Intranasal vaccination with multi-neuraminidase and M2e virus-like particle vaccine results in greater mucosal immunity and protection against influenza than intramuscular injection.

Intramuscular injection of seasonal influenza vaccines provides strain-specific neutralizing antibodies, but not against variants, and no effective mucosal immunity. Here, we report that multi-subtype neuraminidase (NA) and M2 ectodomain repeat (5xM2e) virus-like particle vaccine (NA-M2e) conferred higher efficacy of broad cross-protection after two doses of intranasal delivery than intramuscular injection. The intranasally vaccinated mice displayed high levels of IgA antibodies, IFN-γ CD4 and CD8 T cells, germinal center B cells, plasma cells, and early innate immune cells locally in the lungs.

Dual roles of influenza B virus neuraminidase mRNA vaccine in enhancing cross-lineage protection by supplementing inactivated split vaccination.

The current influenza vaccine is based on immunity to hemagglutinin (HA) and provides poor cross-protection. Here, we generated mRNA vaccine encoding influenza B virus (IBV) neuraminidase (NA) conjugated to influenza A virus M2 ectodomain (M2e), encapsulated in lipid nanoparticles (LNP), capable of inducing cross-lineage IBV protection in a dose-dependent pattern. The combination of low-dose NA mRNA and inactivated split IBV vaccines was found to induce significantly higher levels of cross-reactive IgG responses, NA and HA inhibition titers, effector and memory cellular immune responses as well as cross-lineage protection than either NA mRNA or split vaccine alone.

A strategy of enhancing the protective efficacy of seasonal influenza vaccines by providing additional immunity to neuraminidase and M2e.

It is a high priority to enhance the efficacy of seasonal influenza vaccines based on hemagglutinin (HA) strain-specific neutralizing immunity. Here, we investigated a vaccination strategy of supplementing inactivated split seasonal vaccines with a virus-like particle vaccine containing multi-subtype neuraminidase (NA) and M2 ectodomain (M2e) repeat (NA-M2e) in mice. NA-M2e and split combined vaccine (S + NA-M2e) stimulated a unique pattern of innate immune responses within a day after intramuscular injection of mice.

Influenza 5xM2e mRNA lipid nanoparticle vaccine confers broad immunity and significantly enhances the efficacy of inactivated split vaccination when coadministered.

Current influenza vaccines are not effective in conferring protection against antigenic variants and pandemics. To improve cross-protection of influenza vaccination, we developed a 5xM2e messenger RNA (mRNA) vaccine encoding the tandem repeat conserved ectodomain (M2e) of ion channel protein M2 derived from human, swine, and avian influenza A viruses. The lipid nanoparticle (LNP)-encapsulated 5xM2e mRNA vaccine was immunogenic, eliciting high levels of M2e-specific IgG antibodies, IFN-γ+ T cells, T follicular helper cells, germinal center phenotypic B cells, and plasma cells.

Multilayer Adjuvanted Influenza Protein Nanoparticles Improve Intranasal Delivery and Antigen-Specific Immunity.

Intranasal vaccination is a desired route for protection against influenza viruses by mucosal and systemic immunity. However, the nasal mucosa impedes the intranasal delivery of vaccines. Here, we formulated layer-by-layer (LBL) influenza vaccine nanoparticles for effective intranasal delivery by coating them with alternating mucoadhesive cationic chitosan and muco-inert anionic CpG adjuvants.

Supplementation of seasonal vaccine with multi-subtype neuraminidase and M2 ectodomain virus-like particle improves protection against homologous and heterologous influenza viruses in aged mice.

The conventional inactivated split seasonal influenza vaccine offers low efficacy, particularly in the elderly and against antigenic variants. Here, to improve the efficacy of seasonal vaccination for the elderly population, we tested whether supplementing seasonal bivalent (H1N1 + H3N2) split (S) vaccine with M2 ectodomain repeat and multi-subtype consensus neuraminidase (NA) proteins (N1 NA + N2 NA + flu B NA) on a virus-like particle (NA-M2e) would induce enhanced cross-protection against different influenza viruses in aged mice. Immunization with split vaccine plus NA-M2e (S + NA-M2e) increased vaccine-specific IgG antibodies towards T-helper type 1 responses and hemagglutination inhibition titers.

