Abstract:
:We have previously shown that hepatitis B virus (HBV) replication is controlled by noncytolytic mechanisms that depend primarily on the effector functions of the CD8(+) T cell response, especially the production of IFN-gamma in the liver. The mechanisms that control the nuclear pool of viral covalently closed circular DNA (cccDNA) transcriptional template of HBV, which must be eliminated to eradicate infection, have been difficult to resolve. To examine those mechanisms, we quantitated intrahepatic HBV cccDNA levels in acutely infected chimpanzees whose virological, immunological, and pathological features were previously described. Our results demonstrate that the elimination kinetics of the cccDNA are more rapid than the elimination of HBV antigen-positive hepatocytes during the early phase of viral clearance, and they coincide with the influx of small numbers of IFN-gamma producing CD8(+) T cells into the liver. In contrast, terminal clearance of the cccDNA is associated with the peak of liver disease and hepatocellular turnover and with a surge of IFN-gamma producing CD8(+) T cells in the liver. Collectively, these results suggest that cccDNA clearance is a two-step process mediated by the cellular immune response. The first step reduces the pool of cccDNA molecules noncytolytically, probably by eliminating their relaxed circular DNA precursors and perhaps by destabilizing them. The second step enhances this process by destroying infected hepatocytes and triggering their turnover. Surprisingly, despite this multipronged response, traces of cccDNA persist indefinitely in the liver, likely providing a continuous antigenic stimulus that confers lifelong immunity.
journal_name
Proc Natl Acad Sci U S Aauthors
Wieland SF,Spangenberg HC,Thimme R,Purcell RH,Chisari FVdoi
10.1073/pnas.0308478100keywords:
subject
Has Abstractpub_date
2004-02-17 00:00:00pages
2129-34issue
7eissn
0027-8424issn
1091-6490pii
0308478100journal_volume
101pub_type
杂志文章abstract::Polyadenylylated RNA synthesized after heat shock was isolated from polysomes of cultured cells of Drosophila melanogaster and used as template to prepare cDNA. An excess of poly(A)-RNA from heat-shocked cells hybridized to 80% of the cDNA, whereas cytoplasmic poly(A)-RNA from cells grown at 25 degrees could drive onl...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.2.759
更新日期:1978-02-01 00:00:00
abstract::Human pluripotent stem cells have the potential to provide comprehensive model systems for the earliest stages of human ontogenesis. To serve in this capacity, these cells must undergo a targeted, stepwise differentiation process that follows a normal developmental timeline. Here we demonstrate the ability of both hum...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0905245106
更新日期:2009-09-29 00:00:00
abstract::Blood viscosity decreases with shear stress, a property essential for an efficient perfusion of the vascular tree. Shear thinning is intimately related to the dynamics and mutual interactions of RBCs, the major component of blood. Because of the lack of knowledge about the behavior of RBCs under physiological conditio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1608074113
更新日期:2016-11-22 00:00:00
abstract::Understanding protein-protein interactions is central to our understanding of almost all complex biological processes. Computational tools exploiting rapidly growing genomic databases to characterize protein-protein interactions are urgently needed. Such methods should connect multiple scales from evolutionary conserv...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1607570113
更新日期:2016-10-25 00:00:00
abstract::The plasmid construct pSVO-CAT has been used to test adenovirus promoter activities in the unmethylated or methylated state. We have now observed that the E2A late promoter of adenovirus type 2 (Ad2) DNA also activated the chloramphenicol acetyltransferase (CAT) gene upon transfection of the pAd2E2A-CAT construct into...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.6.1598
更新日期:1986-03-01 00:00:00
abstract::Mitochondrial DNAs were prepared from maize lines with normal cytoplasm and with the T, C, S, and EP sources of male-sterile cytoplasms. Agarose gel electrophoresis of these preparations revealed a main high-molecular-weight DNA band. In addition, the S cytoplasm was characterized by the presence of two faster migrati...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.7.2904
更新日期:1977-07-01 00:00:00
abstract::Coxiella burnetti, the etiologic agent of Q fever, is an oligate intracellular parasite of eukaryotes. Unlike the majority of successful bacterial parasites, which escape the bactericidal environment of the phagolysosome by various means, C. burnetii multiplies only in the phagolysosome. In view of the relatively hars...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.5.3240
