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.

Gut microbiota modulate immune responses to orally and parenterally administered rotavirus in mice.

Rotavirus (RV) remains a significant cause of infantile morbidity and mortality, while oral RV vaccines offer inconsistent protection. This study investigates whether gut microbiota influence immune responses to orally and intramuscularly (IM) administered RV strains. Using murine models, we identified microbiota constituents, including segmented filamentous bacteria, reducing oral RV infection and RV antibody generation.

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.

Cross-protection against influenza viruses by chimeric M2e-H3 stalk protein or multi-subtype neuraminidase plus M2e virus-like particle vaccine in ferrets.

Current influenza vaccine is not effective in providing cross-protection against variants. We evaluated the immunogenicity and efficacy of multi-subtype neuraminidase (NA) and M2 ectodomain virus-like particle (m-cNA-M2e VLP) and chimeric M2e-H3 stalk protein vaccines (M2e-H3 stalk) in ferrets. Our results showed that ferrets with recombinant m-cNA-M2e VLP or M2e-H3 stalk vaccination induced multi-vaccine antigen specific IgG antibodies (M2e, H3 stalk, NA), NA inhibition, antibody-secreting cells, and IFN-γ secreting cell responses.

Multivalent and Sequential Heterologous Spike Protein Vaccinations Effectively Induce Protective Humoral Immunity against SARS-CoV-2 Variants.

The emergence of new SARS-CoV-2 variants continues to cause challenging problems for the effective control of COVID-19. In this study, we tested the hypothesis of whether a strategy of multivalent and sequential heterologous spike protein vaccinations would induce a broader range and higher levels of neutralizing antibodies against SARS-CoV-2 variants and more effective protection than homologous spike protein vaccination in a mouse model. We determined spike-specific IgG, receptor-binding inhibition titers, and protective efficacy in the groups of mice that were vaccinated with multivalent recombinant spike proteins (Wuhan, Delta, Omicron), sequentially with heterologous spike protein variants, or with homologous spike proteins.

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.

Adjuvant Effects of a New Saponin Analog VSA-1 on Enhancing Homologous and Heterosubtypic Protection by Influenza Virus Vaccination.

Adjuvants can increase the magnitude and durability of the immune response generated by the vaccine antigen. Aluminum salts (Alum) remain the main adjuvant licensed for human use. A few new adjuvants have been licensed for use in human vaccines since the 1990s.

Universal protection against influenza viruses by multi-subtype neuraminidase and M2 ectodomain virus-like particle.

Annual influenza vaccination is recommended to update the variable hemagglutinin antigens. Here, we first designed a virus-like particle (VLP) displaying consensus multi-neuraminidase (NA) subtypes (cN1, cN2, B cNA) and M2 ectodomain (M2e) tandem repeat (m-cNA-M2e VLP). Vaccination of mice with m-cNA-M2e VLP induced broad NA inhibition (NAI), and M2e antibodies as well as interferon-gamma secreting T cell responses.

Exploring the antimicrobial properties of vaginal against preterm birth-associated bacteria.

The need to develop new treatments to prevent unprompted premature delivery before 37 weeks of pregnancy remains pressing and unmet. Bacteria ( species) that promote vaginal health produce biochemical compounds that prevent the growth of microbes such as . Overgrowth of can cause vaginal infection with smelly discharge and increase a woman's risk of sexually transmitted infections and premature delivery.

Impact of hemagglutination activity and M2e immunity on conferring protection against influenza viruses.

To improve cross-protection of influenza vaccination, we tested conjugation of conserved M2e epitopes to the surface of inactivated influenza virus (iPR8-M2e*). Treatment of virus with chemical cross-linker led to diminished hemagglutination activity and failure to induce hemagglutination inhibiting antibodies. Conjugated iPR8-M2e* vaccine was less protective against homologous and heterosubtypic viruses, despite the induction of virus-specific binding IgG antibodies.

A chimeric thermostable M2e and H3 stalk-based universal influenza A virus vaccine.

We developed a new chimeric M2e and H3 hemagglutinin (HA) stalk protein vaccine (M2e-H3 stalk) by genetic engineering of modified H3 stalk domain conjugated with conserved M2e epitopes to overcome the drawbacks of low efficacy by monomeric domain-based universal vaccines. M2e-H3 stalk protein expressed and purified from Escherichia coli was thermostable, displaying native-like antigenic epitopes recognized by antisera of different HA subtype proteins and influenza A virus infections. Adjuvanted M2e-H3 stalk vaccination induced M2e and stalk-specific IgG antibodies recognizing viral antigens on virus particles and on the infected cell surface, CD4 and CD8 T-cell responses, and antibody-dependent cytotoxic cell surrogate activity in mice.

Thermostable H1 hemagglutinin stem with M2e epitopes provides broad cross-protection against group1 and 2 influenza A viruses.

