morbillivirus/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Animales , Reacciones Cruzadas , Morbillivirus/genética , Infecciones por Morbillivirus/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Sensibilidad y Especificidad
4.
Front Immunol ; 12: 640093, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33717193

RESUMEN

COVID-19 (SARS-CoV-2) disease severity and stages varies from asymptomatic, mild flu-like symptoms, moderate, severe, critical, and chronic disease. COVID-19 disease progression include lymphopenia, elevated proinflammatory cytokines and chemokines, accumulation of macrophages and neutrophils in lungs, immune dysregulation, cytokine storms, acute respiratory distress syndrome (ARDS), etc. Development of vaccines to severe acute respiratory syndrome (SARS), Middle East Respiratory Syndrome coronavirus (MERS-CoV), and other coronavirus has been difficult to create due to vaccine induced enhanced disease responses in animal models. Multiple betacoronaviruses including SARS-CoV-2 and SARS-CoV-1 expand cellular tropism by infecting some phagocytic cells (immature macrophages and dendritic cells) via antibody bound Fc receptor uptake of virus. Antibody-dependent enhancement (ADE) may be involved in the clinical observation of increased severity of symptoms associated with early high levels of SARS-CoV-2 antibodies in patients. Infants with multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 may also have ADE caused by maternally acquired SARS-CoV-2 antibodies bound to mast cells. ADE risks associated with SARS-CoV-2 has implications for COVID-19 and MIS-C treatments, B-cell vaccines, SARS-CoV-2 antibody therapy, and convalescent plasma therapy for patients. SARS-CoV-2 antibodies bound to mast cells may be involved in MIS-C and multisystem inflammatory syndrome in adults (MIS-A) following initial COVID-19 infection. SARS-CoV-2 antibodies bound to Fc receptors on macrophages and mast cells may represent two different mechanisms for ADE in patients. These two different ADE risks have possible implications for SARS-CoV-2 B-cell vaccines for subsets of populations based on age, cross-reactive antibodies, variabilities in antibody levels over time, and pregnancy. These models place increased emphasis on the importance of developing safe SARS-CoV-2 T cell vaccines that are not dependent upon antibodies.


Asunto(s)
Acrecentamiento Dependiente de Anticuerpo , Mastocitos/inmunología , Coronavirus del Síndrome Respiratorio de Oriente Medio/fisiología , Fagocitos/inmunología , Síndrome de Respuesta Inflamatoria Sistémica/inmunología , Animales , Anticuerpos Antivirales/metabolismo , Niño , Reacciones Cruzadas , Femenino , Humanos , Recién Nacido , Transmisión Vertical de Enfermedad Infecciosa , Modelos Inmunológicos , Embarazo , Receptores Fc/metabolismo , Riesgo , Linfocitos T/inmunología
5.
Virol J ; 18(1): 54, 2021 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-33706767

RESUMEN

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic remains ongoing around the world, including in areas where dengue is endemic. Dengue and COVID-19, to some extent, have similar clinical and laboratory features, which can lead to misdiagnosis, delayed treatment and patient's isolation. The use of rapid diagnostic tests (RDT) is easy and convenient for fast diagnosis, however there may be issues with cross-reactivity with antibodies for other pathogens. METHODS: We assessed the possibility of cross-reactivity between SARS-CoV-2 and dengue antibodies by: (1) testing five brands of COVID-19 IgG / IgM RDTs on 60 RT-PCR-confirmed dengue samples; (2) testing 95 RT-PCR-confirmed COVID-19 samples on dengue RDT; and (3) testing samples positive for COVID-19 IgG and/or IgM on dengue RDT. RESULTS: We observed a high specificity across all five brands of COVID-19 RDTs, ranging from 98.3 to 100%. Out of the confirmed COVID-19 samples, one patient tested positive for dengue IgM only, another tested positive for dengue IgG only. One patient tested positive for dengue IgG, IgM, and NS1, suggesting a co-infection. In COVID-19 IgG and/or IgM samples, 6.3% of COVID-19 IgG-positive samples also tested positive for dengue IgG, while 21.1% of COVID-19 IgM-positive samples also tested positive for dengue IgG. CONCLUSION: Despite the high specificity of the COVID-19 RDT, we observed cross-reactions and false-positive results between dengue and COVID-19. Dengue and COVID-19 co-infection was also found. Health practitioners in dengue endemic areas should be careful when using antibody RDT for the diagnosis of dengue during the COVID-19 pandemic to avoid misdiagnosis.


