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Peng, X.

Publications and source records attributed to Peng, X..

At least 145 records · Page 8Linked to original sources

Arabidopsis ROOT UV-B SENSITIVE 1 and 2 Interact with Aminotransferases to Regulate Vitamin B6 Homeostasis

Pyridoxal-5-phosphate (PLP), the enzymatic cofactor form of Vitamin B6 (vitB6), is a versatile compound that has essential roles in metabolism. Cellular PLP homeostasic regulation is currently not well understood. Here we report that in Arabidopsis, biosynthesized PLP is sequestered by specific aminotransferases (ATs), and that the proteins ROOT UV-B SENSITIVE 1 (RUS1) and RUS2 function with ATs to regulate PLP homeostasis. The stunted growth phenotypes of rus1 and rus2 mutants were previously shown to be rescuable by exogenously supplied vitB6. Specific residue changes near the PLP-binding pocket in ASPARTATE AMINOTRANSFERASE2 (ASP2) also rescued rus1 and rus2 phenotypes. In this study, saturated suppressor screens identified 14 additional suppressor of rus (sor) alleles in four aminotransferase genes (ASP1, ASP2, ASP3, or ALANIN AMINOTRANSFERASE1 (AAT1)), which suppressed the rus phenotypes to varying degrees. Each of the sor mutations altered an amino acid in the PLP-binding pocket of the protein, and sor proteins were found to have reduced levels of PLP conjugation. Genetic data revealed that the availability of PLP normally requires both RUS1 and RUS2, and that increasing the number of sor mutants additively enhanced the suppression of rus phenotypes. Biochemical results showed that RUS1 and RUS2 physically interacted with ATs. Our studies suggest a mechanism in which RUS1, RUS2 and specific ATs work together to regulate PLP homeostasis in Arabidopsis.

genetics↗

Sustained IL-15 response signature predicts RhCMV/SIV vaccine efficacy

Simian immunodeficiency virus (SIV) challenge of rhesus macaques (RMs) vaccinated with Rhesus Cytomegalovirus (RhCMV) vectors expressing SIV proteins (RhCMV/SIV) results in a binary outcome: stringent control and subsequent clearance of highly pathogenic SIV in ~55% of vaccinated RMs with no protection in the remaining 45%. Although previous work suggests that unconventionally restricted, SIV-specific, effector-memory (EM)-biased CD8+ T cell responses are necessary for efficacy, the magnitude of these responses does not predict efficacy, and the basis of protection vs. non-protection in RhCMV/SIV vector-vaccinated RMs has not been elucidated. Here, we report that RhCMV/SIV vector administration strikingly alters the whole blood transcriptome of vaccinated RMs, with the sustained induction of specific immune-related pathways, including non-canonical T cell receptor (TCR), toll-lie receptor (TLR), inflammasome/cell death, and interleukin-15 (IL-15) signaling, significantly predicting protection. The IL-15 gene expression signature was further evaluated in an independent RM IL-15 treatment cohort, revealing that in whole blood the response to IL-15 is inclusive of innate and adaptive immune gene expression networks that link with RhCMV/SIV vaccine efficacy. We also show that this IL-15 response signature similarly tracks with vaccine protection in an independent RhCMV/SIV vaccination/SIV challenge RM validation cohort. Thus, the RhCMV/SIV vaccine imparts a coordinated and persistent induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ T cell function, that enable vaccine-elicited CD8+ T cells to mediate protection against highly pathogenic SIV challenge. Author SummarySIV insert-expressing vaccine vectors based on strain 68-1 RhCMV elicit robust, highly effector-memory-biased T cell responses that are associated with an unprecedented level of SIV control after challenge (replication arrest leading to clearance) in slightly over half of vaccinated monkeys. Since efficacy is not predicted by standard measures of immunogenicity, we used functional genomics analysis of RhCMV/SIV vaccinated monkeys with known challenge outcomes to identify immune correlates of protection. We found that arrest of viral replication after challenge significantly correlates with a vaccine-induced response to IL-15 that includes modulation of T cell, inflammation, TLR signaling, and cell death programming. These data suggest that RhCMV/SIV efficacy is not based on chance, but rather, results from a coordinated and sustained vaccine-mediated induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ effector-memory T cell function, that enable vaccine-elicited CD8+ T cells to mediate efficacy.