Hemagglutinin (HA) stem-based vaccines have limitations in providing broad and effective protection against cross-group influenza viruses, despite being a promising universal vaccine target. To overcome the limited cross-protection and low efficacy by HA stem vaccination, we genetically engineered a chimeric conjugate of thermostable H1 HA stem and highly conserved M2e repeat (M2e-H1stem), which was expressed at high yields in M2e-H1stem protein presented native-like epitopes reactive to antisera of live virus infection. M2e-H1stem protein vaccination of mice induced strong M2e- and HA stem-specific immune responses, conferring broadly effective cross-protection against both antigenically distinct group 1 (H1N1, H5N1, and H9N2 subtypes) and group 2 (H3N2 and H7N9 subtypes) seasonal and pandemic potential influenza viruses.

Influenza Virus-like Particle-Based Hybrid Vaccine Containing RBD Induces Immunity against Influenza and SARS-CoV-2 Viruses.

Several approaches have produced an effective vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since millions of people are exposed to influenza virus and SARS-CoV-2, it is of great interest to develop a two-in-one vaccine that will be able to protect against infection of both viruses. We have developed a hybrid vaccine for SARS-CoV-2 and influenza viruses using influenza virus-like particles (VLP) incorporated by protein transfer with glycosylphosphatidylinositol (GPI)-anchored SARS-CoV-2 RBD fused to GM-CSF as an adjuvant.

Physical radiofrequency adjuvant enhances immune responses to influenza H5N1 vaccination.

Pre-pandemic influenza H5N1 vaccine has relatively low immunogenicity and often requires high antigen amounts and two immunizations to induce protective immunity. Incorporation of vaccine adjuvants is promising to stretch vaccine doses during pandemic outbreaks. This study presents a physical radiofrequency (RF) adjuvant (RFA) to conveniently and effectively increase the immunogenicity and efficacy of H5N1 vaccine without modification of vaccine preparation.

Comparison of the effects of different potent adjuvants on enhancing the immunogenicity and cross-protection by influenza virus vaccination in young and aged mice.

Vaccination against influenza viruses suffers from low efficacy in conferring homologous and cross-protection, particularly in older adults. Here, we compared the effects of three different adjuvant types (QS-21+MPL, CpG+MPL and bacterial cell wall CWS) on enhancing the immunogenicity and homologous and heterosubtypic protection of influenza vaccination in young adult and aged mouse models. A combination of saponin QS-21 and monophosphoryl lipid A (QS-21+MPL) was most effective in inducing T helper type 1 (Th1) T cell and cross-reactive IgG as well as hemagglutination inhibiting antibody responses to influenza vaccination.

Immunogenicity and Neutralizing Activity Comparison of SARS-CoV-2 Spike Full-Length and Subunit Domain Proteins in Young Adult and Old-Aged Mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be expanding the pandemic disease across the globe. Although SARS-CoV-2 vaccines were rapidly developed and approved for emergency use of vaccination in humans, supply and production difficulties are slowing down the global vaccination program. The efficacy of many different versions of vaccine candidates and adjuvant effects remain unknown, particularly in the elderly.

Study of the Pathogen Inactivation Mechanism in Salt-Coated Filters.

As COVID-19 exemplifies, respiratory diseases transmitted through aerosols or droplets are global threats to public health, and respiratory protection measures are essential first lines of infection prevention and control. However, common face masks are single use and can cause cross-infection due to the accumulated infectious pathogens. We developed salt-based formulations to coat membrane fibers to fabricate antimicrobial filters.

Broad cross protection by recombinant live attenuated influenza H3N2 seasonal virus expressing conserved M2 extracellular domain in a chimeric hemagglutinin.

Hemagglutinin (HA)-based current vaccines provide suboptimum cross protection. Influenza A virus contains an ion channel protein M2 conserved extracellular domain (M2e), a target for developing universal vaccines. Here we generated reassortant influenza virus rgH3N2 4xM2e virus (HA and NA from A/Switzerland/9715293/2013/(H3N2)) expressing chimeric 4xM2e-HA fusion proteins with 4xM2e epitopes inserted into the H3 HA N-terminus.

A Strategy to Elicit M2e-Specific Antibodies Using a Recombinant H7N9 Live Attenuated Influenza Vaccine Expressing Multiple M2e Tandem Repeats.

Influenza viruses remain a serious public health problem. Vaccination is the most effective way to prevent the disease; however, seasonal influenza vaccines demonstrate low or no effectiveness against antigenically drifted and newly emerged influenza viruses. Different strategies of eliciting immune responses against conserved parts of various influenza virus proteins are being developed worldwide.

Epithelial derived-matrix metalloproteinase (MMP9) exhibits a novel defensive role of tumor suppressor in colitis associated cancer by activating MMP9-Notch1-ARF-p53 axis.

Colitis associated cancer (CAC) is chronic inflammation driven colon cancer, prevalent among individuals with Inflammatory Bowel Disease. Matrix-metalloproteinase (MMP9) is one of the essential regulators of extra cellular matrix components. We have shown that MMP9 is protective in CAC contrary to its inflammatory role in acute-colitis.