scholarly journals CXCL14 deficiency does not impact the outcome of influenza or Escherichia coli infections in mice

2014 ◽  
Vol 8 (10) ◽  
pp. 1301-1306 ◽  
Author(s):  
Abubaker ME Sidahmed ◽  
Alberto J Leon ◽  
David Banner ◽  
Alyson A Kelvin ◽  
Thomas Rowe ◽  
...  
Keyword(s):  
Viral Infections ◽  
Influenza Infection ◽  
Clinical Signs ◽  
Influenza Virus Infection ◽  
Antibacterial Activities ◽  
Phenotypic Characterization ◽  
E Coli ◽  
Small Proteins ◽  
Conserved Gene ◽  
Deficient Mice

Introduction: Chemokines are small proteins that regulate different cellular functions, such as leukocyte activation, chemoattraction and inflammation. The chemokine CXCL14 (BRAK) is a highly conserved gene among species and through evolution. It has been shown that CXCL14 is locally upregulated during viral infections, also, it has been found that this chemokine possesses direct antibacterial activities. Nonetheless, the exact role that CXCL14 plays during infection remains elusive. Methodology: CXCL14 deficient mice were generated in a C57B6/129 background and followed by phenotypic characterization. Later, the effect of CXCL14 deficiency during influenza infection and E. coli challenge was assessed. Results: Other than a slight weight reduction, CXCL14 deficient mice exhibited no phenotypic alterations. CXCL14 deficiency did not influence the outcome of influenza virus infection or challenge with E. coli, and no statistically significant differences in clinical signs, cellular responses and histopathological findings were observed. Conclusions: CXCL14 does not seem to play a pivotal role during influenza and E. coli infections of the lung; these results are suggestive of functional overlap between CXCL14 and other chemokines that are present during lung infection.

scholarly journals Performance of case definitions and clinical predictors for influenza surveillance among patients followed in a rural cohort in Senegal

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mamadou Aliou Barry ◽  
Florent Arinal ◽  
Cheikh Talla ◽  
Boris Gildas Hedible ◽  
Fatoumata Diene Sarr ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Sore Throat ◽  
Predictive Value ◽  
Influenza Infection ◽  
Clinical Signs ◽  
Influenza Virus Infection ◽  
Nasal Discharge ◽  
Age Group ◽  
Case Definitions

Abstract Background Influenza is a major cause of morbidity and mortality in Africa. However, a lack of epidemiological data remains for this pathology, and the performances of the influenza-like illness (ILI) case definitions used for sentinel surveillance have never been evaluated in Senegal. This study aimed to i) assess the performance of three different ILI case definitions, adopted by the WHO, USA-CDC (CDC) and European-CDC (ECDC) and ii) identify clinical factors associated with a positive diagnosis for Influenza in order to develop an algorithm fitted for the Senegalese context. Methods All 657 patients with a febrile pathological episode (FPE) between January 2013 and December 2016 were followed in a cohort study in two rural villages in Senegal, accounting for 1653 FPE observations with nasopharyngeal sampling and influenza virus screening by rRT-PCR. For each FPE, general characteristics and clinical signs presented by patients were collected. Sensitivity, Specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for the three ILI case definitions were assessed using PCR result as the reference test. Associations between clinical signs and influenza infection were analyzed using logistic regression with generalized estimating equations. Sore throat, arthralgia or myalgia were missing for children under 5 years. Results WHO, CDC and ECDC case definitions had similar sensitivity (81.0%; 95%CI: 77.0–85.0) and NPV (91.0%; 95%CI: 89.0–93.1) while the WHO and CDC ILI case definitions had the highest specificity (52.0%; 95%CI: 49.1–54.5) and PPV (32.0%; 95%CI: 30.0–35.0). These performances varied by age groups. In children < 5 years, the significant predictors of influenza virus infection were cough and nasal discharge. In patients from 5 years, cough, nasal discharge, sore throat and asthenia grade 3 best predicted influenza infection. The addition of “nasal discharge” as a symptom to the WHO case definition decreased sensitivity but increased specificity, particularly in the pediatric population. Conclusion In summary, all three definitions studies (WHO, ECDC & CDC) have similar performance, even by age group. The revised WHO ILI definition could be chosen for surveillance purposes for its simplicity. Symptomatic predictors of influenza virus infection vary according the age group.

scholarly journals Anti-Influenza with Green Tea Catechins: A Systematic Review and Meta-Analysis

