V aricella-zoster virus (VZV) is an alphaherpesvirus causing chickenpox (varicella) during primary infection and shingles (herpes zoster) following reactivation from a latent infection. Following initial exposure to the virus, there is a 10-to 21-day incubation period before the appearance of the varicella rash. During this time it has been proposed that VZV actively evades immune recognition in this period, since the development of adaptive immunity is delayed (reviewed in reference 1). We have postulated that VZV infection of dendritic cells (DCs) and/or modulation of the immune function of these potent antigen-presenting cells would provide a strategy that would enhance the capacity of the virus to be transported from the site of inoculation to the draining lymph nodes to infect T cells while also evading immune detection.We have previously shown that VZV can productively infect human DCs in vitro and in vivo (2,16,22). These studies included demonstration that productively infected immature monocytederived DCs (MDDCs) are unable to upregulate the functionally important immune molecules CD80, CD83, CD86, major histocompatibility complex I, and CCR7, which are required for DC maturation and induction of an effective antiviral immune response (2). The expression of the immune molecules inhibited by VZV are largely regulated by the nuclear factor B (NF-B) signal transduction pathway (4,6,(12)(13)(14). The NF-B signal transduction pathway is an important regulator of innate immunity and inflammation that is triggered by a wide variety of stimuli, including virus infection, tumor necrosis factor alpha (TNF-␣), and other cytokines and pathogens (26,29). Activation of the NF-B pathway via pattern recognition receptors results in the phosphorylation of inhibitor of B kinase complex (IKK), which in turn phosphorylates IB, targeting it for ubiquitination and degradation, allowing NF-B proteins (p50 and p65) to translocate into the nucleus and bind to promoters containing NF-B response elements, initiating transcription of target genes (reviewed in references 26 and 29).Herpesviruses encode multiple proteins that function in immune evasion, and several herpesvirus proteins target and disrupt the NF-B pathway. Viral genes encoded by 27,28), cytomegalovirus (23,34), and herpes simplex virus 1 (HSV-1) (3, 9, 24) have been identified to regulate the NF-B pathway in a cell type-dependent manner. Jones and Arvin (17) reported that VZV inhibits the NF-B pathway in human fibroblasts in vitro and in vivo following the phosphorylation and ubiquitination of IB␣ but prior to the translocation of NF-B proteins into the nucleus.In the present study, we sought to extend these studies and examine the effect of VZV on the NF-B pathway within VZVinfected human MDDCs. Using flow cytometry, immunofluorescent staining, and Western blotting, we establish the point where VZV impacts the NF-B pathway in VZV antigen-positive DCs. In addition, using a transient-transfection approach and flow cytometry, we identified the E3 ubiquitin ligase domai...

Diabetic vascular complications are associated with impaired ischaemia-driven angiogenesis. We recently found that reconstituted high-density lipoproteins (rHDL) rescue diabetes-impaired angiogenesis. microRNAs (miRNAs) regulate angiogenesis and are transported within HDL to sites of injury/repair. The role of miRNAs in the rescue of diabetes-impaired angiogenesis by rHDL is unknown. Using a miRNA array, we found that rHDL inhibits hsa-miR-181c-5p expression in vitro and using a hsa-miR-181c-5p mimic and antimiR identify a novel anti-angiogenic role for miR-181c-5p. miRNA expression was tracked over time post-hindlimb ischaemic induction in diabetic mice. Early post-ischaemia when angiogenesis is important, rHDL suppressed hindlimb mmu-miR-181c-5p. mmu-miR-181c-5p was not detected in the plasma or within HDL, suggesting rHDL specifically targets mmu-miR-181c-5p at the ischaemic site. Three known angiogenic miRNAs (mmu-miR-223-3p, mmu-miR-27b-3p, mmu-miR-92a-3p) were elevated in the HDL fraction of diabetic rHDL-infused mice early post-ischaemia. This was accompanied by a decrease in plasma levels. Only mmu-miR-223-3p levels were elevated in the hindlimb 3 days post-ischaemia, indicating that rHDL regulates mmu-miR-223-3p in a time-dependent and site-specific manner. The early regulation of miRNAs, particularly miR-181c-5p, may underpin the rescue of diabetes-impaired angiogenesis by rHDL and has implications for the treatment of diabetes-related vascular complications.

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Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. Selenomethionine (SeMet) is an organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response by both bolstering the endogenous thioredoxin and glutathione antioxidant defence systems and by directly scavenging damaging oxidant species. This study evaluated the effect of dietary SeMet supplementation within a high fat diet fed apolipoprotein E deficient (ApoE−/-) mouse model of atherosclerosis. Dietary supplementation with SeMet (2 mg/kg) increased the tissue concentration of Se, and the expression and activity of glutathione peroxidase, compared to non-supplemented controls. Supplementation with SeMet significantly reduced atherosclerotic plaque formation in mouse aortae, resulted in a more stable lesion phenotype and improved vessel function. Concurrent with these results, SeMet supplementation decreased lesion accumulation of M1 inflammatory type macrophages, and decreased the extent of extracellular trap release from phorbol myristate acetate (PMA)-stimulated mouse bone marrow-derived cells. Importantly, these latter results were replicated within ex-vivo experiments on cultured neutrophils isolated from acute coronary syndrome patients, indicating the ability of SeMet to alter the acute inflammatory response within a clinically-relevant setting. Together, these data highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.