bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytokine Imbalance after Measles Virus Infection Has No Correlation with Immune Suppression
Authors: Carsillo Mary , Klapproth Kay , Niewiesk Stefan 
Published: May 2009

ABSTRACTMeasles virus infection leads to immune suppression. A potential mechanism is the reduction of interleukin 12 (IL-12) secretion during acute measles, resulting in a TH2 response. Studies in humans have reported conflicting results, detecting either a TH2 or a TH1 response. We have investigated the correlation between a TH2 response and immune suppression in specific-pathogen-free inbred cotton rats which were infected with measles vaccine and wild-type viruses. After infection of bone marrow-derived macrophages with wild-type virus, IL-12 secretion was reduced in contrast to the level for vaccine virus infection. In bronchoalveolar lavage cells, IL-12 secretion was suppressed after infection with both wild-type and vaccine virus on days 2, 4, and 6 and was detectable on days 8 and 10. After stimulation of mediastinal lymph node and spleen cells with UV-inactivated measles virus at various time points after infection, gamma interferon but no IL-4 was found. After stimulation with phorbol myristate acetate-ionomycin, high gamma interferon and low IL-4 levels were detected. To investigate whether the secretion of IL-4 contributes to immune suppression, a recombinant vaccine virus was created which secretes cotton rat IL-4. After infection with this recombinant virus, IL-4 secretion was enhanced. However, neither inhibition of concanavalin A-stimulated spleen cells nor keyhole limpet hemocyanin-specific proliferation of spleen cells was altered after infection with the recombinant virus in comparison to the levels with the parental virus. Our data indicate that measles virus infection leads to a decrease in IL-12 secretion and an increase in IL-4 secretion, but this does not seem to correlate with immune suppression.
The RING Domain and the L79 Residue of Z Protein Are Involved in both the Rescue of Nucleocapsids and the Incorporation of Glycoproteins into Infectious Chimeric Arenavirus-Like Particles
Authors: Casabona Juan Cruz , Levingston Macleod Jesica M. , Loureiro Maria Eugenia , Gomez Guillermo A. , Lopez Nora 
Published: May 2009

ABSTRACT
Arenaviruses, such as Tacaribe virus (TacV) and its closely related pathogenic Junin virus (JunV), are enveloped viruses with a bipartite negative-sense RNA genome that encodes the nucleocapsid protein (N), the precursor of the envelope glycoprotein complex (GP), the polymerase (L), and a RING finger protein (Z), which is the driving force of arenavirus budding. We have established a plasmid-based system which allowed the successful packaging of TacV-like nucleocapsids along with Z and GP of JunV into infectious virus-like particles (VLPs). By coexpressing different combinations of the system components, followed by biochemical analysis of the VLPs, the requirements for the assembly of both N and GP into particles were defined. We found that coexpression of N with Z protein in the absence of minigenome and other viral proteins was sufficient to recruit N within lipid-enveloped Z-containing VLPs. In addition, whereas GP was not required for the incorporation of N, coexpression of N substantially enhanced the ratio of GP to Z into VLPs. Disruption of the RING structure or mutation of residue L79 to alanine within Z protein, although it had no effect on Z self-budding, severely impaired VLP infectivity. These mutations drastically altered intracellular Z-N interactions and the incorporation of both N and GP into VLPs. Our results support the conclusion that the interaction between Z and N is required for assembly of both the nucleocapsids and the glycoproteins into infectious arenavirus budding particles.
Comparison of the Pseudorabies Virus Us9 Protein with Homologs from Other Veterinary and Human Alphaherpesviruses
Authors: Lyman M. G. , Kemp C. D. , Taylor M. P. , Enquist L. W. 
Published: May 2009