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4014
Author(s):  
Anchalee Rawangkan ◽  
Kirati Kengkla ◽  
Sukrit Kanchanasurakit ◽  
Acharaporn Duangjai ◽  
Surasak Saokaew
Keyword(s):  
Systematic Review ◽  
Green Tea ◽  
Viral Infections ◽  
Influenza Infection ◽  
Meta Analysis ◽  
Influenza Virus Infection ◽  
Control Group ◽  
Tea Consumption ◽  
Tea Catechins ◽  
Green Tea Catechins

Influenza is one of the most serious respiratory viral infections worldwide. Although several studies have reported that green tea catechins (GTCs) might prevent influenza virus infection, this remains controversial. We performed a systematic review and meta-analysis of eight studies with 5,048 participants that examined the effect of GTC administration on influenza prevention. In a random-effects meta-analysis of five RCTs, 884 participants treated with GTCs showed statistically significant effects on the prevention of influenza infection compared to the control group (risk ratio (RR) 0.67, 95%CIs 0.51–0.89, P = 0.005) without evidence of heterogeneity (I2= 0%, P = 0.629). Similarly, in three cohort studies with 2,223 participants treated with GTCs, there were also statistically significant effects (RR 0.52, 95%CIs 0.35–0.77, P = 0.001) with very low evidence of heterogeneity (I2 = 3%, P = 0.358). Additionally, the overall effect in the subgroup analysis of gargling and orally ingested items (taking capsules and drinking) showed a pooled RR of 0.62 (95% CIs 0.49–0.77, P = 0.003) without heterogeneity (I2= 0%, P = 0.554). There were no obvious publication biases (Egger’s test (P = 0.138) and Begg’s test (P = 0.103)). Our analysis suggests that green tea consumption is effective in the prophylaxis of influenza infections. To confirm the findings before implementation, longitudinal clinical trials with specific doses of green tea consumption are warranted.

scholarly journals Autoimmune neutropenia associated with influenza virus infection in childhood: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ignacio Callejas Caballero ◽  
Marta Illán Ramos ◽  
Arantxa Berzosa Sánchez ◽  
Eduardo Anguita ◽  
José Tomás Ramos Amador
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Viral Infections ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Rapid Test ◽  
Male Infant ◽  
Severe Neutropenia ◽  
Autoimmune Neutropenia ◽  
Benign Condition

Abstract Background Although neutropenia is relatively frequent in infants and children and is mostly a benign condition with a self-limited course, it can lead to life-threatening severe infections. Autoimmune neutropenia is a relatively uncommon hematological disorder characterized by the autoantibody-induced destruction of neutrophils. It is usually triggered by viral infections with very few documented cases after influenza virus. Case presentation An 8-month-old male infant presented at the emergency room with a 5-days history of fever up to 39.7 °C, cough and runny nose. In the blood test performed, severe neutropenia was diagnosed (neutrophils 109/μL). A nasopharyngeal aspirate revealed a positive rapid test for Influenza A. Serum antineutrophil antibodies were determined with positive results. Neutropenia targeted panel showed no mutations. Despite maintenance of severe neutropenia for 9 months the course was uneventful without treatment. Conclusions When severe neutropenia is diagnosed and confirmed, it is essential to rule out some potential etiologies and underlying conditions, since the appropriate subsequent management will depend on it. Although autoimmune neutropenia triggered by viral infections has been widely reported, it has seldom been reported after influenza infection. The benign course of the disease allows a conservative management in most cases.

scholarly journals Exogenous Interleukin-33 Contributes to Protective Immunity via Cytotoxic T-Cell Priming against Mucosal Influenza Viral Infection

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 840 ◽  
Author(s):  
Chae Won Kim ◽  
Hye Jee Yoo ◽  
Jang Hyun Park ◽  
Ji Eun Oh ◽  
Heung Kyu Lee
Keyword(s):  
Immune Response ◽  
Influenza Virus ◽  
T Cell ◽  
Viral Infections ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Respiratory Illness ◽  
Cytotoxic T Cell ◽  
Antiviral Immune Response ◽  
Cytotoxic T Cell Responses

Influenza is an infectious respiratory illness caused by the influenza virus. Though vaccines against influenza exist, they have limited efficacy. To additionally develop effective treatments, there is a need to study the mechanisms of host defenses from influenza viral infections. To date, the mechanism by which interleukin (IL)-33 modulates the antiviral immune response post-influenza infection is unclear. In this study, we demonstrate that exogenous IL-33 enhanced antiviral protection against influenza virus infection. Exogenous IL-33 induced the recruitment of dendritic cells, increased the secretion of pro-inflammatory cytokine IL-12, and promoted cytotoxic T-cell responses in the local microenvironment. Thus, our findings suggest a role of exogenous IL-33 in the antiviral immune response against influenza infection.

