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1.
Sci Rep ; 10(1): 16219, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004978

RESUMO

COVID-19 pandemic has resulted in 16,114,449 cases with 646,641 deaths from the 217 countries, or territories as on July 27th 2020. Due to multifaceted issues and challenges in the implementation of the safety and preventive measures, inconsistent coordination between societies-governments and most importantly lack of specific vaccine to SARS-CoV-2, the spread of the virus that initially emerged at Wuhan is still uprising after taking a heavy toll on human life. In the present study, we mapped immunogenic epitopes present on the four structural proteins of SARS-CoV-2 and we designed a multi-epitope peptide based vaccine that, demonstrated a high immunogenic response with a vast application on world's human population. On codon optimization and in-silico cloning, we found that candidate vaccine showed high expression in E. coli and immune simulation resulted in inducing a high level of both B-cell and T-cell mediated immunity. The results predicted that exposure of vaccine by administrating three injections significantly subsidized the antigen growth in the system. The proposed candidate vaccine found promising by yielding desired results and hence, should be validated by practical experimentations for its functioning and efficacy to neutralize SARS-CoV-2.


Assuntos
Epitopos/imunologia , Simulação de Acoplamento Molecular , Vacinas de Subunidades/imunologia , Vacinas Virais/imunologia , Complexo Antígeno-Anticorpo/química , Complexo Antígeno-Anticorpo/imunologia , Antígenos Virais/imunologia , Linfócitos B/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos/química , Antígenos HLA/química , Antígenos HLA/imunologia , Humanos , Imunogenicidade da Vacina , Proteínas do Nucleocapsídeo/química , Proteínas do Nucleocapsídeo/imunologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Receptores Toll-Like/imunologia , Vacinas de Subunidades/química , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/imunologia , Vacinas Virais/química
2.
BMC Infect Dis ; 20(1): 641, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32867698

RESUMO

BACKGROUND: Maternal poliovirus antibodies could provide passive immunity to the newborns from poliovirus infection during their first few months of life, but they may impair the immune responses of infants to the poliovirus vaccine as well. In our study, we pooled the data from three clinical trials of the inactivated poliovirus vaccine (IPV) based on Sabin strains to investigate the effect of maternal poliovirus antibodies on the immune responses of infants to poliovirus vaccines. METHODS: There were five groups in the pooled analysis, including low-dose Sabin IPV, medium-dose Sabin IPV, high-dose Sabin IPV, control Sabin IPV, and control Salk IPV groups. We reclassified the infants in different groups according to their maternal poliovirus antibodies by two methods, the first one included maternal antibody negative (< 1:8) and maternal antibody positive (≥1:8), and the second one included maternal antibody titer < 1:8, 1:8 ~ < 1:32 and ≥ 1:32. Then, we compared the geometric mean titers (GMTs), geometric mean antibody fold increases (GMIs) and seroconversion rates of poliovirus type-specific neutralizing antibodies after vaccination among participants with different maternal poliovirus antibody levels. RESULTS: The GMTs and GMIs of three types of poliovirus antibodies after vaccination in maternal antibody negative participants were significantly higher than those in maternal antibody positive participants. The seroconversion rates of type II and type III poliovirus antibodies in maternal antibody positive participants were significantly lower than those in maternal antibody negative participants. Among participants with maternal antibody titer < 1:8, 1:8 ~ < 1:32 and ≥ 1:32, the GMTs and GMIs of three types of poliovirus antibodies after vaccination showed a tendency to decline with the increasing of maternal antibody levels. The seroconversion rates of three types of poliovirus antibodies in participants with maternal antibody titer ≥1:32 were significantly lower than those in participants with maternal antibody titer < 1:8 and 1:8 ~ < 1:32. CONCLUSIONS: Maternal poliovirus antibodies interfered with the immune responses of infants to poliovirus vaccines, and a high level of maternal antibodies exhibited a greater dampening effect. TRIAL REGISTRATION: ClinicalTrials.gov NCT04264598 February 11, 2020; ClinicalTrials.gov NCT04264546 February 11, 2020; ClinicalTrials.gov NCT03902054 April 3, 2019. Retrospectively registered.


