Age-associated changes in immune cells have been linked to an increased risk for infection. However, a global and detailed characterization of the changes that human circulating immune cells undergo with age is lacking. Here, we combined scRNA-seq, mass cytometry and scATAC-seq to compare immune cell types in peripheral blood collected from young and old subjects and patients with COVID-19. We found that the immune cell landscape was reprogrammed with age and was characterized by T cell polarization from naive and memory cells to effector, cytotoxic, exhausted and regulatory cells, along with increased late natural killer cells, age-associated B cells, inflammatory monocytes and age-associated dendritic cells. In addition, the expression of genes, which were implicated in coronavirus susceptibility, was upregulated in a cell subtype-specific manner with age. Notably, COVID-19 promoted age-induced immune cell polarization and gene expression related to inflammation and cellular senescence. Therefore, these findings suggest that a dysregulated immune system and increased gene expression associated with SARS-CoV-2 susceptibility may at least partially account for COVID-19 vulnerability in the elderly.
Adult ; Aged ; Aged, 80 and over ; Aging ; genetics ; immunology ; Betacoronavirus ; CD4-Positive T-Lymphocytes ; metabolism ; Cell Lineage ; Chromatin Assembly and Disassembly ; Coronavirus Infections ; immunology ; Cytokine Release Syndrome ; etiology ; immunology ; Cytokines ; biosynthesis ; genetics ; Disease Susceptibility ; Flow Cytometry ; methods ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Gene Rearrangement ; Humans ; Immune System ; cytology ; growth & development ; immunology ; Immunocompetence ; genetics ; Inflammation ; genetics ; immunology ; Mass Spectrometry ; methods ; Middle Aged ; Pandemics ; Pneumonia, Viral ; immunology ; Sequence Analysis, RNA ; Single-Cell Analysis ; Transcriptome ; Young Adult

To investigate whether transcription of hepatitis B virus (HBV) gene occurs in human sperm, total RNA was extracted from sperm of patients with chronic HBV infection (test-1), from donor sperm transfected with a plasmid containing the full-length HBV genome (test-2), and from nontransfected donor sperm (control), used as the template for reverse transcription-polymerase chain reaction (RT-PCR). Positive bands for HBV DNA were observed in the test groups but not in the control. Next, to identify the role of host genes in regulating viral gene transcription in sperm, total RNA was extracted from 2-cell embryos derived from hamster oocytes fertilized in vitro by HBV-transfected (test) or nontransfected (control) human sperm and successively subjected to SMART-PCR, suppression subtractive hybridization, T/A cloning, bacterial amplification, microarray hybridization, sequencing and the Basic Local Alignment Search Tool (BLAST) search to isolate differentially expressed genes. Twenty-nine sequences showing significant identity to five human gene families were identified, with chorionic somatomammotropin hormone 2 (CSH2), eukaryotic translation initiation factor 4 gamma 2 (EIF4G2), pterin-4 alpha-carbinolamine dehydratase 2 (PCBD2), pregnancy-specific beta-1-glycoprotein 4 (PSG4) and titin (TTN) selected to represent target genes. Using real-time quantitative RT-PCR (qRT-PCR), when CSH2 and PCBD2 (or EIF4G2, PSG4 and TTN) were silenced by RNA interference, transcriptional levels of HBV s and x genes significantly decreased (or increased) (P < 0.05). Silencing of a control gene in sperm did not significantly change transcription of HBV s and x genes (P > 0.05). This study provides the first experimental evidence that transcription of HBV genes occurs in human sperm and is regulated by host genes.
Animals ; Connectin/genetics* ; Cricetinae ; Eukaryotic Initiation Factor-4G/genetics* ; Gene Expression Regulation/genetics* ; Gene Silencing ; Growth Hormone/genetics* ; Hepatitis B Surface Antigens/genetics* ; Hepatitis B virus/genetics* ; Hepatitis B, Chronic/virology* ; Humans ; Hydro-Lyases/metabolism* ; Male ; Pregnancy-Specific beta 1-Glycoproteins/genetics* ; RNA, Viral/analysis* ; Spermatozoa/virology* ; Trans-Activators/genetics* ; Transcription, Genetic ; Transfection ; Viral Regulatory and Accessory Proteins

Enterovirus 71 is a neuroinvasive virus that is associated with severe neurological complications. We had earlier suggested that the replication capacity of a severe strain was higher than that of a mild strain. The recombinant 3CRV and 3CDRV virus strains were successfully rescued in our previous study. In the present study, we found no difference in virulence between 3CRV and severe strains. However, the capacity of replication and to cause cell injury of 3CDRV strain decreased in vitro, especially at 39.5 °C. Replacement of 3CD region in the severe strain led to milder symptoms, less body weight loss, and lower viral load in ICR mice. Histopathological findings indicated less severe injury in mice infected with 3CDRV strain. This study suggests that the 3CD region contributes to the attenuation of the severe strain, including its replication capacity and temperature sensitivity.
Animals ; Cytopathogenic Effect, Viral ; Enterovirus A, Human ; genetics ; pathogenicity ; Enterovirus Infections ; pathology ; virology ; Gene Expression Regulation, Viral ; Mice ; Mice, Inbred ICR ; Mutation ; Viral Load ; Viral Proteins ; genetics ; metabolism ; Virulence ; Virus Replication

The nonstructural protein 1 (NS1) of influenza A virus, which is absent from the viral particle, but highly expressed in infected cells, strongly antagonizes the interferon (IFN)-mediated antiviral response. We engineered an NS1-expressing 293 (293-NS1) cell line with no response to IFN stimulation. Compared with the parental 293 cells, the IFN-nonresponsive 293-NS1 cells improved the growth capacity of various viruses, but the introduction of NS1 barely enhanced the propagation of Tahyna virus, a negative-strand RNA virus. In particular, fastidious enteric adenovirus that replicates poorly in 293 cells may grow more efficiently in 293-NS1 cells; thus, IFN-nonresponsive 293-NS1 cells might be of great value in diagnostic laboratories for the cultivation and isolation of human enteric adenoviruses.
Cell Line ; Gene Expression Regulation ; HEK293 Cells ; Humans ; Influenza A virus ; physiology ; Viral Nonstructural Proteins ; genetics ; metabolism ; Virus Cultivation ; methods ; Virus Replication ; physiology

The host takes use of pattern recognition receptors (PRRs) to defend against pathogen invasion or cellular damage. Among microorganism-associated molecular patterns detected by host PRRs, nucleic acids derived from bacteria or viruses are tightly supervised, providing a fundamental mechanism of host defense. Pathogenic DNAs are supposed to be detected by DNA sensors that induce the activation of NFκB or TBK1-IRF3 pathway. DNA sensor cGAS is widely expressed in innate immune cells and is a key sensor of invading DNAs in several cell types. cGAS binds to DNA, followed by a conformational change that allows the synthesis of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) from adenosine triphosphate and guanosine triphosphate. cGAMP is a strong activator of STING that can activate IRF3 and subsequent type I interferon production. Here we describe recent progresses in DNA sensors especially cGAS in the innate immune responses against pathogenic DNAs.
DNA, Bacterial ; immunology ; metabolism ; DNA, Viral ; immunology ; metabolism ; Gene Expression Regulation ; Host-Pathogen Interactions ; Humans ; Immunity, Innate ; Interferon Regulatory Factor-3 ; genetics ; immunology ; Interferon Type I ; biosynthesis ; immunology ; Membrane Proteins ; genetics ; immunology ; Models, Molecular ; NF-kappa B ; genetics ; immunology ; Nucleotides, Cyclic ; biosynthesis ; immunology ; Nucleotidyltransferases ; genetics ; immunology ; Protein Binding ; Protein-Serine-Threonine Kinases ; genetics ; immunology ; Signal Transduction

A small set of gastric adenocarcinomas (9%) harbor Epstein-Barr virus (EBV) DNA within malignant cells, and the virus is not an innocent bystander but rather is intimately linked to pathogenesis and tumor maintenance. Evidence comes from unique genomic features of host DNA, mRNA, microRNA and CpG methylation profiles as revealed by recent comprehensive genomic analysis by The Cancer Genome Atlas Network. Their data show that gastric cancer is not one disease but rather comprises four major classes: EBV-positive, microsatellite instability (MSI), genomically stable and chromosome instability. The EBV-positive class has even more marked CpG methylation than does the MSI class, and viral cancers have a unique pattern of methylation linked to the downregulation of CDKN2A (p16) but not MLH1. EBV-positive cancers often have mutated PIK3CA and ARID1A and an amplified 9p24.1 locus linked to overexpression of JAK2, CD274 (PD-L1) and PDCD1LG2 (PD-L2). Multiple noncoding viral RNAs are highly expressed. Patients who fail standard therapy may qualify for enrollment in clinical trials targeting cancer-related human gene pathways or promoting destruction of infected cells through lytic induction of EBV genes. Genomic tests such as the GastroGenus Gastric Cancer Classifier are available to identify actionable variants in formalin-fixed cancer tissue of affected patients.
Adenocarcinoma/*diagnosis/*etiology/therapy ; DNA Methylation ; Epstein-Barr Virus Infections/*complications ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Gene Expression Regulation, Viral ; *Genomics/methods ; Herpesvirus 4, Human/*physiology ; Host-Pathogen Interactions/genetics ; Humans ; MicroRNAs/genetics ; Mutation ; RNA, Messenger/genetics ; Signal Transduction ; Stomach Neoplasms/*diagnosis/*etiology/therapy ; Virus Integration

Clinically being applied treatment against chronic hepatitis has three limitations: low response rates, severe adverse effects and a high rate of drug resistance. Hence, novel targets for antiviral therapy need to be developed so as to provide an armory of different strategies. During the replication of hepatitis B virus, the interaction of viral polymerase (P protein, also called P) and epsilonRNA is indispensable for the initiation of reverse transcription via protein priming and the pregenome RNA (pgRNA) packaging. Three strategies are currently developed for blocking P-epsilon interaction: heat shock protein inhibitors, epsilonaptamers and chemical compounds for blocking formation of P-epsilon complex. Previously, our group has for the first time worldwide in vitro screened several aptamers, which are able to interfere with the P-epsilon interaction. A strong inhibition against HBV was observed in vitro and in vivo experiments, respectively. In conclusion, the so far developed chemicals suppressing the P-epsilon interaction may bypass or overcome the viral resistance problems during clinic treatment and represent a highly attractive option for therapeutic intervention.
Animals ; Gene Expression Regulation, Viral ; Gene Products, pol ; antagonists & inhibitors ; genetics ; metabolism ; Hepatitis B ; therapy ; virology ; Hepatitis B virus ; enzymology ; genetics ; physiology ; Humans ; RNA, Viral ; genetics ; metabolism ; Virus Replication

OBJECTIVETo explore the role of HIV-1 tat gene variations in AIDS dementia complex (ADC) pathogenesis.

METHODSHIV-1 tat genes derived from peripheral spleen and central basal ganglia of an AIDS patient with ADC and an AIDS patient without ADC were cloned for sequence analysis. HIV-1 tat gene sequence alignment was performed by using CLUSTAL W and the phylogentic analysis was conducted by using Neighbor-joining with MEGA4 software. All tat genes were used to construct recombinant retroviral expressing vector MSCV-IRES-GFP/tat. The MSCV-IRES-GFP/tat was cotransfected into 293T cells with pCMV-VSV-G and pUMVC vectors to assemble the recombinant retrovirus. After infection of gliomas U87 cells with equal amount of the recombinant retrovirus, TNF-α, and IL-1β concentrations in the supernatant of U87 cells were determined with ELISA.

RESULTSHIV-1 tat genes derived from peripheral spleen and central basal ganglia of the AIDS patient with ADC and the other one without ADC exhibited genetic variations. Tat variations and amino acid mutation sites existed mainly at Tat protein core functional area (38-47aa). All Tat proteins could induce U87 cells to produce TNF-α and IL-1β, but the level of IL-1β production was different among Tat proteins derived from the ADC patient's spleen, basal ganglia, and the non-ADC patient's spleen. The level of Tat proteins derived from the ADC patient's spleen, basal ganglia, and the non-ADC patient's spleen were obviously higher than that from the non-ADC patient's basal ganglia.

CONCLUSIONTat protein core functional area (38-47aa) may serve as the key area of enhancing the secretion of IL-1β. This may be related with the neurotoxicity of HIV-1 Tat.

AIDS Dementia Complex ; metabolism ; pathology ; virology ; Adult ; Amino Acid Sequence ; Basal Ganglia ; virology ; Cell Line, Tumor ; Gene Expression Regulation, Viral ; Genes, tat ; HIV-1 ; genetics ; pathogenicity ; Humans ; Interleukin-1beta ; biosynthesis ; genetics ; secretion ; Middle Aged ; Molecular Sequence Data ; Neuroglia ; pathology ; secretion ; Spleen ; virology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics ; secretion ; tat Gene Products, Human Immunodeficiency Virus ; genetics ; physiology

In order to solve the problem of selection and in vivo delivery problem in siRNA treatment, hepatitis B virus (HBV) HBx gene which could be targeted by siRNA was studied. The siRNA expression plasmid which specific inhibits HBx expression was obtained by in vitro selection via a dual-luciferase plasmid including HBx-Fluc fusion protein expression domain. The selected siRNA expression plasmid was then encapsulated in PEG-modified cationic liposome, which was devoted into pharmacodynamic studies at both cellular and animal level. The results illustrated that the cationic liposome which encapsulated siRNA expression plasmid could effectively inhibit HBx gene expression both in vitro and in vivo.
Cations ; Gene Expression Regulation, Viral ; drug effects ; Hepatitis B virus ; genetics ; Liposomes ; chemistry ; Plasmids ; RNA, Small Interfering ; chemistry ; Trans-Activators ; genetics ; metabolism

Bombyx mori nucleopolyhedrovirus (BmNPV) bm47 gene is found in all sequenced lepidopteran nucleopolyhedroviruses (NPVs). It is one of the core genes of NPVs. However, the role of bm47 in the biological cycle of NPV remains unknown. In this study, the Red recombination system was used to knock out bm47 from BmNPV to construct bm47-ko-Bacmid in E. coli BW25113 system. Then bm47 gene was introduced back to the viral genome using the Bac-to-Bac system to create the repair virus bm47-re-Bacmid. TCID50 assay and real-time PCR (qPCR) were used to evaluate the effects of bm47 deletion on viral DNA replication, gene transcription, and protein expression. qPCR results showed that bm47 knock-out had no significant effect on viral DNA replication. However, the qPCR results showed that bm47-ko-Bacmid significantly decreased the transcription levels of early gene lef-3, late gene vp39, and very late gene p10 at 48 h and 72 h after viral transfection of BmN cells (P < 0.05). This work will provide a foundation for further studies on the biological function of BmNPV bm47 in viral replication and transcription.
Animals ; Bombyx ; virology ; Gene Deletion ; Gene Expression Regulation, Viral ; Nucleopolyhedrovirus ; genetics ; physiology ; Transcription, Genetic ; Viral Proteins ; genetics ; metabolism ; Virus Replication