Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-337718

ABSTRACT

The ongoing SARS-CoV-2 pandemic represents a brutal reminder of the continual threat of mucosal infectious diseases. Mucosal immunity may provide robust protection at the predominant sites of SARS-CoV-2 infection. However, it remains unclear whether respiratory mucosal administration of DNA vaccines could confer protective immune responses against SARS-CoV-2 challenge due to the insurmountable barriers posed by the airway. Here, we applied self-assembled peptide-poloxamine nanoparticles with mucus-penetrating properties for pulmonary inoculation of a COVID-19 DNA vaccine (pSpike/PP-sNp). Not only displays the pSpike/PP-sNp superior gene-transfection and favorable biocompatibility in the mouse airway, but pSpike/PP-sNp promotes a tripartite immunity consisting of systemic, cellular and mucosal immune responses that are characterized by mucosal IgA secretion, high levels of neutralizing antibodies, and resident memory phenotype T-cell responses in the lungs of mice. Most importantly, pSpike/PP-sNp completely eliminates SARS-CoV-2 infection in both upper and lower respiratory tracts and enables 100% survival rate of mice following lethal SARS-CoV-2 challenge. Our findings indicate PP-sNp might be a promising platform in mediating DNA vaccines to elicit all-around mucosal immunity against SARS-CoV-2.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329632

ABSTRACT

Unlike many mammalian vital organs, the lung exhibits a robust, multifaceted regenerative response to severe injuries such as influenza infection, which primarily targets epithelial cells in the airways and alveoli. Quiescent lung-resident epithelial progenitors proliferate, migrate, and differentiate following lung injury, participating in two distinct reparative pathways: functionally beneficial regeneration and dysplastic tissue remodeling. Intrapulmonary airway-resident basal-like p63 + progenitors are one such progenitor cell type that migrates from the airways to form ectopic bronchiolar tissue in the alveoli, generating honeycomb-like cysts that fail to resolve after injury. Though this phenomenon is now well described, the cell-autonomous signals that drive dysplastic alveolar remodeling remain uncertain, a question made especially salient by observations that p63 + progenitors also expand dramatically upon diffuse alveolar damage in humans resulting from a variety of insults including SARS-CoV-2-induced ARDS. Here we show that the master basal cell transcription factor ΔNp63 is required for the immense migratory capacity of intrapulmonary p63 + progenitors and consequently for the dysplastic repair pathway manifest by these cells. We further demonstrate that ΔNp63 restricts the fate plasticity of intrapulmonary p63 + progenitors by regulating their epigenetic landscape, and that loss of ΔNp63 alters the deposition of active and repressive histone modifications at key differentiation gene loci, allowing ΔNp63 KO progenitors to proceed towards airway or alveolar differentiation depending on their surrounding environment. These insights into the regulatory mechanisms of dysplastic repair and intrapulmonary p63 + progenitor fate choice highlight potential therapeutic targets to promote more effective alveolar regeneration following severe lung injuries.

4.
Emerg Microbes Infect ; 11(1): 730-740, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1692301

ABSTRACT

ABSTRACTThe COVID-19 disease caused by infection with SARS-CoV-2 and its variants is devastating to the global public health and economy. To date, over a hundred COVID-19 vaccines are known to be under development, and the few that have been approved to fight the disease are using the spike protein as the primary target antigen. Although virus-neutralizing epitopes are mainly located within the RBD of the spike protein, the presence of T cell epitopes, particularly the CTL epitopes that are likely to be needed for killing infected cells, has received comparatively little attention. This study predicted several potential T cell epitopes with web-based analytic tools and narrowed them down from several potential MHC-I and MHC-II epitopes by ELIspot and cytolytic assays to a conserved MHC-I epitope. The epitope is highly conserved in current viral variants and compatible with a presentation by most HLA alleles worldwide. In conclusion, we identified a CTL epitope suitable for evaluating the CD8+ T cell-mediated cellular response and potentially for addition into future COVID-19 vaccine candidates to maximize CTL responses against SARS-CoV-2.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , COVID-19 Vaccines , Epitopes, T-Lymphocyte/genetics , Humans , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-313393

