A highly sensitive electrochemical immunoassay method for detection of H1N1 influenza virus with the signal amplification of CuO nanoparticles (NPs) has been demonstrated.
Secondary bacterial infection greatly increased the morbidity and mortality of influenza virus infection. To investigate the underlying mechanism by which influenza impairs the pulmonary defense ...against secondary
Pseudomonas aeruginosa
(
P. aeruginosa
) infection, we established a lethal mouse model in which to study secondary
P. aeruginosa
infection after influenza virus infection. We found a significant increase in host susceptibility to a secondary infection with
P. aeruginosa
in mice after an influenza virus infection, and this was accompanied by severe immunopathology and pulmonary inflammation. Importantly, we demonstrated that neutrophils were essential for
P. aeruginosa
clearance in secondarily infected mice. Further, we revealed that influenza impaired the phagocytosis and digestion functions of pulmonary neutrophils for
P. aeruginosa
clearance. We identified that the activity of reactive oxygen species (ROS) and the myeloperoxidase (MPO) activity of neutrophils in the lungs played an important role in antibacterial host defense in influenza-infected lungs. Hereby, influenza virus infection causes deficient MPO activity in neutrophils, and this contributes to the increased susceptibility to secondary
P. aeruginosa
infection. Treatment with Bacillus Calmette-Guerin polysaccharide nucleic acid (BCG-PSN) prior to secondary
P. aeruginosa
infection may improve the function of neutrophils, resulting in significantly reduced lethality during secondary
P. aeruginosa
infection. We also demonstrated that treatment with anti-influenza immune serum during the early stage of an influenza virus infection could decrease the disease severity of secondary
P. aeruginosa
infection. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.
IMPORTANCE
A secondary bacterial infection, such as that of
P. aeruginosa
, often occurs after a pulmonary virus infection and contributes to severe disease. However, the underlying mechanisms responsible for viral-bacterial synergy in the lung remain largely unknown. In this study, we reported that influenza virus infection increases a host’s susceptibility to secondary infection by
P. aeruginosa
by reducing the MPO activity of neutrophils. We also demonstrated that treatment with BCG-PSN or anti-influenza immune serum prior to secondary
P. aeruginosa
infection can reduce the disease severity. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.
ABSTRACT
Latent viral reservoir is recognized as the major obstacle to achieving a functional cure for HIV infection. We previously reported that arsenic trioxide (As
2
O
3
) combined with ...antiretroviral therapy (ART) can reactivate the viral reservoir and delay viral rebound after ART interruption in chronically simian immunodeficiency virus (SIV)-infected macaques. In this study, we further investigated the effect of As
2
O
3
independent of ART in chronically SIV-infected macaques. We found that As
2
O
3
-only treatment significantly increased the CD4/CD8 ratio, improved SIV-specific T cell responses, and reactivated viral latency in chronically SIVmac239-infected macaques. RNA-sequencing analysis revealed that As
2
O
3
treatment downregulated the expression levels of genes related to HIV entry and infection, while the expression levels of genes related to transcription initiation, cell apoptosis, and host restriction factors were significantly upregulated. Importantly, we found that As
2
O
3
treatment specifically induced apoptosis of SIV-infected CD4
+
T cells. These findings revealed that As
2
O
3
might not only impact viral latency, but also induce the apoptosis of HIV-infected cells and thus block the secondary infection of bystanders. Moreover, we investigated the therapeutic potential of this regimen in acutely SIVmac239-infected macaques and found that As
2
O
3
+ ART treatment effectively restored the CD4
+
T cell count, delayed disease progression, and improved survival in acutely SIV-infected macaques. In sum, this work provides new insights to develop As
2
O
3
as a component of the “shock-and-kill” strategy toward HIV functional cure.
IMPORTANCE
Although antiretroviral therapy (ART) can effectively suppress the viral load of AIDS patients, it cannot functionally cure HIV infection due to the existence of HIV reservoir. Strategies toward HIV functional cure are still highly anticipated to ultimately end the pandemic of AIDS. Herein, we investigated the direct role of As
2
O
3
independent of ART in chronically SIV-infected macaques and explored the underlying mechanisms of the potential of As
2
O
3
in the treatment of HIV/SIV infection. Meanwhile, we investigated the therapeutic effects of ART+As
2
O
3
in acutely SIVmac239-infected macaques. This study showed that As
2
O
3
has the potential to be launched into the “shock-and-kill” strategy to suppress HIV/SIV reservoir due to its latency-reversing and apoptosis-inducing properties.