ABSTRACT

Pseudorabies virus (PRV) Us9 is a small, tail-anchored (TA) membrane protein that is essential for axonal sorting of viral structural proteins and is highly conserved among other members of the alphaherpesvirus subfamily. We cloned the Us9 homologs from two human pathogens, varicella-zoster virus (VZV) and herpes simplex virus type 1 (HSV-1), as well as two veterinary pathogens, equine herpesvirus type 1 (EHV-1) and bovine herpesvirus type 1 (BHV-1), and fused them to enhanced green fluorescent protein to examine their subcellular localization and membrane topology. Akin to PRV Us9, all of the Us9 homologs localized to the
trans
-Golgi network and had a type II membrane topology (typical of TA proteins). Furthermore, we examined whether any of the Us9 homologs could compensate for the loss of PRV Us9 in anterograde, neuron-to-cell spread of infection in a compartmented chamber system. EHV-1 and BHV-1 Us9 were able to fully compensate for the loss of PRV Us9, whereas VZV and HSV-1 Us9 proteins were unable to functionally replace PRV Us9 when they were expressed in a PRV background.
Elucidating and Minimizing the Loss by Recombinant Vaccinia Virus of Human Immunodeficiency Virus Gene Expression Resulting from Spontaneous Mutations and Positive Selection
Authors: Wyatt Linda S. , Earl Patricia L. , Xiao Wei , Americo Jeffrey L. , Cotter Catherine A. , Vogt Jennifer , Moss Bernard 
Published: May 2009

ABSTRACT

While characterizing modified vaccinia virus recombinants (rMVAs) containing human immunodeficiency virus
env
and
gag
-
pol
genes, we detected nonexpressing mutants by immunostaining individual plaques. In many cases, the numbers of mutants increased during successive passages, indicating strong selection pressure. This phenomenon provided an opportunity to investigate the formation of spontaneous mutations in vaccinia virus, which encodes its own cytoplasmic replication system, and a challenge to reduce the occurrence of mutations for vaccine production. Analysis of virus from individual plaques indicated that loss of expression was due to frameshift mutations, mostly by addition or deletion of a single nucleotide in runs of four to six Gs or Cs, and large deletions that included MVA DNA flanking the recombinant gene. Interruption of the runs of Gs and Cs by silent codon alterations and moving the recombinant gene to a site between essential, highly conserved MVA genes eliminated or reduced frameshifts and viable deletion mutants, respectively. The rapidity at which nonexpressing mutants accumulated depended on the individual
env
and
gag
-
pol
genes and their suppressive effects on virus replication. Both the extracellular and transmembrane domains contributed to the selection of nonexpressing Env mutants. Stability of an unstable Env was improved by swapping external or transmembrane domains with a more stable Env. Most dramatically, removal of the transmembrane and cytoplasmic domains stabilized even the most highly unstable Env. Understanding the causes of instability and taking preemptive actions will facilitate the development of rMVA and other poxviruses as human and veterinary recombinant vaccines.
Genetic Characterization of Hepatitis B Virus in Peripheral Blood Leukocytes: Evidence for Selection and Compartmentalization of Viral Variants with the Immune Escape G145R Mutation
Authors: Datta Sibnarayan , Panigrahi Rajesh , Biswas Avik , Chandra Partha K. , Banerjee Arup , Mahapatra Pradip K. , Panda Chinmoy K. , Chakrabarti Shekhar , Bhattacharya Sujit K. , Biswas Kuntal , Chakravarty Runu 
Published: May 2009

ABSTRACTThe compartmentalization of viral variants in distinct host tissues is a frequent event in many viral infections. Although hepatitis B virus (HBV) classically is considered hepatotropic, it has strong lymphotropic properties as well. However, unlike other viruses, molecular evolutionary studies to characterize HBV variants in compartments other than hepatocytes or sera have not been performed. The present work attempted to characterize HBV sequences from the peripheral blood leukocytes (PBL) of a large set of subjects, using advanced molecular biology and computational methods. The results of this study revealed the exclusive compartmentalization of HBV subgenotype Ae/A2-specific sequences with a potent immune escape G145R mutation in the PBL of the majority of the subjects. Interestingly, entirely different HBV genotypes/subgenotypes (C, D, or Aa/A1) were found to predominate in the sera of the same study populations. These results suggest that subgenotype Ae/A2 is selectively archived in the PBL, and the high prevalence of G145R indicates high immune pressure and high evolutionary rates of HBV DNA in the PBL. The results are analogous to available literature on the compartmentalization of other viruses. The present work thus provides evidence in favor of the compartment-specific abundance, evolution, and emergence of the potent immune escape mutant. These findings have important implications in the field of HBV molecular epidemiology, transmission, transfusion medicine, organ transplantation, and vaccination strategies.
Induction of Robust Cellular and Humoral Virus-Specific Adaptive Immune Responses in Human Immunodeficiency Virus-Infected Humanized BLT Mice
Authors: Brainard Diana M. , Seung Edward , Frahm Nicole , Cariappa Annaiah , Bailey Charles C. , Hart William K. , Shin Hae-Sook , Brooks Sarah F. , Knight Heather L. , Eichbaum Quentin , Yang Yong-Guang , Sykes Megan , Walker Bruce D. , Freeman Gordon J. , Pillai Shiv , Westmoreland Susan V. , Brander Christian , Luster Andrew D. , Tager Andrew M. 
Published: May 2009

