Abstract:
:The human chemokine receptors CCR5 and CXCR4 have emerged as the predominant cofactors, along with CD4, for cellular entry of HIV-1 in vivo whereas the contribution of other chemokine receptors to HIV disease has not been yet determined. CCR5-specific (R5) viruses predominate during primary HIV-1 infection whereas viruses with specificity for CXCR4 (R5/X4 or X4 viruses) often emerge in late stages of HIV disease. The evolution of X4 viruses is associated with a rapid decline in CD4+ T cells, although a causative relationship between viral tropism and CD4+ T cell depletion has not yet been proven. To rigorously test this relationship, we assessed CD4+ T cell depletion in suspensions of human peripheral blood mononuclear cells and in explants of human lymphoid tissue on exposure to paired viruses that are genetically identical (isogenic) except for select envelope determinants specifying reciprocal tropism for CXCR4 or CCR5. In both systems, X4 HIV-1 massively depleted CD4+ lymphocytes whereas matched R5 viruses depleted such cells only mildly despite comparable viral replication kinetics. These findings demonstrate that the coreceptor specificities of HIV-1 are a causal factor in CD4+ T cell depletion ex vivo and strongly support the hypothesis that the evolution of viral envelope leading to usage of CXCR4 in vivo accelerates loss of CD4+ T cells, causing immunodeficiency.
journal_name
Proc Natl Acad Sci U S Aauthors
Penn ML,Grivel JC,Schramm B,Goldsmith MA,Margolis Ldoi
10.1073/pnas.96.2.663subject
Has Abstractpub_date
1999-01-19 00:00:00pages
663-8issue
2eissn
0027-8424issn
1091-6490journal_volume
96pub_type
杂志文章abstract::We demonstrate here that yeast killer viruses, previously thought to be transmitted only by cytoplasmic mixing during division, mating, or other induced forms of cell fusion, are capable of extracellular transmission. Viral particles from standard K1 and K2 killer strains were used to inoculate sensitive cells of Sacc...
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.84.12.4293
更新日期:1987-06-01 00:00:00
abstract::A sequence-specific single-stranded DNA-binding protein from the trypanosomatid protozoan Crithidia fasciculata binds to a sequence of 12 nucleotides located at the origin of replication of kinetoplast DNA minicircles. This sequence, termed the universal minicircle sequence (UMS), is conserved in the kinetoplast DNA m...
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.89.15.6891
更新日期:1992-08-01 00:00:00
abstract::We have cloned and partially characterized 24 loci from the human genome which are complementary to U1, U2, or U3, the three major species of small nuclear RNA (snRNA) in HeLa cells. When compared to the known U1 (human) and U2 (rat) snRNA sequences, the DNA sequences we report here for the complementary regions from ...
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.78.2.810
更新日期:1981-02-01 00:00:00
abstract::Although the applicability of small subunit ribosomal RNA (16S rRNA) sequences for bacterial classification is now well accepted, the general use of these molecules has been hindered by the technical difficulty of obtaining their sequences. A protocol is described for rapidly generating large blocks of 16S rRNA sequen...
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.82.20.6955
更新日期:1985-10-01 00:00:00
abstract::Photoadaptation, the ability to attenuate a light response on prolonged light exposure while remaining sensitive to escalating changes in light intensity, is essential for organisms to decipher time information appropriately, yet the underlying molecular mechanisms are poorly understood. In Neurospora crassa, VIVID (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.1011190107
更新日期:2010-09-21 00:00:00
abstract::Cryogenic fluorescent light microscopy of flash-frozen cells stands out by artifact-free fixation and very little photobleaching of the fluorophores used. To attain the highest level of resolution, aberration-free immersion objectives with accurately matched immersion media are required, but both do not exist for imag...
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.1717282115
更新日期:2018-02-06 00:00:00
abstract::CCAAT displacement protein (CDP), a nuclear protein of 180-190 kDa, contains a triplicated motif, the cut domain, similar (80-90% conserved) to three repeats of 60-65 amino acids first identified in Drosophila cut, a homeo-domain protein involved in cell-fate decisions in development. Cut repeats bind DNA and exhibit ...
