Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
1.
Front Immunol ; 12: 824728, 2021.
Article in English | MEDLINE | ID: covidwho-1686477

ABSTRACT

We generated an optimized COVID-19 vaccine candidate based on the modified vaccinia virus Ankara (MVA) vector expressing a full-length prefusion-stabilized SARS-CoV-2 spike (S) protein, termed MVA-CoV2-S(3P). The S(3P) protein was expressed at higher levels (2-fold) than the non-stabilized S in cells infected with the corresponding recombinant MVA viruses. One single dose of MVA-CoV2-S(3P) induced higher IgG and neutralizing antibody titers against parental SARS-CoV-2 and variants of concern than MVA-CoV2-S in wild-type C57BL/6 and in transgenic K18-hACE2 mice. In immunized C57BL/6 mice, two doses of MVA-CoV2-S or MVA-CoV2-S(3P) induced similar levels of SARS-CoV-2-specific B- and T-cell immune responses. Remarkably, a single administration of MVA-CoV2-S(3P) protected all K18-hACE2 mice from morbidity and mortality caused by SARS-CoV-2 infection, reducing SARS-CoV-2 viral loads, histopathological lesions, and levels of pro-inflammatory cytokines in the lungs. These results demonstrated that expression of a novel full-length prefusion-stabilized SARS-CoV-2 S protein by the MVA poxvirus vector enhanced immunogenicity and efficacy against SARS-CoV-2 in animal models, further supporting MVA-CoV2-S(3P) as an optimized vaccine candidate for clinical trials.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Viral Vaccines/immunology , Aged , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/mortality , COVID-19 Vaccines/genetics , Cell Line, Tumor , Chick Embryo , Chlorocebus aethiops , Cytokines/analysis , Female , HeLa Cells , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Plasmids/genetics , Spike Glycoprotein, Coronavirus/genetics , Vaccines, DNA/genetics , Vaccinia virus/immunology , Vero Cells , Viral Vaccines/genetics
2.
Front Immunol ; 12: 772240, 2021.
Article in English | MEDLINE | ID: covidwho-1551510

ABSTRACT

Antigen-specific tissue-resident memory T cells (Trms) and neutralizing IgA antibodies provide the most effective protection of the lungs from viral infections. To induce those essential components of lung immunity against SARS-CoV-2, we tested various immunization protocols involving intranasal delivery of a novel Modified Vaccinia virus Ankara (MVA)-SARS-2-spike vaccine candidate. We show that a single intranasal MVA-SARS-CoV-2-S application in mice strongly induced pulmonary spike-specific CD8+ T cells, albeit restricted production of neutralizing antibodies. In prime-boost protocols, intranasal booster vaccine delivery proved to be crucial for a massive expansion of systemic and lung tissue-resident spike-specific CD8+ T cells and the development of Th1 - but not Th2 - CD4+ T cells. Likewise, very high titers of IgG and IgA anti-spike antibodies were present in serum and broncho-alveolar lavages that possessed high virus neutralization capacities to all current SARS-CoV-2 variants of concern. Importantly, the MVA-SARS-2-spike vaccine applied in intramuscular priming and intranasal boosting treatment regimen completely protected hamsters from developing SARS-CoV-2 lung infection and pathology. Together, these results identify intramuscular priming followed by respiratory tract boosting with MVA-SARS-2-S as a promising approach for the induction of local, respiratory as well as systemic immune responses suited to protect from SARS-CoV-2 infections.


Subject(s)
Antibodies, Viral/blood , CD8-Positive T-Lymphocytes/immunology , COVID-19 Vaccines/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Administration, Intranasal , Animals , Antibodies, Neutralizing/blood , Cell Line , Chlorocebus aethiops , Cricetinae , Genetic Vectors , Immunization, Secondary , Immunoglobulin A/blood , Immunoglobulin G/blood , Lung/immunology , Male , Mice , Mice, Inbred C57BL , Th1 Cells/immunology , Vaccination , Vaccines, Subunit/immunology , Vaccinia virus/immunology , Vero Cells , Viral Load/immunology
3.
J Virol ; 96(3): e0150421, 2022 02 09.
Article in English | MEDLINE | ID: covidwho-1546442

