RESUMEN
BACKGROUND: Data on the dynamics and persistence of humoral immunity against SARS-CoV-2 after primary vaccination with two-dose inactivated vaccine (CoronaVac) are limited. This study evaluated the sequential effects of prior infection, heterologous boosting with mRNA-1273 (Moderna), and the occurrence of Omicron vaccine-breakthrough infection (VBI) thereafter. METHODS: We evaluated anti-spike IgG (Abbott) and neutralising (cPASS/GenScript) antibody (nAb) titers up to one year after mRNA-1273 boost in two-dose-CoronaVac-primed Indonesian healthcare workers (August 2021-August 2022). We used linear mixed modeling to estimate the rate of change in antibody levels, and logistic regression to examine associations between antibody levels and VBI. RESULTS: Of 138 participants, 52 (37.7%) had a prior infection and 78 (56.5%) received an mRNA-1273 booster. After two-dose CoronaVac, antibody titers had significantly declined within 180 days, irrespective of prior infection. After mRNA-1273 booster, anti-spike IgG (1.47% decline/day) and Omicron B.1.1.529/BA.2 nAbs declined between day 28-90, and IgG titers plateaued between day 90-360. During the BA.1/BA.2 wave (February-March 2022), 34.6% (27/78) of individuals experienced a VBI (median 181 days after mRNA-1273), although none developed severe illness. VBI was associated with low pre-VBI anti-spike IgG and B.1.1.529/BA.2 nAbs, which were restored post-VBI. CONCLUSIONS: mRNA-1273 booster after two-dose CoronaVac did not prevent BA.1/BA.2 VBI. Periodic vaccine boosters may be warranted against emerging SARS-CoV-2 variants.
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Vacuna nCoV-2019 mRNA-1273 , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infección Irruptiva , Vacunas contra la COVID-19 , COVID-19 , Inmunización Secundaria , SARS-CoV-2 , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vacuna nCoV-2019 mRNA-1273/inmunología , Vacuna nCoV-2019 mRNA-1273/administración & dosificación , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Infección Irruptiva/epidemiología , Infección Irruptiva/inmunología , Infección Irruptiva/prevención & control , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/epidemiología , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/administración & dosificación , Personal de Salud , Inmunoglobulina G/sangre , Indonesia/epidemiología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunación , Vacunas de Productos Inactivados/inmunología , Vacunas de Productos Inactivados/administración & dosificaciónRESUMEN
The COVID-19 pandemic has uncovered the high genetic variability of the SARS-CoV-2 virus and its ability to evade the immune responses that were induced by earlier viral variants. Only a few monoclonal antibodies that have been reported to date are capable of neutralizing a broad spectrum of SARS-CoV-2 variants. Here, we report the isolation of a new broadly neutralizing human monoclonal antibody, iC1. The antibody was identified through sorting the SARS-CoV-1 RBD-stained individual B cells that were isolated from the blood of a vaccinated donor following a breakthrough infection. In vitro, iC1 potently neutralizes pseudoviruses expressing a wide range of SARS-CoV-2 Spike variants, including those of the XBB sublineage. In an hACE2-transgenic mouse model, iC1 provided effective protection against the Wuhan strain of the virus as well as the BA.5 and XBB.1.5 variants. Therefore, iC1 can be considered as a potential component of the broadly neutralizing antibody cocktails resisting the SARS-CoV-2 mutation escape.
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Enzima Convertidora de Angiotensina 2 , Anticuerpos Monoclonales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , Ratones Transgénicos , SARS-CoV-2 , Animales , SARS-CoV-2/inmunología , Humanos , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Enzima Convertidora de Angiotensina 2/inmunología , Enzima Convertidora de Angiotensina 2/genética , Enzima Convertidora de Angiotensina 2/metabolismo , Ratones , Anticuerpos Antivirales/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Pandemias/prevención & control , Betacoronavirus/inmunología , Betacoronavirus/genética , Anticuerpos ampliamente neutralizantes/inmunología , Modelos Animales de Enfermedad , Neumonía Viral/inmunología , Neumonía Viral/virología , Neumonía Viral/prevención & control , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/virología , Infecciones por Coronavirus/prevención & controlRESUMEN
Squalene-based adjuvant compositions that can provide effective induction of specific humoral immune response have been developed. Recombinant receptor-binding domain (RBD) of surface S-protein of SARS-CoV-2 was used to evaluate the properties of the composition. Immunization of mice with the developed squalene-based compositions in combination with RBD allows obtaining high titers of specific antibodies: from 105 to 2×106. The blood sera from immunized mice exhibit neutralizing activity against SARS-CoV-2 Delta variant (B.1.617.2) with a titer up to 1:2000.
