Abstract:
:CD4+ T cells recognize major histocompatibility complex (MHC) class II-bound peptides that are primarily obtained from extracellular sources. Endogenously synthesized proteins that readily enter the MHC class I presentation pathway are generally excluded from the MHC class II presentation pathway. We show here that endogenously synthesized ovalbumin or hen egg lysozyme can be efficiently presented as peptide-MHC class II complexes when they are expressed as fusion proteins with the invariant chain (Ii). Similar to the wild-type Ii, the Ii-antigen fusion proteins were associated intracellularly with MHC molecules. Most efficient expression of endogenous peptide-MHC complex was obtained with fusion proteins that contained the endosomal targeting signal within the N-terminal cytoplasmic Ii residues but did not require the luminal residues of Ii that are known to bind MHC molecules. These results suggest that signals within the Ii can allow endogenously synthesized proteins to efficiently enter the MHC class II presentation pathway. They also suggest a strategy for identifying unknown antigens presented by MHC class II molecules.
journal_name
Proc Natl Acad Sci U S Aauthors
Sanderson S,Frauwirth K,Shastri Ndoi
10.1073/pnas.92.16.7217subject
Has Abstractpub_date
1995-08-01 00:00:00pages
7217-21issue
16eissn
0027-8424issn
1091-6490journal_volume
92pub_type
杂志文章abstract::Apolipoprotein E (apoE) secreted by macrophages in the artery wall exerts an important protective effect against the development of atherosclerosis, presumably through its ability to promote lipid efflux. Previous studies have shown that increases in cellular free cholesterol levels stimulate apoE transcription in mac...
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.021488798
更新日期:2001-01-16 00:00:00
abstract::To examine the role of breast cancer stem cells (BCSCs) in metastasis, we generated human-in-mouse breast cancer orthotopic models using patient tumor specimens, labeled with optical reporter fusion genes. These models recapitulate human cancer features not captured with previous models, including spontaneous metastas...
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.1006732107
更新日期:2010-10-19 00:00:00
abstract::Huntington's disease (HD) is a progressive neurodegenerative disorder caused by an expansion in the number of polyglutamine-encoding CAG repeats in the gene that encodes the huntingtin (htt) protein. A property of the mutant protein that is intimately involved in the development of the disease is the propensity 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.0408134101
更新日期:2004-12-21 00:00:00
abstract::Plasmacytoid dendritic cells (pDCs) are known mainly for their secretion of type I IFN upon viral encounter. We describe a CD2hiCD5+CD81+ pDC subset, distinguished by prominent dendrites and a mature phenotype, in human blood, bone marrow, and tonsil, which can be generated from CD34+ progenitors. These CD2hiCD5+CD81+...
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.1610630114
更新日期:2017-02-21 00:00:00
abstract::Synaptic competition is a basic feature of developing neural connections. To shed light on its dependence on the activity pattern of competing inputs, we investigated in vivo rat motoneuronal firing during late embryonic and early neonatal life, when synapse elimination occurs in muscle. Electromyographic recordings w...
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.202471199
更新日期:2002-10-01 00:00:00
abstract::The recent completion of the deletion of essentially all of the ORFs in yeast is an important new resource for identifying the phenotypes of unknown genes. Each ORF is replaced with a cassette containing unique tag sequences that allow rapid parallel analysis of strains in a pool by using hybridization to a high-densi...
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.231366398
更新日期:2001-10-23 00:00:00
abstract::Phosphorylation of ADP to ATP was induced in nonrespiring submitochondrial particles (SMP) from rat liver by the application of electric pulses with field strengths of 10-35 kV/cm and a decay time of 60 mus. In all cases respiration was inhibited completely by using cyanide or rotenone. Newly formed ATP was measured 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.78.12.7473
更新日期:1981-12-01 00:00:00
abstract::Inadequate target exposure is a major cause of high attrition in drug discovery. Here, we show that a label-free method for quantifying the intracellular bioavailability (Fic) of drug molecules predicts drug access to intracellular targets and hence, pharmacological effect. We determined Fic in multiple cellular assay...