ABSTRACT

The COVID-19 disease caused by infection with SARS-CoV-2 and its variants is devastating to the global public health and economy. To date, over a hundred COVID-19 vaccines are known to be under development and the few that have been approved to fight the disease are using the spike protein as the primary target antigen. Although virus neutralizing epitopes are mainly located within the RBD of the spike protein, the presence of T cell epitopes, particularly the CTL epitopes that are likely to be needed for killing infected cells, has received comparatively little attention. In this study, we predicted several potential T cell epitopes with web-based analytic tools, and narrowed them down from several potential MHC‑I and MHC‑II epitopes by ELIspot and cytolytic assays to a conserved MHC‑I epitope. The epitope is highly conserved in current viral variants and compatible with presentation by most HLA alleles worldwide. In conclusion, we identified a CTL epitope suitable for evaluating the CD8+ T cell-mediated cellular response and potentially for addition into future COVID-19 vaccine candidates to maximize CTL responses against SARS-CoV-2.

6.
Hum Vaccin Immunother ; 18(1): 2016201, 2022 12 31.
Article in English | MEDLINE | ID: covidwho-1642249

ABSTRACT

Genetic optimization of Nucleic Acid immunogens is important for potentially improving their immune potency. A COVID-19 DNA vaccine is in phase III clinical trial which is based on a promising highly developable technology platform. Here, we show optimization in mice generating a pGX-9501 DNA vaccine encoding full-length spike protein, which results in induction of potent humoral and cellular immune responses, including neutralizing antibodies, that block hACE2-RBD binding of live CoV2 virus in vitro. Optimization resulted in improved induction of cellular immunity by pGX-9501 as demonstrated by increased IFN-γ expression in both CD8+ and CD4 + T cells and this was associated with more robust antiviral CTL responses compared to unoptimized constructs. Vaccination with pGX-9501 induced subsequent protection against virus challenge in a rigorous hACE2 transgenic mouse model. Overall, pGX-9501 is a promising optimized COVID-19 DNA vaccine candidate inducing humoral and cellular immunity contributing to the vaccine's protective effects.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Animals , Antibodies, Neutralizing , Antibodies, Viral , Base Sequence , COVID-19/prevention & control , Mice , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics
7.
Cell Rep Med ; 2(11): 100448, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1492754

ABSTRACT

Activation of nucleic acid sensing Toll-like receptors (TLRs) in B cells is involved in antiviral responses by promoting B cell activation and germinal center responses. In order to take advantage of this natural pathway for vaccine development, synthetic pathogen-like antigens (PLAs) constructed of multivalent antigens with encapsulated TLR ligands can be used to activate B cell antigen receptors and TLRs in a synergistic manner. Here we report a PLA-based coronavirus disease 2019 (COVID-19) vaccine candidate designed by combining a phage-derived virus-like particle carrying bacterial RNA as TLR ligands with the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S protein as the target antigen. This PLA-based vaccine candidate induces robust neutralizing antibodies in both mice and non-human primates (NHPs). Using a NHP infection model, we demonstrate that the viral clearance is accelerated in vaccinated animals. In addition, the PLA-based vaccine induces a T helper 1 (Th1)-oriented response and a durable memory, supporting its potential for further clinical development.


Subject(s)
Antibodies, Neutralizing , Antibodies, Viral , B-Lymphocytes/immunology , COVID-19 Vaccines/pharmacology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , COVID-19/immunology , COVID-19/prevention & control , COVID-19 Vaccines/therapeutic use , Cell Line , Female , Lymphocyte Activation , Macaca mulatta/immunology , Male , Mice , SARS-CoV-2/metabolism
8.
Sci Adv ; 6(48)2020 11.
Article in English | MEDLINE | ID: covidwho-1388431