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Adyuvantes Inmunológicos , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Escualeno , Escualeno/inmunología , Animales , Anticuerpos Neutralizantes/inmunología , Adyuvantes Inmunológicos/farmacología , SARS-CoV-2/inmunología , Ratones , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Glicoproteína de la Espiga del Coronavirus/inmunología , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19/inmunología , Femenino , Humanos , Ratones Endogámicos BALB C , Inmunidad Humoral/efectos de los fármacosRESUMEN
BACKGROUND: Reticuloendotheliosis virus (REV), a member of the family Retroviridae, is a hot area of research, and a previous study showed that exosomes purified from REV-positive semen were not blocked by REV-specific neutralizing antibodies and established productive infections. METHODS: To further verify the infectivity of exosomes from REV-infected cells, we isolated and purified exosomes from REV-infected DF-1 cells and identified them using Western blot and a transmission electron microscope. We then inoculated 7-day-old embryonated eggs, 1-day-old chicks and 23-week-old hens with and without antibody treatment. REV was administered simultaneously as a control. RESULTS: In the absence of antibodies, the results indicated that REV-exosomes and REV could infect chicks, resulting in viremia and viral shedding, compared with the infection caused by REV, REV-exosomes reduced the hatching rate and increased mortality after hatching, causing severe growth inhibition and immune organ damage in 1-day-old chicks; both REV and REV-exosomes also could infect hens, however, lead to transient infection. In the presence of antibodies, REV-exosomes were not blocked by REV-specific neutralizing antibodies and infected 7-day-old embryonated eggs. However, REV could not infect 1-day-old chicks and 23-week-old hens. CONCLUSION: In this study, we compared the infectious ability of REV-exosomes and REV, REV-exosomes could escape from REV-specific neutralizing antibodies in embryonated eggs, providing new insights into the immune escape mechanism of REV.
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Anticuerpos Antivirales , Pollos , Exosomas , Enfermedades de las Aves de Corral , Virus de la Reticuloendoteliosis , Infecciones por Retroviridae , Esparcimiento de Virus , Animales , Exosomas/virología , Exosomas/inmunología , Anticuerpos Antivirales/inmunología , Pollos/virología , Virus de la Reticuloendoteliosis/inmunología , Enfermedades de las Aves de Corral/virología , Enfermedades de las Aves de Corral/transmisión , Enfermedades de las Aves de Corral/inmunología , Infecciones por Retroviridae/virología , Infecciones por Retroviridae/transmisión , Infecciones por Retroviridae/inmunología , Infecciones por Retroviridae/veterinaria , Anticuerpos Neutralizantes/inmunología , Línea Celular , Viremia/virología , FemeninoRESUMEN
The recent emergence and rapid response to severe acute respiratory syndrome coronavirus 2 was enabled by prototype pathogen and vaccine platform approaches, driven by the preemptive application of RNA vaccine technology to the related Middle East respiratory syndrome coronavirus. Recently, the National Institutes of Allergy and Infectious Diseases identified nine virus families of concern, eight enveloped virus families and one nonenveloped virus family, for which vaccine generation is a priority. Although RNA vaccines have been described for a variety of enveloped viruses, a roadmap for their use against nonenveloped viruses is lacking. Enterovirus D68 was recently designated a prototype pathogen within the family Picornaviridae of nonenveloped viruses because of its rapid evolution and respiratory route of transmission, coupled with a lack of diverse anti-enterovirus vaccine approaches in development. Here, we describe a proof-of-concept approach using a clinical stage RNA vaccine platform that induced robust enterovirus D68-neutralizing antibody responses in mice and nonhuman primates and prevented upper and lower respiratory tract infections and neurological disease in mice. In addition, we used our platform to rapidly characterize the antigenic diversity within the six genotypes of enterovirus D68, providing the necessary data to inform multivalent vaccine compositions that can elicit optimal breadth of neutralizing responses. These results demonstrate that RNA vaccines can be used as tools in our pandemic-preparedness toolbox for nonenveloped viruses.
