Effect of adenovirus E1A on ICAM-1 promoter activity in human alveolar and bronchial epithelial cells

In previous studies we demonstrated that the E1A DNA and proteins of group C adenovirus are present in excess in the lungs of patients with chronic obstructive pulmonary disease (COPD). Because adenovirus EIA gene products are known to regulate the expression of many genes by interacting with cellular transcription factors, we postulated that E1A enhances the production of inflammatory mediators and exacerbates the inflammatory process in smokers' lungs. We reported that LPS-induced ICAM-1 expression in A549 cells is upregulated by E1A. In the current study we investigated whether this regulation is mediated through the ICAM-1 promoter. A549 cells and primary human bronchial epithelial (HBE) cells were transiently cotransfected with a plasmid containing the ICAM-1 enhancer-promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene (pBS-CAT-P) and either a plasmid carrying the adenovirus 5 E1A gene (pE1Aneo) or a control plasmid (pneo). To compare the effect of transient versus stable E1A expression on the activity of this promoter, we also transiently transfected stable E1A-expressing A549 cells with pBS-CAT-P. Transient cotransfection of pE1Aneo and pBS-CAT-P had no effect on basal ICAM-1 promoter activity in A549 or HBE cells. After stimulation of A549 cells with TNF-alpha, IFN-gamma, or LPS, promoter activity was increased by two- to threefold in the presence of adenovirus EIA. In HBE cells, on the other hand, E1A repressed the ICAM-1 promoter after stimulation with IFN-gamma and LPS with little change after TNF-alpha stimulation. In stable E1A transfectants, ICAM-1 promoter activity was 2 to 2.5 times higher than in control transfectants with or without stimulation with TNF-alpha or LPS. These findings suggest that EIA can modulate the activity of the ICAM-1 promoter in lung epithelial cells and this modulation is different in cells of alveolar origin compared to bronchial epithelial cells.

Solvent Control over Supramolecular Gel Formation and Fluorescence for a Highly Crystalline π-Conjugated Polymer

In π-conjugated polymers (πCPs), crystallinity and fluorescence typically exhibit a trade-off relationship. Here, we have synthesized a highly crystalline and fluorescent π-conjugated polymer with a simple alternating structure of 1,2,4,5-tetrafluorophenylene and 3,3'-dihexyl-2,2'-bithiophene units. In film, the polymer exhibited efficient red-colored fluorescence, an improved quantum yield (Φsol =13 %→Φfilm =23 %) and a crystalline structure. Interestingly, supramolecular gel formation occurred in appropriate solvents, and the macrostructure and fluorescence properties of the gel could be directly controlled by the choice of the solvent. The polymer self-assembled into a spherical form that exhibited red fluorescence in non-aromatic solvent (1,2-dichloroethane) and into a fibrous form that exhibited yellow fluorescence in aromatic solvent (mesitylene).

D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24  GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.

J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8  GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76  TeV in semicentral collisions. At midrapidity, the J/ψ  v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.

Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8  GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. A significant broadening of the peak in the Δη direction at low p_{T} is found from peripheral to central collisions, which vanishes above 4  GeV/c, while in the Δφ direction the peak is almost independent of centrality. For the 10% most central collisions and 1<p_{T,assoc}<2  GeV/c, 1<p_{T,trig}<3  GeV/c a novel feature is observed: a depletion develops around the center of the peak. The results are compared to pp collisions at the same center of mass energy and ampt model simulations. The comparison to the investigated models suggests that the broadening and the development of the depletion is connected to the strength of radial and longitudinal flow.