scholarly journals Disruption of nasal bacteria enhances protective immune responses to influenza A virus and SARS-CoV-2 infection in mice

2020 ◽  
Author(s):  
Minami Nagai ◽  
Miyu Moriyama ◽  
Takeshi Ichinohe
Keyword(s):  
Influenza Virus ◽  
Immune Responses ◽  
Influenza A ◽  
Critical Role ◽  
Influenza Virus Infection ◽  
Oral Bacteria ◽  
Antibody Responses ◽  
Adaptive Immune Responses ◽  
Adjuvant Activity ◽  
Adaptive Immune

AbstractGut microbiota plays a critical role in the induction of adaptive immune responses to influenza virus infection. However, the role of nasal bacteria in the induction of the virus-specific adaptive immunity is less clear. Here we demonstrate that while intranasal administration of influenza virus hemagglutinin vaccine alone was insufficient to induce the vaccine-specific antibody responses, disruption of nasal bacteria by lysozyme or addition of culturable oral bacteria from a healthy human volunteer rescued inability of the nasal bacteria to generate antibody responses to intranasally administered the split-virus vaccine. Myd88-depdnent signaling in the hematopoietic compartment was required for adjuvant activity of intranasally administered oral bacteria. In addition, we found that the oral bacteria-combined intranasal vaccine induced protective antibody response to influenza virus and SARS-CoV-2 infection. Our findings here have identified a previously unappreciated role for nasal bacteria in the induction of the virus-specific adaptive immune responses.

scholarly journals Disruption of Nasal Bacteria Enhances Protective Immune Responses to Influenza A Virus and SARS-CoV-2 Infection

2020 ◽  
Author(s):  
Minami Nagai ◽  
Miyu Moriyama ◽  
Takeshi Ichinohe
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Specific Antibody ◽  
Critical Role ◽  
Influenza Virus Infection ◽  
Oral Bacteria ◽  
Antibody Responses ◽  
Adaptive Immune Responses ◽  
Adaptive Immune

Abstract Background: Gut microbiota and these microbial-derived products play a critical role in the induction of adaptive immune responses to influenza virus infection. However, the role of nasal bacteria in the induction of the virus-specific adaptive immunity is less clear. Here, we examine whether nasal bacteria critically regulates the generation of influenza virus specific adaptive immune response after infection or intranasal vaccination. Results: We demonstrated that disruption of nasal bacteria by topical mucosal application of antibiotic enhances the virus-specific antibody responses to influenza virus infection. Although intranasal administration of hemagglutinin (HA) vaccine alone was insufficient to induce the HA-specific antibody responses, disruption of nasal bacteria by lysozyme or addition of culturable oral bacteria from a healthy human volunteer rescued inability of the nasal bacteria to generate antibody responses to intranasally administered split-virus vaccines. Myd88-depdnent signaling in the hematopoietic compartment was required for adjuvant activity of intranasally administered oral bacteria. In addition, we found that the oral bacteria-combined intranasal vaccine induced protective antibody response to influenza virus and SARS-CoV-2 infection.Conclusion: We show for the first time that disruption of nasal bacteria enhances protective immune responses to influenza virus and SARS-CoV-2 infection. Our findings here have identified a previously unappreciated role for nasal bacteria in the induction of the virus-specific adaptive immune responses.

scholarly journals Benefits and Perils of Necroptosis in Influenza Virus Infection

2020 ◽  
Vol 94 (9) ◽  
Author(s):  
Siddharth Balachandran ◽  
Glenn F. Rall
Keyword(s):  
Cell Death ◽  
Influenza Virus ◽  
Immune Responses ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Cell Types ◽  
Influenza A Viruses ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Infected Cells

ABSTRACT Influenza A viruses (IAV) are lytic viruses that have recently been found to activate necroptosis in many of the cell types they infect. Necroptotic cell death is potently immunogenic and limits IAV spread by directly eliminating infected cells and by mobilizing both innate and adaptive immune responses. The benefits of necroptosis to the host, however, may sometimes be outweighed by the potentially deleterious hyperinflammatory consequences of activating this death modality in pulmonary and other tissues.