Asunto(s)
Anticuerpos Antivirales/inmunología , Reacciones Cruzadas/inmunología , Virus del Dengue/inmunología , Dengue/diagnóstico , /inmunología , Adolescente , Adulto , Niño , Diagnóstico Diferencial , Pruebas Diagnósticas de Rutina , Reacciones Falso Positivas , Femenino , Humanos , Inmunoglobulina A/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Indonesia , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Proteínas no Estructurales Virales/inmunología , Adulto Joven
6.
Arch Immunol Ther Exp (Warsz) ; 69(1): 5, 2021 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-33677719

RESUMEN

Coronaviruses share conservative spike protein (S) on their enveloped membrane surface, where S1 subunit recognizes and binds the cellular receptor, and the S2 subunit mediates membrane fusion. This similarity raises the question: does coronaviral infection by one create protection to others? Convalescent SARS-CoV-2 (COVID-19) sera were tested for cross reactivity with peptides from Middle East respiratory syndrome coronavirus (MERS-CoV) which shares 74% homology. Our results showed significant cross-reactivity with a peptide of the heptad repeat 2 (HR2) domain of the MERS-CoV spike protein. Sera samples of 47 validated seropositive convalescent COVID-19 patients and 40 sera samples of control patients, collected in pre-COVID time were used to establish cross-bind reactivity with the MERS-CoV peptide. Significantly stronger binding (p < 0.0001) was observed for IgG antibodies in convalescent COVID-19 patients compared to the control group. In ELISA, MERS-CoV peptide helps to discriminate post-COVID-19 populations and non-infected ones by the presence of antibodies in blood samples. This suggests that polyclonal antibodies established during SARS-CoV-2 infection can recognize and probably decrease severity of MERS-CoV and other coronaviral infections. The high homology of the spike protein domain also suggests that the opposite effect can be true: coronaviral infections produce cross-reactive antibodies effective against SARS-CoV-2. The collected data prove that despite the core HR2 region is hidden in the native viral conformation, its exposure during cell entry makes it highly immunogenic. Since inhibitory peptides to this region were previously described, this opens new possibilities in fighting coronaviral infections and developing vaccines effective even after possible viral mutations.


Asunto(s)
Anticuerpos Antivirales/inmunología , Convalecencia , Glicoproteína de la Espiga del Coronavirus/inmunología , Reacciones Cruzadas , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Virus del SRAS/inmunología
8.
Front Immunol ; 12: 627285, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33679770

RESUMEN

Introduction: Cross-reactivity to SARS-CoV-2 antigenic peptides has been detected on T-cells from pre-pandemic donors due to recognition of conserved protein fragments within members of the coronavirus's family. Further, preexisting antibodies recognizing SARS-CoV-2 with conserved epitopes in the spike region have been now seen in uninfected individuals. High-dose Intravenous Immunoglobulin (IVIg), derived from thousands of healthy donors, contains natural IgG antibodies against various antigens which can be detected both within the IVIg preparations and in the serum of IVIg-receiving patients. Whether IVIg preparations from pre-pandemic donors also contain antibodies against pre-pandemic coronaviruses or autoreactive antibodies that cross-react with SARS-CoV-2 antigenic epitopes, is unknown. Methods: 13 samples from 5 commercial IVIg preparations from pre-pandemic donors (HyQvia (Baxalta Innovations GmbH); Privigen (CSL Behring); Intratect (Biotest AG); IgVena (Kedrion S.p.A); and Flebogamma (Grifols S.A.) were blindly screened using a semi-quantitative FDA-approved and validated enzyme-linked immunosorbent assay (ELISA) (Euroimmun, Lubeck, Germany). Results: Nine of thirteen preparations (69.2%), all from two different manufactures, were antibody-positive based on the defined cut-off positivity (index of sample OD to calibrator OD > 1.1). From one manufacturer, 7/7 lots (100%) and from another 2/3 lots (67%), tested positive for cross-reacting antibodies. 7/9 of the positive preparations (77%) had titers as seen in asymptomatically infected individuals or recent COVID19-recovered patients, while 2/9 (23%) had higher titers, comparable to those seen in patients with active symptomatic COVID-19 infection (index > 2.2). Conclusion: Pre-pandemic IVIg donors have either natural autoantibodies or pre-pandemic cross-reactive antibodies against antigenic protein fragments conserved among the "common cold" - related coronaviruses. The findings are important in: (a) assessing true anti-SARS-CoV-2-IgG seroprevalence avoiding false positivity in IVIg-receiving patients; (b) exploring potential protective benefits in patients with immune-mediated conditions and immunodeficiencies receiving acute or chronic maintenance IVIg therapy, and (c) validating data from a recent controlled study that showed significantly lower in-hospital mortality in the IVIg- treated group.


