scholarly journals Elevation of CpG frequencies in influenza A genome attenuates pathogenicity but enhances host response to infection

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Eleanor Gaunt ◽  
Helen M Wise ◽  
Huayu Zhang ◽  
Lian N Lee ◽  
Nicky J Atkinson ◽  
...  
Keyword(s):  
Host Response ◽  
Influenza A ◽  
Low Dose ◽  
Lethal Dose ◽  
Antibody Responses ◽  
Clinical Severity ◽  
Viral Loads ◽  
A Genome ◽  
Cpg Dinucleotide

Previously, we demonstrated that frequencies of CpG and UpA dinucleotides profoundly influence the replication ability of echovirus 7 (Tulloch et al., 2014). Here, we show that that influenza A virus (IAV) with maximised frequencies of these dinucleotides in segment 5 showed comparable attenuation in cell culture compared to unmodified virus and a permuted control (CDLR). Attenuation was also manifested in vivo, with 10-100 fold reduced viral loads in lungs of mice infected with 200PFU of CpG-high and UpA-high mutants. However, both induced powerful inflammatory cytokine and adaptive (T cell and neutralising antibody) responses disproportionate to their replication. CpG-high infected mice also showed markedly reduced clinical severity, minimal weight loss and reduced immmunopathology in lung, yet sterilising immunity to lethal dose WT challenge was achieved after low dose (20PFU) pre-immunisation with this mutant. Increasing CpG dinucleotide frequencies represents a generic and potentially highly effective method for generating safe, highly immunoreactive vaccines.

scholarly journals Exacerbation of Influenza A Virus Disease Severity by Respiratory Syncytial Virus Co-Infection in a Mouse Model

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1630 ◽  
Author(s):  
Junu A. George ◽  
Shaikha H. AlShamsi ◽  
Maryam H. Alhammadi ◽  
Ahmed R. Alsuwaidi
Keyword(s):  
T Cells ◽  
Respiratory Syncytial Virus ◽  
Influenza A Virus ◽  
Influenza A ◽  
Immune Cell ◽  
Virus Disease ◽  
Viral Loads ◽  
Syncytial Virus

Influenza A virus (IAV) and respiratory syncytial virus (RSV) are leading causes of childhood infections. RSV and influenza are competitive in vitro. In this study, the in vivo effects of RSV and IAV co-infection were investigated. Mice were intranasally inoculated with RSV, with IAV, or with both viruses (RSV+IAV and IAV+RSV) administered sequentially, 24 h apart. On days 3 and 7 post-infection, lung tissues were processed for viral loads and immune cell populations. Lung functions were also evaluated. Mortality was observed only in the IAV+RSV group (50% of mice did not survive beyond 7 days). On day 3, the viral loads in single-infected and co-infected mice were not significantly different. However, on day 7, the IAV titer was much higher in the IAV+RSV group, and the RSV viral load was reduced. CD4 T cells were reduced in all groups on day 7 except in single-infected mice. CD8 T cells were higher in all experimental groups except the RSV-alone group. Increased airway resistance and reduced thoracic compliance were demonstrated in both co-infected groups. This model indicates that, among all the infection types we studied, infection with IAV followed by RSV is associated with the highest IAV viral loads and the most morbidity and mortality.

scholarly journals Pulmonary Collectins Modulate Strain-Specific Influenza A Virus Infection and Host Responses

2004 ◽  
Vol 78 (16) ◽  
pp. 8565-8572 ◽  
Author(s):  
Samuel Hawgood ◽  
Cynthia Brown ◽  
Jess Edmondson ◽  
Amber Stumbaugh ◽  
Lennell Allen ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Host Response ◽  
Influenza A ◽  
Small Difference ◽  
Alveolar Epithelium ◽  
Host Responses ◽  
Cytokine Release ◽  
Significant Difference

ABSTRACT Collectins are secreted collagen-like lectins that bind, agglutinate, and neutralize influenza A virus (IAV) in vitro. Surfactant proteins A and D (SP-A and SP-D) are collectins expressed in the airway and alveolar epithelium and could have a role in the regulation of IAV infection in vivo. Previous studies have shown that binding of SP-D to IAV is dependent on the glycosylation of specific sites on the HA1 domain of hemagglutinin on the surface of IAV, while the binding of SP-A to the HA1 domain is dependent on the glycosylation of the carbohydrate recognition domain of SP-A. Here, using SP-A and SP-D gene-targeted mice on a common C57BL6 background, we report that viral replication and the host response as measured by weight loss, neutrophil influx into the lung, and local cytokine release are regulated by SP-D but not SP-A when the IAV is glycosylated at a specific site (N165) on the HA1 domain. SP-D does not protect against IAV infection with a strain lacking glycosylation at N165. With the exception of a small difference on day 2 after infection with X-79, we did not find any significant difference in viral load in SP-A−/− mice with either IAV strain, although small differences in the cytokine responses to IAV were detected in SP-A−/− mice. Mice deficient in both SP-A and SP-D responded to IAV similarly to mice deficient in SP-D alone. Since most strains of IAV currently circulating are glycosylated at N165, SP-D may play a role in protection from IAV infection.