Febrile Phase Soluble Urokinase Plasminogen Activator Receptor and Olfactomedin 4 as Prognostic Biomarkers for Severe Dengue in Adults.

Background: Dengue cases continue to rise and can overwhelm healthcare systems during outbreaks. In dengue, neutrophil mediators, soluble urokinase plasminogen activator receptor (suPAR) and olfactomedin 4, and mast cell mediators, chymase and tryptase, have not been measured longitudinally across the dengue phases. The utility of these proteins as prognostic biomarkers for severe dengue has also not been assessed in an older adult population.

Adjuvant effects of combination monophosphoryl lipid A and poly I:C on antigen-specific immune responses and protective efficacy of influenza vaccines.

Toll-like receptor (TLR) agonists improve vaccine immunogenicity and efficacy, but they are currently unlicensed as adjuvants in influenza vaccines. This study aimed to investigate whether a combination of monophosphoryl lipid A (MPL, a TLR4 agonist) and polyriboinosinic polyribocytidylic acid (poly I:C, a TLR3 agonist) can enhance the protective efficacy of an inactivated A/Puerto Rico/8/1934 (A/PR8) H1N1 influenza vaccine against homologous influenza infection and minimize illness outcomes. Results showed that combination MPL and poly I:C adjuvanted influenza vaccination increased the production of antigen-specific antibodies, decreased the levels of cytokines and cellular infiltrates at the infection sites, and induced significant memory T and B cell responses in mice.

Chronic allergic asthma induces T-cell exhaustion and impairs virus clearance in mice.

Background: Allergic asthma, one of the most common types of asthma, is thought to be highly susceptible to respiratory viral infections; however, its pathological mechanism needs to be elucidated. Recent studies have found impaired T-cell function in asthmatic mice. Therefore, we aimed to investigate the way by which asthma induction affects T-cell exhaustion in the lungs and assess the relationship between T-cell exhaustion and influenza viral infection.

Protective and vaccine dose-sparing efficacy of Poly I:C-functionalized calcium phosphate nanoparticle adjuvants in inactivated influenza vaccination.

Adjuvants are required to increase the immunogenicity and efficacy of vaccination and enable vaccine dose sparing. Polyinosinic-polycytidylic acid (Poly I:C), a toll-like receptor 3 agonist, is a promising adjuvant candidate that can induce cell-mediated immune responses; however, it remains unlicensed owing to its low stability and toxicity. Calcium phosphate (CaP), a biocompatible and biodegradable nanoparticle, is widely used in biomedicine for stable and targeted drug delivery.

Functional NK Cell Activation by Ovalbumin Immunization with a Monophosphoryl Lipid A and Poly I:C Combination Adjuvant Promoted Dendritic Cell Maturation.

Natural killer (NK) cells are one of the types of innate immune cells to remove pathogen-infected cells and modulate inflammatory immune responses. Recent studies have revealed that NK cells could enhance vaccine efficacy by coordinating the innate and adaptive immune responses. In this study, we have evaluated the efficacy of intranasal ovalbumin (OVA) immunization with a monophosphoryl lipid A (MPL) and polyriboinosinic polyribocytidylic acid (poly I:C) combination adjuvant in promoting NK cell recruitment, differentiation, and activation.

Monophosphoryl Lipid A and Poly I:C Combination Adjuvant Promoted Ovalbumin-Specific Cell Mediated Immunity in Mice Model.

Induction of antigen-specific cell-mediated immunity (CMI), as well as humoral immunity, is critical for successful vaccination against various type of pathogens. Toll-like receptor (TLR) agonists have been developed as adjuvants to promote vaccine efficacy and induce appropriate immune responses. Monophosphoryl lipid A (MPL); a TLR4 agonist, and Poly I:C; a TLR3 agonist, are known as a strong immuno-stimulator which induce Th1 response.