Asunto(s)
Anticuerpos Antivirales/inmunología , Autoinmunidad , Inmunoglobulinas Intravenosas/inmunología , Estaciones del Año , /epidemiología , Reacciones Cruzadas , Epítopos/inmunología , Humanos , Glicoproteína de la Espiga del Coronavirus/inmunología
9.
Front Immunol ; 12: 637651, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33767706

RESUMEN

As COVID-19 cases continue to rise, it is imperative to learn more about antibodies and T-cells produced against the causative virus, SARS-CoV-2, in order to guide the rapid development of therapies and vaccines. While much of the current antibody and vaccine research focuses on the receptor-binding domain of S1, a less-recognized opportunity is to harness the potential benefits of the more conserved S2 subunit. Similarities between the spike proteins of both SARS-CoV-2 and HIV-1 warrant exploring S2. Possible benefits of employing S2 in therapies and vaccines include the structural conservation of S2, extant cross-reactive neutralizing antibodies in populations (due to prior exposure to common cold coronaviruses), the steric neutralization potential of antibodies against S2, and the stronger memory B-cell and T-cell responses. More research is necessary on the effect of glycans on the accessibility and stability of S2, SARS-CoV-2 mutants that may affect infectivity, the neutralization potential of antibodies produced by memory B-cells, cross-reactive T-cell responses, antibody-dependent enhancement, and antigen competition. This perspective aims to highlight the evidence for the potential advantages of using S2 as a target of therapy or vaccine design.


Asunto(s)
/uso terapéutico , /inmunología , Glicoproteína de la Espiga del Coronavirus/uso terapéutico , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Especificidad de Anticuerpos , /virología , Reacciones Cruzadas , Epítopos , Interacciones Huésped-Patógeno , Humanos , Inmunogenicidad Vacunal , Subunidades de Proteína , Glicoproteína de la Espiga del Coronavirus/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/virología , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/uso terapéutico
10.
PLoS One ; 16(2): e0245914, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33596236

RESUMEN

In the emergency of the SARS-CoV-2 pandemic, great efforts were made to quickly provide serology testing to the medical community however, these methods have been introduced into clinical practice without the complete validation usually required by the regulatory organizations. SARS-CoV-2 patient samples (n = 43) were analyzed alongside pre-pandemic control specimen (n = 50), confirmed respiratory infections (n = 50), inflammatory polyarthritis (n = 22) and positive for thyroid stimulating immunoglobulin (n = 30). Imprecision, diagnostic sensitivity and specificity and concordance were evaluated on IgG serologic assays from EuroImmun, Epitope Diagnostics (EDI), Abbott Diagnostics and DiaSorin and a rapid IgG/IgM test from Healgen. EDI and EuroImmun imprecision was 0.02-14.0% CV. Abbott and DiaSorin imprecision (CV) ranged from 5.2%-8.1% and 8.2%-9.6% respectively. Diagnostic sensitivity of the assays was 100% (CI: 80-100%) for Abbott, EDI and EuroImmun and 95% (CI: 73-100%) for DiaSorin at ≥14 days post PCR. Only the Abbott assay had a diagnostic specificity of 100% (CI: 91-100%). EuroImmun cross-reacted in 3 non-SARS-CoV-2 respiratory infections and 2 controls. The DiaSorin displayed more false negative results and cross-reacted in six cases across all conditions tested. EDI had one cross-reactive sample. The Healgen rapid test showed excellent sensitivity and specificity. Overall, concordance of the assays ranged from 76.1% to 97.9%. Serological tests for SARS-CoV-2 showed good analytical performance. The head-to-head analysis of samples revealed differences in results that may be linked to the use of nucleocapsid or spike proteins. The point of care device tested demonstrated adequate performance for antibody detection.


Asunto(s)
/métodos , /inmunología , Anticuerpos Antivirales/sangre , Brasil/epidemiología , /inmunología , /tendencias , Técnicas de Laboratorio Clínico/métodos , Reacciones Cruzadas , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Pandemias , Sistemas de Atención de Punto , Sensibilidad y Especificidad
11.
Int J Mol Sci ; 22(4)2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33572480

RESUMEN

BACKGROUND: Preexisting immunity to SARS-CoV-2 could be related to cross-reactive antibodies to common human-coronaviruses (HCoVs). This study aimed to evaluate whether human milk antibodies against to S1 and S2 subunits SARS-CoV-2 are cross-reactive to S1 and S2 subunits HCoV-OC43 and HCoV-229E in mothers with a confirmed COVID-19 PCR test, in mothers with previous viral symptoms during COVID-19 pandemic, and in unexposed mothers; Methods: The levels of secretory IgA (SIgA)/IgA, secretory IgM (SIgM)/IgM, and IgG specific to S1 and S2 SARS-CoV-2, and reactive to S1 + S2 HCoV-OC43, and HCoV-229E were measured in milk from 7 mothers with a confirmed COVID-19 PCR test, 20 mothers with viral symptoms, and unexposed mothers (6 Ctl1-2018 and 16 Ctl2-2018) using ELISA; Results: The S2 SARS-CoV-2 IgG levels were higher in the COVID-19 PCR (p = 0.014) and viral symptom (p = 0.040) groups than in the Ctl1-2018 group. We detected a higher number of positive correlations between the antigens and secretory antibodies in the COVID-19 PCR group than in the viral symptom and Ctl-2018 groups. S1 + S2 HCoV-OC43-reactive IgG was higher in the COVID-19 group than in the control group (p = 0.002) but did not differ for the other antibodies; Conclusions: Mothers with a confirmed COVID-19 PCR and mothers with previous viral symptoms had preexisting human milk antibodies against S2 subunit SARS-CoV-2. Human milk IgG were more specific to S2 subunit SARS-CoV-2 than other antibodies, whereas SIgA and SIgM were polyreactive and cross-reactive to S1 or S2 subunit SARS-CoV-2.


Asunto(s)
Anticuerpos Antivirales/inmunología , Coronavirus Humano 229E/metabolismo , Coronavirus Humano OC43/metabolismo , Leche Humana/metabolismo , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto , Reacciones Antígeno-Anticuerpo , Reacciones Cruzadas , Femenino , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Inmunoglobulina M/inmunología , Madres , Reacción en Cadena de la Polimerasa , ARN Viral/metabolismo , /aislamiento & purificación , /metabolismo
12.
N Biotechnol ; 62: 79-85, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-33556628

RESUMEN

A phage library displaying 1010 variants of the fibronectin type III (FN3) domain was affinity selected with the biotinylated form of the receptor binding domain (RBD, residues 319-541) of the SARS-CoV-2 virus spike protein. Nine binding FN3 variants (i.e. monobodies) were recovered, representing four different primary structures. Soluble forms of the monobodies bound to several different preparations of the RBD and the S1 spike subunit, with affinities ranging from 3 to 14 nM as measured by bio-layer interferometry. Three of the four monobodies bound selectively to the RBD of SARS-CoV-2, with the fourth monobody showing slight cross-reactivity to the RBD of SARS-CoV-1 virus. Examination of binding to the spike fragments and its trimeric form revealed that the monobodies recognise at least three overlapping epitopes on the RBD of SARS-CoV-2. While pairwise tests failed to identify a monobody pair that could bind simultaneously to the RBD, one monobody could simultaneously bind to the RBD with the ectodomain of the cellular receptor angiotensin converting enzyme 2 (ACE2). All four monobodies successfully bound the RBD after overexpression in Chinese hamster ovary (CHO) cells as fusions to the Fc domain of human IgG1.