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Anticuerpos Neutralizantes , Enterovirus Humano D , Infecciones por Enterovirus , Animales , Infecciones por Enterovirus/prevención & control , Infecciones por Enterovirus/inmunología , Infecciones por Enterovirus/virología , Enterovirus Humano D/inmunología , Enterovirus Humano D/genética , Anticuerpos Neutralizantes/inmunología , Ratones , Vacunas Virales/inmunología , Modelos Animales de Enfermedad , Humanos , Vacunas de ARNm , Anticuerpos Antivirales/inmunología , FemeninoRESUMEN
Current vaccines against COVID-19 elicit immune responses that are overall strong but wane rapidly. As a consequence, the necessary booster shots have contributed to vaccine fatigue. Hence, vaccines that would provide lasting protection against COVID-19 are needed, but are still unavailable. Cytomegaloviruses (CMVs) elicit lasting and uniquely strong immune responses. Used as vaccine vectors, they may be attractive tools that obviate the need for boosters. Therefore, we tested the murine CMV (MCMV) as a vaccine vector against COVID-19 in relevant preclinical models of immunization and challenge. We have previously developed a recombinant MCMV vaccine vector expressing the spike protein of the ancestral SARS-CoV-2 (MCMVS). In this study, we show that the MCMVS elicits a robust and lasting protection in young and aged mice. Notably, spike-specific humoral and cellular immunity was not only maintained but also even increased over a period of at least 6 months. During that time, antibody avidity continuously increased and expanded in breadth, resulting in neutralization of genetically distant variants, like Omicron BA.1. A single dose of MCMVS conferred rapid virus clearance upon challenge. Moreover, MCMVS vaccination controlled two variants of concern (VOCs), the Beta (B.1.135) and the Omicron (BA.1) variants. Thus, CMV vectors provide unique advantages over other vaccine technologies, eliciting broadly reactive and long-lasting immune responses against COVID-19.
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Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Animales , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Ratones , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , COVID-19/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Muromegalovirus/inmunología , Muromegalovirus/genética , Femenino , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Ratones Endogámicos BALB C , Humanos , Vectores Genéticos , Inmunidad Celular , Inmunidad Humoral , Modelos Animales de EnfermedadRESUMEN
With the rapid global spread of COVID-19 and the continuous emergence of variants, there is an urgent need to develop safe and effective vaccines. Here, we developed a novel mRNA vaccine, HC009, based on new formulation by the QTsome delivery platform. Immunogenicity results showed that the prime-boost immunization strategy with HC009 was able to induce robust and durable humoral immunity, as well as Th1-biased cellular responses in rodents or non-human primates (NHPs). After further challenge with live SARS-CoV-2 virus, HC009 provided adequate protection against virus infection in hACE2 transgenic mice. Therefore, HC009 could provide significant immune protection against SARS-CoV-2.
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Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , Inmunogenicidad Vacunal , Ratones Transgénicos , SARS-CoV-2 , Vacunas de ARNm , Animales , SARS-CoV-2/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , COVID-19/inmunología , Ratones , Vacunas de ARNm/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Humanos , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificación , Inmunidad Humoral , Femenino , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Ratones Endogámicos BALB C , Eficacia de las VacunasRESUMEN
INTRODUCTION: Quantifying antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and neutralising antibodies may help to understand protection at the individual and population levels. Determination of neutralising antibodies using classical virus neutralisation tests (VNT) is considered the gold standard, but they are costly and time-intensive. Enzyme-linked immunosorbent assay (ELISA)-based surrogate VNTs (sVNT) or anti-SARS-CoV-2 spike protein receptor binding domain immunoglobulins (anti-S-RBD Ig) may be suitable alternatives to VNTs. We aimed to (a) explore the correlations between anti-S-RBD Ig, VNT, and sVNT measurements and (b) describe humoral immunity against SARS-CoV-2 after vaccination, natural infection, and vaccine breakthrough infection in healthy blood donors. METHODS: We measured total anti-SARS-CoV-2 Ig in 5714 serum samples from 2748 healthy individuals visiting the Swiss Red Cross Blood Donation Centre in Basel from 03/2020 to 04/2022. We used the Elecsys® Anti-SARS-CoV-2 immunoassay (Roche) against the N- and S-receptor binding domain (RBD) proteins. In a subset of 548 samples from 123 donors, we conducted sVNTs against the Wuhan wild-type SARS-CoV-2 (SARS-CoV-2 Neutralizing Antibodies Detection Kit; Adipogen™). In 100 samples from 40 donors, we correlated sVNT and VNTs against the wild-type (D614G WU1) virus. Surveys were sent to the blood donors to collect data on their SARS-CoV-2 infection and vaccination status. Using this data, donors were categorised as "vaccination only", "infection before vaccination", "post-vaccine breakthrough infection", and "natural infection only". RESULTS: Our longitudinal observation study cohort consisted of 50.7% males with a median age of 31 years (range 18-75 y). Anti-SARS-CoV-2 N protein positivity rates per month indicate 57.1% (88/154) of the cohort was infected up to 04/2022. No differences in seropositivity were found between sexes, age groups, blood types (AB0 or RhD), and cytomegalovirus serostatus. We observed a high correlation between anti-S-RBD Ig and inhibition percentage (Spearman's ρ = 0.92, Kendall's τ = 0.77, p <0.0001). We determined the sensitivity and specificity for the manufacturers' thresholds for detecting virus-neutralising effects and computed the "best" cut-off based on our real-world data. We categorised 722/1138 (63.5%) donors as vaccination only (82.3%), post-vaccine breakthrough infection (7.8%), infection before vaccination (5.8%), and natural infection only (4.2%). We observed a lower inhibition percentage in the natural infection-only group than in all other vaccinated groups. The infection before vaccination group had higher anti-S-RBD Ig titres after the first vaccine dose than the other vaccinated groups. CONCLUSION: In total, 57.1% of healthy blood donors were infected with SARS-CoV-2, but natural infection without evidence of vaccination seems to result in substantially lower neutralising antibody levels. An estimate of antibody neutralisation may be helpful to assess reinfection risk. Total anti-S-RBD Ig correlates with surrogate virus neutralisation test results, a surrogate for neutralisation; therefore, we suggest that total anti-S-RBD Ig may estimate the level of neutralising antibodies. The threshold for protection from an unfavourable clinical outcome must be evaluated in prospective clinical cohorts.
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Anticuerpos Neutralizantes , Anticuerpos Antivirales , Donantes de Sangre , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/inmunología , COVID-19/prevención & control , Donantes de Sangre/estadística & datos numéricos , SARS-CoV-2/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Estudios Longitudinales , Masculino , Femenino , Adulto , Persona de Mediana Edad , Pruebas de Neutralización , Suiza , Ensayo de Inmunoadsorción Enzimática , Glicoproteína de la Espiga del Coronavirus/inmunología , Anciano , Adolescente , Adulto JovenRESUMEN
Despite advancements in antiretroviral therapy (ART) suppressing HIV-1 replication, existing antiviral drugs pose limitations, including lifelong medication, frequent administration, side effects and viral resistance, necessitating novel HIV-1 treatment approaches. CD4, pivotal for HIV-1 entry, poses challenges for drug development due to neutralization and cytotoxicity concerns. Nevertheless, Ibalizumab, the sole approved CD4-specific antibody for HIV-1 treatment, reignites interest in exploring alternative anti-HIV targets, emphasizing CD4's potential value for effective drug development. Here, we explore anti-CD4 nanobodies, particularly Nb457 from a CD4-immunized alpaca. Nb457 displays high potency and broad-spectrum activity against HIV-1, surpassing Ibalizumab's efficacy. Strikingly, engineered trimeric Nb457 nanobodies achieve complete inhibition against live HIV-1, outperforming Ibalizumab and parental Nb457. Structural analysis unveils Nb457-induced CD4 conformational changes impeding viral entry. Notably, Nb457 demonstrates therapeutic efficacy in humanized female mouse models. Our findings highlight anti-CD4 nanobodies as promising HIV-1 therapeutics, with potential implications for advancing clinical treatment against this global health challenge.
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Antígenos CD4 , Camélidos del Nuevo Mundo , Anticuerpos Anti-VIH , Infecciones por VIH , VIH-1 , Anticuerpos de Dominio Único , VIH-1/inmunología , VIH-1/efectos de los fármacos , Anticuerpos de Dominio Único/farmacología , Anticuerpos de Dominio Único/inmunología , Animales , Antígenos CD4/inmunología , Antígenos CD4/metabolismo , Humanos , Infecciones por VIH/inmunología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Camélidos del Nuevo Mundo/inmunología , Anticuerpos Anti-VIH/inmunología , Anticuerpos Anti-VIH/farmacología , Ratones , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/farmacología , Conformación Proteica , Femenino , Internalización del Virus/efectos de los fármacos , Células HEK293 , Fármacos Anti-VIH/farmacología , Fármacos Anti-VIH/uso terapéutico , Anticuerpos MonoclonalesRESUMEN
Although neutralizing antibody is an established correlate of protection for measles, T cell-mediated responses play at least two critical roles in immunity to measles: first, through provision of 'help' enabling robust humoral immune responses; and second, through clearance of measles virus-infected cells. Previously, we identified 13 measles-derived peptides that bound to human leukocyte antigen (HLA) molecules in Priess cells infected with measles virus. In this study, we evaluated the immunogenicity of these peptides in a transgenic mouse model. Our results demonstrated that these peptides induced Th1-biased immune responses at varying levels. Of the 13 peptides, the top four immunogenic peptides were further selected for a viral challenge study in mice. A vaccine based on a combination of these four peptides reduced morbidity and weight loss after viral challenge compared to placebo. Our results emphasize the potential of T cell-mediated, peptide-based vaccines against measles.