scholarly journals TRIM35 mediates protection against influenza infection by activating TRAF3 and degrading viral PB2

2020 ◽  
Vol 11 (12) ◽  
pp. 894-914
Author(s):  
Nan Sun ◽  
Li Jiang ◽  
Miaomiao Ye ◽  
Yihan Wang ◽  
Guangwen Wang ◽  
...  
Keyword(s):  
Influenza A ◽  
Viral Infections ◽  
Influenza Infection ◽  
Type I ◽  
Subsequent Formation ◽  
Antiviral Immune Response ◽  
Signaling Complex ◽  
Deficient Mice

AbstractTripartite motif (TRIM) family proteins are important effectors of innate immunity against viral infections. Here we identified TRIM35 as a regulator of TRAF3 activation. Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon (IFN) in response to viral infection. Trim35-deficient mice were more susceptible to influenza A virus (IAV) infection than were wild-type mice. TRIM35 promoted the RIG-I-mediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1. IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3. TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2, thereby antagonizing its suppression of TRAF3 activation. Our in vitro and in vivo findings thus reveal novel roles of TRIM35, through catalyzing Lys63- or Lys48-linked polyubiquitination, in RIG-I antiviral immunity and mechanism of defense against IAV infection.

Nocardia seriolae: a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China

2020 ◽  
Vol 142 ◽  
pp. 13-21
Author(s):  
X Lei ◽  
R Zhao ◽  
Y Geng ◽  
K Wang ◽  
PO Yang ◽  
...  
Keyword(s):  
Largemouth Bass ◽  
Southwest China ◽  
Micropterus Salmoides ◽  
Clinical Signs ◽  
Antibacterial Activities ◽  
Phenotypic Characterization ◽  
Diseased Fish ◽  
Bacterial Aggregates ◽  
Nocardia Seriolae

Nocardia seriolae is the causative agent of nocardiosis in both marine and freshwater fish. Here, we report on multiple outbreaks of nocardiosis associated with elevated mortality (23-35%) in farmed largemouth bass in Sichuan, China, from 2017 to 2018. A total of 9 strains isolated from diseased largemouth bass were identified as N. seriolae by phenotypic characterization, 16S rRNA and hsp65 gene sequence analysis. The clinical signs of infected largemouth bass included hemorrhage, skin ulcers and prominent tubercles varying in size in the gill, liver, spleen and kidney. Experimental infection indicated that these isolates were the pathogens responsible for the mortalities. In vitro antibacterial activities of 12 antibiotics against N. seriolae isolates were determined as minimum inhibitory concentrations. Histopathological observation of diseased fish infected with N. seriolae showed necrotizing granulomatous hepatitis, nephritis, splenitis, epithelial hypertrophy and hyperplasia with degenerative changes of the epithelium in the gill. Large quantities of bacterial aggregates were found in the necrotic area of the granuloma by Lillie-Twort Gram stain and immunocytochemistry. Our findings indicated that N. seriolae is a serious threat to the largemouth bass Micropterus salmoides industry in Southwest China.

scholarly journals Influenza virus infection augments susceptibility to respiratory Yersinia pestis exposure and impacts the efficacy of antiplague antibiotic treatments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yaron Vagima ◽  
David Gur ◽  
Noam Erez ◽  
Hagit Achdout ◽  
Moshe Aftalion ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Yersinia Pestis ◽  
Bacterial Infections ◽  
Animal Studies ◽  
Viral Infections ◽  
Respiratory Infections ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Neutrophil Infiltration ◽  
Large Populations

Abstract Various respiratory viral infections in general and seasonal influenza in particular may increase the susceptibility to bacterial infections. Plague caused by Yersinia pestis endangers large populations during outbreaks or bioterrorism attacks. Recommended antibiotic countermeasures include well-established protocols based on animal studies and corroborated by effective treatment of human cases. Until now, prior exposure to viral respiratory infections was not taken into consideration when selecting the appropriate treatment for plague. Here, we show that as late as 25 days after exposure to influenza virus, convalescent mice still exhibited an increased susceptibility to sublethal doses of Y. pestis, presented with aberrant cytokine expression, and impaired neutrophil infiltration in the lungs. Increased levels of M2 alveolar macrophages and type II epithelial cells, as well as induction in metalloproteases expression and collagen and laminin degradation, suggested that the previous viral infection was under resolution, correlating with enhanced susceptibility to plague. Surprisingly, postexposure prophylaxis treatment with the recommended drugs revealed that ciprofloxacin was superior to doxycycline in mice recovering from influenza infection. These results suggest that after an influenza infection, the consequences, such as impaired immunity and lung tissue remodeling and damage, should be considered when treating subsequent Y. pestis exposure.

