Electroweak Symmetry Breaking at the LHC

One of the major goals of the Large Hadron Collider is to probe the electroweak symmetry breaking mechanism and the generation of the masses of the elementary particles. We review the physics of the Higgs sector in the Standard Model and some of its extensions such as supersymmetric theories and models of extra dimensions. The prospects for discovering the Higgs particles at the LHC and the study of their fundamental properties are summarised.Comment: 27 pages, 45 figures, uses LaTeX (insa.sty). Invited review for volume on LHC physics to celebrate the Platinum Jubilee of the Indian National Science Academy, edited by Amitava Datta, Biswarup Mukhopadhyaya and Amitava Raychaudhuri. Expanded the acronym in the title in the annoncement. No other change in the text or reference

Search for jet extinction in the inclusive jet-pT spectrum from proton-proton collisions at s=8 TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7  fb−1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale

Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV

Searches for supersymmetry (SUSY) are presented based on the electroweak pair production of neutralinos and charginos, leading to decay channels with Higgs, Z, and W bosons and undetected lightest SUSY particles (LSPs). The data sample corresponds to an integrated luminosity of about 19.5 fb(-1) of proton-proton collisions at a center-of-mass energy of 8 TeV collected in 2012 with the CMS detector at the LHC. The main emphasis is neutralino pair production in which each neutralino decays either to a Higgs boson (h) and an LSP or to a Z boson and an LSP, leading to hh, hZ, and ZZ states with missing transverse energy (E-T(miss)). A second aspect is chargino-neutralino pair production, leading to hW states with E-T(miss). The decays of a Higgs boson to a bottom-quark pair, to a photon pair, and to final states with leptons are considered in conjunction with hadronic and leptonic decay modes of the Z and W bosons. No evidence is found for supersymmetric particles, and 95% confidence level upper limits are evaluated for the respective pair production cross sections and for neutralino and chargino mass values

Purification by DNA affinity chromatography of two polypeptides that contact the NF-AT DNA binding site in the interleukin 2 promoter.

NF-AT is a lymphoid-specific transcription factor that is though to be largely responsible for determining the cell type-specific expression of the interleukin 2 (IL2) gene. Using two different purification schemes, we found that the NF-AT binding site present in the IL2 promoter is the target for two distinct polypeptides with a relative molecular weight of 45,000 and 90,000. Direct extraction of NF-AT binding activity from highly purified nuclei confirms that p45 and p90 are components of the NF-AT complex. UV-induced covalent cross-linking of p45 and p90 to the NF-AT sequence indicates that both polypeptides interact with DNA. We demonstrate using in vitro transcription that antibodies to subunits p45 and p90 strongly reduce activation of an artificial promoter carrying three NF-AT recognition sites. The complex we have purified has the potential to interact with cis-acting elements identified in the promoter of genes expressed early during T cell activation and to the HIV long terminal repeat. We also show that phosphorylation modulates interaction of NF-AT to its cognate binding site. All together, our data suggest that p45 and p90 form the constitutively expressed nuclear factor(s) proposed by Yaseen et al. (Yaseen, N.R., Maizel, A. L., Wang, F., and Sharma, S. (1993) J. Biol. Chem. 268, 14285-14293)

Cloning and expression of cyclosporin A- and FK506-sensitive nuclear factor of activated T-cells: NF45 and NF90.

Nuclear Factor of Activated T-cells (NF-AT) is a crucial transcription factor required for T-cell expression of interleukin 2. Purified NF-AT contains 45-kDa and 90-kDa subunits (Corthésy, B., and Kao, P. N. (1994) J. Biol. Chem. 269, 20682-20690). Partial internal amino acid sequences derived from each subunit indicate that these proteins are novel. The amino acid sequences were used to clone the cDNAs encoding each subunit. The cDNAs predict proteins of novel structures: NF45 has limited similarity to prokaryotic transcription factor sigma-54 and to human DNA topoisomerase II; NF90 has limited similarity to Drosophila Staufen in a domain predicted to bind double-stranded RNA. RNA encoding NF45 and NF90 exists in nonstimulated Jurkat T-cells and in all other cell types examined (HeLa, HepG2, K562). Immunofluorescence microscopy was used to demonstrate that both proteins are located in the nucleus of Jurkat T-cells. Clones NF45 and NF90 with a polyhistidine fusion tag were transiently expressed and processed in the native environment of Jurkat T-cells. Histidine-tagged NF45 and NF90 proteins, affinity-purified on nickel chelate columns, encode a NF-AT DNA-binding activity that is enhanced following T-cell stimulation, and this enhancement is blocked when T-cells are stimulated in the presence of cyclosporin A or FK506

Increased PD-1 and decreased CD28 expression in chronic hepatitis B patients with advanced hepatocellular carcinoma

Background/aims: Hepatitis B infection is a well-known cause of hepatocellular carcinoma (HCC). This study aims to investigate the role that the costimulatory molecule CD28 and co-inhibitory molecule programmed death-1 (PD-1) play in compromising the function of tumour-infiltrating lymphocytes (TIL) in hepatitis B virus (HBV)-related HCC. Methods: A total of 45 patients with HBV-related HCC were enrolled during the period February 2008 to March 2010. The immune phenotype and the expression of PD-1, CD28 and CD127 in TIL in biopsy specimens and in peripheral blood lymphocytes (PBL) from the same patients were analysed by flow cytometry. Results: Among the 45 patients, there was a male predominance (80%) and the mean age was 50 +/- 13.68 years (range: 29-71). The majority of TIL were CD45RO(+)CD69(+). PD-1 expression was higher and CD28 and CD127 expression levels were lower in TIL than in PBL. The prevalence of portal vein thrombosis was 40%. Furthermore, tumour thrombosis invasion into the portal vein correlated with the expression level of the PD-1 co-inhibitory molecule. Conclusion: PD-1(+) tumour-infiltrating lymphocytes correlate with portal vein thrombosis and might serve as a potential prognostic marker of and a novel therapeutic target for HBV-related HCC

Ribosome inactivating protein B-chain induces osteoclast differentiation from monocyte/macrophage lineage precursor cells

Human osteoclast formation from mononuclear phagocyte precursors involves interactions between lectins and their receptors. A type-2 ribosome inactivating protein consists of an A chain and a B chain. The glycosylated B chain binds specifically to galactose moieties of sugar molecules. In this study we showed that the recombinant ribosome inactivating protein B-chain (rRBC) could induce osteoclast formation from human monocytes and murine RAW264.7 macrophages. Tartrate-resistant acid phosphatase (TRAP) staining and bone resorption assays demonstrated that differentiation of osteoclast-like cells was induced in the presence of rRBC in a dose-dependent manner. The rRBC-induced osteoclast differentiation was independent of caspase activation and apoptosis induction activity; however, rRBC-induced osteoclastogenesis was dependent on activation of NF-kappa B, ERK1/2, and p38 MAP kinase. Thus, our data demonstrated that rRBC induced osteoclast differentiation through a non-apoptotic signaling pathway. In addition to triggering apoptosis, the rRBC also induced osteoclast differentiation. According to this study, a novel role is proposed for rRBC in regulating osteoclast differentiation and in osteoimmunology. (C) 2011 Elsevier Inc. All rights reserved

Expression of CD25(high) Regulatory T Cells and PD-1 in Gastric Infiltrating CD4(+) T Lymphocytes in Patients with Helicobacter pylori Infection

We observed by flow cytometry that the frequency of both gastric infiltrating Tregs and PD-1-positive CD4 T cells is correlated with the density of Helicobacter pylori, suggesting that cellular immunity against this pathogen is inhibited