Impact of the ground-state 4f4f symmetry for anisotropic cfcf-hybridization in the heavy fermion superconductor CeNi2_{2}Ge2_{2}

We report the ground-state symmetry of the Ce $4f$ states in the heavy fermion superconductor CeNi$_{2}$Ge$_{2}$, yielding anisotropic $cf$-hybridization between the Ce $4f$ states and conducting electrons. By analyzing linear dichroism in soft x-ray absorption and core-level hard x-ray photoemission spectra, the $4f$ symmetry is determined as $\Sigma$-type $\Gamma_{7}$, promoting predominant hybridization with the conducting electrons originating from the Ge site. The band structures probed by the soft x-ray angle-resolved photoemission indicates that the Ge $4p$ components contribute to the band renormalization through the anisotropic hybridization effects, suggesting that the control of the electronic structures of Ge orbital gives an impact to achieve the exotic phenomena in CeNi$_{2}$Ge$_{2}$

Host Factors interacting with the Pestivirus N terminal protease, Npro are Components of the Ribonucleoprotein Complex

The viral N-terminal protease N(pro) of pestiviruses counteracts cellular antiviral defenses through inhibition of IRF3. Here we used mass spectrometry to identify a new role for N(pro) through its interaction with over 55 associated proteins, mainly ribosomal proteins and ribonucleoproteins, including RNA helicase A (DHX9), Y-box binding protein (YBX1), DDX3, DDX5, eIF3, IGF2BP1, multiple myeloma tumor protein 2, interleukin enhancer binding factor 3 (IEBP3), guanine nucleotide binding protein 3, and polyadenylate-binding protein 1 (PABP-1). These are components of the translation machinery, ribonucleoprotein particles (RNPs), and stress granules. Significantly, we found that stress granule formation was inhibited in MDBK cells infected with a noncytopathic bovine viral diarrhea virus (BVDV) strain, Kyle. However, ribonucleoproteins binding to N(pro) did not inhibit these proteins from aggregating into stress granules. N(pro) interacted with YBX1 though its TRASH domain, since the mutant C112R protein with an inactive TRASH domain no longer redistributed to stress granules. Interestingly, RNA helicase A and La autoantigen relocated from a nuclear location to form cytoplasmic granules with N(pro). To address a proviral role for N(pro) in RNP granules, we investigated whether N(pro) affected RNA interference (RNAi), since interacting proteins are involved in RISC function during RNA silencing. Using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) silencing with small interfering RNAs (siRNAs) followed by Northern blotting of GAPDH, expression of N(pro) had no effect on RNAi silencing activity, contrasting with other viral suppressors of interferon. We propose that N(pro) is involved with virus RNA translation in the cytoplasm for virus particle production, and when translation is inhibited following stress, it redistributes to the replication complex. IMPORTANCE Although the pestivirus N-terminal protease, N(pro), has been shown to have an important role in degrading IRF3 to prevent apoptosis and interferon production during infection, the function of this unique viral protease in the pestivirus life cycle remains to be elucidated. We used proteomic mass spectrometry to identify novel interacting proteins and have shown that N(pro) is present in ribosomal and ribonucleoprotein particles (RNPs), indicating a translational role in virus particle production. The virus itself can prevent stress granule assembly from these complexes, but this inhibition is not due to N(pro). A proviral role to subvert RNA silencing through binding of these host RNP proteins was not identified for this viral suppressor of interferon

Production of scFv-Conjugated Affinity Silk Powder by Transgenic Silkworm Technology

Bombyx mori (silkworm) silk proteins are being utilized as unique biomaterials for medical applications. Chemical modification or post-conjugation of bioactive ligands expand the applicability of silk proteins; however, the processes are elaborate and costly. In this study, we used transgenic silkworm technology to develop single-chain variable fragment (scFv)-conjugated silk fibroin. The cocoons of the transgenic silkworm contain fibroin L-chain linked with scFv as a fusion protein. After dissolving the cocoons in lithium bromide, the silk solution was dialyzed, concentrated, freeze-dried, and crushed into powder. Immunoprecipitation analyses demonstrate that the scFv domain retains its specific binding activity to the target molecule after multiple processing steps. These results strongly suggest the promise of scFv-conjugated silk fibroin as an alternative affinity reagent, which can be manufactured using transgenic silkworm technology at lower cost than traditional affinity carriers

