Identification of New SRF Binding Sites in Genes Modulated by SRF Over-Expression in Mouse Hearts

Background To identify in vivo new cardiac binding sites of serum response factor (SRF) in genes and to study the response of these genes to mild over-expression of SRF, we employed a cardiac-specific, transgenic mouse model, with mild over-expression of SRF (Mild-O SRF Tg). Methodology Microarray experiments were performed on hearts of Mild-O-SRF Tg at 6 months of age. We identified 207 genes that are important for cardiac function that were differentially expressed in vivo. Among them the promoter region of 192 genes had SRF binding motifs, the classic CArG or CArG-like (CArG-L) elements. Fifty-one of the 56 genes with classic SRF binding sites had not been previously reported. These SRF-modulated genes were grouped into 12 categories based on their function. It was observed that genes associated with cardiac energy metabolism shifted toward that of carbohydrate metabolism and away from that of fatty acid metabolism. The expression of genes that are involved in transcription and ion regulation were decreased, but expression of cytoskeletal genes was significantly increased. Using public databases of mouse models of hemodynamic stress (GEO database), we also found that similar altered expression of the SRF-modulated genes occurred in these hearts with cardiac ischemia or aortic constriction as well. Conclusion and significance SRF-modulated genes are actively regulated under various physiological and pathological conditions. We have discovered that a large number of cardiac genes have classic SRF binding sites and were significantly modulated in the Mild-O-SRF Tg mouse hearts. Hence, the mild elevation of SRF protein in the heart that is observed during typical adult aging may have a major impact on many SRF-modulated genes, thereby affecting Cardiac structure and performance. The results from our study could help to enhance our understanding of SRF regulation of cellular processes in the aged heart

Measurement of Z0 decays to hadrons, and a precise determination of the number of neutrino species

We have made a precise measurement of the cross section for e+e--->Z0-->hadrons with the L3 detector at LEP, covering the range from 88.28 to 95.04 GeV. From a fit to the Z0 mass, total width, and the hadronic cross section to be MZ0=91.160 +/- 0.024 (experiment) +/-0.030(LEP) GeV, [Gamma]Z0=2.539+/-0.054 GeV, and [sigma]h(MZ0)=29.5+/-0.7 nb. We also used the fit to the Z0 peak cross section and the width todetermine [Gamma]invisible=0.548+/-0.029 GeV, which corresponds to 3.29+/-0.17 species of light neutrinos. The possibility of four or more neutrino flavors is thus ruled out at the 4[sigma] confidence level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28683/3/0000500.pd

A measurement of the Z0 leptonic partial widths and the vector and axial vector coupling constants

We have measured the partial widths of the Z0 into lepton pairs, and the forward-backward charge asymmetry for the process e+e--->[mu]+[mu]- using the L3 detector at LEP. We obtain an average [Gamma]ll of 83.0+/-2.1+/-1.1 MeV.From this result and the asymmetry measurement, we extract the values of the vector and axial vector couplings of the Z0 to leptons: grmv=-0.066-0.027+0.046 and grmA= -0.495-0.007+0.007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28666/3/0000483.pd

Immunogenicity of envelope GP5 protein displayed on baculovirus and protective efficacy against virulent porcine reproductive and respiratory syndrome virus challenge in piglets

In the present study, one recombinant baculovirus BacSC-GP5, expressing His6-tagged GP5 with the transmembrane domain (TM) and cytoplasmic domain (CTD) derived from baculovirus envelope protein gp64, was constructed and its immunogenicity and protective efficiency was evaluated in piglets. The results obtained show that, His6-tagged recombinant GP5 was expressed and anchored on the plasma membrane of Sf-9 cells, as revealed by Western blot and confocal microscopy. Immunogold electron microscopy demonstrated that, the GP5 glycoprotein was displayed successfully on the viral surface. Piglets immunized with BacSC-GP5 induced successfully GP5-specific enzyme-linked immunosorbent assay (ELISA) antibody, neutralizing antibody and lymphocyte proliferation response at 6 weeks after primary immunization. An in vivo challenge result indicated that piglets immunized with BacSC-GP5 did not show any obvious clinical signs and histological changes, and the quantitative real-time polymerase chain reaction (RT-PCR) also indicated that the porcine reproductive and respiratory syndrome virus (PRRSV) viral load from the serum in BacSC-GP5 group was significantly reduced at 14 and 21 days post-challenge compared to that in the negative control group. These results indicate that baculovirus-mediated gene delivery can be utilized as an alternative strategy to develop a new generation of vaccine against PRRSV infection

Immunogenicity of the envelope GP3 protein of porcine reproductive and respiratory syndrome virus displayed on baculovirus

Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized as one of the most important pathogens of pigs throughout the world. The minor envelope protein GP3 of PRRSV plays an important role in clearing of the virus infection and protecting the animals. In this study, a recombinant baculovirus (BacSC-GP3) expressing His6-tagged GP3 with the transmembrane (TM) and cytoplasmic (CT) domains of envelope protein gp64 was constructed and its immunogenicity was evaluated in mouse and piglet models. The His6-tagged GP3 was successfully displayed on the surface of virions as well as virus-infected Sf-9 cells. The animals immunized with BacSC-GP3 gave a slightly higher (piglets) up to a markedly higher (mice) humoral and lymphocyte proliferation responses than those that received a commercial killed vaccine. This is the first study on the immunogenicity of recombinant GP3-baculovirus, which indicates that the latter can represent an alternative strategy for developing a more effective PRRSV vaccine

Baculovirus Virions Displaying Infectious Bursal Disease Virus VP2 Protein Protect Chickens Against Infectious Bursal Disease Virus Infection

Infectious bursal disease (IBD) is an acute and contagious viral infection of young chickens caused by IBD virus (IBDV). The VP2 protein of IBDV is the only antigen for inducing neutralizing antibodies and protective immunity in the natural host. In the current study, we have succeeded in construction of one recombinant baculovirus BacSC-VP2 expressing His6-tagged VP2 with the baculovirus envelope protein gp64 transmembrane domain (TM) and cytoplasmic domain (CTD). The His6-tagged recombinant VP2 was expressed and anchored on the plasma membrane of Sf-9 cells, as examined by western blot and confocal microscopy. Immunogold electron microscopy demonstrated that the VP2 protein of IBDV was successfully displayed on the viral surface. Vaccination of chickens with the VP2-pseudotyped baculovirus vaccine (BacSC-VP2) elicited significantly higher levels of VP2-specific enzyme-linked immunosorbent assay antibodies and neutralizing antibodies than the control groups. IBDV-specific proliferation of lymphocytes was observed in chickens immunized with the recombinant BacSC-VP2. An in vivo challenge study of the recombinant baculovirus BacSC-VP2 showed effective protection against a very virulent (vv) IBDV infection in chickens. In addition, mortality and gross and histopathological findings in the bursa demonstrated the efficacy of the vaccine in reducing virulence of the disease. These results indicate that the recombinant baculovirus BacSC-VP2 can be a potential vaccine against IBDV infections