Asunto(s)
/inmunología , Especificidad de Anticuerpos , Epítopos/inmunología , Anticuerpos de Cadena Única/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Línea Celular , Reacciones Cruzadas , Humanos , Dominios Proteicos
13.
Nat Commun ; 12(1): 1152, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608538

RESUMEN

The humoral immune response to SARS-CoV-2 is a benchmark for immunity and detailed analysis is required to understand the manifestation and progression of COVID-19, monitor seroconversion within the general population, and support vaccine development. The majority of currently available commercial serological assays only quantify the SARS-CoV-2 antibody response against individual antigens, limiting our understanding of the immune response. To overcome this, we have developed a multiplex immunoassay (MultiCoV-Ab) including spike and nucleocapsid proteins of SARS-CoV-2 and the endemic human coronaviruses. Compared to three broadly used commercial in vitro diagnostic tests, our MultiCoV-Ab achieves a higher sensitivity and specificity when analyzing a well-characterized sample set of SARS-CoV-2 infected and uninfected individuals. We find a high response against endemic coronaviruses in our sample set, but no consistent cross-reactive IgG response patterns against SARS-CoV-2. Here we show a robust, high-content-enabled, antigen-saving multiplex assay suited to both monitoring vaccination studies and facilitating epidemiologic screenings for humoral immunity towards pandemic and endemic coronaviruses.


Asunto(s)
Anticuerpos Antivirales/inmunología , /inmunología , Reacciones Cruzadas , Inmunidad Humoral , /diagnóstico , Humanos , Inmunoensayo , Inmunoglobulina G/inmunología , Fosfoproteínas/inmunología , Sensibilidad y Especificidad , Glicoproteína de la Espiga del Coronavirus/inmunología
14.
Virology ; 556: 73-78, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33548599

RESUMEN

The need to stem the current outbreak of SARS-CoV-2 responsible for COVID-19 is driving the search for inhibitors that will block coronavirus replication and pathogenesis. The coronavirus 3C-like protease (3CLpro) encoded in the replicase polyprotein is an attractive target for antiviral drug development because protease activity is required for generating a functional replication complex. Reagents that can be used to screen for protease inhibitors and for identifying the replicase products of SARS-CoV-2 are urgently needed. Here we describe a luminescence-based biosensor assay for evaluating small molecule inhibitors of SARS-CoV-2 3CLpro/main protease. We also document that a polyclonal rabbit antiserum developed against SARS-CoV 3CLpro cross reacts with the highly conserved 3CLpro of SARS-CoV-2. These reagents will facilitate the pre-clinical evaluation of SARS-CoV-2 protease inhibitors.


Asunto(s)
Técnicas Biosensibles/métodos , Sueros Inmunes/inmunología , Luciferasas/metabolismo , /metabolismo , Animales , Antivirales/farmacología , /genética , Reacciones Cruzadas , Luciferasas/genética , Inhibidores de Proteasas/farmacología , Conejos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Virus del SRAS/inmunología , Virus del SRAS/metabolismo , /genética , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/inmunología , Proteínas no Estructurales Virales/metabolismo , Replicación Viral/efectos de los fármacos
15.
Sci Immunol ; 6(56)2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33622975

RESUMEN

A comprehensive understanding of the kinetics and evolution of the human B cell response to SARS-CoV-2 infection will facilitate the development of next-generation vaccines and therapies. Here, we longitudinally profiled this response in mild and severe COVID-19 patients over a period of five months. Serum neutralizing antibody (nAb) responses waned rapidly but spike (S)-specific IgG+ memory B cells (MBCs) remained stable or increased over time. Analysis of 1,213 monoclonal antibodies (mAbs) isolated from S-specific MBCs revealed a primarily de novo response that displayed increased somatic hypermutation, binding affinity, and neutralization potency over time, providing evidence for prolonged antibody affinity maturation. B cell immunodominance hierarchies were similar across donor repertoires and remained relatively stable as the immune response progressed. Cross-reactive B cell populations, likely re-called from prior endemic beta-coronavirus exposures, comprised a small but stable fraction of the repertoires and did not contribute to the neutralizing response. The neutralizing antibody response was dominated by public clonotypes that displayed significantly reduced activity against SARS-CoV-2 variants emerging in Brazil and South Africa that harbor mutations at positions 501, 484 and 417 in the S protein. Overall, the results provide insight into the dynamics, durability, and functional properties of the human B cell response to SARS-CoV-2 infection and have implications for the design of immunogens that preferentially stimulate protective B cell responses.