Assuntos
Anticorpos Antivirais/imunologia , Imunidade Materno-Adquirida/imunologia , Imunogenicidade da Vacina , Poliomielite/prevenção & controle , Vacina Antipólio de Vírus Inativado/uso terapêutico , Poliovirus/imunologia , Vacinação/métodos , Anticorpos Neutralizantes/imunologia , China , Feminino , Humanos , Lactente , Masculino , Poliomielite/virologia , Vacina Antipólio de Vírus Inativado/efeitos adversos , Soroconversão
3.
Vaccine ; 38(42): 6487-6499, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32907757

RESUMO

The many carbohydrate chains on Covid-19 coronavirus SARS-CoV-2 and its S-protein form a glycan-shield that masks antigenic peptides and decreases uptake of inactivated virus or S-protein vaccines by APC. Studies on inactivated influenza virus and recombinant gp120 of HIV vaccines indicate that glycoengineering of glycan-shields to present α-gal epitopes (Galα1-3Galß1-4GlcNAc-R) enables harnessing of the natural anti-Gal antibody for amplifying vaccine efficacy, as evaluated in mice producing anti-Gal. The α-gal epitope is the ligand for the natural anti-Gal antibody which constitutes ~1% of immunoglobulins in humans. Upon administration of vaccines presenting α-gal epitopes, anti-Gal binds to these epitopes at the vaccination site and forms immune complexes with the vaccines. These immune complexes are targeted for extensive uptake by APC as a result of binding of the Fc portion of immunocomplexed anti-Gal to Fc receptors on APC. This anti-Gal mediated effective uptake of vaccines by APC results in 10-200-fold higher anti-viral immune response and in 8-fold higher survival rate following challenge with a lethal dose of live influenza virus, than same vaccines lacking α-gal epitopes. It is suggested that glycoengineering of carbohydrate chains on the glycan-shield of inactivated SARS-CoV-2 or on S-protein vaccines, for presenting α-gal epitopes, will have similar amplifying effects on vaccine efficacy. α-Gal epitope synthesis on coronavirus vaccines can be achieved with recombinant α1,3galactosyltransferase, replication of the virus in cells with high α1,3galactosyltransferase activity as a result of stable transfection of cells with several copies of the α1,3galactosyltransferase gene (GGTA1), or by transduction of host cells with replication defective adenovirus containing this gene. In addition, recombinant S-protein presenting multiple α-gal epitopes on the glycan-shield may be produced in glycoengineered yeast or bacteria expression systems containing the corresponding glycosyltransferases. Prospective Covid-19 vaccines presenting α-gal epitopes may provide better protection than vaccines lacking this epitope because of increased uptake by APC.


Assuntos
Antígenos Virais/genética , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/genética , Trissacarídeos/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/biossíntese , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/virologia , Engenharia Genética , Proteína do Núcleo p24 do HIV/química , Proteína do Núcleo p24 do HIV/genética , Proteína do Núcleo p24 do HIV/imunologia , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Imunogenicidade da Vacina , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/virologia , Camundongos , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/metabolismo , Trissacarídeos/química , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese , Vacinas Virais/genética
4.
Vaccine ; 38(42): 6500-6507, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32863069

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) was declared a pandemic in March 2020. Several prophylactic vaccines against COVID-19 are currently in development, yet little is known about people's acceptability of a COVID-19 vaccine. METHODS: We conducted an online survey of adults ages 18 and older in the United States (n = 2,006) in May 2020. Multivariable relative risk regression identified correlates of participants' willingness to get a COVID-19 vaccine (i.e., vaccine acceptability). RESULTS: Overall, 69% of participants were willing to get a COVID-19 vaccine. Participants were more likely to be willing to get vaccinated if they thought their healthcare provider would recommend vaccination (RR = 1.73, 95% CI: 1.49-2.02) or if they were moderate (RR = 1.09, 95% CI: 1.02-1.16) or liberal (RR = 1.14, 95% CI: 1.07-1.22) in their political leaning. Participants were also more likely to be willing to get vaccinated if they reported higher levels of perceived likelihood getting a COVID-19 infection in the future (RR = 1.05, 95% CI: 1.01-1.09), perceived severity of COVID-19 infection (RR = 1.08, 95% CI: 1.04-1.11), or perceived effectiveness of a COVID-19 vaccine (RR = 1.46, 95% CI: 1.40-1.52). Participants were less likely to be willing to get vaccinated if they were non-Latinx black (RR = 0.81, 95% CI: 0.74-0.90) or reported a higher level of perceived potential vaccine harms (RR = 0.95, 95% CI: 0.92-0.98). CONCLUSIONS: Many adults are willing to get a COVID-19 vaccine, though acceptability should be monitored as vaccine development continues. Our findings can help guide future efforts to increase COVID-19 vaccine acceptability (and uptake if a vaccine becomes available).


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Vacinação/psicologia , Adolescente , Adulto , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/psicologia , Infecções por Coronavirus/virologia , Estudos Transversais , Humanos , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/psicologia , Cooperação do Paciente/estatística & dados numéricos , Segurança do Paciente , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Medição de Risco/tendências , Recusa do Paciente ao Tratamento/psicologia , Recusa do Paciente ao Tratamento/estatística & dados numéricos , Estados Unidos/epidemiologia , Vacinas Virais/administração & dosagem
5.
Cell ; 183(1): 169-184.e13, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931734

RESUMO

The coronavirus disease 2019 pandemic has made deployment of an effective vaccine a global health priority. We evaluated the protective activity of a chimpanzee adenovirus-vectored vaccine encoding a prefusion stabilized spike protein (ChAd-SARS-CoV-2-S) in challenge studies with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and mice expressing the human angiotensin-converting enzyme 2 receptor. Intramuscular dosing of ChAd-SARS-CoV-2-S induces robust systemic humoral and cell-mediated immune responses and protects against lung infection, inflammation, and pathology but does not confer sterilizing immunity, as evidenced by detection of viral RNA and induction of anti-nucleoprotein antibodies after SARS-CoV-2 challenge. In contrast, a single intranasal dose of ChAd-SARS-CoV-2-S induces high levels of neutralizing antibodies, promotes systemic and mucosal immunoglobulin A (IgA) and T cell responses, and almost entirely prevents SARS-CoV-2 infection in both the upper and lower respiratory tracts. Intranasal administration of ChAd-SARS-CoV-2-S is a candidate for preventing SARS-CoV-2 infection and transmission and curtailing pandemic spread.


Assuntos
Infecções por Coronavirus/imunologia , Imunogenicidade da Vacina , Pneumonia Viral/imunologia , Vacinas Virais/imunologia , Adenoviridae/genética , Administração Intranasal , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Chlorocebus aethiops , Infecções por Coronavirus/patologia , Infecções por Coronavirus/prevenção & controle , Feminino , Células HEK293 , Humanos , Injeções Intramusculares , Camundongos , Camundongos Endogâmicos BALB C , Pandemias , Pneumonia Viral/patologia , Mucosa Respiratória/imunologia , Mucosa Respiratória/patologia , Mucosa Respiratória/virologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero , Vacinas Virais/administração & dosagem
6.
Emerg Microbes Infect ; 9(1): 2076-2090, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32897177

RESUMO

The current coronavirus disease 2019 (COVID-19) pandemic was the result of the rapid transmission of a highly pathogenic coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), for which there is no efficacious vaccine or therapeutic. Toward the development of a vaccine, here we expressed and evaluated as potential candidates four versions of the spike (S) protein using an insect cell expression system: receptor binding domain (RBD), S1 subunit, the wild-type S ectodomain (S-WT), and the prefusion trimer-stabilized form (S-2P). We showed that RBD appears as a monomer in solution, whereas S1, S-WT, and S-2P associate as homotrimers with substantial glycosylation. Cryo-electron microscopy analyses suggested that S-2P assumes an identical trimer conformation as the similarly engineered S protein expressed in 293 mammalian cells but with reduced glycosylation. Overall, the four proteins confer excellent antigenicity with convalescent COVID-19 patient sera in enzyme-linked immunosorbent assay (ELISA), yet show distinct reactivities in immunoblotting. RBD, S-WT and S-2P, but not S1, induce high neutralization titres (>3-log) in mice after a three-round immunization regimen. The high immunogenicity of S-2P could be maintained at the lowest dose (1 µg) with the inclusion of an aluminium adjuvant. Higher doses (20 µg) of S-2P can elicit high neutralization titres in non-human primates that exceed 40-times the mean titres measured in convalescent COVID-19 subjects. Our results suggest that the prefusion trimer-stabilized SARS-CoV-2 S-protein from insect cells may offer a potential candidate strategy for the development of a recombinant COVID-19 vaccine.


Assuntos
Antígenos Virais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Imunogenicidade da Vacina/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Linhagem Celular , Infecções por Coronavirus/imunologia , Microscopia Crioeletrônica , Ensaio de Imunoadsorção Enzimática , Humanos , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Peptidil Dipeptidase A/metabolismo , Domínios Proteicos/genética , Domínios Proteicos/imunologia , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera , Vacinação , Proteínas do Envelope Viral/imunologia
7.
Front Immunol ; 11: 1836, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32983097