scholarly journals Low-Dose Arsenic Compromises the Immune Response to Influenza A Infection in Vivo

2009 ◽  
Vol 117 (9) ◽  
pp. 1441-1447 ◽  
Author(s):  
Courtney D. Kozul ◽  
Kenneth H. Ely ◽  
Richard I. Enelow ◽  
Joshua W. Hamilton
Keyword(s):  
Immune Response ◽  
Influenza A ◽  
Low Dose

scholarly journals Hemagglutinin stalk-based monoclonal antibody elicits broadly reactivity against group 1 influenza A virus

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Jingjin Huang ◽  
Nan Huang ◽  
Menglu Fan ◽  
Lingcai Zhao ◽  
Yan Luo ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Broad Spectrum ◽  
Influenza A ◽  
Lethal Dose ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
Linear Epitope ◽  
Group 1

Abstract Background Influenza virus remains a continuous and severe threat to public health worldwide, and its prevention and treatment have always been a major international issue. Because of its ability to evade immune surveillance through rapid antigenic drift and antigenic shift, broad-spectrum vaccines seem increasingly important. Methods A mAb named 3C12 from an immortalized hybrid cell was generated via immunizing mice with HA2 protein from A/chicken/Anhui/BRI99/2016 (AH/BRI99/16, H9N2) generated by prokaryotic expression. Then, its broad-spectrum activity was analyzed by WB and IFA. Next, the minimal linear epitope was identified via analyzing the reaction of a series of HA truncations with 3C12. Finally, the protective effects of 3C12 were evaluated in vitro and in vivo infection experiments. Results The mAb could react with the viruses of subtypes H1, H2, H5, H8, H9, H12, H13, H16, and HA protein of H18 in group 1, but failed to react with viruses in group 2. The minimal linear epitope targeted by the mAb was 433NAELLVL439 in full length of HA and localized in the C-helix region of HA2 (residue 95-101, HA2 numbering). What’s more, the mAb 3C12 inhibited H1, H2, H5, H8, H9, H12, H13 and H16 virus-replication in vitro and also has shown effectiveness in preventing and treating disease in mice challenged with lethal dose of AH/BRI99/16 (H9N2) virus in vivo. These results suggested that the broadly reactive anti-HA stem mAb 3C12 exhibited prophylactic and therapeutic efficacy. Conclusions Here, we have demonstrated that the linear epitope identified in this study could be a novel target for developing broad-spectrum influenza diagnostics or vaccine design, and the HA2-based monoclonal antibody is indeed a promising strategy for broad-spectrum protection against seasonal and pandemic influenza viruses.

scholarly journals Hemagglutinin Stalk-based Monoclonal Antibody Elicits Broadly Reactivity Against Group 1 Influenza A Virus

2020 ◽  
Author(s):  
Jingjin Huang ◽  
Nan Huang ◽  
Menglu Fan ◽  
Lingcai Zhao ◽  
Yan Luo ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Broad Spectrum ◽  
Influenza A ◽  
Lethal Dose ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
Linear Epitope ◽  
Group 1

Abstract Background: Influenza virus remains a continuous and serious threat to public health worldwide, and its prevention and treatment have always been a major international issue. Because of its ability to evade immune surveillance through rapid antigenic drift and antigenic shift, broad-spectrum vaccines seem increasingly important. Methods: A mAb named 3C12 from an immortalized hybrid cell was generated via immunizing mice with HA2 protein from A/chicken/Anhui/BRI99/2016 (AH/BRI99/16, H9N2) generated by prokaryotic expression. Then, its broad-spectrum activity was analyzed by WB and IFA. Next, the minimal linear epitope was identified via analyzing the reaction of a series of HA truncations with 3C12. Finally, the protective effects of 3C12 were evaluated in vitro and in vivo infection experiments.Results: The mAb could react with the viruses of subtypes H1, H2, H5, H8, H9, H12, H13, H16, and HA protein of H18 in group 1, but failed to react with viruses in group 2. The minimal linear epitope targeted by the mAb was 433NAELLVL439 in full length of HA and localized in the C-helix region of HA2 (residue 95-101, HA2 numbering). What’s more, the mAb 3C12 inhibited H1, H2, H5, H8, H9, H12, H13 and H16 virus-replication in vitro and also has shown effectiveness in preventing and treating disease in mice challenged with lethal dose of AH/BRI99/16 (H9N2) virus in vivo. These results suggested that the broadly reactive anti-HA stem mAb 3C12 exhibited prophylactic and therapeutic efficacy.Conclusions: Here, we have demonstrated that the linear epitope identified in this study could be a novel target for developing broad-spectrum influenza diagnostics or vaccine design, and the HA2-based monoclonal antibody is indeed a promising strategy for broad-spectrum protection against seasonal and pandemic influenza viruses.