ABSTRACT

In the age of COVID, nucleic acid vaccines have garnered much attention, at least in part, because of the simplicity of construction, production, and flexibility to adjust and adapt to an evolving outbreak. Orthopoxviruses remain a threat on multiple fronts, especially as emerging zoonoses. In response, we developed a DNA vaccine, termed 4pox, that protected nonhuman primates against monkeypox virus (MPXV)-induced severe disease. Here, we examined the protective efficacy of the 4pox DNA vaccine delivered by intramuscular (i.m.) electroporation (EP) in rabbits challenged with aerosolized rabbitpox virus (RPXV), a model that recapitulates the respiratory route of exposure and low dose associated with natural smallpox exposure in humans. We found that 4pox-vaccinated rabbits developed immunogen-specific antibodies, including neutralizing antibodies, and did not develop any clinical disease, indicating protection against aerosolized RPXV. In contrast, unvaccinated animals developed significant signs of disease, including lesions, and were euthanized. These findings demonstrate that an unformulated, nonadjuvanted DNA vaccine delivered i.m. can protect against an aerosol exposure. IMPORTANCE The eradication of smallpox and subsequent cessation of vaccination have left a majority of the population susceptible to variola virus or other emerging poxviruses. This is exemplified by human monkeypox, as evidenced by the increase in reported endemic and imported cases over the past decades. Therefore, a malleable vaccine technology that can be mass produced and does not require complex conditions for distribution and storage is sought. Herein, we show that a DNA vaccine, in the absence of a specialized formulation or adjuvant, can protect against a lethal aerosol insult of rabbitpox virus.


Subject(s)
/immunology , Orthopoxvirus/immunology , Poxviridae Infections/prevention & control , Vaccinia virus/immunology , Vaccinia/prevention & control , Viral Proteins/immunology , Viral Vaccines/immunology , Animals , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Dose-Response Relationship, Immunologic , Electroporation , Female , Immunization/methods , Immunogenicity, Vaccine , Lymphocyte Activation/immunology , Oligodeoxyribonucleotides/administration & dosage , Oligodeoxyribonucleotides/immunology , Rabbits , Vaccines, DNA/immunology , Vaccinia virus/genetics , Viral Vaccines/administration & dosage
4.
Nat Immunol ; 23(1): 50-61, 2022 01.
Article in English | MEDLINE | ID: covidwho-1545628

ABSTRACT

NP105-113-B*07:02-specific CD8+ T cell responses are considered among the most dominant in SARS-CoV-2-infected individuals. We found strong association of this response with mild disease. Analysis of NP105-113-B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP105-113-B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP105-113-B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP105-113-B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.


Subject(s)
HLA-B7 Antigen/immunology , Immunodominant Epitopes/immunology , Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , T-Lymphocytes, Cytotoxic/immunology , Aged , Amino Acid Sequence , Antibodies, Viral/immunology , Antibody Affinity/immunology , COVID-19/immunology , COVID-19/pathology , Cell Line, Transformed , Female , Gene Expression Profiling , Humans , Immunologic Memory/immunology , Male , Middle Aged , Receptors, Antigen, T-Cell/immunology , Severity of Illness Index , Vaccinia virus/genetics , Vaccinia virus/immunology , Vaccinia virus/metabolism
5.
Ann Rheum Dis ; 80(12): 1537-1544, 2021 12.
Article in English | MEDLINE | ID: covidwho-1515258

ABSTRACT

OBJECTIVES: The monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses. METHODS: CD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens. RESULTS: Rituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I. CONCLUSIONS: Depending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses.


Subject(s)
Antirheumatic Agents/adverse effects , Arthritis, Rheumatoid/drug therapy , B-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Immunogenicity, Vaccine/immunology , Influenza Vaccines/immunology , Interferon Type I/immunology , Rituximab/adverse effects , Animals , Case-Control Studies , Cytokines/immunology , Histocompatibility Antigens Class I/immunology , Humans , Influenza Vaccines/therapeutic use , Influenza, Human/prevention & control , Mice , Orthomyxoviridae/immunology , Orthomyxoviridae Infections/immunology , Vaccinia/immunology , Vaccinia virus/immunology
6.
Front Immunol ; 12: 645210, 2021.
Article in English | MEDLINE | ID: covidwho-1383856