RESUMO

Examining CD8+ and CD4+ T cell responses after primary Yellow Fever vaccination in a cohort of 210 volunteers, we have identified and tetramer-validated 92 CD8+ and 50 CD4+ T cell epitopes, many inducing strong and prevalent (i.e., immunodominant) T cell responses. Restricted by 40 and 14 HLA-class I and II allotypes, respectively, these responses have wide population coverage and might be of considerable academic, diagnostic and therapeutic interest. The broad coverage of epitopes and HLA overcame the otherwise confounding effects of HLA diversity and non-HLA background providing the first evidence of T cell immunodomination in humans. Also, double-staining of CD4+ T cells with tetramers representing the same HLA-binding core, albeit with different flanking regions, demonstrated an extensive diversification of the specificities of many CD4+ T cell responses. We suggest that this could reduce the risk of pathogen escape, and that multi-tetramer staining is required to reveal the true magnitude and diversity of CD4+ T cell responses. Our T cell epitope discovery approach uses a combination of (1) overlapping peptides representing the entire Yellow Fever virus proteome to search for peptides containing CD4+ and/or CD8+ T cell epitopes, (2) predictors of peptide-HLA binding to suggest epitopes and their restricting HLA allotypes, (3) generation of peptide-HLA tetramers to identify T cell epitopes, and (4) analysis of ex vivo T cell responses to validate the same. This approach is systematic, exhaustive, and can be done in any individual of any HLA haplotype. It is all-inclusive in the sense that it includes all protein antigens and peptide epitopes, and encompasses both CD4+ and CD8+ T cell epitopes. It is efficient and, importantly, reduces the false discovery rate. The unbiased nature of the T cell epitope discovery approach presented here should support the refinement of future peptide-HLA class I and II predictors and tetramer technologies, which eventually should cover all HLA class I and II isotypes. We believe that future investigations of emerging pathogens (e.g., SARS-CoV-2) should include population-wide T cell epitope discovery using blood samples from patients, convalescents and/or long-term survivors, who might all hold important information on T cell epitopes and responses.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Vacinação , Vacina contra Febre Amarela/imunologia , Febre Amarela/prevenção & controle , Vírus da Febre Amarela/imunologia , Betacoronavirus/imunologia , Estudos de Coortes , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Voluntários Saudáveis , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunogenicidade da Vacina , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Febre Amarela/virologia
9.
Infect Dis Poverty ; 9(1): 132, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938504

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) linked with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause severe illness and life-threatening pneumonia in humans. The current COVID-19 pandemic demands an effective vaccine to acquire protection against the infection. Therefore, the present study was aimed to design a multiepitope-based subunit vaccine (MESV) against COVID-19. METHODS: Structural proteins (Surface glycoprotein, Envelope protein, and Membrane glycoprotein) of SARS-CoV-2 are responsible for its prime functions. Sequences of proteins were downloaded from GenBank and several immunoinformatics coupled with computational approaches were employed to forecast B- and T- cell epitopes from the SARS-CoV-2 highly antigenic structural proteins to design an effective MESV. RESULTS: Predicted epitopes suggested high antigenicity, conserveness, substantial interactions with the human leukocyte antigen (HLA) binding alleles, and collective global population coverage of 88.40%. Taken together, 276 amino acids long MESV was designed by connecting 3 cytotoxic T lymphocytes (CTL), 6 helper T lymphocyte (HTL) and 4 B-cell epitopes with suitable adjuvant and linkers. The MESV construct was non-allergenic, stable, and highly antigenic. Molecular docking showed a stable and high binding affinity of MESV with human pathogenic toll-like receptors-3 (TLR3). Furthermore, in silico immune simulation revealed significant immunogenic response of MESV. Finally, MEV codons were optimized for its in silico cloning into the Escherichia coli K-12 system, to ensure its increased expression. CONCLUSION: The MESV developed in this study is capable of generating immune response against COVID-19. Therefore, if designed MESV further investigated experimentally, it would be an effective vaccine candidate against SARS-CoV-2 to control and prevent COVID-19.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Epitopos de Linfócito B/química , Epitopos de Linfócito B/genética , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Humanos , Imunogenicidade da Vacina/imunologia , Simulação de Acoplamento Molecular , Pneumonia Viral/imunologia , Análise de Sequência de Proteína , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Receptor 3 Toll-Like/química , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/imunologia , Vacinas de Subunidades/química , Vacinas de Subunidades/genética , Vacinas de Subunidades/imunologia , Vacinologia/métodos , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/imunologia , Vacinas Virais/química , Vacinas Virais/genética
10.
Nat Rev Immunol ; 20(10): 615-632, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32887954

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the most formidable challenge to humanity in a century. It is widely believed that prepandemic normalcy will never return until a safe and effective vaccine strategy becomes available and a global vaccination programme is implemented successfully. Here, we discuss the immunological principles that need to be taken into consideration in the development of COVID-19 vaccine strategies. On the basis of these principles, we examine the current COVID-19 vaccine candidates, their strengths and potential shortfalls, and make inferences about their chances of success. Finally, we discuss the scientific and practical challenges that will be faced in the process of developing a successful vaccine and the ways in which COVID-19 vaccine strategies may evolve over the next few years.