ABSTRACTThe generation of humanized BLT mice by the cotransplantation of human fetal thymus and liver tissues and CD34+fetal liver cells into nonobese diabetic/severe combined immunodeficiency mice allows for the long-term reconstitution of a functional human immune system, with human T cells, B cells, dendritic cells, and monocytes/macrophages repopulating mouse tissues. Here, we show that humanized BLT mice sustained high-level disseminated human immunodeficiency virus (HIV) infection, resulting in CD4+T-cell depletion and generalized immune activation. Following infection, HIV-specific humoral responses were present in all mice by 3 months, and HIV-specific CD4+and CD8+T-cell responses were detected in the majority of mice tested after 9 weeks of infection. Despite robust HIV-specific responses, however, viral loads remained elevated in infected BLT mice, raising the possibility that these responses are dysfunctional. The increased T-cell expression of the negative costimulator PD-1 recently has been postulated to contribute to T-cell dysfunction in chronic HIV infection. As seen in human infection, both CD4+and CD8+T cells demonstrated increased PD-1 expression in HIV-infected BLT mice, and PD-1 levels in these cells correlated positively with viral load and inversely with CD4+cell levels. The ability of humanized BLT mice to generate both cellular and humoral immune responses to HIV will allow the further investigation of human HIV-specific immune responses in vivo and suggests that these mice are able to provide a platform to assess candidate HIV vaccines and other immunotherapeutic strategies.
Initiation of Antiretroviral Therapy 48 Hours after Infection with Simian Immunodeficiency Virus Potently Suppresses Acute-Phase Viremia and Blocks the Massive Loss of Memory CD4
+
T Cells but Fails To Prevent Disease
Authors: Kubo Makoto , Nishimura Yoshiaki , Shingai Masashi , Lee Wendy , Brenchley Jason , Lafont Bernard , Buckler-White Alicia , Igarashi Tatsuhiko , Martin Malcolm A. 
Published: May 2009

ABSTRACT

We investigated whether a 28-day course of potent antiretroviral therapy, initiated at a time point (48 h postinoculation) following simian immunodeficiency virus (SIV) inoculation when the acquisition of a viral infection was virtually assured, would sufficiently sensitize the immune system and result in controlled virus replication when treatment was stopped. The administration of tenofovir 48 h after SIV inoculation to six
Mamu-A*01
-negative rhesus macaques did, in fact, potently suppress virus replication in all of the treated rhesus macaques, but plasma viral RNA rapidly became detectable in all six animals following its cessation. Unexpectedly, the viral set points in the treated monkeys became established at two distinct levels. Three controller macaques had chronic phase virus loads in the range of 1 × 10
3
RNA copies/ml, whereas three noncontroller animals had set points of 2 × 10
5
to 8 × 10
5
RNA copies/ml. All of the noncontroller monkeys died with symptoms of immunodeficiency by week 60 postinfection, whereas two of the three controller animals were alive at week 80. Interestingly, the three controller macaques each carried major histocompatibility complex class I alleles that previously were reported to confer protection against SIV, and two of these animals generated cytotoxic T-lymphocyte escape viral variants during the course of their infections.
On the growth of colloform textures: a case study of sphalerite from the Galmoy ore body, Ireland
Authors: Barrie Craig D. , Boyce Adrian J. , Boyle Alan P. , Williams Patrick J. , Blake Kevin , Wilkinson Jamie J. , Lowther Mike , McDermott Paul , Prior David J. 
Published: May 2009

Abstract:

Colloform textures have been described from many of the world's sulphide ore deposits and involve formation of distinct microcrystalline layers. These textures provide information related to sequential stages of ore formation, yet their mechanism of growth is poorly understood. This study has analysed a series of colloform samples from the Galmoy Zn + Pb mine, Ireland. Results indicate that the growth sequence is not always intuitive and layers that appear stratigraphic upon cursory observation may not be. The crystal preferred orientation (CPO) of discrete colloform layers abruptly switches between different orientation axes. Examination of the same layers using
in situ
laser sulphur isotope analysis reveals equally striking changes in δ
34
S signature between end-member bacteriogenic (−25‰) and hydrothermal (+10‰) sources. Although these results, combined with petrographic observation, allow the determination of a probable growth history, there is no correlation between shifting CPO and δ
34
S signature. Trace element analysis reveals changes in trace element sequestration between colloform layers. Cadmium- and chlorine-rich layers correspond to a hydrothermal sulphur source, whereas iron-rich layers correspond to a bacteriogenic sulphur source. In the absence of alternative mechanisms we suggest that the most likely factors influencing CPO changes are temperature and degree of supersaturation during two-fluid mixing.
Early Jurassic normal faulting in a carbonate extensional basin: characterization of tectonically driven platform drowning (High Atlas rift, Morocco)
Authors: Lachkar Nadifa , Guiraud Michel , Harfi Abdelghani El , Dommergues Jean-Louis , Dera Guillaume , Durlet Christophe 
Published: May 2009

Abstract:

This paper describes a tectonostratigraphic model of the synrift evolution of the Early Jurassic High Atlas rift of Morocco. The model is constrained by mapping of a set of inverted extensional blocks, by facies analysis of carbonate platform and turbiditic to hemipelagic synrift deposits, and by high-resolution (
n
× 100 ka) biostratigraphy of the Early Jurassic succession. The chronostratigraphic packages of the High Atlas of Rich vary significantly in thickness, facies and architecture from one tectonic block to another. Our study shows how synrift strain varied in space and time over a long time interval (14 Ma) around the High Atlas rift. Initially, in Sinemurian time, the High Atlas rift was affected by low-strain normal faulting that controlled the growth of an extensive, low-gradient carbonate platform, except in the northern domain (towards the rift axis), where hemipelagic deposition related to high-rate faulting prevailed. Subsequently, in Carixian–Domerian time, a rapid increase in accommodation space and block subsidence caused by high-strain normal faulting brought about localized drowning of the carbonate platform and the development of calciturbidites and of starved deposits towards the rift axis. During this interval, high-strain, upper-crustal normal faulting migrated rapidly (over a period of 5 Ma) towards the rift periphery.
Early Ordovician rifting of Avalonia and birth of the Rheic Ocean: U–Pb detrital zircon constraints from Newfoundland
Authors: Pollock Jeffrey C. , Hibbard James P. , Sylvester Paul J. 
Published: May 2009

Abstract:

Avalonia is the largest accreted crustal block in the Appalachian orogen and comprises a collection of late Neoproterozoic volcano-sedimentary sequences that are overlain by a Palaeozoic platformal sedimentary succession. Detrital zircons from the Conception Group are dominated by 570–620 Ma ages and contain a significant component generated by erosion of coeval igneous arc-volcanic rocks. Overlying samples from the Cuckold and Crown Hill formations are dominated by Neoproterozoic populations with ages between 600 and 650 Ma and are interpreted to be derived from the underlying calc-alkaline arc-plutonic rocks. Early Palaeozoic platform units are dominated by
c
. 620 Ma zircons with lesser Mesoproterozoic and Palaeoproterozoic zircons. The range of detrital zircon ages is inconsistent with a West African provenance and suggests that Avalonia originated along the Gondwanan margin of the Amazon craton. The influx of Mesoproterozoic and Palaeoproterozoic detritus in the Avalonian platform suggests a major change in tectonic regime. The prominent change in provenance is interpreted to be related to separation of Avalonia from Gondwana during the Early Ordovician opening of the Rheic Ocean. The Redmans Formation is interpreted to represent the rift–drift transition of the Rheic Ocean, which imposes important constraints on the palaeotectonic evolution of Avalonia.