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.1701848114
更新日期:2017-07-25 00:00:00
abstract::Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation of ...
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.1607745113
更新日期:2016-07-26 00:00:00
abstract::To investigate the earliest steps of the intrinsic clotting pathway, Hageman factor (Factor XII) was exposed to Sephadex gels to which ellagic acid had been adsorbed; Hageman factor was then separated from the gels and studied in the fluid phase. Sephadex-ellagic acid-exposed Hageman factor, whether purified or in pla...
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.76.2.958
更新日期:1979-02-01 00:00:00
abstract::The molecular nature of the cell surface-cytoskeleton interaction in microvilli isolated from ascites 13762 rat mammary adenocarcinoma sublines with immobile (MAT-C1) and mobile (MAT-B1) receptors was investigated by extraction and fractionation studies on the microvillar membranes. Extraction of membranes from MAT-C1...
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.80.2.430
更新日期:1983-01-01 00:00:00
abstract::We have previously reported the cloning, sequencing, and partial characterization of Kid-1, a zinc finger-encoding cDNA from the rat kidney. The Kid-1 protein and approximately one-third of all other zinc finger proteins contain a highly conserved region of approximately 75 amino acids at their NH2 terminus named Krüp...
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.91.10.4514
更新日期:1994-05-10 00:00:00
abstract::The formation and migration of disconnections (line defects constrained to the grain boundary [GB] plane with both dislocation and step character) control many of the kinetic and dynamical properties of GBs and the polycrystalline materials of which they are central constituents. We demonstrate that GBs undergo a fini...
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.2017390117
更新日期:2020-12-29 00:00:00
abstract::Chromosome translocations between Ig (Ig) and non-Ig genes are frequently associated with B-cell lymphomas in humans and mice. The best characterized of these is c-myc/IgH translocation, which is associated with Burkitt's lymphoma. These translocations are caused by activation-induced cytidine deaminase (AID), which p...
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.0908946107
更新日期:2010-01-05 00:00:00
abstract::All of the heme-degrading enzymes that have been characterized to date require molecular oxygen as a cosubstrate. Escherichia coli O157:H7 has been shown to express heme uptake and transport proteins, as well as use heme as an iron source. This enteric pathogen colonizes the anaerobic space of the lower intestine in 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.1603209113
更新日期:2016-10-25 00:00:00
abstract::We have investigated the mycorrhizal associations of two nonphotosynthetic orchids from distant tribes within the Orchidaceae. The two orchids were found to associate exclusively with two distinct clades of ectomycorrhizal basidiomycetous fungi over wide geographic ranges. Yet both orchids retained the internal mycorr...
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.94.9.4510
更新日期:1997-04-29 00:00:00
abstract::Noncanonical DNA structures that stall DNA replication can cause errors in genomic DNA. Here, we investigated how the noncanonical structures formed by sequences in genes associated with a number of diseases impacted DNA polymerization by the Klenow fragment of DNA polymerase. Replication of a DNA sequence forming an ...
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.1704258114
更新日期:2017-09-05 00:00:00
abstract::We used 5,6-dichloro-beta D-ribofuranosyl-benzimidazole (DRB), a selective and reversible inhibitor of mRNA production, to investigate the regulation of the pathway leading to resistance to viruses in cells treated with interferon (IF). DRB allows initiation of transcription but promotes premature termination of the n...
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.77.1.452
更新日期:1980-01-01 00:00:00
abstract::X-linked dystonia-parkinsonism (XDP) is a neurodegenerative disease associated with an antisense insertion of a SINE-VNTR-Alu (SVA)-type retrotransposon within an intron of TAF1 This unique insertion coincides with six additional noncoding sequence changes in TAF1, the gene that encodes TATA-binding protein-associated...