genomics↗

Petabyte-Scale Multi-Morphometry of Single Neurons for Whole Brains

Recent advances in neuroscience make the extraction of full neuronal morphology at whole brain dataset available. To produce quality morphometry at large scale, it is highly desirable but extremely challenging to efficiently handle petabyte-scale high-resolution whole brain imaging database. Here, we developed a multi-level method to produce high quality somatic, dendritic, axonal, and potential synaptic morphometry, which was made possible by utilizing necessary petabyte hardware and software platform to optimize both the data and workflow management. Our method also boosts data sharing and remote collaborative validation. We highlight a petabyte application dataset involving 62 whole mouse brains, from which we identified 50,233 somata of individual neurons, profiled the dendrites of 11,322 neurons, reconstructed the full 3-D morphology of more than one thousand neurons including their dendrites and full axons, and detected million scale putative synaptic sites derived from axonal boutons. Analysis and simulation of these data indicate the promise of this approach for modern large-scale morphology applications.

neuroscience↗

Epigenetic control of coordinated hematopoietic and cardiovascular development by Rnf2 in zebrafish

Early embryogenesis requires the coordinated development of cardiovascular and hematopoietic lineages. However, the underlying cellular and genetic mechanisms are poorly understood. Here, we show that Rnf2, the core enzymatic component of Polycomb repressive complex 1 (PRC1), plays an important role in the control of cardiovascular and hematopoietic development and differentiation via suppressing the master hematoendothelial progenitor genes in zebrafish. In the absence of Rnf2, a group of transcription factor (TF) genes crucial for hematoendothelial specification such as etv2, gata2, lmo2 and tal1 are significantly up-regulated, which causes an expansion of hematopoietic and endothelial progenitors at the expense of myocardial differentiation, resulting in severe defects in both cardiogenesis and hematopoiesis. Although the number of hematopoietic stem cells (HSCs) is increased, both primitive and definitive waves of hematopoiesis are severely compromised in rnf2 mutant embryos, suggesting that Rnf2 is required for differentiation of blood progenitor cells. Combined ChIP-seq and RNA-seq analysis shows that Rnf2 directly binds to key hematoendothelial progenitor genes and represses its expression. We further show that Rnf2-mediated gene repression depends on its H2Aub1 catalytic activity. We propose that PRC1/Rnf2-mediated epigenetic mechanism plays a key role in coordinated development of cardiovascular and hematopoietic lineages by repressing key hematoendothelial progenitor genes. HighlightsO_LIRnf2 is required for suppressing the expression of key hematoendothelial TF genes in precursors and its differentiated descendants. C_LIO_LIRnf2 mutant zebrafish embryos display defective hematopoiesis and cardiogenesis. C_LIO_LILoss of Rnf2 results in increased HSC numbers and arrested differentiation, hallmarks of leukemia. C_LIO_LIRnf2 suppresses hematoendothelial progenitor genes via depositing H2Aub1. C_LI

developmental biology↗

Bifurcations and mutation hot-spots in the SARS-CoV-2 spike protein

Novel topological methods are introduced to protein research. The aim is to identify hot-spot sites where a bifurcation can change the local topology of the protein backbone. Since the shape of a protein is intimately related to its biological function, a mutation that takes place at such a bifurcation hot-spot has an enhanced capacity to change the proteins biological function. The methodology applies to any protein but it is developed with the SARS-CoV-2 spike protein as a timely example. First, topological criteria are introduced to identify and classify potential mutation hot-spot sites along the protein backbone. Then, the expected outcome of a substitution mutation is estimated for a general class of hot-spots, by a comparative analysis of the backbone segments that surround the hot-spot sites. This analysis employs the statistics of commensurable amino acid fragments in the Protein Data Bank, in combination with general stereochemical considerations. It is observed that the notorious D614G substitution of the spike protein is a good example of such a mutation hot-spot. Several topologically similar examples are then analyzed in detail, some of them are even better candidates for a mutation hot-spot than D614G. The local topology of the recently observed N501Y mutation is also inspected, and it is found that this site is prone to a different kind of local topology changing bifurcation.

biophysics↗

Transferrin receptor is another receptor for SARS-CoV-2 entry

Angiotensin-converting enzyme 2 (ACE2) has been suggested as a receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry to cause coronavirus disease 2019 (COVID-19). However, no ACE2 inhibitors have shown definite beneficiaries for COVID-19 patients, applying the presence of another receptor for SARS-CoV-2 entry. Here we show that ACE2 knockout dose not completely block virus entry, while TfR directly interacts with virus Spike protein to mediate virus entry and SARS-CoV-2 can infect mice with over-expressed humanized transferrin receptor (TfR) and without humanized ACE2. TfR-virus co-localization is found both on the membranes and in the cytoplasma, suggesting SARS-CoV-2 transporting by TfR, the iron-transporting receptor shuttling between cell membranes and cytoplasma. Interfering TfR-Spike interaction blocks virus entry to exert significant anti-viral effects. Anti-TfR antibody (EC50 ~16.6 nM) shows promising anti-viral effects in mouse model. Collectively, this report indicates that TfR is another receptor for SARS-CoV-2 entry and a promising anti-COVID-19 target.

microbiology↗

Type I Interferon Limits Viral Dissemination-Driven Clinical Heterogeneity in a Native Murine Betacoronavirus Model of COVID-19

Emerging clinical data demonstrates that COVID-19, the disease caused by SARS-CoV2, is a syndrome that variably affects nearly every organ system. Indeed, the clinical heterogeneity of COVID-19 ranges from relatively asymptomatic to severe disease with death resultant from multiple constellations of organ failures. In addition to genetics and host characteristics, it is likely that viral dissemination is a key determinant of disease manifestation. Given the complexity of disease expression, one major limitation in current animal models is the ability to capture this clinical heterogeneity due to technical limitations related to murinizing SARS-CoV2 or humanizing mice to render susceptible to infection. Here we describe a murine model of COVID-19 using respiratory infection with the native mouse betacoronavirus MHV-A59. We find that whereas high viral inoculums uniformly led to hypoxemic respiratory failure and death, lethal dose 50% (LD50) inoculums led to a recapitulation of most hallmark clinical features of COVID-19, including lymphocytopenias, heart and liver damage, and autonomic dysfunction. We find that extrapulmonary manifestations are due to viral metastasis and identify a critical role for type-I but not type-III interferons in preventing systemic viral dissemination. Early, but not late treatment with intrapulmonary type-I interferon, as well as convalescent serum, provided significant protection from lethality by limiting viral dissemination. We thus establish a Biosafety Level II model that may be a useful addition to the current pre-clinical animal models of COVID-19 for understanding disease pathogenesis and facilitating therapeutic development for human translation.

immunology↗

Azetidines kill Mycobacterium tuberculosis without detectable resistance by blocking mycolate assembly.

Tuberculosis (TB) is the leading cause of global morbidity and mortality resulting from infectious disease, with over 10 million new cases and 1.5 million deaths in 2019. This global emergency is exacerbated by the emergence of multi-drug-resistant MDR-TB and extensively-drug-resistant XDR-TB, therefore new drugs and new drug targets are urgently required. From a whole-cell phenotypic screen a series of azetidines derivatives termed BGAz, that elicit potent bactericidal activity with MIC99 values <10 M against drug-sensitive Mycobacterium tuberculosis and MDR-TB were identified. These compounds demonstrate no detectable drug resistance. Mode of action and target deconvolution studies suggest that these compounds inhibit mycobacterial growth by interfering with cell envelope biogenesis, specifically late-stage mycolic acid biosynthesis. Transcriptomic analysis demonstrates that the BGAz compounds tested display a mode of action distinct from existing mycobacterial cell-wall inhibitors. In addition, the compounds tested exhibit toxicological and PK/PD profiles that pave the way for their development as anti-tubercular chemotherapies.

microbiology↗

In-depth analysis reveals complex molecular etiology of idiopathic cerebral palsy