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Modelos Animales de Enfermedad , Vacuna Antisarampión , Virus del Sarampión , Sarampión , Ratones Transgénicos , Vacunas de Subunidad , Animales , Sarampión/prevención & control , Sarampión/inmunología , Ratones , Vacuna Antisarampión/inmunología , Virus del Sarampión/inmunología , Humanos , Vacunas de Subunidad/inmunología , Proyectos Piloto , Anticuerpos Antivirales/inmunología , Péptidos/inmunología , Péptidos/química , Anticuerpos Neutralizantes/inmunología , Femenino , Células TH1/inmunología , Inmunogenicidad VacunalRESUMEN
Artificial Intelligence (AI) techniques have made great advances in assisting antibody design. However, antibody design still heavily relies on isolating antigen-specific antibodies from serum, which is a resource-intensive and time-consuming process. To address this issue, we propose a Pre-trained Antibody generative large Language Model (PALM-H3) for the de novo generation of artificial antibodies heavy chain complementarity-determining region 3 (CDRH3) with desired antigen-binding specificity, reducing the reliance on natural antibodies. We also build a high-precision model antigen-antibody binder (A2binder) that pairs antigen epitope sequences with antibody sequences to predict binding specificity and affinity. PALM-H3-generated antibodies exhibit binding ability to SARS-CoV-2 antigens, including the emerging XBB variant, as confirmed through in-silico analysis and in-vitro assays. The in-vitro assays validate that PALM-H3-generated antibodies achieve high binding affinity and potent neutralization capability against spike proteins of SARS-CoV-2 wild-type, Alpha, Delta, and the emerging XBB variant. Meanwhile, A2binder demonstrates exceptional predictive performance on binding specificity for various epitopes and variants. Furthermore, by incorporating the attention mechanism inherent in the Roformer architecture into the PALM-H3 model, we improve its interpretability, providing crucial insights into the fundamental principles of antibody design.
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Anticuerpos Antivirales , COVID-19 , Regiones Determinantes de Complementariedad , Epítopos , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , SARS-CoV-2/inmunología , Humanos , Anticuerpos Antivirales/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Regiones Determinantes de Complementariedad/inmunología , Regiones Determinantes de Complementariedad/química , Regiones Determinantes de Complementariedad/genética , COVID-19/inmunología , COVID-19/virología , Epítopos/inmunología , Anticuerpos Neutralizantes/inmunología , Inteligencia ArtificialRESUMEN
BACKGROUND: A definition of the immunological features of COVID-19 pneumonia is needed to support clinical management of aged patients. In this study, we characterized the humoral and cellular immune responses in presence or absence of SARS-CoV-2 vaccination, in aged patients admitted to the IRCCS San Raffaele Hospital (Italy) for COVID-19 pneumonia between November 2021 and March 2022. METHODS: The study was approved by local authorities. Disease severity was evaluated according to WHO guidelines. We tested: (A) anti-SARS-CoV-2 humoral response (anti-RBD-S IgG, anti-S IgM, anti-N IgG, neutralizing activity against Delta, BA1, BA4/5 variants); (B) Lymphocyte B, CD4 and CD8 T-cell phenotype; (C) plasma cytokines. The impact of vaccine administration and different variants on the immunological responses was evaluated using standard linear regression models and Tobit models for censored outcomes adjusted for age, vaccine doses and gender. RESULT: We studied 47 aged patients (median age 78.41), 22 (47%) female, 33 (70%) older than 70 years (elderly). At hospital admission, 36% were unvaccinated (VACno), whilst 63% had received 2 (VAC2) or 3 doses (VAC3) of vaccine. During hospitalization, WHO score > 5 was higher in unvaccinated (14% in VAC3 vs. 43% in VAC2 and 44% VACno). Independently from vaccination doses and gender, elderly had overall reduced anti-SARS-CoV-2 humoral response (IgG-RBD-S, p = 0.0075). By linear regression, the anti-RBD-S (p = 0.0060), B (p = 0.0079), CD8 (p = 0.0043) and Th2 cell counts (p = 0.0131) were higher in VAC2 + 3 compared to VACno. Delta variant was the most representative in VAC2 (n = 13/18, 72%), detected in 41% of VACno, whereas undetected in VAC3, and anti-RBD-S production was higher in VAC2 vs. VACno (p = 0.0001), alongside neutralization against Delta (p = 0141), BA1 (p = 0.0255), BA4/5 (p = 0.0162). Infections with Delta also drove an increase of pro-inflammatory cytokines (IFN-α, p = 0.0463; IL-6, p = 0.0010). CONCLUSIONS: Administration of 3 vaccination doses reduces the severe symptomatology in aged and elderly. Vaccination showed a strong association with anti-SARS-CoV-2 humoral response and an expansion of Th2 T-cells populations, independently of age. Delta variants and number of vaccine doses affected the magnitude of the humoral response against the original SARS-CoV-2 and emerging variants. A systematic surveillance of the emerging variants is paramount to define future vaccination strategies.
