N-myristoyltransferase (NMT) exists in two isoforms, NMT1 and NMT2, that catalyze myristoylation of various proteins crucial in signal transduction, cellular transformation, and oncogenesis. We have recently demonstrated that NMT1 is essential for the early development of mouse embryo. In this report, we have demonstrated that an invariant consequence of NMT1 knock out is defective myelopoesis. Suppressed macrophage colony forming units were observed in M-CSF-stimulated bone marrow cells from heterozygous (+/–) Nmt1-deficient mice. Homozygous (−/−) Nmt1-deficient mouse embryonic stem cells resulted in drastic reduction of macrophages when stimulated to differentiate by M-CSF. Furthermore, to understand the requirement of NMT1 in the monocytic differentiation we investigated the role of NMT, pp60c−Src (NMT substrate) and heat shock cognate protein 70 (inhibitor of NMT), during PMA-induced differentiation of U937 cells. Src kinase activity and protein expression increased during the differentiation process along with regulation of NMT activity by hsc70. NMT1 knock down in PMA treated U937 cells showed defective monocytic differentiation. We report in this study novel observation that regulated total NMT activity and NMT1 is essential for proper monocytic differentiation of the mouse bone marrow cells.

Bovine herpesvirus type 1 (BHV-1) is an alphaherpesvirus which is an important pathogen of cattle, causing a variety of clinical manifestations in its natural host (46). BHV-1 virions have a typical herpesvirus structure characterized by the presence of a double-stranded DNA genome enclosed in an icosahedral capsid, the tegument surrounding the capsid, and the outer host-derived lipid envelope bearing virus-encoded glycoproteins. While the major constituents of the viral envelope have been extensively studied (reviewed in reference 17), the proteins present in the tegument and nucleocapsid of BHV-1 have been poorly characterized. Compositionally, the tegument is the most complex compartment of the virion, containing more than 15 viral gene products (32). In addition to their structural role, various regulatory functions, including modulation of transcription (34, 47), kinase activity (39), RNase activity (41), and DNA packaging (43), have been assigned to some tegument proteins, suggesting that these virion constituents function at several stages during virus infection, establishing conditions for efficient viral replication and promoting virus assembly and egress.Although the U L 47 gene product, tegument protein VP8, is the most abundant component of mature BHV-1 virions (5), its function is unknown. Like its herpes simplex virus type 1 (HSV-1) homologue (31), VP8 is posttranslationally modified by phosphorylation (5,23) and by the addition of O-linked carbohydrates (49). Both HSV-1 and BHV-1 U L 47 homologues possess nuclear localization and nuclear export signatures (7,51,53,56), enabling them to shuttle between the nucleus and cytoplasm when expressed in transiently transfected cells (51,56) or during viral infection (52, 53). Furthermore, both proteins exhibit a steady-state nuclear localization at early stages of infection and during transient expression (6,35,49,51,52,56), suggesting a functional role for these homologues in the nucleus. Nucleocytoplasmic shuttling of VP8 is sensitive to treatment with a RNA polymerase II inhibitor, actinomycin D (52). This observation coupled with recently demonstrated RNA binding activity of the HSV-1 and BHV-1

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Respiratory syncytial virus (RSV) is the leading cause of serious respiratory tract disease in children and calves; however, RSV vaccine development has been slow due to early observations that formalin-inactivated vaccines induced Th2-type immune responses and led to disease enhancement upon subsequent exposure. Hence, there is a need for novel adjuvants that will promote a protective Th1-type or balanced immune response against RSV. CpG oligodeoxynucleotides (ODNs), indolicidin, and polyphosphazene were examined for their ability to enhance antigen-specific immune responses and influence the Th-bias when co-formulated with a recombinant truncated bovine RSV (BRSV) fusion protein (DF). Mice immunized with DF co-formulated with CpG ODN, indolicidin, and polyphosphazene (DF/CpG/indol/PP) developed higher levels of DF-specific serum IgG, IgG1 and IgG2a antibodies when compared with DF alone, and displayed an increase in the frequency of gamma interferon-secreting cells and decreased interleukin (IL)-5 production by in vitro restimulated splenocytes, characteristic of a Th1 immune response. These results were observed in both C57BL/6 and BALB/c strains of mice. When evaluated in a BRSV challenge model, mice immunized with DF/CpG/indol/PP developed significantly higher levels of BRSV-neutralizing serum antibodies than mice immunized with the DF protein alone, and displayed significantly less pulmonary IL-4, IL-5, IL-13 and eotaxin and reduced eosinophilia after challenge. These results suggest that co-formulation of DF with CpG ODN, host defence peptide and polyphosphazene may result in a safe and effective vaccine for the prevention of BRSV and may have implications for the development of novel human RSV vaccines. INTRODUCTIONHuman respiratory syncytial virus (HRSV) is the leading cause of serious lower respiratory tract infections in infants, and almost all children will have been infected by the age of two (Glezen et al., 1986; Shay et al., 1999). Severe HRSV infection in infancy has been strongly associated with the development of asthma and allergic sensitization later in life (Sigurs et al., 1995(Sigurs et al., , 2000, and it may also cause disease in adults, especially in elderly and immunosuppressed individuals (Meyer et al., 2008). Likewise, bovine respiratory syncytial virus (BRSV) causes considerable economic loss in the cattle industry (Gershwin, 2007). BRSV and HRSV are closely related, displaying similar epidemiology and pathogenesis (Van der Poel et al., 1994), making BRSV a good model for the study of RSV vaccines (Valarcher & Taylor, 2007 , 1996). More recent evidence has suggested that the failure of the FI-RSV vaccine may also have been due to the inability of the formalin-inactivated virus to prime for CD8 + T cell responses (Srikiatkhachorn & Braciale, 1997), as well as the resultant generation of low avidity, nonprotective antibody responses (Delgado et al., 2009;Polack et al., 2002). To date, there is still no licensed vaccine against HRSV, and BRSV vaccines are only moderately effective. The...

At present, infections with bovine viral diarrhea virus (BVDV) type 2 occur nearly as frequently as those with BVDV type 1, so development of vaccines that protect cattle from both type 1 and type 2 BVDV has become critical. In this study, we compared various DNA prime-protein boost vaccination strategies to protect cattle from challenge with BVDV-2 using the major protective antigen of BVDV, glycoprotein E2. Calves were immunized with a plasmid encoding either type 1 E2 (E2.1) or type 2 E2 (E2.2) or with both plasmids (E2.1+E2.2). This was followed by a heterologous boost with E2.1, E2.2 or E2.1 and E2.2 protein formulated with Emulsigen and a CpG oligodeoxynucleotide. Subsequently, the calves were challenged with BVDV-2 strain 1373. All vaccinated calves developed both humoral and cell-mediated immune responses, including virus-neutralizing antibodies and IFN-c-secreting cells in the peripheral blood. Depletion studies showed that CD4+ T cells were responsible for IFN-c production. Furthermore, the calves vaccinated with either the E2.2 or the E2.1+E2.2 vaccines were very well protected from challenge with BVDV-2, having little leukopenia and showing no weight loss or temperature response. In addition, the animals vaccinated with the E2.1 vaccine were partially protected, so there was a certain level of cross-protection. These data demonstrate that a vaccination strategy consisting of priming with E2.2 or E2.1+E2.2 DNA and boosting with E2.2 or E2.1+E2.2 protein fully protects cattle from BVDV-2 challenge.

The U S 3 gene product of bovine herpesvirus-1 (BoHV-1) is a protein kinase that is expressed early during infection and capable of autophosphorylation. By examining differentially labelled US3 moieties by co-immunoprecipitation, we demonstrated that the protein kinase interacts with itself in vitro, which supports autophosphorylation by US3. Based on its homology to other serine/ threonine protein kinases, we defined two highly conserved lysines in US3, at position 195 within the ATP-binding pocket and at position 282 within the catalytic loop; altering either residue resulted in kinase-dead mutants, demonstrating that these two residues are critical for the catalytic activity of BoHV-1 US3. During immunoprecipitation experiments, US3 interacted weakly with VP22, another tegument protein of BoHV-1. Furthermore, VP22 co-localized with US3 inside the nucleus in BoHV-1-infected cells. In vitro kinase assays demonstrated that VP22 is phosphorylated not only by US3, but also by the cellular casein kinase 2 (CK2) protein. The selective CK2 protein kinase inhibitor, 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) and the less specific CK2 inhibitor Kenpaullone reduced VP22 phosphorylation, while CK1, protein kinase C or protein kinase A inhibitors did not affect phosphorylation. When US3 was included with VP22 in the kinase assay in the presence of DMAT, a low level of VP22 phosphorylation was observed. These data demonstrate that BoHV-1 VP22 interacts with both CK2 and US3, and that CK2 is the major kinase phosphorylating VP22, with US3 playing a minor role.

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