Assuntos
Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Vacinas Virais/imunologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/patogenicidade , Ensaios Clínicos como Assunto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Vetores Genéticos/química , Vetores Genéticos/imunologia , Humanos , Imunidade Coletiva/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Esquemas de Imunização , Imunogenicidade da Vacina , Segurança do Paciente , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/virologia , Vacinas Atenuadas , Vacinas de DNA , Vacinas de Subunidades , Vacinas de Partículas Semelhantes a Vírus , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese
11.
Genome Med ; 12(1): 70, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32791978

RESUMO

BACKGROUND: The ongoing COVID-19 pandemic has created an urgency to identify novel vaccine targets for protective immunity against SARS-CoV-2. Early reports identify protective roles for both humoral and cell-mediated immunity for SARS-CoV-2. METHODS: We leveraged our bioinformatics binding prediction tools for human leukocyte antigen (HLA)-I and HLA-II alleles that were developed using mass spectrometry-based profiling of individual HLA-I and HLA-II alleles to predict peptide binding to diverse allele sets. We applied these binding predictors to viral genomes from the Coronaviridae family and specifically focused on T cell epitopes from SARS-CoV-2 proteins. We assayed a subset of these epitopes in a T cell induction assay for their ability to elicit CD8+ T cell responses. RESULTS: We first validated HLA-I and HLA-II predictions on Coronaviridae family epitopes deposited in the Virus Pathogen Database and Analysis Resource (ViPR) database. We then utilized our HLA-I and HLA-II predictors to identify 11,897 HLA-I and 8046 HLA-II candidate peptides which were highly ranked for binding across 13 open reading frames (ORFs) of SARS-CoV-2. These peptides are predicted to provide over 99% allele coverage for the US, European, and Asian populations. From our SARS-CoV-2-predicted peptide-HLA-I allele pairs, 374 pairs identically matched what was previously reported in the ViPR database, originating from other coronaviruses with identical sequences. Of these pairs, 333 (89%) had a positive HLA binding assay result, reinforcing the validity of our predictions. We then demonstrated that a subset of these highly predicted epitopes were immunogenic based on their recognition by specific CD8+ T cells in healthy human donor peripheral blood mononuclear cells (PBMCs). Finally, we characterized the expression of SARS-CoV-2 proteins in virally infected cells to prioritize those which could be potential targets for T cell immunity. CONCLUSIONS: Using our bioinformatics platform, we identify multiple putative epitopes that are potential targets for CD4+ and CD8+ T cells, whose HLA binding properties cover nearly the entire population. We also confirm that our binding predictors can predict epitopes eliciting CD8+ T cell responses from multiple SARS-CoV-2 proteins. Protein expression and population HLA allele coverage, combined with the ability to identify T cell epitopes, should be considered in SARS-CoV-2 vaccine design strategies and immune monitoring.


Assuntos
Infecções por Coronavirus/imunologia , Epitopos/imunologia , Antígenos HLA/imunologia , Pneumonia Viral/imunologia , Linfócitos T/imunologia , Vacinas Virais/imunologia , Alelos , Afinidade de Anticorpos , Biologia Computacional , Infecções por Coronavirus/genética , Infecções por Coronavirus/prevenção & controle , Epitopos/química , Epitopos/genética , Genoma Viral , Antígenos HLA/química , Antígenos HLA/genética , Humanos , Imunogenicidade da Vacina , Espectrometria de Massas , Pandemias , Vacinas Virais/química , Vacinas Virais/genética
12.
J Immunol Res ; 2020: 8624963, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802896

RESUMO

Single-cell RNA sequencing allows highly detailed profiling of cellular immune responses from limited-volume samples, advancing prospects of a new era of systems immunology. The power of single-cell RNA sequencing offers various opportunities to decipher the immune response to infectious diseases and vaccines. Here, we describe the potential uses of single-cell RNA sequencing methods in prophylactic vaccine development, concentrating on infectious diseases including COVID-19. Using examples from several diseases, we review how single-cell RNA sequencing has been used to evaluate the immunological response to different vaccine platforms and regimens. By highlighting published and unpublished single-cell RNA sequencing studies relevant to vaccinology, we discuss some general considerations how the field could be enriched with the widespread adoption of this technology.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , RNA-Seq/métodos , Análise de Célula Única , Vacinologia/métodos , Vacinas Virais/administração & dosagem , Animais , Linhagem Celular , Ensaios Clínicos como Assunto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Celular/genética , Imunidade Inata/genética , Imunogenicidade da Vacina , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , RNA Viral/isolamento & purificação , Vacinas Virais/imunologia
13.
Sheng Wu Gong Cheng Xue Bao ; 36(7): 1314-1322, 2020 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-32748589