scholarly journals High ambient temperature dampens adaptive immune responses to influenza A virus infection

2019 ◽  
Vol 116 (8) ◽  
pp. 3118-3125 ◽  
Author(s):  
Miyu Moriyama ◽  
Takeshi Ichinohe
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Ambient Temperature ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
High Heat ◽  
High Ambient Temperature ◽  
Adaptive Immune Responses ◽  
Adaptive Immune

Although climate change may expand the geographical distribution of several vector-borne diseases, the effects of environmental temperature in host defense to viral infection in vivo are unknown. Here, we demonstrate that exposure of mice to the high ambient temperature of 36 °C impaired adaptive immune responses against infection with viral pathogens, influenza, Zika, and severe fever with thrombocytopenia syndrome phlebovirus. Following influenza virus infection, the high heat-exposed mice failed to stimulate inflammasome-dependent cytokine secretion and respiratory dendritic cell migration to lymph nodes. Although commensal microbiota composition remained intact, the high heat-exposed mice decreased their food intake and increased autophagy in lung tissue. Induction of autophagy in room temperature-exposed mice severely impaired virus-specific CD8 T cells and antibody responses following respiratory influenza virus infection. In addition, we found that administration of glucose or dietary short-chain fatty acids restored influenza virus-specific adaptive immune responses in high heat-exposed mice. These findings uncover an unexpected mechanism by which ambient temperature and nutritional status control virus-specific adaptive immune responses.

scholarly journals The Role of Alpha/Beta and Gamma Interferons in Development of Immunity to Influenza A Virus in Mice

2000 ◽  
Vol 74 (9) ◽  
pp. 3996-4003 ◽  
Author(s):  
Graeme E. Price ◽  
Anna Gaszewska-Mastarlarz ◽  
Demetrius Moskophidis
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Antibody Responses ◽  
Adaptive Immune ◽  
Ifn Γ ◽  
Alpha Beta

ABSTRACT During influenza virus infection innate and adaptive immune defenses are activated to eliminate the virus and thereby bring about recovery from illness. Both arms of the adaptive immune system, antibody neutralization of free virus and termination of intracellular virus replication by antiviral cytotoxic T cells (CTLs), play pivotal roles in virus elimination and protection from disease. Innate cytokine responses, such as alpha/beta interferon (IFN-α/β) or IFN-γ, can have roles in determining the rate of virus replication in the initial stages of infection and in shaping the initial inflammatory and downstream adaptive immune responses. The effect of these cytokines on the replication of pneumotropic influenza A virus in the respiratory tract and in the regulation of adaptive antiviral immunity was examined after intranasal infection of mice with null mutations in receptors for IFN-α/β, IFN-γ, and both IFNs. Virus titers in the lungs of mice unable to respond to IFNs were not significantly different from congenic controls for both primary and secondary infection. Likewise the mice were comparably susceptible to X31 (H3N2) influenza virus infection. No significant disruption to the development of normal antiviral CTL or antibody responses was observed. In contrast, mice bearing the disrupted IFN-α/β receptor exhibited accelerated kinetics and significantly higher levels of neutralizing antibody activity during primary or secondary heterosubtypic influenza virus infection. Thus, these observations reveal no significant contribution for IFN-controlled pathways in shaping acute or memory T-cell responses to pneumotropic influenza virus infection but do indicate some role for IFN-α/β in the regulation of antibody responses. Recognizing the pivotal role of CTLs and antibody in virus clearance, it is reasonable to assume a redundancy in IFN-mediated antiviral effects in pulmonary influenza. However, IFN-α/β seems to be a valid factor in determining tissue tropism and replicative rates of highly virulent influenza virus strains as reported previously by others, and this aspect is discussed here.