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.91.16.7757
更新日期:1994-08-02 00:00:00
abstract::Duplexes of 21-nt RNAs, known as short-interfering RNAs (siRNAs), efficiently inhibit gene expression by RNA interference (RNAi) when introduced into mammalian cells. We show that siRNAs can be synthesized by in vitro transcription with T7 RNA polymerase, providing an economical alternative to chemical synthesis of si...
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.092143499
更新日期:2002-04-30 00:00:00
abstract::We prove that the property of excision in algebraic K-theory is for a Q-algebra A equivalent to the H-unitality of the latter. Our excision theorem, in particular, implies Karoubi's conjecture on the equality of algebraic and topological K-theory groups of stable C*-algebras. It also allows us to identify the algebrai...
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.87.24.9582
更新日期:1990-12-15 00:00:00
abstract::Ocular dominance (OD) plasticity in mouse primary visual cortex (V1) declines during postnatal development and is absent beyond postnatal day 110 if mice are raised in standard cages (SCs). An enriched environment (EE) promotes OD plasticity in adult rats. Here, we explored cellular mechanisms of EE in mouse V1 and th...
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.1313385111
更新日期:2014-01-21 00:00:00
abstract::An approach combining signal detection theory and precise 3D reconstructions from serial section electron microscopy (3DEM) was used to investigate synaptic plasticity and information storage capacity at medial perforant path synapses in adult hippocampal dentate gyrus in vivo. Induction of long-term potentiation (LTP...
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.1716189115
更新日期:2018-03-06 00:00:00
abstract::Like other guanine nucleotide-exchange proteins (GEPs) that activate ADP-ribosylation factor (ARF) GTPases, brefeldin A-inhibited GEP2, BIG2, contains an approximately 200-aa Sec7 domain that is responsible for this catalytic activity and its inhibition by brefeldin A. The Sec7 domain is located near the center of 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.0337678100
更新日期:2003-02-18 00:00:00
abstract::We have compared the efficiency of transformation by linear DNA fragments in yeast strains carrying different numbers of homologous targets for recombination. In strains carrying dispersed copies of a target and in strains carrying tandem arrays, the frequency of transformation is proportional to the number of targets...
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.91.1.177
更新日期:1994-01-04 00:00:00
abstract::In this study we compared the cellular concentrations and stability of the mRNA transcribed from the aprE (subtilisin) gene (a gene preferentially expressed in stationary growth phase) with those of a vegetative mRNA, succinate dehydrogenase (SDH) mRNA. The subtilisin transcript was shown to be at least 3 times more 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.87.21.8355
更新日期:1990-11-01 00:00:00
abstract::Familial multiple system tauopathy with presenile dementia (MSTD) is a neurodegenerative disease with an abundant filamentous tau protein pathology. It belongs to the group of familial frontotemporal dementias with Parkinsonism linked to chromosome 17 (FTDP-17), a major class of inherited dementing disorders whose gen...
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.95.13.7737
更新日期:1998-06-23 00:00:00
abstract::Pyramidal cells in piriform cortex receive excitatory inputs from two different sources that are segregated onto adjacent segments of their apical dendrites. The present studies show that excitatory postsynaptic potentials (EPSPs) evoked by primary olfactory tract afferents that terminate on distal apical segments dis...
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.83.4.1115
更新日期:1986-02-01 00:00:00
abstract::Swarming and mass migration are spectacular and sometimes devastating features of the biology of various animal species. These phenomena are typically associated with actual or anticipated depletion of food resources after an increase in population density, but the mechanisms driving such collective movements are poor...
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.0508915103
更新日期:2006-03-14 00:00:00
abstract::In this report we examine the effects of chronic anaerobic exposure and subsequent reoxygenation on protein synthesis patterns in Chinese hamster ovary cells. It is observed by two-dimensional gel electrophoresis (isoelectric focusing/NaDodSO4/PAGE) that the transition from an atmospheric environment to an anaerobic 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.81.15.4843
更新日期:1984-08-01 00:00:00
abstract::A somatic mutation in the X linked PIGA gene is responsible for the deficiency of glycosyl phosphatidylinositol (GPI)-anchored proteins on blood cells from patients with paroxysmal nocturnal hemoglobinuria. No inherited form of GPI-anchor deficiency has been described. Because conventional Piga gene knockout is associ...