Cerebral palsy (CP), the most prevalent physical disability in children, has long been ignored with regard to its inherent molecular mechanism. In this work, we performed in-depth clinical and molecular analysis on 120 idiopathic CP families, and identified in half of the patients the underlying risk factors. By a compilation of 117 CP-related genes, we recognized the characteristic features in terms of inheritance and function, and proposed a dichotomous classification system according to the expression patterns. In two patients with both CP and intellectual disability, we revealed that the defective TYW1, a tRNA hypermodification enzyme, caused microcephaly and problems in motion and cognition by hindering neuronal proliferation and migration. We developed an algorithm and proved in mice brain that this malfunctioning hypermodification specifically perturbed the translation of a subset of proteins involved in cell cycling. In a CP patient with normal intelligence, we identified a mitochondrial enzyme GPAM, the hypomorphic form of which led to hypomyelination of corticospinal tract. We confirmed that the aberrant Gpam in mice perturbed the lipid metabolism in astrocyte, resulting in suppressed astrocyte proliferation and a shortage of lipid contents supplied for oligodendrocyte myelination. This work broadened the scope of understanding of CP etiology and paved a way for innovative therapeutic strategies.

genetics↗

Pancreatic α and β cells are globally phase-locked

The Ca2+ modulated pulsatile secretion of glucagon and insulin by pancreatic and {beta} cells plays a key role in glucose homeostasis. However, how and {beta} cells coordinate via paracrine interaction to produce various Ca2+ oscillation patterns is still elusive. Using a microfluidic device and transgenic mice in which and {beta} cells were labeled with different colors, we were able to record islet Ca2+ signals at single cell level for long times. Upon glucose stimulation, we observed heterogeneous Ca2+ oscillation patterns intrinsic to each islet. After a transient period, the oscillations of and {beta} cells were globally phase-locked, i.e., the two types of cells in an islet each oscillate synchronously but with a phase shift between the two. While the activation of cells displayed a fixed time delay of ~20 s to that of {beta} cells, {beta} cells activated with a tunable delay after the cells. As a result, the tunable phase shift between and {beta} cells set the islet oscillation period and pattern. Furthermore, we demonstrated that the phase shift can be modulated by glucagon. A mathematical model of islet Ca2+ oscillation taking into consideration of the paracrine interaction was constructed, which quantitatively agreed with the experimental data. Our study highlights the importance of cell-cell interaction to generate stable but tunable islet oscillation patterns.

systems biology↗

Transcriptome Analysis of Human Induced Excitatory Neurons Supports a Strong Effect of Clozapine on Cholesterol Biosynthesis

Antipsychotics are known to modulate dopamine and other neurotransmitters which is often thought to be the mechanism underlying their therapeutic effects. Nevertheless, other less studied consequences of antipsychotics on neuronal function may contribute to their efficacy. Revealing the complete picture behind their action is of paramount importance for precision medicine and accurate drug selection. Progress in cell engineering allows the generation of induced pluripotent stem cells (iPSCs) and their differentiation to a variety of neuronal types, providing new tools to study antipsychotics. Here we use excitatory cortical neurons derived from iPSCs to explore their response to therapeutic levels of Clozapine as measured by their transcriptomic output, a proxy for neuronal homeostasis. To our surprise, but in agreement with the results of many investigators studying glial-like cells, Clozapine had a very strong effect on cholesterol metabolism. More than a quarter (12) of all annotated cholesterol genes (46) in the genome were significantly changed at FDR<0.1, all upregulated. This is a 35-fold enrichment with an adjusted p = 8 x10-11. Notably no other functional category showed evidence of enrichment. Cholesterol is a major component of the neuronal membrane and myelin but it does not cross the blood brain barrier, it is produced locally mostly by glia but also by neurons. By singling out increased expression of cholesterol metabolism genes as the main response of cortical excitatory neurons to antipsychotics, our work supports the hypothesis that cholesterol metabolism may be a contributing mechanism to the beneficial effects of Clozapine and possibly other antipsychotics

neuroscience↗

Susceptibility of tree shrew to SARS-CoV-2 infection

Since SARS-CoV-2 became a pandemic event in the world, it has not only caused huge economic losses, but also a serious threat to global public health. Many scientific questions about SARS-CoV-2 and COVID-19 were raised and urgently need to be answered, including the susceptibility of animals to SARS-CoV-2 infection. Here we tested whether tree shrew, an emerging experimental animal domesticated from wild animal, is susceptible to SARS-CoV-2 infection. No clinical signs were observed in SARS-CoV-2 inoculated tree shrews during this experiment except the increasing body temperature (above 39{degrees} C) particular in female animals during infection. Low levels of virus shedding and replication in tissues occurred in all three age groups, each of which showed his own characteristics. Histopathological examine revealed that pulmonary abnormalities were mild but the main changes although slight lesions were also observed in other tissues. In summary, tree shrew is not susceptible to SARS-CoV-2 infection and may not be a suitable animal for COVID-19 related researches.