AKAP95 regulates splicing through scaffolding RNAs and RNA processing factors

YesAlternative splicing of pre-mRNAs significantly contributes to the complexity of gene expression in higher organisms, but the regulation of the splice site selection remains incompletely understood. We have previously demonstrated that a chromatin-associated protein, AKAP95 (AKAP8), has a remarkable activity in enhancing chromatin transcription. In this study, we have shown that AKAP95 physically interacts with many factors involved in transcription and RNA processing, and functionally regulates pre-mRNA splicing. AKAP95 directly promotes splicing in vitro and the inclusion of a specific exon of an endogenous gene FAM126A. The N-terminal YG-rich domain of AKAP95 is important for its binding to RNA processing factors including selective groups of hnRNP proteins, and its zinc finger domains are critical for pre-mRNA binding. Genome-wide binding assays revealed that AKAP95 bound preferentially to proximal intronic regions on a large number of pre-mRNAs in human transcriptome, and AKAP95 depletion predominantly resulted in reduced inclusion of many exons. AKAP95 also selectively coordinates with hnRNP H/F and U proteins in regulating alternative splicing events. We have further shown that AKAP95 directly interacts with itself. Taken together, our results establish AKAP95 as a novel and mostly positive regulator of premRNA splicing and a possible integrator of transcription and splicing regulation, and support a model that AKAP95 facilitates the splice site communication by looping out introns through both RNA-binding and protein-protein interaction.This work was supported by a UAB start-up fund to H.J

Th1-Th17 Cells Mediate Protective Adaptive Immunity against Staphylococcus aureus and Candida albicans Infection in Mice

We sought to define protective mechanisms of immunity to Staphylococcus aureus and Candida albicans bloodstream infections in mice immunized with the recombinant N-terminus of Als3p (rAls3p-N) vaccine plus aluminum hydroxide (Al(OH3) adjuvant, or adjuvant controls. Deficiency of IFN-γ but not IL-17A enhanced susceptibility of control mice to both infections. However, vaccine-induced protective immunity against both infections required CD4+ T-cell-derived IFN-γ and IL-17A, and functional phagocytic effectors. Vaccination primed Th1, Th17, and Th1/17 lymphocytes, which produced pro-inflammatory cytokines that enhanced phagocytic killing of both organisms. Vaccinated, infected mice had increased IFN-γ, IL-17, and KC, increased neutrophil influx, and decreased organism burden in tissues. In summary, rAls3p-N vaccination induced a Th1/Th17 response, resulting in recruitment and activation of phagocytes at sites of infection, and more effective clearance of S. aureus and C. albicans from tissues. Thus, vaccine-mediated adaptive immunity can protect against both infections by targeting microbes for destruction by innate effectors

Abnormally High Levels of Virus-Infected IFN-γ+CCR4+CD4+CD25+ T Cells in a Retrovirus-Associated Neuroinflammatory Disorder

BACKGROUND:Human T-lymphotropic virus type 1 (HTLV-1) is a human retrovirus associated with both HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which is a chronic neuroinflammatory disease, and adult T-cell leukemia (ATL). The pathogenesis of HAM/TSP is known to be as follows: HTLV-1-infected T cells trigger a hyperimmune response leading to neuroinflammation. However, the HTLV-1-infected T cell subset that plays a major role in the accelerated immune response has not yet been identified. PRINCIPAL FINDINGS:Here, we demonstrate that CD4(+)CD25(+)CCR4(+) T cells are the predominant viral reservoir, and their levels are increased in HAM/TSP patients. While CCR4 is known to be selectively expressed on T helper type 2 (Th2), Th17, and regulatory T (Treg) cells in healthy individuals, we demonstrate that IFN-gamma production is extraordinarily increased and IL-4, IL-10, IL-17, and Foxp3 expression is decreased in the CD4(+)CD25(+)CCR4(+) T cells of HAM/TSP patients as compared to those in healthy individuals, and the alteration in function is specific to this cell subtype. Notably, the frequency of IFN-gamma-producing CD4(+)CD25(+)CCR4(+)Foxp3(-) T cells is dramatically increased in HAM/TSP patients, and this was found to be correlated with disease activity and severity. CONCLUSIONS:We have defined a unique T cell subset--IFN-gamma(+)CCR4(+)CD4(+)CD25(+) T cells--that is abnormally increased and functionally altered in this retrovirus-associated inflammatory disorder of the central nervous system