Asunto(s)
Linfocitos B/inmunología , /inmunología , Adulto , Anciano , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Sitios de Unión , Estudios de Cohortes , Reacciones Cruzadas , Femenino , Humanos , Memoria Inmunológica , Estudios Longitudinales , Masculino , Persona de Mediana Edad , /inmunología
16.
Cell Rep ; 34(7): 108737, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33545052

RESUMEN

In the ongoing coronavirus disease 2019 (COVID-19) pandemic, there remain unanswered questions regarding the nature and significance of the humoral immune response toward other coronavirus infections. Here, we investigate the cross-reactivity of antibodies raised against the first severe acute respiratory syndrome coronavirus (SARS-CoV) for their reactivity toward SARS-CoV-2. We extensively characterize a selection of 10 antibodies covering all of the SARS-CoV structural proteins: spike, membrane, nucleocapsid, and envelope. Although nearly all of the examined SARS-CoV antibodies display some level of reactivity to SARS-CoV-2, we find only partial cross-neutralization for the spike antibodies. The implications of our work are two-fold. First, we establish a set of antibodies with known reactivity to both SARS-CoV and SARS-CoV-2, which will allow further study of both viruses. Second, we provide empirical evidence of the high propensity for antibody cross-reactivity between distinct strains of human coronaviruses, which is critical information for designing diagnostic and vaccine strategies for COVID-19.


Asunto(s)
Anticuerpos Antivirales/inmunología , Virus del SRAS/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , /inmunología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Reacciones Cruzadas/inmunología , Células HEK293 , Humanos , Inmunidad Humoral/inmunología , Pandemias , Virus del SRAS/genética , Glicoproteína de la Espiga del Coronavirus/genética
17.
Nat Commun ; 12(1): 1203, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33619277

RESUMEN

Influenza A virus infection in swine impacts the agricultural industry in addition to its zoonotic potential. Here, we utilize epigraph, a computational algorithm, to design a universal swine H3 influenza vaccine. The epigraph hemagglutinin proteins are delivered using an Adenovirus type 5 vector and are compared to a wild type hemagglutinin and the commercial inactivated vaccine, FluSure. In mice, epigraph vaccination leads to significant cross-reactive antibody and T-cell responses against a diverse panel of swH3 isolates. Epigraph vaccination also reduces weight loss and lung viral titers in mice after challenge with three divergent swH3 viruses. Vaccination studies in swine, the target species for this vaccine, show stronger levels of cross-reactive antibodies and T-cell responses after immunization with the epigraph vaccine compared to the wild type and FluSure vaccines. In both murine and swine models, epigraph vaccination shows superior cross-reactive immunity that should be further investigated as a universal swH3 vaccine.


Asunto(s)
Algoritmos , Reacciones Cruzadas/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Inmunidad , Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Animales , Formación de Anticuerpos/inmunología , Epítopos/inmunología , Femenino , Humanos , Gripe Humana/sangre , Gripe Humana/inmunología , Gripe Humana/virología , Pulmón/patología , Pulmón/virología , Masculino , Ratones Endogámicos BALB C , Infecciones por Orthomyxoviridae/sangre , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Porcinos , Linfocitos T/inmunología , Vacunación , Pérdida de Peso
18.
JCI Insight ; 6(5)2021 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-33529170

RESUMEN

The development of prophylactic and therapeutic agents for coronavirus disease 2019 (COVID-19) is a current global health priority. Here, we investigated the presence of cross-neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dromedary camels that were Middle East respiratory syndrome coronavirus (MERS-CoV) seropositive but MERS-CoV free. The tested 229 dromedaries had anti-MERS-CoV camel antibodies with variable cross-reactivity patterns against SARS-CoV-2 proteins, including the S trimer and M, N, and E proteins. Using SARS-CoV-2 competitive immunofluorescence immunoassays and pseudovirus neutralization assays, we found medium-to-high titers of cross-neutralizing antibodies against SARS-CoV-2 in these animals. Through linear B cell epitope mapping using phage immunoprecipitation sequencing and a SARS-CoV-2 peptide/proteome microarray, we identified a large repertoire of Betacoronavirus cross-reactive antibody specificities in these dromedaries and demonstrated that the SARS-CoV-2-specific VHH antibody repertoire is qualitatively diverse. This analysis revealed not only several SARS-CoV-2 epitopes that are highly immunogenic in humans, including a neutralizing epitope, but also epitopes exclusively targeted by camel antibodies. The identified SARS-CoV-2 cross-neutralizing camel antibodies are not proposed as a potential treatment for COVID-19. Rather, their presence in nonimmunized camels supports the development of SARS-CoV-2 hyperimmune camels, which could be a prominent source of therapeutic agents for the prevention and treatment of COVID-19.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Camelus/inmunología , /inmunología , Anticuerpos de Dominio Único/farmacología , Animales , Anticuerpos Neutralizantes/farmacología , Anticuerpos Antivirales/inmunología , Betacoronavirus/inmunología , Camelus/virología , Reacciones Cruzadas , Epítopos , Femenino , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/inmunología , Virus del SRAS/inmunología
19.
Clin Biochem ; 90: 1-7, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33476578