microbiology↗

Comparison of SARS-CoV-2 infections among 3 species of non-human primates

COVID-19, caused by SARS-CoV-2 infection, has recently been announced as a pandemic all over the world. Plenty of diagnostic, preventive and therapeutic knowledges have been enriched from clinical studies since December 2019. However, animal models, particularly non-human primate models, are urgently needed for critical questions that could not be answered in clinical patients, evaluations of anti-viral drugs and vaccines. In this study, two families of non-human primates, Old world monkeys (12 Macaca mulatta, 6 Macaca fascicularis) and New world monkeys (6 Callithrix jacchus), were experimentally inoculated with SARS-CoV-2. Clinical signs were recorded. Samples were collected for analysis of viral shedding, viremia and histopathological examination. Increased body temperature was observed in 100% (12/12) M. mulatta, 33.3% (2/6) M. fascicularis and none (0/6) of C. jacchus post inoculation of SARS-CoV-2. All of M. mulatta and M. fascicularis showed chest radiographic abnormality. Viral genomes were detected in nasal swabs, throat swabs, anal swabs and blood from all 3 species of monkeys. Viral shedding from upper respiratory samples reached the peak between day 6 and day 8 post inoculation. From necropsied M. mulatta and M. fascicularis, the tissues showing virus positive were mainly lung, weasand, bronchus and spleen. No viral genome was seen in any of tissues from 2 necropsied C. jacchus. Severe gross lesions and histopathological changes were observed in lung, heart and stomach of SARS-CoV-2 infected animals. In summary, we have established a NHP model for COVID-19, which could be used to evaluate drugs and vaccines, and investigate viral pathogenesis. M. mulatta is the most susceptible to SARS-CoV-2 infection, followed by M. fascicularis and C. jacchus. One Sentence SummaryM. mulatta is the most susceptible to SARS-CoV-2 infection as compared to M. fascicularis and C. jacchus.

microbiology↗

Ecology and molecular targets of hypermutation in the global microbiome.

Changes in the sequence of an organisms genome, i.e. mutations, are the raw material of evolution1. The frequency and location of mutations can be constrained by specific molecular mechanisms, such as Diversity-generating retroelements (DGRs)2-4. DGRs introduce mutations in specific target genes, and were characterized from several cultivated bacteria and bacteriophages2. Whilst a larger diversity of DGR loci has been identified in genomic data from environmental samples, i.e. metagenomes, the ecological role of these DGRs and their associated evolutionary drivers remain poorly understood5-7. Here we built and analyzed an extensive dataset of >30,000 metagenome-derived DGRs, and determine that DGRs have a single evolutionary origin and a universal bias towards adenine mutations. We further identified six major lineages of DGRs, each associated with a specific ecological niche defined as a genome type, i.e. whether the DGR is encoded on a viral or cellular genome, a limited set of taxa and environments, and a distinct type of target. Finally, we leverage read mapping and metagenomic time series to demonstrate that DGRs are consistently and broadly active, and responsible for >10% of all amino acid changes in some organisms at a conservative estimate. Overall, these results highlight the strong constraints under which DGRs diversify and expand, and elucidate several distinct roles these elements play in natural communities and in shaping microbial community structure and function in our environment.

microbiology↗

Isopropoxy benzene guanidine kills Staphylococcus aureus without detectable resistance

