Gammaherpesvirus Alters Alveolar Macrophages According to the Host Genetic Background and Promotes Beneficial Inflammatory Control over Pneumovirus Infection

Human respiratory syncytial virus (hRSV) infection brings a wide spectrum of clinical outcomes, from a mild cold to severe bronchiolitis or even acute interstitial pneumonia. Among the known factors influencing this clinical diversity, genetic background has often been mentioned. In parallel, recent evidence has also pointed out that an early infectious experience affects heterologous infections severity. Here, we analyzed the importance of these two host-related factors in shaping the immune response in pneumoviral disease. We show that a prior gammaherpesvirus infection improves, in a genetic background-dependent manner, the immune system response against a subsequent lethal dose of pneumovirus primary infection notably by inducing a systematic expansion of the CD8+ bystander cell pool and by modifying the resident alveolar macrophages (AMs) phenotype to induce immediate cyto/chemokinic responses upon pneumovirus exposure, thereby drastically attenuating the host inflammatory response without affecting viral replication. Moreover, we show that these AMs present similar rapid and increased production of neutrophil chemokines both in front of pneumoviral or bacterial challenge, confirming recent studies attributing a critical antibacterial role of primed AMs. These results corroborate other recent studies suggesting that the innate immunity cells are themselves capable of memory, a capacity hitherto reserved for acquired immunity.

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TNF-mediated alveolar macrophage necroptosis drives disease pathogenesis during Respiratory Syncytial Virus infection

European Respiratory Journal ◽

10.1183/13993003.03764-2020 ◽

2020 ◽

pp. 2003764

Author(s):

Leonardo Duarte Santos ◽

Krist Helen Antunes ◽

Stéfanie Primon Muraro ◽

Gabriela Fabiano de Souza ◽

Amanda Gonzalez da Silva ◽

...

Keyword(s):

Gene Expression ◽

Weight Loss ◽

Respiratory Syncytial Virus ◽

Alveolar Macrophage ◽

Alveolar Macrophages ◽

Dependent Manner ◽

Macrophage Depletion ◽

Primary Mouse ◽

Rsv Infection ◽

Syncytial Virus

Respiratory Syncytial Virus (RSV) is the major cause of acute bronchiolitis in infants under 2 years old. Necroptosis has been implicated in the outcomes of respiratory virus infections. Here we report that RSV infection triggers necroptosis in primary mouse macrophages and human monocytes in a RIPK1-, RIPK3-, and MLKL-dependent manner. Moreover, necroptosis pathways are harmful to RSV clearance from alveolar macrophages. Additionally, Ripk3-/- mice were protected from RSV-induced weight loss and presented reduced viral loads in the lungs.Alveolar macrophage depletion also protected mice from weight loss and decreased lung RSV virus load. Importantly, alveolar macrophage depletion abolished the upregulation of Ripk3 and Mlkl gene expression induced by RSV infection in the lung tissue.Autocrine TNF mediated RSV-triggered macrophage necroptosis and necroptosis pathways were also involved in TNF secretion even when macrophages were committed to cell death, which can worsen lung injury during RSV infection. In line, Tnfr1-/- mice had a marked decrease in Ripk3 and Mlkl gene expression and a sharp reduction in the numbers of necrotic alveolar macrophages in the lungs. Finally, we provide evidence that elevated nasal levels of TNF are associated with disease severity in infants with RSV bronchiolitis.We propose that targeting TNF and/or the necroptotic machinery may be valuable as therapeutic approaches to reduce the respiratory morbidity caused by RSV infection in young children.

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Evaluation of Dimer of Epicatechin from an Endophytic Fungus Curvularia australiensis FC2AP on Acute Toxicity Levels, Anti-Inflammatory and Anti-Cervical Cancer Activity in Animal Models

Molecules ◽

10.3390/molecules26030654 ◽

2021 ◽

Vol 26 (3) ◽

pp. 654

Author(s):

Vellingiri Manon Mani ◽

Arockiam Jeyasundar Parimala Gnana Soundari ◽

Balamuralikrishnan Balasubramanian ◽

Sungkwon Park ◽

Utthapon Issara ◽

...