ABSTRACT

Vaccination is one of the most efficient public healthcare measures to fight infectious diseases. Nevertheless, the immune mechanisms induced in vivo by vaccination are still unclear. The route of administration, an important vaccination parameter, can substantially modify the quality of the response. How the route of administration affects the generation and profile of immune responses is of major interest. Here, we aimed to extensively characterize the profiles of the innate and adaptive response to vaccination induced after intradermal, subcutaneous, or intramuscular administration with a modified vaccinia virus Ankara model vaccine in non-human primates. The adaptive response following subcutaneous immunization was clearly different from that following intradermal or intramuscular immunization. The subcutaneous route induced a higher level of neutralizing antibodies than the intradermal and intramuscular vaccination routes. In contrast, polyfunctional CD8+ T-cell responses were preferentially induced after intradermal or intramuscular injection. We observed the same dichotomy when analyzing the early molecular and cellular immune events, highlighting the recruitment of cell populations, such as CD8+ T lymphocytes and myeloid-derived suppressive cells, and the activation of key immunomodulatory gene pathways. These results demonstrate that the quality of the vaccine response induced by an attenuated vaccine is shaped by early and subtle modifications of the innate immune response. In this immunization context, the route of administration must be tailored to the desired type of protective immune response. This will be achieved through systems vaccinology and mathematical modeling, which will be critical for predicting the efficacy of the vaccination route for personalized medicine.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , CD8-Positive T-Lymphocytes/immunology , Myeloid-Derived Suppressor Cells/immunology , Vaccination , Vaccinia virus/immunology , Vaccinia/immunology , Viral Vaccines/pharmacology , Animals , Injections, Intradermal , Injections, Intramuscular , Macaca fascicularis , Male , Vaccines, Attenuated/pharmacology
7.
J Immunol ; 206(11): 2596-2604, 2021 06 01.
Article in English | MEDLINE | ID: covidwho-1224288

ABSTRACT

The COVID-19 pandemic is a global health emergency, and the development of a successful vaccine will ultimately be required to prevent the continued spread and seasonal recurrence of this disease within the human population. However, very little is known about either the quality of the adaptive immune response or the viral Ag targets that will be necessary to prevent the spread of the infection. In this study, we generated recombinant Vaccinia virus expressing the full-length spike protein from SARS-CoV-2 (VacV-S) to evaluate the cellular and humoral immune response mounted against this viral Ag in mice. Both CD8+ and CD4+ T cells specific to the SARS-CoV-2 spike protein underwent robust expansion, contraction, and persisted for at least 40 d following a single immunization with VacV-S. Vaccination also caused the rapid emergence of spike-specific IgG-neutralizing Abs. Interestingly, both the cellular and humoral immune responses strongly targeted the S1 domain of spike following VacV-S immunization. Notably, immunization with VacV-expressing spike conjugated to the MHC class II invariant chain, a strategy previously reported by us and others to enhance the immunogenicity of antigenic peptides, did not promote stronger spike-specific T cell or Ab responses in vivo. Overall, these findings demonstrate that an immunization approach using VacV or attenuated versions of VacV expressing the native, full-length SARS-CoV-2 spike protein could be used for further vaccine development to prevent the spread of COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Immunity, Cellular , Immunity, Humoral , Immunoglobulin G/immunology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccinia virus , Animals , Cell Line , Immunization , Mice , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccinia virus/genetics , Vaccinia virus/immunology
8.
Nat Commun ; 11(1): 6121, 2020 11 30.
Article in English | MEDLINE | ID: covidwho-951617

ABSTRACT

Modified Vaccinia Ankara (MVA) is a highly attenuated poxvirus vector that is widely used to develop vaccines for infectious diseases and cancer. We demonstrate the construction of a vaccine platform based on a unique three-plasmid system to efficiently generate recombinant MVA vectors from chemically synthesized DNA. In response to the ongoing global pandemic caused by SARS coronavirus-2 (SARS-CoV-2), we use this vaccine platform to rapidly produce fully synthetic MVA (sMVA) vectors co-expressing SARS-CoV-2 spike and nucleocapsid antigens, two immunodominant antigens implicated in protective immunity. We show that mice immunized with these sMVA vectors develop robust SARS-CoV-2 antigen-specific humoral and cellular immune responses, including potent neutralizing antibodies. These results demonstrate the potential of a vaccine platform based on synthetic DNA to efficiently generate recombinant MVA vectors and to rapidly develop a multi-antigenic poxvirus-based SARS-CoV-2 vaccine candidate.