Although antiretroviral therapy (ART) can effectively suppress the viral load of AIDS patients, it cannot functionally cure HIV infection due to the existence of HIV reservoir. Strategies toward HIV functional cure are still highly anticipated to ultimately end the pandemic of AIDS. Herein, we investigated the direct role of As
2
O
3
independent of ART in chronically SIV-infected macaques and explored the underlying mechanisms of the potential of As
2
O
3
in the treatment of HIV/SIV infection. Meanwhile, we investigated the therapeutic effects of ART+As
2
O
3
in acutely SIVmac239-infected macaques. This study showed that As
2
O
3
has the potential to be launched into the “shock-and-kill” strategy to suppress HIV/SIV reservoir due to its latency-reversing and apoptosis-inducing properties.
•We first constructed Rps14 knock-in floxed mice and explored the role of Rps14 in sensory HC regeneration in vivo.•Overexpression of Rps14 specifically in Lgr5+ progenitor cells significantly ...promoted HC regeneration, and the ectopic HCs are most likely derived from Lgr5+ progenitor cells by direct trans-differentiation.•Rps14 overexpression increases the expression of Atoh1 and Gfi1 transcription factors to facilitate HC regeneration.
Sensory hair cells (HCs) in the cochlea cannot regenerate spontaneously in adult mammals after being damaged by external or genetic factors. However, several genes and signaling pathways are reported to induce cochlear HC regeneration at the early neonatal stage. Rps14 encodes a ribosomal protein that is involved in the regulation of cell differentiation and proliferation in mammals. However, its roles in the cochlea have not been reported in vivo. Here, we specifically overexpressed Rps14 in Lgr5+ progenitor cells in the newborn mouse cochlea and found that Rps14 conditional overexpression (cOE) mice had significantly increased the ectopic HCs, including inner and outer HCs. We further explored the source of these ectopic HCs and found no EdU+ supporting cells observed in the Rps14 cOE mice. The lineage tracing results, on the other hand, revealed that Rps14 cOE mice had significantly more tdTomato+ HCs in their cochleae than control mice. These results indicated that regenerated HCs by cOE of Rps14 are most likely derived from inducing the direct trans-differentiation of Lgr5+ progenitor cells into HCs. Moreover, real-time qPCR results suggested that the transcription factor genes Atoh1 and Gfi1, which are important in regulating HC differentiation, were upregulated in the cochlear basilar membrane of Rps14 cOE mice. In summary, this study provides in vivo evidence that, in the postnatal mouse cochlea, Rps14 is a potential gene that can promote the spontaneous trans-differentiation of Lgr5+ progenitor cells into HCs. This gene may one day be exploited as a therapeutic target for treating hearing loss.
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•A deep neural network called EDHRN is proposed to reconstruct NMR spectra.•Encoder-Decoder (ED) block is introduced to improve artifact removal.•The causality of NMR spectra and ...virtual echo mode are utilized in the method.•The training process of EDHRN can be very easy and fast while the reconstruction quality of EDHRN is also comparable to those of SMILE and hmsIST.
Multidimensional nuclear magnetic resonance (NMR) spectroscopy is used to examine the chemical structures of the studied systems. Unfortunately, the application of NMR spectra is limited by their long acquisition time, especially for 3D, 4D, and higher dimensional spectra. Non-uniform sampling (NUS) has been widely recognized as a powerful tool to reduce the NMR experimental time. But the quality of NUS spectra depends on appropriate reconstruction algorithms. As an effective data processing method, deep learning has been widely used in many fields in recent years. In this work, a deep learning-based strategy for fast reconstruction of non-uniform sampling NMR spectra is proposed. In our experiments, the proposed deep neural network has better performance in removing artifacts and preserving weak peaks than typical convolutional neural networks of U-Net and DenseNet. Besides, a novel approach of generating training data is utilized to reduce the computational burden of neural networks, and thus training our network can be easier and faster than previous deep learning-based works. Compared with the two currently available methods, SMILE and hmsIST, our strategy can provide comparable reconstruction quality in terms of peak intensities and the fidelity of peak shape. The reconstruction time of our methods is also comparable to or faster than the two methods, especially for 3D spectra.