Keyword(s):

Cervical Cancer ◽

Acute Toxicity ◽

Endophytic Fungus ◽

Lethal Dose ◽

Chemotherapeutic Agents ◽

Cancer Drug ◽

Dependent Manner ◽

Anti Cancer ◽

Albino Mice ◽

Anti Inflammatory

Cervical cancer, as the most frequent cancer in women globally and accounts almost 14% in India. It can be prevented or treated with vaccines, radiation, chemotherapy, and brachytherapy. The chemotherapeutic agents cause adverse post effects by the destruction of the neighboring normal cells or altering the properties of the cells. In order to reduce the severity of the side effects caused by the chemically synthesized therapeutic agents, the current research developed an anti-cancer agent dimer of epicatechin (DoE), a natural bioactive secondary metabolite (BSM) mediated from an endophytic fungus Curvularia australiensis FC2AP. The investigation has initiated with the evaluation of inhibiting the angiogenesis which is a main activity in metastasis, and it was assessed through Hen’s Egg Test on Chorio Allantoic Membrane (HET-CAM) test; the BSM inhibited the growth of blood vessels in the developing chick embryo. Further the DoE was evaluated for its acute toxicity levels in albino mice, whereas the survival dose was found to be 1250 mg/kg and the lethal dose was 1500 mg/kg body weight of albino mice; hematological, biochemical, and histopathological analyses were assessed. The anti-inflammatory responses of the DoE were evaluated in carrageenan induced Wistar rats and the reduction of inflammation occurred in a dose-dependent manner. By fixing the effective dose for anti-inflammation analysis, the DoE was taken for the anti-cervical cancer analysis in benzo (a) pyrene induced female Sprague-Dawley rats for 60 days trial. After the stipulated days, the rats were taken for hematological antioxidants, lipid peroxidation (LPO), member bound enzymes, cervical histopathological and carcinogenic markers analyses. The results specified that the DoE has the capability of reducing the tumor in an efficient way. This is the first report of flavonoid-DoE production from an endophytic fungus C. australiensis has the anticancer potentiality and it can be stated as anti-cancer drug.

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Modulatory Effects of Osthole on Lipopolysaccharides-Induced Inflammation in Caco-2 Cell Monolayer and Co-Cultures with THP-1 and THP-1-Derived Macrophages

Nutrients ◽

10.3390/nu13010123 ◽

2020 ◽

Vol 13 (1) ◽

pp. 123

Author(s):

Natalia K. Kordulewska ◽

Justyna Topa ◽

Małgorzata Tańska ◽

Anna Cieślińska ◽

Ewa Fiedorowicz ◽

...

Keyword(s):

Gene Expression ◽

Inflammatory Reaction ◽

Wide Spectrum ◽

Cell Monolayer ◽

In Vivo Studies ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Tnf Α

Lipopolysaccharydes (LPS) are responsible for the intestinal inflammatory reaction, as they may disrupt tight junctions and induce cytokines (CKs) secretion. Osthole has a wide spectrum of pharmacological effects, thus its anti-inflammatory potential in the LPS-treated Caco-2 cell line as well as in Caco-2/THP-1 and Caco-2/macrophages co-cultures was investigated. In brief, Caco-2 cells and co-cultures were incubated with LPS to induce an inflammatory reaction, after which osthole (150–450 ng/mL) was applied to reduce this effect. After 24 h, the level of secreted CKs and changes in gene expression were examined. LPS significantly increased the levels of IL-1β, -6, -8, and TNF-α, while osthole reduced this effect in a concentration-dependent manner, with the most significant decrease when a 450 ng/mL dose was applied (p < 0.0001). A similar trend was observed in changes in gene expression, with the significant osthole efficiency at a concentration of 450 ng/μL for IL1R1 and COX-2 (p < 0.01) and 300 ng/μL for NF-κB (p < 0.001). Osthole increased Caco-2 monolayer permeability, thus if it would ever be considered as a potential drug for minimizing intestinal inflammatory symptoms, its safety should be confirmed in extended in vitro and in vivo studies.

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Experimental Assessment of Possible Factors Associated with Tick-Borne Encephalitis Vaccine Failure

Microorganisms ◽

10.3390/microorganisms9061172 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1172

Author(s):

Ksenia Tuchynskaya ◽

Viktor Volok ◽

Victoria Illarionova ◽

Egor Okhezin ◽

Alexandra Polienko ◽

...