Antibiotic resistance is a serious public health crisis. The challenge caused by Staphylococcus aureus infections clearly urges the development of novel antimicrobial therapy. Drug repurposing has emerged as an alternative approach to rapidly identify effective drugs against multidrug-resistant bacteria. Recently, substituted benzene guanidine compounds have been used as leading structures to discover new promising drugs in both synthetic and medicinal chemistry. We investigated the antimicrobial activity of an analog of substituted benzene guanidine compounds (isopropoxy benzene guanidine) and further explored its antibacterial mechanism against S. aureus. Isopropoxy benzene guanidine had a MIC of 0.125-4g/ml against S. aureus and displayed potent activity against S. aureus by disrupting cell membrane. Unlike conventional antibiotics, repeated use of isopropoxy benzene guanidine had a low probability of resistance section. The most substantial isopropoxy benzene guanidine-induced changes occurred in transcript levels of membrane transport functions-regulated genes, and genes involved in purine- and pyrimidine-synthesis pathway and virulence factors. Furthermore, in vivo studies demonstrated that isopropoxy benzene guanidine is capable of treating invasive MRSA infections. These findings provided strong evidence that isopropoxy benzene guanidine represents a new chemical lead for novel antibacterial agent against multidrug-resistant S. aureus infections.

microbiology↗

Circ_0005962 functions as an oncogene to aggravate non-small cell lung cancer progression via circ_0005962/miR-382-5p/PDK4 regulatory network

Non-small cell lung cancer (NSCLC) is a leading threat to human lives with high incidence and mortality. Circular RNAs (circRNAs) were reported to play important roles in human cancers. The purpose of this study was to investigate the role of circ_0005962 and explore the underlying functional mechanisms. The expression of circ_0005962, miR-382-5p and pyruvate dehydrogenase kinase 4 (PDK4) was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and cell apoptosis were assessed by cell counting kit-8 (CCK-8) assay and flow cytometry assay, respectively. The protein levels of Beclin 1, light chain3 (LC3-II/LC3-I), PDK4, Cleaved Caspase 3 (C-caspase 3) and proliferating cell nuclear antigen (PCNA) were examined using western blot analysis. Glycolysis was determined according to the levels of glucose consumption and lactate production. The interaction between miR-382-5p and circ_0005962 or PDK4 was predicted by the online tool CircInteractome or starbase and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Xenograft model was constructed to investigate the role of circ_0005962 in vivo. circ_0005962 expressed with a high level in NSCLC tissues and cells. Circ_0005962 knockdown inhibited proliferation, autophagy, and glycolysis but promoted apoptosis in NSCLC cells. MiR-382-5p was targeted by circ_0005962, and its inhibition reversed the role of circ_0005962 knockdown. Besides, PDK4, a target of miR-382-5p, was regulated by circ_0005962 through miR-382-5p, and its overexpression abolished the effects of miR-382-5p reintroduction. Circ_0005962 knockdown suppressed tumor growth in vivo. Circ_0005962 knockdown restrained cell proliferation, autophagy, and glycolysis but stimulated apoptosis through modulating the circ_0005962/miR-382-5p/PDK4 axis. Our study broadened the insights into understanding the mechanism of NSCLC progression.

cell biology↗

AmpliCI: A High-resolution Model-Based Approach for Denoising Illumina Amplicon Data

MotivationNext-generation amplicon sequencing is a powerful tool for investigating microbial communities. One main challenge is to distinguish true biological variants from errors caused by PCR and sequencing. In the traditional analysis pipeline, such errors are eliminated by clustering reads within a sequence similarity threshold, usually 97%, and constructing operational taxonomic units, but the arbitrary threshold leads to low resolution and high false positive rates. Recently developed "denoising" methods have proven able to resolve single-nucleotide amplicon variants, but they still miss low frequency sequences, especially those near abundant variants, because they ignore the sequencing quality information. ResultsWe introduce AmpliCI, a reference-free, model-based method for rapidly resolving the number, abundance and identity of error-free sequences in massive Illumina amplicon datasets. AmpliCI takes into account quality information and allows the data, not an arbitrary threshold or an external database, to drive conclusions. AmpliCI estimates a finite mixture model, using a greedy strategy to gradually select error-free sequences and approximately maximize the likelihood. We show that AmpliCI is superior to three popular denoising methods, with acceptable computation time and memory usage. AvailabilitySource code available at https://github.com/DormanLab/AmpliCI

bioinformatics↗

The Pathogenicity of 2019 Novel Coronavirus in hACE2 Transgenic Mice

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.

microbiology↗