Impact of influenza virus during pregnancy: from disease severity to vaccine efficacy

2020 ◽  
Vol 15 (7) ◽  
pp. 441-453
Author(s):  
Ana Vazquez-Pagan ◽  
Rebekah Honce ◽  
Stacey Schultz-Cherry
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Immune Responses ◽  
Pregnant Women ◽  
Disease Severity ◽  
Influenza A ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
Severe Influenza ◽  
The Impact

Pregnant women are among the individuals at the highest risk for severe influenza virus infection. Infection of the mother during pregnancy increases the probability of adverse fetal outcomes such as small for gestational age, preterm birth and fetal death. Animal models of syngeneic and allogeneic mating can recapitulate the increased disease severity observed in pregnant women and are used to define the mechanism(s) of that increased severity. This review focuses on influenza A virus pathogenesis, the unique immunological landscape during pregnancy, the impact of maternal influenza virus infection on the fetus and the immune responses at the maternal–fetal interface. Finally, we summarize the importance of immunization and antiviral treatment in this population and highlight issues that warrant further investigation.

scholarly journals Chimeric Hemagglutinin-Based Live-Attenuated Vaccines Confer Durable Protective Immunity against Influenza A Viruses in a Preclinical Ferret Model

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
Wen-Chun Liu ◽  
Raffael Nachbagauer ◽  
Daniel Stadlbauer ◽  
Shirin Strohmeier ◽  
Alicia Solórzano ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Influenza Virus Vaccine ◽  
Antibody Responses ◽  
Upper Respiratory Tract ◽  
Influenza A Viruses ◽  
Humoral And Cellular Immunity ◽  
Stalk Domain ◽  
One Year

Epidemic or pandemic influenza can annually cause significant morbidity and mortality in humans. We developed novel chimeric hemagglutinin (cHA)-based universal influenza virus vaccines, which contain a conserved HA stalk domain from a 2009 pandemic H1N1 (pH1N1) strain combined with globular head domains from avian influenza A viruses. Our previous reports demonstrated that prime-boost sequential immunizations induced robust antibody responses directed toward the conserved HA stalk domain in ferrets. Herein, we further followed vaccinated animals for one year to compare the efficacy and durability of these vaccines in the preclinical ferret model of influenza. Although all cHA-based immunization regimens induced durable HA stalk-specific and heterosubtypic antibody responses in ferrets, sequential immunization with live-attenuated influenza virus vaccines (LAIV-LAIV) conferred the best protection against upper respiratory tract infection by a pH1N1 influenza A virus. The findings from this study suggest that our sequential immunization strategy for a cHA-based universal influenza virus vaccine provides durable protective humoral and cellular immunity against influenza virus infection.

scholarly journals Dendritic Cells in Innate and Adaptive Immune Responses against Influenza Virus

Viruses ◽  
2009 ◽  
Vol 1 (3) ◽  
pp. 1022-1034 ◽  
Author(s):  
Artur Summerfield ◽  
Kenneth McCullough
Keyword(s):  
Dendritic Cells ◽  
Influenza Virus ◽  
Immune Responses ◽  
Adaptive Immune Responses ◽  
Adaptive Immune

scholarly journals Integrated time-serial transcriptome networks reveal common innate and tissue-specific adaptive immune responses to PRRSV infection

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Byeonghwi Lim ◽  
Sangwook Kim ◽  
Kyu-Sang Lim ◽  
Chang-Gi Jeong ◽  
Seung-Chai Kim ◽  
...  
Keyword(s):  
Immune Responses ◽  
Influenza A ◽  
Vaccine Development ◽  
Expression Patterns ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Specific Group ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Gene Expression Control