更新日期:1981-05-01 00:00:00
abstract::Viral infection leads to activation of the transcription factors interferon regulatory factor-3 and NF-kappaB, which collaborate to induce type I IFNs. The RNA helicase proteins RIG-I and MDA5 were recently identified as two cytoplasmic viral RNA sensors that recognize different species of viral RNAs produced during v...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0700544104
更新日期:2007-07-10 00:00:00
abstract::The phosphorylation of protein I, a specific neuronal protein, has been found to be regulated both by cyclic AMP (cAMP) and by calcium, in intact as well as in lysed synaptosome preparations from rat brain. In order to determine the phosphorylation site(s) of protein I that were regulated by cAMP and calcium, protein ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.10.5402
更新日期:1979-10-01 00:00:00
abstract::Whole-genome duplication (WGD) is believed to be a significant source of major evolutionary innovation. Redundant genes resulting from WGD are thought to be lost or acquire new functions. However, the rates of gene loss and thus temporal process of genome reshaping after WGD remain unclear. The WGD shared by all teleo...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1507669112
更新日期:2015-12-01 00:00:00
abstract::Streptococcus pneumoniae is a major human pathogen that successfully adapts to the host environment via an efficient uptake system for free DNA liberated from other organisms in the upper respiratory tract, facilitating immune evasion and drug resistance. Although the initial signaling events leading to pneumococcal c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1313860111
更新日期:2014-02-18 00:00:00
abstract::A paradox in bone tissue is that tissue-level strains due to animal and human locomotion are too small to initiate intracellular chemical responses directly. A model recently was proposed to resolve this paradox, which predicts that the fluid flow through the pericellular matrix in the lacunar-canalicular porosity due...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0407429101
更新日期:2004-11-23 00:00:00
abstract::Alzheimer's disease (AD) is an irreversible neurodegenerative disorder that has a progression that is closely associated with oxidative stress. It has long been speculated that the reactive oxygen species (ROS) level in AD brains is much higher than that in healthy brains. However, evidence from living beings is scarc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1706248114
更新日期:2017-11-21 00:00:00
abstract::Sea urchins are a major component of recent marine communities where they exert a key role as grazers and benthic predators. However, their impact on past marine organisms, such as crinoids, is hard to infer in the fossil record. Analysis of bite mark frequencies on crinoid columnals and comprehensive genus-level dive...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.1201573109
更新日期:2012-05-01 00:00:00
abstract::cDNA clones encoding a glutamic acid-rich protein were isolated from a bovine retina cDNA expression library. The cDNA sequence contained an open reading frame of 1770 base pairs encoding a protein of 590 amino acids (64,509 Da) and untranslated regions of 60 and 490 base pairs at the 5' and 3' ends, respectively. The...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.8.3116
更新日期:1991-04-15 00:00:00
abstract::Excessive poly(ADP-ribose) (PAR) polymerase-1 (PARP-1) activation kills cells via a cell-death process designated "parthanatos" in which PAR induces the mitochondrial release and nuclear translocation of apoptosis-inducing factor to initiate chromatinolysis and cell death. Accompanying the formation of PAR are the red...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1405158111
更新日期:2014-07-15 00:00:00
abstract::1,N(6)-Ethenoadenosine triphosphate (epsilon-ATP) has been found to be inactive as a substrate for firefly luciferase. However, chemically synthesized luciferyl-epsilonAMP is oxidized by luciferase and light is emitted. The color of the light is red in contrast to the normal yellow-green observed with luciferyladenyla...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.70.6.1664
更新日期:1973-06-01 00:00:00
abstract::C1q, a member of the immune complement cascade, is implicated in the selective pruning of synapses by microglial phagocytosis. C1q-mediated synapse elimination has been shown to occur during brain development, while increased activation and complement-dependent synapse loss is observed in neurodegenerative diseases. H...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1722613115
更新日期:2018-06-12 00:00:00