ABSTRACT

Acute respiratory distress syndrome is associated with a robust inflammatory response that damages the vascular endothelium, impairing gas exchange. While restoration of microcapillaries is critical to avoid mortality, therapeutic targeting of this process requires a greater understanding of endothelial repair mechanisms. Here, we demonstrate that lung endothelium possesses substantial regenerative capacity and lineage tracing reveals that native endothelium is the source of vascular repair after influenza injury. Ablation of chicken ovalbumin upstream promoter-transcription factor 2 (COUP-TF2) (Nr2f2), a transcription factor implicated in developmental angiogenesis, reduced endothelial proliferation, exacerbating viral lung injury in vivo. In vitro, COUP-TF2 regulates proliferation and migration through activation of cyclin D1 and neuropilin 1. Upon influenza injury, nuclear factor κB suppresses COUP-TF2, but surviving endothelial cells ultimately reestablish vascular homeostasis dependent on restoration of COUP-TF2. Therefore, stabilization of COUP-TF2 may represent a therapeutic strategy to enhance recovery from pathogens, including H1N1 influenza and SARS-CoV-2.


Subject(s)
COUP Transcription Factor II/metabolism , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Influenza A Virus, H1N1 Subtype , Lung/cytology , Lung/physiology , Orthomyxoviridae Infections/metabolism , Regeneration/genetics , Animals , COUP Transcription Factor II/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Disease Models, Animal , Female , Gene Knockout Techniques , HEK293 Cells , Humans , Male , Mice , Mice, Transgenic , Orthomyxoviridae Infections/virology , Transfection
9.
Vaccine ; 38(35): 5653-5658, 2020 07 31.
Article in English | MEDLINE | ID: covidwho-612504

ABSTRACT

The COVID-19 outbreak has become a global pandemic responsible for over 2,000,000 confirmed cases and over 126,000 deaths worldwide. In this study, we examined the immunogenicity of CHO-expressed recombinant SARS-CoV-2 S1-Fc fusion protein in mice, rabbits, and monkeys as a potential candidate for a COVID-19 vaccine. We demonstrate that the S1-Fc fusion protein is extremely immunogenic, as evidenced by strong antibody titers observed by day 7. Strong virus neutralizing activity was observed on day 14 in rabbits immunized with the S1-Fc fusion protein using a pseudovirus neutralization assay. Most importantly, in <20 days and three injections of the S1-Fc fusion protein, two monkeys developed higher virus neutralizing titers than a recovered COVID-19 patient in a live SARS-CoV-2 infection assay. Our data strongly suggests that the CHO-expressed SARS-CoV-2 S1-Fc recombinant protein could be a strong candidate for vaccine development against COVID-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Coronavirus Infections/immunology , Immunoglobulin Fc Fragments/chemistry , Macaca/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/immunology , Animals , CHO Cells , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/prevention & control , Coronavirus Infections/therapy , Cricetulus , Female , HEK293 Cells , Humans , Immunization, Passive , Immunoglobulin Fc Fragments/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Mice , Pandemics , Rabbits
10.
Nat Commun ; 11(1): 2601, 2020 05 20.
Article in English | MEDLINE | ID: covidwho-326048

ABSTRACT

The coronavirus family member, SARS-CoV-2 has been identified as the causal agent for the pandemic viral pneumonia disease, COVID-19. At this time, no vaccine is available to control further dissemination of the disease. We have previously engineered a synthetic DNA vaccine targeting the MERS coronavirus Spike (S) protein, the major surface antigen of coronaviruses, which is currently in clinical study. Here we build on this prior experience to generate a synthetic DNA-based vaccine candidate targeting SARS-CoV-2 S protein. The engineered construct, INO-4800, results in robust expression of the S protein in vitro. Following immunization of mice and guinea pigs with INO-4800 we measure antigen-specific T cell responses, functional antibodies which neutralize the SARS-CoV-2 infection and block Spike protein binding to the ACE2 receptor, and biodistribution of SARS-CoV-2 targeting antibodies to the lungs. This preliminary dataset identifies INO-4800 as a potential COVID-19 vaccine candidate, supporting further translational study.


Subject(s)
Antigens, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/immunology , Viral Vaccines/immunology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/immunology , Antigens, Viral/chemistry , COVID-19 Vaccines , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Epitope Mapping , Guinea Pigs , Immunity, Humoral , Immunoglobulin G/immunology , Lung/immunology , Mice , Mice, Inbred BALB C , Middle East Respiratory Syndrome Coronavirus , Models, Animal , Peptidyl-Dipeptidase A/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Viral Vaccines/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL