Simulation and diagnosis of stratosphere-troposphere exchange

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A Transmissible Gastroenteritis Coronavirus Nucleoprotein Epitope Elicits T Helper Cells That Collaborate in the in Vitro Antibody Synthesis to the Three Major Structural Viral Proteins

AbstractFour strong T cell epitopes have been identified studying the blastogenic response of lymphocytes from haplotype-defined transmissible gastroenteritis virus (TGEV) immune miniswine to sixty-one 15-mer synthetic peptides. Three of these epitopes are located on the nucleoprotein (N48 amino acids 46 to 60; N272, amino acids 272 to 286; and N321 amino acid 321 to 335), and one on the membrane protein (M196, amino acids 196 to 210). N321, peptide induced the highest T cell response and was recognized by immune miniswine lymphocytes with haplotypes dd, aa , and cc. T lymphocytes from peptide N321-immune miniswine reconstituted the in vitro synthesis of TGEV-specific antibodies by complementing CD4- TGEV-immune cells. This response was directed at least against the three major structural proteins. The synthesized antibodies specific for S protein preferentially recognized discontinous epitopes and neutralized TGEV infectivity. These results show that peptide N321 defines a functional T helper epitope eliciting T cells capable of collaborating with B cells specific for different proteins of TGEV

A single amino acid substitution in hypervariable region 5 of the envelope protein of feline immunodeficiency virus allows escape from virus neutralization.

We infected a specific-pathogen-free cat (cat 14) with molecularly cloned feline immunodeficiency virus clone 19k1 (FIV19k1 [K. H. J. Siebelink, I. Chu, G. F. Rimmelzwaan, K. Weijer, A. D. M. E. Osterhaus, and M. L. Bosch, J. Virol. 66:1091-1097, 1992]). Serum of this cat obtained 22 weeks postinfection (serum 1422) neutralized FIV19k1 but not FIV19k32, which is 99.3% identical to FIV19k1 in the envel

Antigenic Profile of African Horse Sickness Virus Serotype 4 VP5 and Identification of a Neutralizing Epitope Shared with Bluetongue Virus and Epizootic Hemorrhagic Disease Virus

AbstractAfrican horse sickness virus (AHSV) causes a fatal disease in horses. The virus capsid is composed of a double protein layer, the outermost of which is formed by two proteins: VP2 and VP5. VP2 is known to determine the serotype of the virus and to contain the neutralizing epitopes. The biological function of VP5, the other component of the capsid, is unknown. In this report, AHSV VP5, expressed in insect cells alone or together with VP2, was able to induce AHSV-specific neutralizing antibodies. Moreover, two VP5-specific monoclonal antibodies (MAbs) that were able to neutralize the virus in a plaque reduction assay were generated. To dissect the antigenic structure of AHSV VP5, the protein was cloned inEscherichia coliusing the pET3 system. The immunoreactivity of both MAbs, and horse and rabbit polyclonal antisera, with 17 overlapping fragments from VP5 was analyzed. The most immunodominant region was found in the N-terminal 330 residues of VP5, defining two antigenic regions, I (residues 151–200) and II (residues 83–120). The epitopes were further defined by PEPSCAN analysis with 12mer peptides, which determined eight antigenic sites in the N-terminal half of the molecule. Neutralizing epitopes were defined at positions 85–92 (PDPLSPGE) for MAb 10AE12 and at 179–185 (EEDLRTR) for MAb 10AC6. Epitope 10AE12 is highly conserved between the different orbiviruses. MAb 10AE12 was able to recognize bluetongue virus VP5 and epizootic hemorrhagic disease virus VP5 by several techniques. These data will be especially useful for vaccine development and diagnostic purposes

Identification of a protein encoded in the EB-viral open reading frame BMRF2

Using monospecific rabbit sera against a peptide derived from a potential antigenic region of the Epstein-Barr viral amino acid sequence encoded in the open reading frame BMRF2 we could identify a protein-complex of 53/55 kDa in chemically induced B95-8, P3HR1 and Raji cell lines. This protein could be shown to be membrane-associated, as predicted by previous computer analysis of the secondary structure and hydrophilicity pattern, and may be a member of EBV-induced membrane proteins in lytically infected cells

Internal and external threat in relationship with right-wing attitudes

Objective Previous studies on the relationship between threat and right-wing attitudes have tended to focus on either internal threat, emanating from one's private life, or external threat, originating from society. However, these studies failed to examine whether these types of threats constitute two distinctive dimensions and which of these threats is most closely related to right-wing attitudes. Method In order to explore the dimensions underlying threat, a factor analysis on a variety of threat scales was conducted (Study 1; N?=?300). Furthermore, in a meta-analysis (Study 2; total N?=?22,086) and a questionnaire study in a large representative sample (Study 3, N?=?800) the strength of the relationships of internal and external threat with right-wing attitudes were investigated. Results The present studies revealed that internal and external threat can be considered as two distinct dimensions underlying threat. Moreover, whereas external threat yielded strong relationships with right-wing attitudes, internal threat only explained a minor part of the variance in these attitudes. Conclusions External rather than internal threat underlies the relationship between threat and right-wing attitudes

Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study

Reconstructions of the atmospheric sulfate aerosol burdens resulting from past volcanic eruptions are based on ice core-derived estimates of volcanic sulfate deposition and the assumption that the two quantities are directly proportional. We test this assumption within simulations of tropical volcanic stratospheric sulfur injections with the MAECHAM5-HAM aerosol-climate model. An ensemble of 70 simulations is analyzed, with SO2 injections ranging from 8.5 to 700 Tg, with eruptions in January and July. Modeled sulfate deposition flux to Antarctica shows excellent spatial correlation with ice core-derived estimates for Pinatubo and Tambora, although the comparison suggests the modeled flux to the ice sheets is 4–5 times too large. We find that Greenland and Antarctic deposition efficiencies (the ratio of sulfate flux to each ice sheet to the maximum hemispheric stratospheric sulfate aerosol burden) vary as a function of the magnitude and season of stratospheric sulfur injection. Changes in simulated sulfate deposition for large SO2 injections are connected to increases in aerosol particle size, which impact aerosol sedimentation velocity and radiative properties, the latter leading to strong dynamical changes including strengthening of the winter polar vortices, which inhibits the transport of stratospheric aerosols to high latitudes. The resulting relationship between Antarctic and Greenland volcanic sulfate deposition is nonlinear for very large eruptions, with significantly less sulfate deposition to Antarctica than to Greenland. These model results suggest that variability of deposition efficiency may be an important consideration in the interpretation of ice core sulfate signals for eruptions of Tambora-magnitude and larger