scholarly journals Low-dose cadmium potentiates lung inflammatory response to 2009 pandemic H1N1 influenza virus in mice

2018 ◽  
Author(s):  
Joshua D. Chandler ◽  
Xin Hu ◽  
Eunju Ko ◽  
Soojin Park ◽  
Jolyn Fernandes ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Low Dose ◽  
Immune Cell ◽  
Inflammatory Responses ◽  
Lethal Dose ◽  
Inflammatory Cells ◽  
H1n1 Influenza ◽  
H1n1 Infection ◽  
Cell Counts

AbstractBACKGROUNDCadmium (Cd) is a toxic, pro-inflammatory metal ubiquitous in the diet that accumulates in body organs due to inefficient elimination. Many individuals exposed to dietary Cd are also infected by seasonal influenza virus. The H1N1 strain causes mild to severe pneumonia which can be fatal.OBJECTIVESTo determine the influence of low-dose Cd exposure on inflammatory responses to H1N1 influenza A virus.METHODSWe exposed mice to low-dose (1 mg CdCl2/l) Cd or vehicle (water) for 16 weeks prior to infection with a sub-lethal dose of H1N1. Lung inflammation was assessed by histopathology and flow cytometry. We used a combination of transcriptomics, metabolomics and bioinformatics to determine the molecular associations of inflammatory cells important in Cd-exacerbated responses.RESULTSCd-treated mice had increased lung tissue inflammatory cells, including neutrophils, monocytes, T lymphocytes and dendritic cells, following H1N1 infection. Lung genetic responses to infection (increasing TNF-a, interferon and complement, and decreasing myogenesis) were also exacerbated. Global correlations with immune cell counts, leading edge gene transcripts and metabolites revealed that Cd increased correlation of myeloid immune cells with pro-inflammatory genes, particularly interferon-γ, and metabolites in amino acid, nucleobase, glycerophospholipid and vitamin B3 pathways.DISCUSSIONCd burden in mice increased inflammation in response to sub-lethal H1N1 challenge, which was coordinated by genetic and metabolic responses, and could provide new targets for intervention against lethal inflammatory pathology of clinical H1N1 infection.

Sensitive Tumor Cell Line for Annonaceous Acetogenins and High Therapeutic Efficacy at a Low Dose for Choriocarcinoma Therapy

2021 ◽  
Vol 17 (10) ◽  
pp. 2062-2070
Author(s):  
Hui Ao ◽  
Hao-Wen Li ◽  
Li-Kang Lu ◽  
Jing-Xin Fu ◽  
Mei-Hua Han ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Line ◽  
Low Dose ◽  
Drug Loading ◽  
Lethal Dose ◽  
Tumor Cell Line ◽  
A431 Cells ◽  
Annonaceous Acetogenins ◽  
New Type

Annonaceous acetogenins (ACGs) have attracted much attention because of excellent antitumor activity. However, the lack of selectivity and the accompanying serious toxicity have eventually prevented ACGs from entering clinical application. To decrease the side effects of ACGs, the cytotoxicity of ACGs on 10 types of tumor cell lines was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) test to identify one that was very sensitive to ACGs. Meanwhile, ACGs nanoparticles (ACGs-NPs) were prepared using poloxamer 188 (P188) as an excipient so as to solve the problem of poor solubility and the in vivo delivery of ACGs. ACG-NPs were 163.9±2.5 nm in diameter, negatively charged, and spherical with a high drug loading content (DLC) of 44.9±1.2%. MTS assays demonstrated that ACGs had strong cytotoxicity against JEG-3, HeLa, SiHa, MCF-7, A375, A2058, A875, U-118MG, LN- 229, and A431 cells, among which JEG-3 cell line was extremely sensitive to ACGs with a 50% inhibitory concentration (IC50) value of 0.26 ng/mL, a very encouraging discovery. ACGs-NPs demonstrated very good dose-dependent antitumor efficacy in a broad range of 45?1200 μg/kg on JEG-3 tumor-bearing mice. At a very low dose (1200 μg/kg), ACGs-NPs achieved a high tumor inhibition rate (TIR) of 77.6% through oral administration, displaying a significant advantage over paclitaxel (PTX) injections that are currently used as first-line anti-choriocarcinoma drugs. In the acute toxicity study, the half lethal dose (LD50) of ACGs-NPs was 135.5 mg/kg, which was over 100 times as of the effective antitumor dose, indicating good safety of ACGs-NPs. ACGs-NPs show promise as a new type of and potent anti-choriocarcinoma drug in the future.