Supplementary material:

U–Pb isotopic data of LA-ICP-MS analysis of detrital zircons are available at
http://www.geolsoc.org.uk/SUP18346
.
Devonian arc-related magmatism in the Tseel terrane of SW Mongolia: chronological and geochemical evidence
Authors: Demoux Antoine , Kröner Alfred , Hegner Ernst , Badarch Gombosuren 
Published: May 2009

Abstract:
The Tseel terrane in the Gobi Desert of SW Mongolia consists of a composite crustal segment of imbricated sheets of high- and low-grade metamorphic rocks of predominantly middle Palaeozoic age. New sensitive high-resolution ion microprobe (SHRIMP) zircon ages of 396 ± 3 Ma (2σ) and 397 ± 3 Ma (2σ) for two calc-alkaline metarhyolite samples indicate arc volcanism during the early Devonian. An undeformed feldspar porphyry cross-cutting the early Devonian low-grade sequence yielded an emplacement age of 279 ± 2 Ma (2σ). Geochemical and Nd isotopic data for low-grade mafic metavolcanic rocks are consistent with melting of moderately depleted upper mantle sources in a transitional arc–back-arc setting. In addition, there are high- and low-grade felsic metaigneous rocks with subduction-related chemical signatures and heterogeneous Nd isotopic compositions indicating an origin from mixed sources, including juvenile and Precambrian crustal components. The field observations combined with the geochemical and isotopic data suggest that the Tseel terrane represents a segment of a mature Japan-type arc associated with a juvenile back-arc basin.

Supplementary material:

Latitudes and longitudes of sample localities, major- and trace-element abundances for rock samples, data for reference materials obtained by LA-ICP-MS and Sm–Nd isotopic data for rock samples are available at
http://www.geolsoc.org.uk/SUP18338
.
Crustal affinities in the Arctic Uralides, northern Russia: significance of detrital zircon ages from Neoproterozoic and Palaeozoic sediments in Novaya Zemlya and Taimyr
Authors: Pease V. , Scott R.A. 
Published: May 2009

Abstract:

U–Pb ion microprobe detrital zircon provenance investigations of pre-Mesozoic sediment samples from southern Novaya Zemlya and northern Taimyr, Arctic Russia, provide new constraints on the tectonic evolution of northern Eurasia. Sediments from both areas previously assigned a Neoproterozoic age are shown to be Palaeozoic (≤500 Ma), changing our understanding of the timing of tectonic events and their regional correlation. Samples from Novaya Zemlya provide an
a priori
Baltica signature, and dominant cumulative probability age peaks between 610 and 530 Ma are consistent with derivation from Timanide sources. Samples from northern Taimyr also contain the unique Timanian ’fingerprint' and are also inferred to be derived from the continental slope of northeastern Baltica, implying that the North Kara block was a part of Baltica in the early Palaeozoic. These data constrain the timing of deformation, metamorphism and development of an unconformity in southern Novaya Zemlya to a restricted period no earlier than late Cambrian–early Ordovician and at least 50 Ma after the peak Timanian event. The unconformity on Novaya Zemlya can be correlated in style and timing with an unconformity on Severnaya Zemlya and may record post-Timanian extensional collapse and onset of spreading in the Uralian Ocean.

Supplementary material:

U–Th–Pb ion-microprobe analytical results are available at
http://www.geolsoc.org.uk/SUP18340
.
A strike-slip terrane boundary in Wedel Jarlsberg Land, Svalbard, and its bearing on correlations of SW Spitsbergen with the Pearya terrane and Timanide belt
Authors: Mazur Stanisław , Czerny Jerzy , Majka Jarosław , Manecki Maciej , Holm Daniel , Smyrak Aleksandra , Wypych Alicja 
Published: May 2009

Abstract:Southwest Spitsbergen, Wedel Jarlsberg Land, consists of two Proterozoic terranes with differing structural and metamorphic histories. The northern terrane experienced two Early Palaeozoic deformation events both accompanied by greenschist-facies metamorphism of similar grade. The southern terrane records a Neoproterozoic pervasive amphibolite-facies metamorphism and strong deformational fabric only locally retrogressed during a Caledonian greenschist-grade event. These terranes are separated by an important sinistral ductile shear zone defined as the Vimsodden–Kosibapasset zone, which comprises wrench- and contraction-dominated domains characteristic of strain partitioning in transpression zones; in this case apparently controlled by contrasting rheologies of the juxtaposed crustal domains. The northern terrane of Wedel Jarlsberg Land shares affinities with Pearya in northern Ellesmere Island of Arctic Canada whereas the southern one resembles the Timanide belt of NE Europe. A quantitative approach facilitated by a numerical plate model demonstrates that correlation with Pearya is feasible if sinistral displacement ofc. 600 km occurred during the Caledonian orogeny. The correlation with the Timanides is valid if the southern terrane represents an outlier of the Timanide belt separated from Baltica by the opening of the Iapetus Ocean.