abstract::Many cortical neurons combine the information ascending and descending the cortical hierarchy. In the classical view, this information is combined nonlinearly to give rise to a single firing-rate output, which collapses all input streams into one. We analyze the extent to which neurons can simultaneously represent mul...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1720995115
更新日期:2018-07-03 00:00:00
abstract::It is possible, by using Fourier-transform infrared (FTIR) difference spectroscopy, to detect the conformational changes occurring in both the protein and the chromophore of bacteriorhodopsin during the photocycle. In contrast to Raman spectroscopy, a laser is unnecessary and hence the problem of a perturbing probe be...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.13.4045
更新日期:1982-07-01 00:00:00
abstract::Combinatorial antibody libraries have the potential to display the entire immunological record of an individual, allowing one to detect and recover any antibody ever made, irrespective of whether it is currently being produced. We have termed this the "fossil record" of an individual's antibody response. To determine ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0407869101
更新日期:2004-12-07 00:00:00
abstract::Pyrimethamine (Pyr) targets dihydrofolate reductase of Plasmodium vivax (PvDHFR) as well as other malarial parasites, but its use as antimalarial is hampered by the widespread high resistance. Comparison of the crystal structures of PvDHFR from wild-type and the Pyr-resistant (SP21, Ser-58 --> Arg + Ser-117 --> Asn) s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0501747102
更新日期:2005-09-13 00:00:00
abstract::Five recombinant DNA plasmids have been constructed that contain structural gene sequences for rat tyrosine hydroxylase [TyrOHase; tyrosine 3-monooxygenase; L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2]. Rat pheochromocytoma PC 12 cell line, which contains relatively high level...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.12.3881
更新日期:1982-06-01 00:00:00
abstract::The Watson-Crick model for DNA duplex duplication proposes that the two parental chains separate and that each directs the synthesis of a complementary chain with which it is found associated after the duplication act. Previous experiments have left unchallenged alternative models which propose that in any single act ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.65.2.363
更新日期:1970-02-01 00:00:00
abstract::Nuclear lamins are components of the nuclear lamina, a structural scaffolding for the cell nucleus. Defects in lamins A and C cause an array of human diseases, including muscular dystrophy, lipodystrophy, and progeria, but no diseases have been linked to the loss of lamins B1 or B2. To explore the functional relevance...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0908790107
更新日期:2010-03-16 00:00:00
abstract::A mutant subline of V79 Chinese hamster cells resistant to antimycin A (ANT) was obtained by treatment with ethyl methanesulfonate followed by serial selection in ANT-containing medium. Clonal derivatives of the resistant line are less susceptible than parent cells to growth inhibition by ANT in mass populations and s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.11.5604
更新日期:1978-11-01 00:00:00
abstract::Although most nuclear hormone receptors are ligand-dependent transcriptional activators, certain members of this superfamily, such as thyroid hormone receptor (TR) and retinoic acid receptor (RAR), are involved in transcriptional repression. The silencing function of these receptors has been localized to the ligand bi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.25.11691
更新日期:1995-12-05 00:00:00
abstract::Chlorophyll d-producing cyanobacteria are a recently described group of phototrophic bacteria that is a major focus of photosynthesis research, previously known only from marine environments in symbiosis with eukaryotes. We have discovered a free-living member of this group from a eutrophic hypersaline lake. Phylogene...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0405667102
更新日期:2005-01-18 00:00:00
abstract::Fatty acid compositions of phospholipids of heart, liver, kidney, aorta, and serum from rats having streptozotocin-induced diabetes were determined and compared with those of nondiabetic controls. Linoleic and dihomo-gamma-linolenic acids were increased whereas arachidonic acid was decreased in most tissues, suggestin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.80.8.2375
更新日期:1983-04-01 00:00:00
abstract::Ammonium sulfate fractionation of crude extracts of E. coli yields a soluble enzyme fraction (about 25-fold purification) that catalyzes the conversion of phiX174 single-stranded DNA to duplex DNA. The reaction is rifampicin-resistant, requires single-stranded DNA, Mg++, deoxynucleoside triphosphates, and ATP, and is ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.72.10.3907
更新日期:1975-10-01 00:00:00