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Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Vacunación , Humanos , Femenino , Masculino , COVID-19/inmunología , Anciano , SARS-CoV-2/inmunología , Anciano de 80 o más Años , Vacunas contra la COVID-19/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Inmunidad Humoral , Citocinas/sangre , Italia , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunologíaRESUMEN
BACKGROUND: Omicron variant impacts populations with its rapid contagiousness, and part of patients suffered from persistent symptoms termed as long COVID. The molecular and immune mechanisms of this currently dominant global variant leading to long COVID remain unclear, due to long COVID heterogeneity across populations. METHODS: We recruited 66 participants in total, 22 out of 66 were healthy control without COVID-19 infection history, and 22 complaining about long COVID symptoms 6 months after first infection of Omicron, referred as long COVID (LC) Group. The left ones were defined as non-long COVID (NLC) Group. We profiled them via plasma neutralizing antibody titer, SARS-CoV-2 viral load, transcriptomic and proteomics screening, and machine learning. RESULTS: No serum residual SARS-CoV-2 was observed in the participants 6 months post COVID-19 infection. No significant difference in neutralizing antibody titers was found between the long COVID (LC) Group and the non-long COVID (NLC) Group. Transcriptomic and proteomic profiling allow the stratification of long COVID into neutrophil function upregulated (NU-LC) and downregulated types (ND-LC). The NU-LC, identifiable through a refined set of 5 blood gene markers (ABCA13, CEACAM6, CRISP3, CTSG and BPI), displays evidence of relatively higher neutrophil counts and function of degranulation than the ND-LC at 6 months after infection, while recovered at 12 months post COVID-19. CONCLUSION: The transcriptomic and proteomic profiling revealed heterogeneity among long COVID patients. We discovered a subgroup of long COVID population characterized by neutrophil activation, which might associate with the development of psychiatric symptoms and indicate a higher inflammatory state. Meanwhile, a cluster of 5 genes was manually curated as the most potent discriminators of NU-LC from long COVID population. This study can serve as a foundational exploration of the heterogeneity in the pathogenesis of long COVID and assist in therapeutic targeting and detailed epidemiological investigation of long COVID.
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COVID-19 , Neutrófilos , Proteómica , SARS-CoV-2 , Humanos , COVID-19/inmunología , COVID-19/virología , COVID-19/sangre , Neutrófilos/inmunología , Masculino , Femenino , Persona de Mediana Edad , Transcriptoma/genética , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Adulto , Síndrome Post Agudo de COVID-19 , Carga Viral , Anciano , Perfilación de la Expresión Génica , Activación Neutrófila , MultiómicaRESUMEN
Recombinant SARS-CoV-2 S protein expression was examined in Vero cells by imaging using the human monoclonal antibody panel (PD4, PD5, sc23, and sc29). The PD4 and sc29 antibodies recognised conformational specific epitopes in the S2 protein subunit at the Endoplasmic reticulum and Golgi complex. While PD5 and sc23 detected conformationally specific epitopes in the S1 protein subunit at the Golgi complex, only PD5 recognised the receptor binding domain (RBD). A comparison of the staining patterns of PD5 with non-conformationally specific antibodies that recognises the S1 subunit and RBD suggested the PD5 recognised a conformational structure within the S1 protein subunit. Our data suggests the antibody binding epitopes recognised by the human monoclonal antibodies formed at different locations in the secretory pathway during S protein transport, but a conformational change in the S1 protein subunit at the Golgi complex formed antibody binding epitopes that are recognised by virus neutralising antibodies.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Epítopos , Aparato de Golgi , Conformación Proteica , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Aparato de Golgi/metabolismo , Chlorocebus aethiops , Animales , Células Vero , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/metabolismo , Glicoproteína de la Espiga del Coronavirus/química , Humanos , Anticuerpos Neutralizantes/inmunología , SARS-CoV-2/inmunología , SARS-CoV-2/metabolismo , Epítopos/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/metabolismo , Anticuerpos Monoclonales/inmunología , COVID-19/inmunología , COVID-19/virologíaRESUMEN
Reovirus (Reo) has shown promising potential in specifically killing tumor cells, and offering new possibilities for ovarian cancer (OC) treatment. However, neutralizing antibodies in the ascites from OC patients greatly limit the further application of Reo. In this study, we employed cationic liposomes (Lipo) to deliver Reo, significantly enhancing its ability to enter OC cells and its effectiveness in killing these cells under ascitic conditions. Pre-treatment with the MßCD inhibitor notably decreased Reo-mediated tumor cell death, indicating that Lipo primarily enables Reo's cellular uptake through caveolin-mediated endocytosis. Our results demonstrate that Lipo effectively facilitates the entry of Reo into the cytoplasm and triggers cell apoptosis. The above findings provide a new strategy to overcome the obstacle of neutralizing antibodies in the clinical application of Reo.