RESUMO

To screen the best genotypeⅠJapanese encephalitis virus subunit vaccine candidate antigens, the prMEIII gene, the polytope gene and the prMEIII-polytope fusion gene of the GenotypeⅠJapanese encephalitis virus GS strain were cloned into prokaryotic expression vector pET-30a. The recombinant proteins were obtained after the induction and purification. The prepared recombinant proteins were immunized to mice, and the immunogenicity of the subunit vaccine candidate antigens was evaluated through monitoring the humoral immune response by ELISA, detecting the neutralizing antibody titer by plaque reduction neutralization test, and testing the cell-mediated immune response by lymphocyte proliferation assay and cytokine profiling. The recombinant proteins with the molecular weights of 35 (prMEIII), 28 (polytope antigen) and 57 kDa (prMEIII-polytope) induced strong humoral and cellular immune responses in mice. Compared with prMEIII-polytope and polytope proteins, the prMEIII protein induced a significant expression of IL-2 and IFN-γ (P<0.05) and the significant lymphoproliferation of splenocytes (P<0.05). The neutralizing antibody titer induced by the prMEIII protein was close to that induced by the commercial attenuated vaccine SA14-14-2 (P>0.05). The study suggests that the prMEIII protein can be used for the development of the Japanese encephalitis virus subunit vaccine.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Vacinas Virais , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Vírus da Encefalite Japonesa (Espécie)/imunologia , Encefalite Japonesa/imunologia , Encefalite Japonesa/prevenção & controle , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Vacinas de Subunidades/imunologia , Vacinas Virais/imunologia
14.
Front Immunol ; 11: 1784, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849643

RESUMO

COVID-19 has recently become the most serious threat to public health, and its prevalence has been increasing at an alarming rate. The incubation period for the virus is ~1-14 days and all age groups may be susceptible to a fatality rate of about 5.9%. COVID-19 is caused by a novel single-stranded, positive (+) sense RNA beta coronavirus. The development of a vaccine for SARS-CoV-2 is an urgent need worldwide. Immunoinformatics approaches are both cost-effective and convenient, as in silico predictions can reduce the number of experiments needed. In this study, with the aid of immunoinformatics tools, we tried to design a multi-epitope vaccine that can be used for the prevention and treatment of COVID-19. The epitopes were computed by using B cells, cytotoxic T lymphocytes (CTL), and helper T lymphocytes (HTL) base on the proteins of SARS-CoV-2. A vaccine was devised by fusing together the B cell, HTL, and CTL epitopes with linkers. To enhance the immunogenicity, the ß-defensin (45 mer) amino acid sequence, and pan-HLA DR binding epitopes (13aa) were adjoined to the N-terminal of the vaccine with the help of the EAAAK linker. To enable the intracellular delivery of the modeled vaccine, a TAT sequence (11aa) was appended to C-terminal. Linkers play vital roles in producing an extended conformation (flexibility), protein folding, and separation of functional domains, and therefore, make the protein structure more stable. The secondary and three-dimensional (3D) structure of the final vaccine was then predicted. Furthermore, the complex between the final vaccine and immune receptors (toll-like receptor-3 (TLR-3), major histocompatibility complex (MHC-I), and MHC-II) were evaluated by molecular docking. Lastly, to confirm the expression of the designed vaccine, the mRNA of the vaccine was enhanced with the aid of the Java Codon Adaptation Tool, and the secondary structure was generated from Mfold. Then we performed in silico cloning. The final vaccine requires experimental validation to determine its safety and efficacy in controlling SARS-CoV-2 infections.


Assuntos
Betacoronavirus/química , Biologia Computacional/métodos , Infecções por Coronavirus/prevenção & controle , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Proteínas Virais/imunologia , Vacinas Virais/imunologia , Sequência de Aminoácidos , Infecções por Coronavirus/virologia , Antígenos HLA-DR/imunologia , Humanos , Imunogenicidade da Vacina , Simulação de Acoplamento Molecular , Pneumonia Viral/virologia , Dobramento de Proteína , Estrutura Terciária de Proteína , Linfócitos T Citotóxicos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vacinas de Subunidades/imunologia , beta-Defensinas/imunologia
15.
J Exp Med ; 217(12)2020 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-32820330

RESUMO

Type I interferons (IFN-I) are a major antiviral defense and are critical for the activation of the adaptive immune system. However, early viral clearance by IFN-I could limit antigen availability, which could in turn impinge upon the priming of the adaptive immune system. In this study, we hypothesized that transient IFN-I blockade could increase antigen presentation after acute viral infection. To test this hypothesis, we infected mice with viruses coadministered with a single dose of IFN-I receptor-blocking antibody to induce a short-term blockade of the IFN-I pathway. This resulted in a transient "spike" in antigen levels, followed by rapid antigen clearance. Interestingly, short-term IFN-I blockade after coronavirus, flavivirus, rhabdovirus, or arenavirus infection induced a long-lasting enhancement of immunological memory that conferred improved protection upon subsequent reinfections. Short-term IFN-I blockade also improved the efficacy of viral vaccines. These findings demonstrate a novel mechanism by which IFN-I regulate immunological memory and provide insights for rational vaccine design.