Nuclear magnetic resonance (NMR) is one of the most powerful analytical tools and is extensively applied in many fields. However, compared to other spectroscopic techniques, NMR has lower ...sensitivity, impeding its wider applications. Using data postprocessing techniques to increase the NMR spectral signal-to-noise ratio (SNR) is a relatively simple and cost-effective method. In this work, a deep neural network, termed as DN-Unet, is devised to suppress noise in liquid-state NMR spectra to enhance SNR. It combines structures of encoder–decoder and convolutional neural network. Different from traditional deep learning training strategy, M-to-S strategy is developed to enhance DN-Unet capability that multiple noisy spectra (inputs) correspond to a same single noiseless spectrum (label) in the training stage. The trained 1D model can be used for denoising not only 1D but also high dimension spectra, further improving DN-Unet’s performance. 1D, 2D, and 3D NMR spectra were utilized to evaluate DN-Unet performance. The results suggest that DN-Unet provides larger than 200-fold increase in SNR with weak peaks hidden in noise perfectly recovered and spurious peaks suppressed well. Since DN-Unet developed here to increase SNR is based on data postprocessing, it is universal for a variety of samples and NMR platforms. The great SNR enhancement and extreme excellence in differentiating signal and noise would greatly promote various liquid-state NMR applications.
Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical tool that enables one to study molecular properties and interactions. Homonuclear couplings provide valuable structural ...information but are often difficult to disentangle in crowded 1H NMR spectra where complex multiplets and signal overlap commonly exist. Multidimensional NMR experiments push the power of NMR to a new level by providing better signal dispersion. Among them, 2D J-resolved spectroscopy is widely used for multiplet analysis and the measurement of scalar coupling constants. Here, we present a new 2D J-resolved method, CASCADE, through which easier multiplet analysis and unambiguous measurement of specific coupling constants can be achieved at the same time, fully exploiting the power of 2D J-resolved spectroscopy. It is expected that this method may replace a conventional 2D J experiment in many cases, facilitating structural and configurational studies as well as chemical and biological analyses.
Resolution is an essential challenge in NMR spectroscopy. Narrow chemical shift range and extensive signal splittings due to scalar couplings often give rise to spectral congestion and even overlap ...in NMR spectra. Magnetic field strength is directly responsible for spectral resolution as higher magnetic field strength offers better signal dispersion. However, the process of further increasing magnetic field strength of NMR instruments is slow and expensive. Methodology aimed at resolution issue has long been developing. Here, we present a chemical shift upscaling method, in which chemical shifts are upscaled by a given factor while scalar couplings are unchanged. As a result, signal dispersion and hence the resolution are improved. Therefore, it is possible to separate multiplets which originally overlap with each other and to extract their integrals for quantitative analysis. Improved signal dispersion and the preservation of scalar couplings also facilitate multiplet analysis and signal assignment. Chemical shift upscaling offers a method for enhancing resolution limited by magnetic field strength.
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•A chemical shift upscaling method is presented to offer better signal dispersion in NMR spectroscopy.•Chemical shifts can be upscaled by a specific factor, while scalar couplings are unaffected.•This approach allows rapid access of all spectral information.•Overlapping signals can be separated by chemical shift upscaling, facilitating signal assignment and quantification.
Nuclear magnetic resonance (NMR) is one of the most powerful analytical techniques. In order to obtain high-quality NMR spectra, a real-time Zangger–Sterk (ZS) pulse sequence is employed to collect ...low-quality pure shift NMR data with high efficiency. Then, a neural network named AC-ResNet and a loss function named SM-CDMANE are developed to train a network model. The model with excellent abilities of suppressing noise, reducing line widths, discerning peaks, and removing artifacts is utilized to process the acquired NMR data. The processed spectra with noise and artifact suppression and small line widths are ultraclean and high-resolution. Peaks overlapped heavily can be resolved. Weak peaks, even hidden in the noise, can be discerned from noise. Artifacts, even as high as spectral peaks, can be removed completely while not suppressing peaks. Eliminating perfectly noise and artifacts and smoothing baseline make spectra ultraclean. The proposed methodology would greatly promote various NMR applications.