Immunoreactivity and neutralization capacity of Philippine cobra antivenom against Naja philippinensis and Naja samarensis venoms

2020 ◽  
Author(s):  
Choo Hock Tan ◽  
Praneetha Palasuberniam ◽  
Francis Bonn Blanco ◽  
Kae Yi Tan
Keyword(s):  
Low Dose ◽  
Lethal Dose ◽  
The Philippines ◽  
Knowledge Gap ◽  
High Efficacy ◽  
Neutralization Capacity ◽  
Median Lethal Dose ◽  
Venomous Snakes ◽  
Allopatric Species

Abstract Background The Philippine cobra (Naja philippinensis) and Samar cobra (Naja samarensis) are two WHO Category 1 medically important venomous snakes in the Philippines. Philippine cobra antivenom (PCAV) is the only antivenom available in the country, but its neutralization capacity against the venoms of N. philippinensis and hetero-specific N. samarensis has not been reported. This knowledge gap greatly hinders the optimization of antivenom use in the region. Methods This study examined the immunological binding and neutralization capacity of PCAV against the two cobra venoms using WHO-recommended protocols. Results In mice, both venoms were highly neurotoxic and lethal with a median lethal dose of 0.18 and 0.20 µg/g, respectively. PCAV exhibited strong and comparable immunoreactivity toward the venoms, indicating conserved venom antigenicity between the two allopatric species. In in vivo assay, PCAV was only moderately effective in neutralizing the toxicity of both venoms. Its potency was even lower against the hetero-specific N. samarensis venom by approximately two-fold compared with its potency against N. philippinensis venom. Conclusion The results indicated that PCAV could be used to treat N. samarensis envenomation but at a higher dose, which might increase the risk of hypersensitivity and worsen the shortage of antivenom supply in the field. Antivenom manufacturing should be improved by developing a low-dose, high-efficacy product against cobra envenomation.

scholarly journals Multiple effects of dendritic cell depletion on murine norovirus infection

2013 ◽  
Vol 94 (8) ◽  
pp. 1761-1768 ◽  
Author(s):  
Michael D. Elftman ◽  
Mariam B. Gonzalez-Hernandez ◽  
Nobuhiko Kamada ◽  
Cheryl Perkins ◽  
Kenneth S. Henderson ◽  
...  
Keyword(s):  
Early Time ◽  
Multiple Roles ◽  
Antibody Responses ◽  
Lymphoid Tissues ◽  
Murine Norovirus ◽  
Viral Loads ◽  
Secondary Lymphoid Organs

Dendritic cells (DCs) are permissive to murine norovirus (MNV) infection in vitro and in vivo. However, their roles during infection in vivo are not well defined. To determine the role of DCs during infection, conventional DCs were depleted from CD11c-DTR mice and infected with a persistent MNV strain. Viral titres in the intestine and secondary lymphoid organs were determined at early time points during infection, and anti-MNV antibody responses were analysed later during infection. Depletion of conventional DCs resulted in increased viral loads in intestinal tissues, impaired generation of antibody responses, and a failure of MNV to efficiently infect lymphoid tissues. These data suggest that DCs play multiple roles in MNV pathogenesis, in both innate immunity and the efficient generation of adaptive immune responses against MNV, as well as by promoting the dissemination of MNV to secondary lymphoid tissues. This is the first study to probe the roles of DCs in controlling and/or facilitating a norovirus infection in vivo and provides the basis for further studies aimed at defining mechanisms by which DCs control MNV replication and promote viral dissemination.

scholarly journals Author response: Elevation of CpG frequencies in influenza A genome attenuates pathogenicity but enhances host response to infection

2016 ◽  
Author(s):  
Eleanor Gaunt ◽  
Helen M Wise ◽  
Huayu Zhang ◽  
Lian N Lee ◽  
Nicky J Atkinson ◽  
...  
Keyword(s):  
Host Response ◽  
Influenza A ◽  
Author Response ◽  
A Genome
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