Abstract Porcine reproductive and respiratory syndrome virus (PRRSV) infection is the most important viral disease causing severe economic losses in the swine industry. However, mechanisms underlying gene expression control in immunity-responsible tissues at different time points during PRRSV infection are poorly understood. We constructed an integrated gene co-expression network and identified tissue- and time-dependent biological mechanisms of PRRSV infection through bioinformatics analysis using three tissues (lungs, bronchial lymph nodes [BLNs], and tonsils) via RNA-Seq. Three groups with specific expression patterns (i.e., the 3-dpi, lung, and BLN groups) were discovered. The 3 dpi-specific group showed antiviral and innate-immune signalling similar to the case for influenza A infection. Moreover, we observed adaptive immune responses in the lung-specific group based on various cytokines, while the BLN-specific group showed down-regulated AMPK signalling related to viral replication. Our study may provide comprehensive insights into PRRSV infection, as well as useful information for vaccine development.

scholarly journals Mechanisms of Mixed Th1/Th2 Responses in Mice Induced by Albizia julibrissin Saponin Active Fraction by in Silico Analysis

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 48 ◽  
Author(s):  
Jing Du ◽  
Junjie Jin ◽  
Juanjuan Wang ◽  
Hongxiang Sun
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
In Silico Analysis ◽  
Active Fraction ◽  
Adaptive Immune Responses ◽  
Adjuvant Activity ◽  
Albizia Julibrissin ◽  
Adaptive Immune ◽  
Flight Mass Spectrometry ◽  
Th2 Responses

The purified active fraction of Albizia julibrissin saponin (AJSAF) is an ideal adjuvant candidate that improves antigen-specific both cellular and humoral immune responses and elicits mixed Th1/Th2 responses, but its mechanisms remain unclear. The key features of action of AJSAF were investigated in mice immunized with Newcastle disease virus-based recombinant influenza vaccine (rL-H5) and AJSAF at the same leg (AJSAF+rL-H5) or different legs (AJSAF/rL-H5). The adjuvant activity of AJSAF on rL-H5 is strictly dependent on their spatial colocalization. Serum H5 antigen (H5Ag)-specific IgG, IgG1, IgG2a, and IgG2b antibody titers in AJSAF+rL-H5 group were significantly higher than those in AJSAF/rL-H5 group. The mechanisms of selectivity of Th1 or Th2 in mice induced by AJSAF was explored by the transcriptomic and proteomic profiles of H5Ag-stimulated splenocytes from the immunized mice using gene microarray and two-dimensional difference gel electrophoresis coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Compared to rL-H5 alone, AJSAF/rL-H5 induced more differentially expressed genes (DEGs) than AJSAF+rL-H5, whereas AJSAF+rL-H5 upregulated higher mRNA expression of Th1 (T-bet, IFN-γ, TNF-α, IL-12β, and IL-12Rβ1) and Th2 (IL-10 and AICDA) immune response genes. The neutrophil response and its derived S100A8 and S100A9 might be involved in the AJSAF-mediated Th1 response. Meanwhile, AJSAF might induce the adaptive immune responses by improving a local innate immune microenvironment. These findings expanded the current knowledge on the mechanisms of action of saponin-based adjuvants, and provided new insights into how adjuvants shape adaptive immune responses.

scholarly journals Crosstalk between Dendritic Cells and Immune Modulatory Agents against Sepsis

Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 323 ◽  
Author(s):  
Guoying Wang ◽  
Xianghui Li ◽  
Lei Zhang ◽  
Abualgasim Elgaili Abdalla ◽  
Tieshan Teng ◽  
...  
Keyword(s):  
Immune Response ◽  
Dendritic Cells ◽  
Immune Responses ◽  
Critical Role ◽  
Innate Immune ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Th2 Responses ◽  
Novel Strategy

Dendritic cells (DCs) play a critical role in the immune system which sense pathogens and present their antigens to prime the adaptive immune responses. As the progression of sepsis occurs, DCs are capable of orchestrating the aberrant innate immune response by sustaining the Th1/Th2 responses that are essential for host survival. Hence, an in-depth understanding of the characteristics of DCs would have a beneficial effect in overcoming the obstacle occurring in sepsis. This paper focuses on the role of DCs in the progression of sepsis and we also discuss the reverse sepsis-induced immunosuppression through manipulating the DC function. In addition, we highlight some potent immunotherapies that could be used as a novel strategy in the early treatment of sepsis.

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