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.1712526114
更新日期:2017-12-19 00:00:00
abstract::Argonaute and Piwi proteins are key players in the RNA silencing pathway, with the former interacting with micro-RNAs (miRNAs) and siRNAs, whereas the latter targets piwi-interacting RNAs (piRNAs) that are 2'-O-methylated (2(')-OCH(3)) at their 3' ends. Germline-specific piRNAs and Piwi proteins play a critical role i...
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.1017762108
更新日期:2011-01-18 00:00:00
abstract::Antigenic variation of infectious organisms is a major factor in evasion of the host immune response. However, there has been no definitive demonstration of this phenomenon in the malaria parasite Plasmodium falciparum. In this study, cloned parasites were examined serologically and biochemically for the expression of...
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.88.20.9171
更新日期:1991-10-15 00:00:00
abstract::Depending on the cellular context, BCL2-like proteins promote mitochondrial fusion or fission. What determines which of these two opposing processes they promote has so far been unknown. Furthermore, the mechanisms through which BCL2-like proteins affect mitochondrial dynamics remain to be fully understood. The BCL2-l...
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.1103218108
更新日期:2011-10-11 00:00:00
abstract::Toll-like receptor 3 (TLR3) is a key effector of the innate immune system against viruses. Activation of TLR3 exerts an antitumoral effect through a mechanism of action still poorly understood. Here we show that TLR3 activation by polyinosinic:polycytidylic acid induces up-regulation of microRNA-29b, -29c, -148b, and ...
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.1304610110
更新日期:2013-06-11 00:00:00
abstract::The matrix of second derivatives of 21 apparent local energy minima of deca-L-alanine has been computed. The results show that all these conformations are true local energy minima and, therefore, potentially stable conformations for this peptide. Calculations of the relative statistical weights of these conformations ...
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.63.2.242
更新日期:1969-06-01 00:00:00
abstract::Stress can either promote or impair learning and memory. Such opposing effects depend on whether synapses persist or decay after learning. Maintenance of new synapses formed at the time of learning upon neuronal network activation depends on the stress hormone-activated glucocorticoid receptor (GR) and neurotrophic fa...
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.1903203116
更新日期:2019-06-25 00:00:00
abstract::The enzymic activity of crystalline mitochondrial aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1) was determined in suspensions of noncrosslinked microcrystals in 30% (wt/vol) polyethylene glycol. The crystals (average dimensions, 22 x 5 x 0.8 micron) were small enough to preclude ...
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.80.7.1807
更新日期:1983-04-01 00:00:00
abstract::This paper reviews food (especially cereal) production trends and prospects for the world and its main regions. Despite fears to the contrary, in recent years we have seen continued progress toward better methods of feeding humanity. Sub-Saharan Africa is the sole major exception. Looking to the future, this paper arg...
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.96.11.5929
更新日期:1999-05-25 00:00:00
abstract::The feasibility of long-term information storage by brain type II Ca2+/calmodulin-dependent protein kinase molecules is explored. Recent evidence indicates that this protein has switch-like properties. Equations are derived showing that a single kinase holoenzyme could form a bistable switch having the stability neces...
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.85.14.5320
更新日期:1988-07-01 00:00:00
abstract::DNA origami enables the precise fabrication of nanoscale geometries. We demonstrate an approach to engineer complex and reversible motion of nanoscale DNA origami machine elements. We first design, fabricate, and characterize the mechanical behavior of flexible DNA origami rotational and linear joints that integrate 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.1408869112
更新日期:2015-01-20 00:00:00
abstract::The transmission of complexity during DNA replication has been investigated to clarify the significance of this molecular property in a deterministic process. Complexity was equated with the amount of randomness within an ordered molecular structure and measured by the entropy of a posteriori probabilities for discret...
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.76.5.2288
更新日期:1979-05-01 00:00:00