Assuntos
Imunogenicidade da Vacina/imunologia , Interferon Tipo I/antagonistas & inibidores , Interferon-alfa/imunologia , Receptor de Interferon alfa e beta/imunologia , Vacinas Virais/imunologia , Infecção por Zika virus/imunologia , Zika virus/imunologia , Animais , Anticorpos Bloqueadores/imunologia , Anticorpos Bloqueadores/farmacologia , Anticorpos Antivirais/imunologia , Apresentação do Antígeno/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/imunologia , Modelos Animais de Doenças , Expressão Gênica/imunologia , Células HEK293 , Humanos , Memória Imunológica , Interferon-alfa/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Interferon alfa e beta/genética , Transfecção , Infecção por Zika virus/virologia
16.
Arch Virol ; 165(10): 2301-2309, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32757056

RESUMO

Porcine circovirus type 2 (PCV2) is a major pathogen associated with swine diseases. It is the smallest single-stranded DNA virus, and its genome contains four major open reading frames (ORFs). ORF2 encodes the major structural protein Cap, which can self-assemble into virus-like particles (VLPs) in vitro and contains the primary antigenic determinants. In this study, we developed a high-efficiency method for obtaining VLPs and optimized the purification conditions. In this method, we expressed the protein Cap with a 6× His tag using baculovirus-infected silkworm larvae as well as the E. coli BL21(DE3) prokaryotic expression system. The PCV2 Cap proteins produced by the silkworm larvae and E. coli BL21(DE3) were purified. Cap proteins purified from silkworm larvae self-assembled into VLPs in vitro, while the Cap proteins purified from bacteria were unable to self-assemble. Transmission electron microscopy confirmed the self-assembly of VLPs. The immunogenicity of the VLPs produced using the baculovirus system was demonstrated using an enzyme-linked immunosorbent assay (ELISA). Furthermore, the purification process was optimized. The results demonstrated that the expression system using baculovirus-infected silkworm larvae is a good choice for obtaining VLPs of PCV2 and has potential for the development of a low-cost and efficient vaccine.


Assuntos
Anticorpos Antivirais/biossíntese , Baculoviridae/genética , Bombyx/virologia , Proteínas do Capsídeo/imunologia , Circovirus/imunologia , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas Virais/biossíntese , Animais , Antígenos Virais/química , Antígenos Virais/imunologia , Baculoviridae/imunologia , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/genética , Epitopos/química , Epitopos/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Histidina/genética , Histidina/imunologia , Soros Imunes/química , Imunogenicidade da Vacina , Larva/virologia , Camundongos , Oligopeptídeos/genética , Oligopeptídeos/imunologia , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação , Vacinas Virais/administração & dosagem , Vacinas Virais/genética , Vacinas Virais/isolamento & purificação
17.
Cell ; 182(5): 1271-1283.e16, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32795413

RESUMO

There is an urgent need for vaccines against coronavirus disease 2019 (COVID-19) because of the ongoing SARS-CoV-2 pandemic. Among all approaches, a messenger RNA (mRNA)-based vaccine has emerged as a rapid and versatile platform to quickly respond to this challenge. Here, we developed a lipid nanoparticle-encapsulated mRNA (mRNA-LNP) encoding the receptor binding domain (RBD) of SARS-CoV-2 as a vaccine candidate (called ARCoV). Intramuscular immunization of ARCoV mRNA-LNP elicited robust neutralizing antibodies against SARS-CoV-2 as well as a Th1-biased cellular response in mice and non-human primates. Two doses of ARCoV immunization in mice conferred complete protection against the challenge of a SARS-CoV-2 mouse-adapted strain. Additionally, ARCoV is manufactured as a liquid formulation and can be stored at room temperature for at least 1 week. ARCoV is currently being evaluated in phase 1 clinical trials.


Assuntos
RNA Mensageiro/genética , RNA Viral/genética , Vacinas Sintéticas/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Chlorocebus aethiops , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Feminino , Células HEK293 , Células HeLa , Humanos , Imunogenicidade da Vacina , Injeções Intramusculares , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos ICR , Nanopartículas/química , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Células Th1/imunologia , Potência de Vacina , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Células Vero , Vacinas Virais/administração & dosagem , Vacinas Virais/genética
18.
Virus Res ; 288: 198114, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32800805

