Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Emerg Infect Dis ; 29(6): 1236-1239, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37209676

RESUMO

We developed an ELISPOT assay for evaluating Middle East respiratory syndrome coronavirus (MERS-CoV)‒specific T-cell responses in dromedary camels. After single modified vaccinia virus Ankara-MERS-S vaccination, seropositive camels showed increased levels of MERS-CoV‒specific T cells and antibodies, indicating suitability of camel vaccinations in disease-endemic areas as a promising approach to control infection.


Assuntos
Camelus , Infecções por Coronavirus , Linfócitos T , Vacinas Virais , Animais , Camelus/imunologia , Linfócitos T/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Vacinas Virais/imunologia , Vacinação/veterinária , ELISPOT , Anticorpos Antivirais
2.
Vaccines (Basel) ; 12(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38250865

RESUMO

Aging is associated with a decline in immune system functionality. So-called immunosenescence may impair the successful vaccination of elderly people. Thus, improved vaccination strategies also suitable for an aged immune system are required. Modified Vaccinia virus Ankara (MVA) is a highly attenuated and replication-deficient vaccinia virus that has been established as a multipurpose viral vector for vaccine development against various infections. We characterized a recombinant MVA expressing a prefusion-stabilized version of SARS-CoV-2 S protein (MVA-ST) in an aged-hamster model for COVID-19. Intramuscular MVA-ST immunization resulted in protection from disease and severe lung pathology. Importantly, this protection was correlated with a potent activation of SARS-CoV-2 specific T-cells and neutralizing antibodies. Our results suggest that MVA vector vaccines merit further evaluation in preclinical models to contribute to future clinical development as candidate vaccines in elderly people to overcome the limitations of age-dependent immunosenescence.

3.
Viruses ; 16(3)2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38543782

RESUMO

The sudden emergence of SARS-CoV-2 demonstrates the need for new vaccines that rapidly protect in the case of an emergency. In this study, we developed a recombinant MVA vaccine co-expressing SARS-CoV-2 prefusion-stabilized spike protein (ST) and SARS-CoV-2 nucleoprotein (N, MVA-SARS-2-ST/N) as an approach to further improve vaccine-induced immunogenicity and efficacy. Single MVA-SARS-2-ST/N vaccination in K18-hACE2 mice induced robust protection against lethal respiratory SARS-CoV-2 challenge infection 28 days later. The protective outcome of MVA-SARS-2-ST/N vaccination correlated with the activation of SARS-CoV-2-neutralizing antibodies (nABs) and substantial amounts of SARS-CoV-2-specific T cells especially in the lung of MVA-SARS-2-ST/N-vaccinated mice. Emergency vaccination with MVA-SARS-2-ST/N just 2 days before lethal SARS-CoV-2 challenge infection resulted in a delayed onset of clinical disease outcome in these mice and increased titers of nAB or SARS-CoV-2-specific T cells in the spleen and lung. These data highlight the potential of a multivalent COVID-19 vaccine co-expressing S- and N-protein, which further contributes to the development of rapidly protective vaccination strategies against emerging pathogens.


Assuntos
COVID-19 , Melfalan , SARS-CoV-2 , Vacinas de DNA , Vacinas Virais , gama-Globulinas , Animais , Humanos , Camundongos , SARS-CoV-2/genética , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Anticorpos Antivirais , Glicoproteína da Espícula de Coronavírus/genética , Vacinação , Anticorpos Neutralizantes
4.
Innate Immun ; 28(6): 199-210, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35876352

RESUMO

Innate immune training is defined as a property of innate immune cells to react stronger to a secondary contact with pathogens. Induction of innate immune training has been reported for a variety of pathogens and selected pattern recognition receptor-ligands, such as ß-glucans (ßG). We examined whether Saccharomyces cerevisiae cell wall component ßG induces training in bovine monocytes in vitro based on a heightened TNF secretion after stimulation by trained monocyte-derived macrophages with Escherichia coli LPS. Sorted CD14-expressing monocytes (classical and intermediate monocytes), as well as single populations of sorted classical, intermediate and non-classical monocytes could not be trained by ßG, whereas macrophages derived from plastic-adherent mononuclear cell preparations displayed features of a trained function. The hypothesis, that non-classical monocytes need to be present in a mixed monocyte population in order to be trained by ßG could be verified by a successful training of positively sorted whole monocyte populations (CD14CD16/M) containing all three monocyte subpopulations. The trainability depended on conditions favoring M1 polarization of macrophages. Altogether, innate immune training of bovine monocytes seems to depend on the presence of non-classical monocytes. This adds new information to the role of this monocyte subpopulation in the bovine immune system.


Assuntos
Macrófagos , Monócitos , Animais , Bovinos , Imunidade Inata
5.
J Clin Invest ; 132(24)2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36301637

RESUMO

The SARS-CoV-2 spike (S) glycoprotein is synthesized as a large precursor protein and must be activated by proteolytic cleavage into S1 and S2. A recombinant modified vaccinia virus Ankara (MVA) expressing native, full-length S protein (MVA-SARS-2-S) is currently under investigation as a candidate vaccine in phase I clinical studies. Initial results from immunogenicity monitoring revealed induction of S-specific antibodies binding to S2, but low-level antibody responses to the S1 domain. Follow-up investigations of native S antigen synthesis in MVA-SARS-2-S-infected cells revealed limited levels of S1 protein on the cell surface. In contrast, we found superior S1 cell surface presentation upon infection with a recombinant MVA expressing a stabilized version of SARS-CoV-2 S protein with an inactivated S1/S2 cleavage site and K986P and V987P mutations (MVA-SARS-2-ST). When comparing immunogenicity of MVA vector vaccines, mice vaccinated with MVA-SARS-2-ST mounted substantial levels of broadly reactive anti-S antibodies that effectively neutralized different SARS-CoV-2 variants. Importantly, intramuscular MVA-SARS-2-ST immunization of hamsters and mice resulted in potent immune responses upon challenge infection and protected from disease and severe lung pathology. Our results suggest that MVA-SARS-2-ST represents an improved clinical candidate vaccine and that the presence of plasma membrane-bound S1 is highly beneficial to induce protective antibody levels.


Assuntos
COVID-19 , Vacinas Virais , Humanos , Camundongos , Animais , Imunogenicidade da Vacina , SARS-CoV-2/genética , Vacinas Virais/genética , COVID-19/prevenção & controle , Vaccinia virus/genética , Anticorpos Antivirais , Anticorpos Neutralizantes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA