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

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

To construct a recombinant T7 phage expressing matrix protein 2 ectodomain (M2e) peptides of avian influenza A virus and test immunological and protective efficacy in the immunized SPF chickens. M2e gene sequence was obtained from Genbank and two copies of M2e gene were artificially synthesised, the M2e gene was then cloned into the T7 select 415-1b phage in the multiple cloning sites to construct the recombinant phage T7-M2e. The positive recombinant phage was identified by PCR and sequencing, and the expression of surface fusion protein was confirmed by SDS-PAGE and Western-blot. SPF chickens were subcutaneously injected with 1 X 10(10) pfu phage T7-M2e, sera samples were collected pre- and post-vaccination, and were tested for anti-M2e antibody by ELISA. The binding capacity of serum to virus was also examined by indirect immunofluorescence assay in virus- infected CEF. The immunized chickens were challenged with 200 EID50 of H9 type avian influenza virus and viral isolation rate was calculated to evaluate the immune protective efficacy. A recombinant T7 phage was obtained displaying M2e peptides of avian influenza A virus, and the fusion protein had favorable immunoreactivity. All chickens developed a certain amount of anti-M2e antibody which could specially bind to the viral particles. In addition, the protection efficacy of phage T7-M2e vaccine against H9 type avian influenza viruses was 4/5 (80%). These results indicate that the recombinant T7 phage displaying M2e peptides of avian influenza A virus has a great potential to be developed into a novel vaccine for the prevention of avian influenza infection.
Animals ; Antibodies, Viral ; blood ; Bacteriophage T7 ; genetics ; immunology ; metabolism ; Chickens ; Enzyme-Linked Immunosorbent Assay ; Gene Expression Regulation, Viral ; Immunization ; Influenza A virus ; genetics ; immunology ; Influenza Vaccines ; immunology ; Influenza in Birds ; immunology ; metabolism ; prevention & control ; Peptides ; genetics ; immunology ; metabolism ; Polymerase Chain Reaction ; Recombinant Fusion Proteins ; Specific Pathogen-Free Organisms ; Viral Matrix Proteins ; genetics ; immunology ; metabolism

Rabbit hemorrhagic disease (RHD) is contagious and highly lethal. Commercial vaccines against RHD are produced from the livers of experimentally infected rabbits. Although several groups have reported that recombinant subunit vaccines against rabbit hemorrhagic disease virus (RHDV) are promising, application of the vaccines has been restricted due to high production costs or low yield. In the present study, we performed codon optimization of the capsid gene to increase the number of preference codons and eliminate rare codons in Spodoptera frugiperda 9 (Sf9) cells. The capsid gene was then subcloned into the pFastBac plasmid, and the recombinant baculoviruses were identified with a plaque assay. As expected, expression of the optimized capsid protein was markedly increased in the Sf9 cells, and the recombinant capsid proteins self-assembled into virus-like particles (VLPs) that were released into the cell supernatant. Rabbits inoculated with the supernatant and the purified VLPs were protected against RHDV challenge. A rapid, specific antibody response against RHDV was detected by an ELISA in all of the experimental groups. In conclusion, this strategy of producing a recombinant subunit vaccine antigen can be used to develop a low-cost, insect cell-derived recombinant subunit vaccine against RHDV.
Animals ; Antigens, Viral/genetics/metabolism ; Caliciviridae Infections/prevention & control/*veterinary/virology ; Capsid Proteins/*genetics/metabolism ; Cell Culture Techniques/*methods ; Codon/genetics/metabolism ; Enzyme-Linked Immunosorbent Assay/veterinary ; *Gene Expression Regulation, Viral ; Hemorrhagic Disease Virus, Rabbit/*genetics/immunology ; *Rabbits ; Recombinant Proteins/genetics/metabolism ; Sf9 Cells ; Spodoptera ; Viral Structural Proteins/*genetics/metabolism ; Viral Vaccines/genetics/immunology

Human papillomavirus (HPV)-induced cervical cancer is the second most common cancer among women worldwide. Despite the encouraging development of the preventive vaccine for HPV, a vaccine for both prevention and therapy or pre-cancerous lesions remains in high priority. Thus far, most of the HPV therapeutic vaccines are focused on HPV E6 and E7 oncogene. However these vaccines could not completely eradicate the lesions. Recently, HPV E5, which is considered as an oncogene, is getting more and more attention. In this study, we predicted the epitopes of HPV16 E5 by bioinformatics as candidate peptide, then, evaluated the efficacy and chose an effective one to do the further test. To evaluate the effect of vaccine, rTC-1 (TC-1 cells infected by rAAV-HPV16E5) served as cell tumor model and rTC-1 loading mice as an ectopic tumor model. We prepared vaccine by muscle injection. The vaccine effects were determined by evaluating the function of tumor-specific T cells by cell proliferation assay and ELISPOT, calculating the tumor volume in mice and estimating the survival time of mice. Our in vitro and in vivo studies revealed that injection of E5 peptide+CpG resulted in strong cell-mediated immunity (CMI) and protected mice from tumor growth, meanwhile, prolonged the survival time after tumor cell loading. This study provides new insights into HPV16 E5 as a possible target on the therapeutic strategies about cervical cancer.
Adult ; Aged ; Amino Acid Sequence ; Animals ; Cancer Vaccines ; administration & dosage ; immunology ; Cell Line ; Cell Line, Tumor ; Dependovirus ; genetics ; Female ; Gene Expression Regulation, Viral ; immunology ; Genetic Vectors ; genetics ; Human papillomavirus 16 ; genetics ; immunology ; Humans ; Mice ; Mice, Inbred C57BL ; Middle Aged ; Neoplasms, Experimental ; immunology ; prevention & control ; virology ; Oncogene Proteins, Viral ; genetics ; immunology ; Papillomavirus Infections ; immunology ; prevention & control ; virology ; Papillomavirus Vaccines ; administration & dosage ; immunology ; Survival Analysis ; T-Lymphocytes ; immunology ; metabolism ; Tumor Burden ; immunology ; Uterine Cervical Neoplasms ; immunology ; prevention & control ; virology ; Vaccines, Subunit ; administration & dosage ; immunology

Heat shock protein 27 (HSP27) is a member of the small heat shock proteins (sHSP) and has multiple functions, it also plays an important role in the life cycle of some viruses. To investigate the regulatory effect of HSP27 during influenza virus infection, we cloned and expressed human HSP27 in both prokaryotic and eukaryotic cells, and demonstrated that HSP27 interacted with influenza A virus NS1 protein both in vivo and in vitro. Luciferase assay showed that HSP27 inhibited the expression of interferon-beta (IFN-beta) in infected cells, and independent of its phosphorylation. Moreover, HSP27 enhanced the inhibitory effect of NS1 on the expression of IFN-beta. Further analysis indicated that HSP27 exerted the inhibitory effect probably through influencing MDA5 of the RIG-I like helicase (RLH) pathway. The results suggested that HSP27 play a role in the innate immunity of infected cells, contributed to our understanding of the regulatory effect of host factors during influenza virus infection.
Cell Line ; Gene Expression Regulation, Viral ; HEK293 Cells ; HSP27 Heat-Shock Proteins ; genetics ; pharmacology ; Humans ; Influenza, Human ; genetics ; immunology ; Interferon-beta ; antagonists & inhibitors ; metabolism ; Viral Nonstructural Proteins ; genetics ; pharmacology

Foamy virus can establish lifelong persistent infection in mammal hosts without inducing diseases. Such special characteristic stimulates the interests of researchers. As reported, the accessory protein Bet of foamy virus could regulate the gene expression and infection cycle of foamy virus and take part in the generation of chronic viral infection. And also, Bet might prevent the host cellular defense factor APO-BEC3 from interfering the replication of virus and play a role in maintaining viral persistent infection. In order to elucidate the roles of Bet in the foamy virus replication and infection, this review summarized the research progress of Bet protein reported in recent years.
Animals ; Gene Expression Regulation, Viral ; Humans ; Retroviridae Infections ; immunology ; virology ; Retroviridae Proteins ; genetics ; metabolism ; Spumavirus ; genetics ; metabolism

Contagious ecthyma (also known as orf) is an acute skin zoonosis caused by orf virus (ORFV), which affects sheep, goats and humans. As one of the typical species of the Parapoxvirus genus of the Poxviridae family, orf virus has distinctive and unique characteristics of these species. A range of immuno-modulatory/pathogenesis -related genes acquired by virus that function is to limit (at least transiently) the effectiveness of host immunity during its evolution. This review is aimed to describe the latest progress on the molecular characteristics of ORFV, and upon which we analyzed molecular mechanism of the immune escape designed and a set of strategies developed for ORFV to effective against immune clearance of the host. Known as an essential component in evolutionary system, host is regulated by ORFV for using in population evolution. By the ORFV evolutional immune regulation components and its effect approach, we can understand the viral biological characteristics of ORFV, and it is helpful for us to further study the counter-measures of this disease.
Animals ; Ecthyma, Contagious ; immunology ; virology ; Gene Expression Regulation, Viral ; Immune Evasion ; Orf virus ; genetics ; immunology ; Viral Proteins ; genetics ; immunology

Coxsackievirus Infections ; immunology ; virology ; Enterovirus A, Human ; physiology ; Enterovirus Infections ; immunology ; virology ; Gene Expression Regulation ; immunology ; Gene Expression Regulation, Viral ; Host-Pathogen Interactions ; immunology ; Humans

Gene Expression Regulation ; immunology ; Gene Expression Regulation, Viral ; HIV Infections ; genetics ; immunology ; metabolism ; HIV-1 ; genetics ; immunology ; Humans ; Immunity, Innate ; genetics ; immunology