Frontiers in cellular and infection microbiology
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Front Cell Infect Microbiol · Jan 2017
Geldanamycin Reduces Acute Respiratory Distress Syndrome and Promotes the Survival of Mice Infected with the Highly Virulent H5N1 Influenza Virus.
Infections with lethal influenza viruses lead to acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), which may be related to the activation of the host's immune system. Here, in our study, male C57BL/6 mice were infected with 10 LD50 of the H5N1 influenza virus and treated with geldanamycin or oseltamivir 2 h after infection. Lung injury was assessed by histopathology on days 4 and 7. ⋯ Viral loads in geldanamycin-treated mice also significantly reduced compared with non-treated mice, but not to the extent as the oseltamivir-treated mice. Furthermore, the geldanamycin treatment markedly reduced the production of major proinflammatory cytokines and chemokines and attenuated the infiltration and activation of immune cells, but it did not alter the generation of virus-neutralizing antibodies. In conclusion, geldanamycin plays an important role in attenuating virus infection-induced ALI/ARDS by reducing the host's inflammatory responses and may provide an important reference for clinical treatments.
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Front Cell Infect Microbiol · Jan 2017
ReviewWith Friends Like These: The Complex Role of Neutrophils in the Progression of Severe Pneumonia.
Pneumonia is a leading cause of death from infection in the United States and across the globe. During pulmonary infection, clear resolution of host inflammatory responses occurs in the absence of appreciable lung damage. Neutrophils are the first wave of leukocytes to arrive in the lung upon infection. ⋯ In extreme cases, the damage caused by neutrophils and other innate immune mediators become the primary source of morbidity and mortality. Here, we review the complex role of neutrophils during severe pneumonia by highlighting specific molecules and processes that contribute to pulmonary immunity, but can also drive progression of severe disease. Depending on the identity of the infectious agent, enhancing or suppressing neutrophil-mediated responses may be key to effectively treating severe and typically lethal pneumonia.
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Front Cell Infect Microbiol · Jan 2017
ReviewModulation of Host Immunity by Human Respiratory Syncytial Virus Virulence Factors: A Synergic Inhibition of Both Innate and Adaptive Immunity.
The Human Respiratory Syncytial Virus (hRSV) is a major cause of acute lower respiratory tract infections (ARTIs) and high rates of hospitalizations in children and in the elderly worldwide. Symptoms of hRSV infection include bronchiolitis and pneumonia. The lung pathology observed during hRSV infection is due in part to an exacerbated host immune response, characterized by immune cell infiltration to the lungs. ⋯ Also, hRSV NS-1 and NS-2 proteins have been shown to inhibit the activation of the type I interferon response. Furthermore, the hRSV nucleoprotein has been shown to inhibit the immunological synapsis between the dendritic cells and T cells during infection, resulting in an inefficient T cell activation. Here, we discuss the hRSV virulence factors and the host immunological features raised during infection with this virus.
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Front Cell Infect Microbiol · Jan 2017
Scaffold of Selenium Nanovectors and Honey Phytochemicals for Inhibition of Pseudomonas aeruginosa Quorum Sensing and Biofilm Formation.
Honey is an excellent source of polyphenolic compounds that are effective in attenuating quorum sensing (QS), a chemical process of cell-to-cell communication system used by the opportunistic pathogen Pseudomonas aeruginosa to regulate virulence and biofilm formation. However, lower water solubility and inadequate bioavailability remains major concerns of these therapeutic polyphenols. Its therapeutic index can be improved by using nano-carrier systems to target QS signaling potently. ⋯ LasR is inhibited by selenium nano-scaffold in-vitro. Using computational molecular docking studies, we have also demonstrated that the anti-virulence activity of selenium nano-scaffold is reliant on molecular binding that occurs between HP and the QS receptor LasR through hydrogen bonding and hydrophobic interactions. Our preliminary investigations with selenium-based nano-carriers hold significant promise to improve anti-virulence effectiveness of phytochemicals by enhancing effective intracellular delivery.
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Zika virus (ZIKV) is an emerging healthcare threat. The presence of the mosquito Aedes species across South and Central America in combination with complementary climates have incited an epidemic of locally transmitted cases of ZIKV infection in Brazil. As one of the most significant current public health concerns in the Americas, ZIKV epidemic has been a cause of alarm due to its known and unknown complications. ⋯ As such, diagnostic tools are limited and no effective modalities are available to treat ZIKV. This article will review the recent advancements in understanding the pathogenesis of ZIKV infection as well as diagnostic tests available to detect the infection. Due to the increase in incidence of ZIKV infections, there is an immediate need to develop new diagnostic tools and novel preventive as well as therapeutic modalities based on understanding the molecular mechanisms underlying the disease.