Asunto(s)
Anticuerpos Neutralizantes , Liposomas , Neoplasias Ováricas , Reoviridae , Femenino , Humanos , Neoplasias Ováricas/inmunología , Anticuerpos Neutralizantes/inmunología , Reoviridae/inmunología , Reoviridae/fisiología , Línea Celular Tumoral , Viroterapia Oncolítica/métodos , Apoptosis , Animales , Cationes , Virus Oncolíticos/inmunología , RatonesAsunto(s)
Anticuerpos Neutralizantes , Donantes de Sangre , ARN Viral , Fiebre del Nilo Occidental , Virus del Nilo Occidental , Humanos , Virus del Nilo Occidental/inmunología , ARN Viral/sangre , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Masculino , Femenino , Fiebre del Nilo Occidental/sangre , Anticuerpos Antivirales/sangre , Adulto , Persona de Mediana EdadRESUMEN
The virus neutralization test (VNT) is a functional immunoassay which detects the presence and quantity of neutralizing antibodies. It is a highly sensitive and specific test. As with most neutralization assays, the EHDV VNT does not react with all virus-targeting antibodies, but specifically with those antibodies that bind to VP2, the outermost capsid structural protein of the virus. The interaction between VP2 and neutralizing antibodies can block EHDV cell binding, neutralizing its infectivity. The detection and quantification of neutralizing antibodies are indicative of how protected an animal is against reinfection. The EHD VNT can therefore be a useful tool to monitor the efficacy of a vaccination campaign. VP2 is also the main determinant of EHDV serotype specificity, and so EHDV-neutralizing antibodies which target VP2 are also serotype-specific. Throughdetecting and quantifying neutralizing antibodies, the VNT can discriminate the EHDV serotype responsible for an infection and provides insights into the time of infection. It is considered the gold standard test for identifying and quantifying antibodies against EHDV serotypes present in test serum samples. The assay is performed in vitro and is based on inhibition of virus infectivity in the presence of neutralizing antibodies. A neutralizing antibody titer is determined through the presence or absence of cytopathic effect in a cell monolayer. The VNT is a relatively inexpensive assay using standard laboratory equipment; however, to perform the assay, cell cultures, significant time, intensive labor, and technical skill are required.
Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Virus de la Enfermedad Hemorrágica Epizoótica , Pruebas de Neutralización , Pruebas de Neutralización/métodos , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Animales , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Virus de la Enfermedad Hemorrágica Epizoótica/inmunología , Serogrupo , Infecciones por Reoviridae/inmunología , Infecciones por Reoviridae/diagnóstico , Infecciones por Reoviridae/veterinaria , Infecciones por Reoviridae/virologíaRESUMEN
The HIV-1 envelope glycoprotein (Env) is the sole neutralizing determinant on the surface of the virus. The Env gp120 and gp41 subunits mediate receptor binding and membrane fusion and are generated from the gp160 precursor by cellular furins. This cleavage event is required for viral entry. One approach to generate HIV-1 neutralizing antibodies following immunization is to express membrane-bound Env anchored on the cell-surface by genetic means using the natural HIV gp41 transmembrane (TM) spanning domain. To simplify the process of Env trimer membrane expression we sought to remove the need for Env precursor cleavage while maintaining native-like conformation following genetic expression. To accomplish these objectives, we selected our previously developed 'native flexibly linked' (NFL) stabilized soluble trimers that are both near-native in conformation and cleavage-independent. We genetically fused the NFL construct to the HIV TM domain by using a short linker or by restoring the native membrane external proximal region, absent in soluble trimers, to express the full HIV Env ectodomain on the plasma membrane. Both forms of cell-surface NFL trimers, without and with the MPER, displayed favorable antigenic profiles by flow cytometry when expressed from plasmid DNA or mRNA. These results were consistent with the presence of well-ordered cell surface native-like trimeric Env, a necessary requirement to generate neutralizing antibodies by vaccination. Inoculation of rabbits with mRNA lipid nanoparticles (LNP) expressing membrane-bound stabilized HIV Env NFL trimers generated tier 2 neutralizing antibody serum titers in immunized animals. Multiple inoculations of mRNA LNPs generated similar neutralizing antibody titers compared to immunizations of matched NFL soluble proteins in adjuvant. Given the recent success of mRNA vaccines to prevent severe COVID, these are important developments for genetic expression of native-like HIV Env trimers in animals and potentially in humans.
