The development and widespread use of vaccines against infectious agents have been a great triumph of medical science. One reason for the success of currently available vaccines is that they are capable of inducing long-lived antibody responses, which are the principal agents of immune protection against most viruses and bacteria. Despite these successes, vaccination against intracellular organisms that require cell-mediated immunity, such as the agents of tuberculosis, malaria, leishmaniasis, and human immunodeficiency virus infection, are either not available or not uniformly effective. Owing to the substantial morbidity and mortality associated with these diseases worldwide, an understanding of the mechanisms involved in generating long-lived cellular immune responses has tremendous practical importance. For these reasons, a new form of vaccination, using DNA that contains the gene for the antigen of interest, is under intensive investigation, because it can engender both humoral and cellular immune re...

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DNA vaccines: immunology, application, and optimization*.

IP: 54.70.40.11 On: Sat, 15 Dec 2018 21:37:32 Journal of General Virology (2000), 81, 2341–2364. Printed in Great Britain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

/pdf/interferons-cell-signalling-immune-modulation-antiviral-2w6111tljc.pdf

Interferons: cell signalling, immune modulation, antiviral response and virus countermeasures.

Little is known about the mechanism by which IFNs inhibit human cytomegalovirus (HCMV) replication. Indeed, infection of fibroblasts with HCMV initiates the expression of a subset of type I IFN-inducible genes whose role in the infectious process is unclear. We describe here the identification of a cytoplasmic antiviral protein that is induced by IFNs, by HCMV infection, and by the HCMV envelope protein, glycoprotein B (gB). Stable expression of the protein in fibroblasts inhibits productive HCMV infection, down-regulating several HCMV structural proteins (gB, pp28, and pp65) known to be indispensable for viral assembly and maturation. We have named the protein viperin (for virus inhibitory protein, endoplasmic reticulum-associated, interferon-inducible). HCMV infection causes the redistribution of the induced viperin from its normal endoplasmic reticulum association, first to the Golgi apparatus and then to cytoplasmic vacuoles containing gB and pp28. Expression before HCMV infection reduces viperin redistribution from the endoplasmic reticulum to the Golgi apparatus and prevents vacuolar localization, perhaps reflecting the mechanism used by HCMV to evade the antiviral function.

https://www.pnas.org/content/pnas/98/26/15125.full.pdf

Viperin (cig5), an IFN-inducible antiviral protein directly induced by human cytomegalovirus

Plasmacytoid dendritic cells (PDC) produce high levels of type I IFN upon stimulation with viruses, while monocytes and monocyte-derived dendritic cells (MDDC) produce significantly lower levels. To find what determines the high production of type I IFN in PDC, we examined the relative levels of IRF transcription factors, some of which play critical roles in the induction of IFN. Furthermore, to determine whether the differences could result from expression of distinct IFNA subtypes, the profile of IFNA genes expressed was examined. PDC responded equally well to stimulation with HSV-1 and Sendai virus (SV) by producing high levels of type I IFN, whereas the MDDC and monocyte response to SV were lower, and neither responded well to HSV-1. All three populations constitutively expressed most of the IRF genes. However, real-time RT-PCR demonstrated increased levels of IRF-7 transcripts in PDC compared with monocytes. As determined by intracellular flow cytometry, the PDC constitutively expressed significantly higher levels of IRF-7 protein than the other populations while IRF-3 levels were similar among populations. Analysis of the profile of IFNA genes expressed in virus-stimulated PDC, monocytes and MDDC demonstrated that each population expressed IFNA1 as the major subtype but that the range of the subtypes expressed in PDC was broader, with some donor and stimulus-dependent variability. We conclude that PDC but not MDDC are uniquely preprogrammed to respond rapidly and effectively to a range of viral pathogens with high levels of IFN-alpha production due to the high levels of constitutively expressed IRF-7.

https://jlb.onlinelibrary.wiley.com/doi/epdf/10.1189/jlb.0603255

Comparative analysis of IRF and IFN-alpha expression in human plasmacytoid and monocyte-derived dendritic cells.

From Infection to Autoimmunity

The IFN-alpha cytokines belong to a multigene family. However, the in vivo biological functions of each of the IFN-alpha subtypes is unknown. Recently, we developed an experimental model in which the tibialis anterior muscles of mice were transfected in situ with naked DNA plasmids encoding an IFN transgene. Here we use this model to investigate the in vivo effect of the expression of three murine IFN-alpha subtypes (A1, A4, and A9) on murine CMV replication in C57BL/6, BALB/c, and A/J mice. CMV was shown to replicate in the tibialis anterior muscles of mice for at least 6 days and induced an inflammatory infiltrate. However, mice expressing the IFN-alpha transgenes showed a marked reduction in the peak titers of virus replication, with less severe inflammation in the muscles compared with control mice that were inoculated with blank vectors. Moreover, mice expressing the IFN-alpha1 transgene had significantly lower CMV titers in the inoculated muscle than mice expressing either the IFN-alpha4 or the IFN-alpha9 transgenes. Furthermore, IFN-alpha/beta receptor knockout mice had markedly higher levels of CMV replication in the tibialis anterior muscles than the wild-type parental strain (129/Sv/Ev) following IFN-alpha1 transgene inoculation, suggesting that the protection observed is due to host cell-mediated IFN signaling. These data provide the first evidence indicating that there are in vivo differences in the antiviral efficacy of the IFN-alpha subtypes.

Antiviral activities of individual murine IFN-alpha subtypes in vivo: intramuscular injection of IFN expression constructs reduces cytomegalovirus replication.

Acid-stable type I interferons belong to a multigene family. The biologic relevance of each subtype in vivo remains unknown. We have developed an experimental model in which muscles were transfected in situ with naked DNA plasmids encoding an IFN transgene to assess the roles of individual IFN subtypes in vivo. Murine IFN-α 9 gene was subcloned into several mammalian expression vectors. Adult C57BL/6 mice were injected bilaterally in regenerating tibialis anterior muscles with naked DNA 5 days after muscle injury to enhance DNA uptake and expression. In the muscles of mice given the IFN-α9 plasmid constructs, acid-stable IFNs were detected by bioassay using reduction in cytopathic effect of encephalomyocarditis virus-infected L929 cells. In these same muscles, IFN-α9 transcripts were identified by RT-PCR, indicating that transcription had occurred. Acid-stable IFNs were detected from days 7 to 28 post-DNA inoculation. Furthermore, these proteins were found in the sera of DNA-inoculated mice. Control group...

/pdf/in-vivo-expression-of-an-interferon-alpha-gene-by-587oxi1urp.pdf

Wen-Shuz Yeow

Papers

Antiviral activities of individual murine IFN-alpha subtypes in vivo: intramuscular injection of IFN expression constructs reduces cytomegalovirus replication.

In vivo expression of an interferon-alpha gene by intramuscular injection of naked DNA.

The in vivo expression patterns of individual type I interferon genes in murine cytomegalovirus infections.

Differential expression patterns of type I interferon subtypes in mouse embryo fibroblasts: Influence of genotype and viral inducer

The in vitro expression patterns of individual type I interferon genes in newcastle disease virus infected murine splenocytes and fibroblasts