Subject(s)
COVID-19 Vaccines/immunology , Coronavirus Nucleocapsid Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Synthetic/immunology , Adaptive Immunity , Animals , Antibodies, Neutralizing , Antibodies, Viral/immunology , Antigens, Viral/immunology , Genetic Vectors/immunology , Humans , Immunity, Cellular , Mice , Phosphoproteins/immunology , SARS-CoV-2/immunology , Vaccines, Attenuated/immunology , Vaccinia virus/immunology , Viral Vaccines/immunology
9.
Front Immunol ; 11: 1959, 2020.
Article in English | MEDLINE | ID: covidwho-732901

ABSTRACT

The lung is the vital target organ of coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the majority of patients the most active virus replication seems to be found in the upper respiratory tract, severe cases however suffer from SARS-like disease associated with virus replication in lung tissues. Due to the current lack of suitable anti-viral drugs the induction of protective immunity such as neutralizing antibodies in the lung is the key aim of the only alternative approach-the development and application of SARS-CoV-2 vaccines. However, past experience from experimental animals, livestock, and humans showed that induction of immunity in the lung is limited following application of vaccines at peripheral sides such as skin or muscles. Based on several considerations we therefore propose here to consider the application of a Modified Vaccinia virus Ankara (MVA)-based vaccine to mucosal surfaces of the respiratory tract as a favorable approach to combat COVID-19.


Subject(s)
Betacoronavirus/chemistry , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Vaccinia virus/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/immunology , Administration, Mucosal , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Bronchi/immunology , COVID-19 , Coronavirus Infections/virology , Humans , Immunoglobulin A/metabolism , Lymphoid Tissue/immunology , Plasma Cells/immunology , Pneumonia, Viral/virology , Respiratory Mucosa/drug effects , Respiratory Mucosa/immunology , SARS-CoV-2 , T-Lymphocytes/immunology , Vaccination , Vaccines, Attenuated/immunology
10.
Viral Immunol ; 33(6): 434-443, 2020.
Article in English | MEDLINE | ID: covidwho-165137

ABSTRACT

Canine parvovirus type 2 (CPV2) is a highly contagious cause of serious and often fatal disease in young dogs. Despite the widespread availability of attenuated vaccines, safer, more stable, and more effective CPV2 vaccine candidates are still under exploration. Vaccinia virus (VV) has already been proved to be a safe, stable, and effective vaccine vector. In this study, we generated a VV-based CPV2 vaccine candidate (VV-CPV-VP2) and then evaluated its immunogenicity in mice and dogs. The exogenous vp2 gene of CPV2, which replaced the major virulence gene hemagglutinin (ha) of VV, expressed efficiently and stably in vitro. Subsequently, intramuscular immunization of mice induced robust and lasting systemic immune responses, including neutralizing antibody against both CPV2a and CPV2b, and CPV2-VP2-specific interferon gamma (IFN-γ) secreting T cell. In addition, administration with a high-dose of VV-CPV-VP2 did not cause significant side effects for mice, thus indicating marked safety of this vaccine candidate. Most importantly, a single-dose vaccination of VV-CPV2-VP2 elicited substantial antibody responses and provided comparable protection for dogs with attenuated CPV2 vaccine. Collectively, this study demonstrated that VV-CPV2-VP2 could be used as a promising vaccine candidate preventing CPV2 from infection for dogs.


Subject(s)
Capsid Proteins/immunology , Parvoviridae Infections/prevention & control , Parvoviridae Infections/veterinary , Parvovirus, Canine/genetics , Vaccinia virus/genetics , Viral Vaccines/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibodies, Viral/immunology , Capsid Proteins/genetics , Chlorocebus aethiops , Dog Diseases/prevention & control , Dog Diseases/virology , Dogs , Female , Male , Mice , Mice, Inbred BALB C , Parvovirus, Canine/immunology , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/immunology , Vaccinia virus/immunology , Vero Cells , Viral Vaccines/administration & dosage , Viral Vaccines/genetics
SELECTION OF CITATIONS
SEARCH DETAIL