scholarly journals Resistance to and Recovery from Lethal Influenza Virus Infection in B Lymphocyte–deficient Mice

1997 ◽  
Vol 186 (12) ◽  
pp. 2063-2068 ◽  
Author(s):  
Mary Beth Graham ◽  
Thomas J. Braciale
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Influenza Virus ◽  
Virus Infection ◽  
B Cell ◽  
B Lymphocyte ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Effector T Cells ◽  
Deficient Mice

In the adaptive immune response to most viruses, both the cellular and humoral arms of the immune system play complementary roles in eliminating virus and virus-infected cells and in promoting recovery. To evaluate the relative contribution of CD4+ and CD8+ effector T lymphocytes in virus clearance and recovery, we have examined the host response to lethal type A influenza virus infection in B lymphocyte–deficient mice with a targeted disruption in the immunoglobulin mu heavy chain. Our results indicate that naive B cell–deficient mice have a 50– 100-fold greater susceptibility to lethal type A influenza virus infection than do wild type mice. However, after priming with sublethal doses of influenza, immune B cell–deficient animals show an enhanced resistance to lethal virus infection. This finding indicates that an antibody-independent immune-mediated antiviral mechanism accounts for the increased resistance to lethal virus challenge. To assess the contribution of influenza-specific CD4+ and CD8+ effector T cells in this process, defined clonal populations of influenza-specific CD4+ and CD8+ effector T cells were adoptively transferred into lethally infected B cell–deficient mice. Cloned CD8+ effectors efficiently promoted recovery from lethal infection, whereas cloned CD4+ T cells conferred only partial protection. These results suggest that memory T lymphocytes can act independently of a humoral immune response in order to confer resistance to influenza infection in immune individuals. The potential implications of these results for vaccination against human influenza infection are discussed.

Comprehensive phenotypic characterization of ABCB4 deficient mice reveals systemic effects of spontaneous biliary fibrosis

2009 ◽  
Vol 47 (01) ◽  
Author(s):  
K Hochrath ◽  
S Hillebrandt ◽  
F Lammert ◽  
B Rathkolb ◽  
H Fuchs ◽  
...  
Keyword(s):  
Phenotypic Characterization ◽  
Systemic Effects ◽  
Deficient Mice

scholarly journals Soluble Expression and Efficient Purification of Recombinant Class I Hydrophobin DewA

2021 ◽  
Vol 22 (15) ◽  
pp. 7843
Author(s):  
Sang-Oh Ahn ◽  
Ho-Dong Lim ◽  
Sung-Hwan You ◽  
Dae-Eun Cheong ◽  
Geun-Joong Kim
Keyword(s):  
Tertiary Structure ◽  
Signal Sequence ◽  
Soluble Expression ◽  
Class I ◽  
Soluble Form ◽  
Two Phase ◽  
E Coli ◽  
Small Proteins ◽  
Industrial Use ◽  
Shed Light

Hydrophobins are small proteins (<20 kDa) with an amphipathic tertiary structure that are secreted by various filamentous fungi. Their amphipathic properties provide surfactant-like activity, leading to the formation of robust amphipathic layers at hydrophilic–hydrophobic interfaces, which make them useful for a wide variety of industrial fields spanning protein immobilization to surface functionalization. However, the industrial use of recombinant hydrophobins has been hampered due to low yield from inclusion bodies owing to the complicated process, including an auxiliary refolding step. Herein, we report the soluble expression of a recombinant class I hydrophobin DewA originating from Aspergillus nidulans, and its efficient purification from recombinant Escherichia coli. Soluble expression of the recombinant hydrophobin DewA was achieved by a tagging strategy using a systematically designed expression tag (ramp tag) that was fused to the N-terminus of DewA lacking the innate signal sequence. Highly expressed recombinant hydrophobin DewA in a soluble form was efficiently purified by a modified aqueous two-phase separation technique using isopropyl alcohol. Our approach for expression and purification of the recombinant hydrophobin DewA in E. coli shed light on the industrial production of hydrophobins from prokaryotic hosts.

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