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.96.13.7479
更新日期:1999-06-22 00:00:00
abstract::Renal cell carcinoma (RCC) and normal kidney tissues have been examined from 34 patients with sporadic, nonhereditary RCC. Eighteen of the 21 cytogenetically examined tumors (86%) had a detectable anomaly of chromosome arm 3p distal to band 3p11.2-p13, manifested as a deletion, combined with the nonreciprocal transloc...
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.85.5.1571
更新日期:1988-03-01 00:00:00
abstract::This paper describes experiments in which cytosolic Ca2+ concentrations ([Ca2+]i) and catecholamine release were measured in two populations of chromaffin cells stimulated with a solution enriched in K+ (100 mM). Once depolarized, external Ca2+ or Ba2+ ions were offered to cells either as a single 2.5 mM step or as a ...
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.90.8.3284
更新日期:1993-04-15 00:00:00
abstract::Because mouse models play a crucial role in biomedical research related to the human nervous system, understanding the similarities and differences between mouse and human brain is of fundamental importance. Studies comparing transcription in human and mouse have come to varied conclusions, in part because of their re...
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.0914257107
更新日期:2010-07-13 00:00:00
abstract::Almost all theoretical and experimental studies of the mechanisms underlying learning and memory focus on synaptic efficacy and make the implicit assumption that changes in synaptic efficacy are both necessary and sufficient to account for learning and memory. However, network dynamics depends on the complex interacti...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.93.24.13481
更新日期:1996-11-26 00:00:00
abstract::Networks are widely used in the biological, physical, and social sciences as a concise mathematical representation of the topology of systems of interacting components. Understanding the structure of these networks is one of the outstanding challenges in the study of complex systems. Here we describe a general techniq...
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.0610537104
更新日期:2007-06-05 00:00:00
abstract::There is now abundant evidence to substantiate an important role of hepatitis C virus (HCV) core protein in cellular gene expression as well as in the viral cycle. Thus the subcellular localization of this protein has important implications. However, several studies have shown controversial results: the HCV core has b...
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.94.4.1200
更新日期:1997-02-18 00:00:00
abstract::The antigen-presenting molecule MR1 presents riboflavin-based metabolites to Mucosal-Associated Invariant T (MAIT) cells. While MR1 egress to the cell surface is ligand-dependent, the ability of small-molecule ligands to impact on MR1 cellular trafficking remains unknown. Arising from an in silico screen of the MR1 li...
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.2003136117
更新日期:2020-05-12 00:00:00
abstract::Yawn contagion in humans has been proposed to be related to our capacity for empathy. It is presently unclear whether this capacity is uniquely human or shared with other primates, especially monkeys. Here, we show that in gelada baboons (Theropithecus gelada) yawning is contagious between individuals, especially thos...
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.0910891106
更新日期:2009-11-17 00:00:00
abstract::H-2M3 encodes HMT, the major histocompatibility complex (MHC) class I heavy chain of the maternally transmitted antigen (Mta). Like classical MHC class I genes, the expression of M3 can be stimulated by gamma-interferon and its message can be detected from mid-gestational embryos (day 8) through adulthood. HMTb, a non...
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.90.7.2784
更新日期:1993-04-01 00:00:00
abstract::A general model is proposed for genetic recombination. Its essential new feature is the hypothesis that recombination is initiated by a single-strand (or asymmetric) transfer, which may, after isomerization, become a two-strand (or symmetric) exchange. The likelihood of this transition from asymmetric to symmetric str...
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.72.1.358
更新日期:1975-01-01 00:00:00
abstract::Genetic data in the mouse have shown that endothelin 3 (ET3) and its receptor B (ETRB) are essential for the development of two neural crest (NC) derivatives, the melanocytes and the enteric nervous system. We report here the effects of ET3 in vitro on the differentiation of quail trunk NC cells (NCC) in mass and clon...
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.95.24.14214
更新日期:1998-11-24 00:00:00