RESUMO

The current COVID-19 pandemic has urged the scientific community internationally to find answers in terms of therapeutics and vaccines to control SARS-CoV-2. Published investigations mostly on SARS-CoV and to some extent on MERS has taught lessons on vaccination strategies to this novel coronavirus. This is attributed to the fact that SARS-CoV-2 uses the same receptor as SARS-CoV on the host cell i.e. human Angiotensin Converting Enzyme 2 (hACE2) and is approximately 79% similar genetically to SARS-CoV. Though the efforts on COVID-19 vaccines started very early, initially in China, as soon as the outbreak of novel coronavirus erupted and then world-over as the disease was declared a pandemic by WHO. But we will not be having an effective COVID-19 vaccine before September, 2020 as per very optimistic estimates. This is because a successful COVID-19 vaccine will require a cautious validation of efficacy and adverse reactivity as the target vaccinee population include high-risk individuals over the age of 60, particularly those with chronic co-morbid conditions, frontline healthcare workers and those involved in essentials industries. Various platforms for vaccine development are available namely: virus vectored vaccines, protein subunit vaccines, genetic vaccines, and monoclonal antibodies for passive immunization which are under evaluations for SARS-CoV-2, with each having discrete benefits and hindrances. The COVID-19 pandemic which probably is the most devastating one in the last 100 years after Spanish flu mandates the speedy evaluation of the multiple approaches for competence to elicit protective immunity and safety to curtail unwanted immune-potentiation which plays an important role in the pathogenesis of this virus. This review is aimed at providing an overview of the efforts dedicated to an effective vaccine for this novel coronavirus which has crippled the world in terms of economy, human health and life.


Assuntos
Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/imunologia , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/patogenicidade , Ensaios Clínicos como Assunto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/terapia , Infecções por Coronavirus/virologia , Vetores Genéticos/química , Vetores Genéticos/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Imunização Passiva/métodos , Imunogenicidade da Vacina , Segurança do Paciente , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/imunologia , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Receptores Virais/genética , Receptores Virais/imunologia , Receptores Virais/metabolismo , Vacinas Atenuadas , Vacinas de DNA , Vacinas de Subunidades , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese
19.
Virus Res ; 288: 198141, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32846196

RESUMO

The recent outbreak of the betacoronavirus SARS-CoV-2 has become a significant concern to public health care worldwide. As of August 19, 2020, more than 22,140,472 people are infected, and over 781,135 people have died due to this deadly virus. In the USA alone, over 5,482,602 people are currently infected, and more than 171,823 people have died. SARS-CoV-2 has shown a higher infectivity rate and a more extended incubation period as compared to previous coronaviruses. SARS-CoV-2 binds much more strongly than SARS-CoV to the same host receptor, angiotensin-converting enzyme 2 (ACE2). Previously, several methods to develop a vaccine against SARS-CoV or MERS-CoV have been tried with limited success. Since SARS-CoV-2 uses the spike (S) protein for entry to the host cell, it is one of the most preferred targets for making vaccines or therapeutics against SARS-CoV-2. In this review, we have summarised the characteristics of the S protein, as well as the different approaches being used for the development of vaccines and/or therapeutics based on the S protein.


Assuntos
Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas Virais/imunologia , Anticorpos Facilitadores/efeitos dos fármacos , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/patogenicidade , Ensaios Clínicos como Assunto , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Vetores Genéticos/química , Vetores Genéticos/imunologia , Humanos , Imunogenicidade da Vacina , Segurança do Paciente , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/imunologia , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Receptores Virais/genética , Receptores Virais/imunologia , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinas Atenuadas , Vacinas de DNA , Vacinas de Subunidades , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/biossíntese
20.
Cell ; 182(3): 713-721.e9, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32778225

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global public health. The development of a vaccine is urgently needed for the prevention and control of COVID-19. Here, we report the pilot-scale production of an inactivated SARS-CoV-2 vaccine candidate (BBIBP-CorV) that induces high levels of neutralizing antibodies titers in mice, rats, guinea pigs, rabbits, and nonhuman primates (cynomolgus monkeys and rhesus macaques) to provide protection against SARS-CoV-2. Two-dose immunizations using 2 µg/dose of BBIBP-CorV provided highly efficient protection against SARS-CoV-2 intratracheal challenge in rhesus macaques, without detectable antibody-dependent enhancement of infection. In addition, BBIBP-CorV exhibits efficient productivity and good genetic stability for vaccine manufacture. These results support the further evaluation of BBIBP-CorV in a clinical trial.


Assuntos
Betacoronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Avaliação Pré-Clínica de Medicamentos/métodos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas de Produtos Inativados/uso terapêutico , Vacinas Virais/uso terapêutico , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/genética , Chlorocebus aethiops , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Feminino , Cobaias , Imunogenicidade da Vacina , Macaca fascicularis , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Pneumonia Viral/virologia , Coelhos , Ratos , Ratos Wistar , Vacinas de Produtos Inativados/efeitos adversos , Células Vero , Vacinas Virais/efeitos adversos
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