Keyword(s):

Vaccine Efficacy ◽

Protective Efficacy ◽

Viral Rna ◽

Dependent Manner ◽

Related Factors ◽

Effective Measure ◽

Challenge Virus ◽

Tick Borne Encephalitis ◽

Tbe Virus ◽

The Brain

Currently the only effective measure against tick-borne encephalitis (TBE) is vaccination. Despite the high efficacy of approved vaccines against TBE, rare cases of vaccine failures are well documented. Both host- and virus-related factors can account for such failures. In this work, we studied the influence of mouse strain and sex and the effects of cyclophosphamide-induced immunosuppression on the efficacy of an inactivated TBE vaccine. We also investigated how an increased proportion of non-infectious particles in the challenge TBE virus would affect the protectivity of the vaccine. The vaccine efficacy was assessed by mortality, morbidity, levels of viral RNA in the brain of surviving mice, and neutralizing antibody (NAb) titers against the vaccine strain and the challenge virus. Two-dose vaccination protected most animals against TBE symptoms and death, and protectivity depended on strain and sex of mice. Immunosuppression decreased the vaccine efficacy in a dose-dependent manner and changed the vaccine-induced NAb spectrum. The vaccination protected mice against TBE virus neuroinvasion and persistence. However, viral RNA was detected in the brain of some asymptomatic animals at 21 and 42 dpi. Challenge with TBE virus enriched with non-infectious particles led to lower NAb titers in vaccinated mice after the challenge but did not affect the protective efficacy.

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Activation of Nuclear Factor κB and Induction of Inducible Nitric Oxide Synthase by Ureaplasma urealyticumin Macrophages

Infection and Immunity ◽

10.1128/iai.68.12.7087-7093.2000 ◽

2000 ◽

Vol 68 (12) ◽

pp. 7087-7093 ◽

Cited By ~ 28

Author(s):

Y.-H. Li ◽

Z.-Q. Yan ◽

J. Skov Jensen ◽

K. Tullus ◽

A. Brauner

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Inducible Nitric Oxide Synthase ◽

Alveolar Macrophages ◽

Nuclear Factor Κb ◽

Inos Expression ◽

Dependent Manner ◽

Nuclear Factor ◽

Oxide Synthase ◽

Inducible Nitric Oxide

ABSTRACT Chronic lung disease (CLD) of prematurity is an inflammatory disease with a multifactorial etiology. The importance ofUreaplasma urealyticum in the development of CLD is debated, and steroids produce some improvement in neonates with this disease. In the present study, the capability of U. urealyticum to stimulate rat alveolar macrophages to produce nitric oxide (NO), express inducible nitric oxide synthase (iNOS), and activate nuclear factor κB (NF-κB) in vitro was characterized. The effect of NO on the growth of U. urealyticum was also investigated. In addition, the impact of dexamethasone and budesonide on these processes was examined. We found that U. urealyticum antigen (≥4 × 107 color-changing units/ml) stimulated alveolar macrophages to produce NO in a dose- and time-dependent manner (P < 0.05). This effect was further enhanced by gamma interferon (100 IU/ml; P < 0.05) but was attenuated by budesonide and dexamethasone (10−4 to 10−6 M) (P < 0.05). The mRNA and protein levels of iNOS were also induced in response to U. urealyticum and inhibited by steroids.U. urealyticum antigen triggered NF-κB activation, a possible mechanism for the induced iNOS expression, which also was inhibited by steroids. NO induced by U. urealyticum caused a sixfold reduction of its own growth after infection for 10 h. Our findings imply that U. urealyticum may be an important factor in the development of CLD. The host defense response againstU. urealyticum infection may also be influenced by NO. The down-regulatory effect of steroids on NF-κB activation, iNOS expression, and NO production might partly explain the beneficial effect of steroids in neonates with CLD.