RESUMEN

INTRODUCTION: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is diagnosed by molecular-based detection of SARS-CoV-2 RNA. Serologic testing detects antibodies specific to SARS-CoV-2 and IgM specifically may serve as an adjunct test to PCR early in disease. We evaluated the Abbott anti-SARS-CoV-2 IgM and IgG assays along with DiaSorin anti-SARS-CoV-2 IgG and Roche anti-SARS-CoV-2 Total. METHODS: Specimens from 175 PCR-positive patients and 107 control specimens were analyzed using Abbott IgM and IgG, DiaSorin IgG, and Roche Total (IgA, IgG, IgM) assays. Sensitivity, specificity, cross-reactivity, concordance between assays, trends over time, positive predictive value (PPV), and negative predictive value (NPV) were determined. RESULTS: Abbott IgM sensitivity was 63.6% at 0 days post-PCR positivity, 76.5% at 1-5d, 76.3% at 6-14d, 85.2% at 15-30d, and 63.6% at > 30d. All assays exhibited highest sensitivity 15-30d post-PCR positivity (83.3-85.2%). Combining Abbott IgM and IgG improved sensitivity by 22.7% compared to IgG alone when tested 0d post-PCR positivity. All assays had a specificity of 100% and only Abbott IgG exhibited cross-reactivity (anti-dsDNA). Cohen's kappa varied between 0.86 and 0.93. Time to seroconversion from PCR positivity was lowest for Abbott IgM and highest for Abbott IgG. NPV was highest for Abbott IgM < 14 days post-PCR positivity and Abbott IgG ≥ 14 days. CONCLUSION: The Abbott IgM assay exhibited the earliest response and greatest signal in most patients evaluated for serial sampling and had the highest NPV < 14 days post-PCR positivity, suggesting its potential utility as an adjunct test to PCR early in disease course.


Asunto(s)
Anticuerpos Antivirales/sangre , /inmunología , Inmunoglobulina M/sangre , /inmunología , /diagnóstico , Reacciones Cruzadas , Humanos , Inmunoensayo/métodos , Inmunoglobulina G , Reacción en Cadena de la Polimerasa/métodos , Valor Predictivo de las Pruebas , ARN Viral , Sensibilidad y Especificidad
20.
Science ; 371(6525): 194-200, 2021 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-33414220

RESUMEN

Medically important flaviviruses cause diverse disease pathologies and collectively are responsible for a major global disease burden. A contributing factor to pathogenesis is secreted flavivirus nonstructural protein 1 (NS1). Despite demonstrated protection by NS1-specific antibodies against lethal flavivirus challenge, the structural and mechanistic basis remains unknown. Here, we present three crystal structures of full-length dengue virus NS1 complexed with a flavivirus-cross-reactive, NS1-specific monoclonal antibody, 2B7, at resolutions between 2.89 and 3.96 angstroms. These structures reveal a protective mechanism by which two domains of NS1 are antagonized simultaneously. The NS1 wing domain mediates cell binding, whereas the ß-ladder triggers downstream events, both of which are required for dengue, Zika, and West Nile virus NS1-mediated endothelial dysfunction. These observations provide a mechanistic explanation for 2B7 protection against NS1-induced pathology and demonstrate the potential of one antibody to treat infections by multiple flaviviruses.


Asunto(s)
Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/química , Virus del Dengue/inmunología , Proteínas no Estructurales Virales/inmunología , Virus del Nilo Occidental/inmunología , Virus Zika/inmunología , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Reacciones Cruzadas , Cristalografía por Rayos X , Dengue/prevención & control , Dengue/terapia , Endotelio/inmunología , Glicocálix/inmunología , Humanos , Ratones , Conformación Proteica en Lámina beta , Dominios Proteicos , Proteínas no Estructurales Virales/química , Fiebre del Nilo Occidental/prevención & control , Fiebre del Nilo Occidental/terapia , Infección por el Virus Zika/prevención & control , Infección por el Virus Zika/terapia
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