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Vacunas contra el SIDA , Anticuerpos Neutralizantes , Anticuerpos Anti-VIH , VIH-1 , Nanopartículas , ARN Mensajero , Productos del Gen env del Virus de la Inmunodeficiencia Humana , Animales , Anticuerpos Anti-VIH/inmunología , VIH-1/inmunología , Anticuerpos Neutralizantes/inmunología , Humanos , Productos del Gen env del Virus de la Inmunodeficiencia Humana/inmunología , Productos del Gen env del Virus de la Inmunodeficiencia Humana/genética , Vacunas contra el SIDA/inmunología , Conejos , ARN Mensajero/inmunología , ARN Mensajero/genética , Lípidos/inmunología , Multimerización de Proteína , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Infecciones por VIH/prevención & control , Femenino , LiposomasRESUMEN
The severe acute respiratory syndrome coronavirus 2 variant JN.1 recently emerged as the dominant variant despite having only one amino acid change on the spike (S) protein receptor binding domain (RBD) compared with the ancestral BA.2.86, which never represented more than 5% of global variants. To define at the molecular level the JN.1 ability to spread globally, we interrogated a panel of 899 neutralizing human monoclonal antibodies. Our data show that the single leucine-455-to-serine mutation in the JN.1 spike protein RBD unleashed the global spread of JN.1, likely occurring by elimination of more than 70% of the neutralizing antibodies mediated by IGHV3-53/3-66 germlines. However, the resilience of class 3 antibodies with low neutralization potency but strong Fc functions may explain the absence of JN.1 severe disease.
Asunto(s)
Anticuerpos Neutralizantes , COVID-19 , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Humanos , SARS-CoV-2/inmunología , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/genética , COVID-19/inmunología , Anticuerpos Neutralizantes/inmunología , Linfocitos B/inmunología , Anticuerpos Antivirales/inmunología , Evasión Inmune/inmunología , Anticuerpos Monoclonales/inmunología , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Pesadas de Inmunoglobulina/inmunología , Células Germinativas/inmunologíaRESUMEN
Rabies is a lethal zoonotic disease that threatens human health. As the only viral surface protein, the rabies virus (RABV) glycoprotein (G) induces main neutralizing antibody (Nab) responses; however, Nab titre is closely correlated with the conformation of G. Virus-like particles (VLP) formed by the co-expression of RABV G and matrix protein (M) improve retention and antigen presentation, inducing broad, durable immune responses. RABV nucleoprotein (N) can elicit humoral and cellular immune responses. Hence, we developed a series of nucleoside-modified RABV mRNA vaccines encoding wild-type G, soluble trimeric RABV G formed by an artificial trimer motif (tG-MTQ), membrane-anchored prefusion-stabilized G (preG). Furthermore, we also developed RABV VLP mRNA vaccine co-expressing preG and M to generate VLPs, and VLP/N mRNA vaccine co-expressing preG, M, and N. The RABV mRNA vaccines induced higher humoral and cellular responses than inactivated rabies vaccine, and completely protected mice against intracerebral challenge. Additionally, the IgG and Nab titres in RABV preG, VLP and VLP/N mRNA groups were significantly higher than those in G and tG-MTQ groups. A single administration of VLP or VLP/N mRNA vaccines elicited protective Nab responses, the Nab titres were significantly higher than that in inactivated rabies vaccine group at day 7. Moreover, RABV VLP and VLP/N mRNA vaccines showed superior capacities to elicit potent germinal centre, long-lived plasma cell and memory B cell responses, which linked to high titre and durable Nab responses. In summary, our data demonstrated that RABV VLP and VLP/N mRNA vaccines could be promising candidates against rabies.