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Identification of Wild-Derived Inbred Mouse Strains Highly Susceptible to Monkeypox Virus Infection for Use as Small Animal Models

Journal of Virology ◽

10.1128/jvi.00621-10 ◽

2010 ◽

Vol 84 (16) ◽

pp. 8172-8180 ◽

Cited By ~ 43

Author(s):

Jeffrey L. Americo ◽

Bernard Moss ◽

Patricia L. Earl

Keyword(s):

Animal Models ◽

B Lymphocyte ◽

Inbred Mouse ◽

Lethal Dose ◽

Small Animal ◽

Congo Basin ◽

Mouse Strains ◽

Dependent Manner ◽

Inbred Mouse Strains ◽

Monkeypox Virus

ABSTRACT Infection with monkeypox virus (MPXV) causes disease manifestations in humans that are similar, although usually less severe, than those of smallpox. Since routine vaccination for smallpox ceased more than 30 years ago, there is concern that MPXV could be used for bioterrorism. Thus, there is a need to develop animal models to study MPXV infection. Accordingly, we screened 38 inbred mouse strains for susceptibility to MPXV. Three highly susceptible wild-derived inbred strains were identified, of which CAST/EiJ was further developed as a model. Using an intranasal route of infection with an isolate of the Congo Basin clade of MPXV, CAST/EiJ mice exhibited weight loss, morbidity, and death in a dose-dependent manner with a calculated 50% lethal dose (LD50) of 680 PFU, whereas there were no deaths of BALB/c mice at a 10,000-fold higher dose. CAST/EiJ mice exhibited greater MPXV sensitivity when infected via the intraperitoneal route, with an LD50 of 14 PFU. Both routes resulted in MPXV replication in the lung, spleen, and liver. Intranasal infection with an isolate of the less-pathogenic West African clade yielded an LD50 of 7,600 PFU. The immune competence of CAST/EiJ mice was established by immunization with vaccinia virus, which induced antigen-specific T- and B-lymphocyte responses and fully protected mice from lethal doses of MPXV. The new mouse model has the following advantages for studying pathogenesis of MPXV, as well as for evaluation of potential vaccines and therapeutics: relative sensitivity to MPXV through multiple routes, genetic homogeneity, available immunological reagents, and commercial production.

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RESPIRATORY SYNCYTIAL VIRUS LUNG INFECTION IN INFANTS: IMMUNOREGULATORY ROLE OF INFECTED ALVEOLAR MACROPHAGES

PEDIATRICS ◽

10.1542/peds.96.2.391 ◽

1995 ◽

Vol 96 (2) ◽

pp. 391-391

Author(s):

Leon S. Greos

Keyword(s):

Immune Response ◽

Respiratory Syncytial Virus ◽

Lung Injury ◽

Alveolar Macrophages ◽

Lung Infection ◽

Local Immune Response ◽

Rsv Infection ◽

Syncytial Virus

Alveolar macrophages are infected by RSV in vivo and coexpress potent immunomodulatory molecules that potentially regulate local immune response or lung injury caused by RSV infection.

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Human Recombinant Fab Fragment Neutralizes Shiga Toxin Type 2 Cytotoxic Effects in vitro and in vivo

Toxins ◽

10.3390/toxins10120508 ◽

2018 ◽

Vol 10 (12) ◽

pp. 508 ◽

Cited By ~ 4

Author(s):

Daniela Luz ◽

Maria Amaral ◽

Flavia Sacerdoti ◽

Alan Bernal ◽

Wagner Quintilio ◽

...

Keyword(s):

Shiga Toxin ◽

Lethal Dose ◽

Dependent Manner ◽

Fab Fragment ◽

Cell Viability Assay ◽

Cytotoxic Effects ◽

Morphological Alterations ◽

Viability Assay

Shiga toxin (Stx) producing Escherichia coli (STEC) is responsible for causing hemolytic uremic syndrome (HUS), a life-threatening thrombotic microangiopathy characterized by thrombocytopenia, hemolytic anemia, and acute renal failure after bacterially induced hemorrhagic diarrhea. Until now, there has been neither an effective treatment nor method of prevention for the deleterious effects caused by Stx intoxication. Antibodies are well recognized as affinity components of therapeutic drugs; thus, a previously obtained recombinant human FabC11:Stx2 fragment was used to neutralize Stx2 in vitro in a Vero cell viability assay. Herein, we demonstrated that this fragment neutralized, in a dose-dependent manner, the cytotoxic effects of Stx2 on human glomerular endothelial cells, on human proximal tubular epithelial cells, and prevented the morphological alterations induced by Stx2. FabC11:Stx2 protected mice from a lethal dose of Stx2 by toxin-antibody pre-incubation. Altogether, our results show the ability of a new encouraging molecule to prevent Stx-intoxication symptoms during STEC infection.

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