Human interferon (IFN)-inducible IFI16 protein, an innate immune sensor of intracellular DNA, modulates various cell functions, however, its role in regulating virus growth remains unresolved. Here, we adopt two approaches to investigate whether IFI16 exerts pro- and/or anti-viral actions. First, the IFI16 gene was silenced using specific small interfering RNAs (siRNA) in human embryo lung fibroblasts (HELF) and replication of DNA and RNA viruses evaluated. IFI16-knockdown resulted in enhanced replication of Herpesviruses, in particular, Human Cytomegalovirus (HCMV). Consistent with this, HELF transduction with a dominant negative form of IFI16 lacking the PYRIN domain (PYD) enhanced the replication of HCMV. Second, HCMV replication was compared between HELFs overexpressing either the IFI16 gene or the LacZ gene. IFI16 overexpression decreased both virus yield and viral DNA copy number. Early and late, but not immediate-early, mRNAs and proteins were strongly down-regulated, thus IFI16 may exert its antiviral effect by impairing viral DNA synthesis. Constructs with the luciferase reporter gene driven by deleted or site-specific mutated forms of the HCMV DNA polymerase (UL54) promoter demonstrated that the inverted repeat element 1 (IR-1), located between −54 and −43 relative to the transcription start site, is the target of IFI16 suppression. Indeed, electrophoretic mobility shift assays and chromatin immunoprecipitation demonstrated that suppression of the UL54 promoter is mediated by IFI16-induced blocking of Sp1-like factors. Consistent with these results, deletion of the putative Sp1 responsive element from the HCMV UL44 promoter also relieved IFI16 suppression. Together, these data implicate IFI16 as a novel restriction factor against HCMV replication and provide new insight into the physiological functions of the IFN-inducible gene IFI16 as a viral restriction factor.

bThe human cytomegalovirus (HCMV) US12 gene family comprises a set of 10 contiguous genes (US12 to US21), each encoding a predicted seven-transmembrane protein and whose specific functions have yet to be ascertained. While inactivation of individual US12 family members in laboratory strains of HCMV has not been found to affect viral replication in fibroblasts, inactivation of US16 was reported to increase replication in microvascular endothelial cells. Here, we investigate the properties of US16 further by ascertaining the expression pattern of its product. A recombinant HCMV encoding a tagged version of the US16 protein expressed a 33-kDa polypeptide that accumulated with late kinetics in the cytoplasmic virion assembly compartment. To elucidate the function(s) of pUS16, we generated US16-deficient mutants in the TR clinical strain of HCMV. According to previous studies, inactivation of US16 had no effect on viral replication in fibroblasts. In contrast, the US16-deficient viruses exhibited a major growth defect in both microvascular endothelial cells and retinal pigment epithelial cells. The expression of representative IE, E, and L viral proteins was impaired in endothelial cells infected with a US16 mutant virus, suggesting a defect in the replication cycle that occurs prior to IE gene expression. This defect must be due to an inefficient entry and/or postentry event, since pp65 and viral DNA did not move to the nucleus in US16 mutant-infected cells. Taken together, these data indicate that the US16 gene encodes a novel virus tropism factor that regulates, in a cell-specific manner, a pre-immediate-early phase of the HCMV replication cycle.

A hallmark of human cytomegalovirus (HCMV) pathogenesis is its ability to productively replicate in a remarkably broad range of different cell types, including epithelial, fibroblast, endothelial, macrophage, dendritic, smooth-muscle, and neuronal cells, as well as hepatocytes (2,5,19,23,29,38,39). Macrophages and neurons are terminally differentiated and do not undergo cellular division, whereas endothelial, epithelial, and smooth-muscle cells remain predominantly within the stationary phase of the cell cycle and divide only when specific circumstances are presented, such as tissue injury. It therefore seems that the coevolution of HCMV with its host has resulted in HCMV developing mechanisms that enable it to manipulate the host cell's regulatory systems in nonproliferating cell types that present intracellular environments that are unfavorable for high levels of viral DNA replication and virus production. Numerous studies have indeed demonstrated the ability of HCMV to modulate (both activate and repress) various cellular signaling pathways and transcription factor systems that positively regulate viral gene expression. However, despite the fact that most of the cell types susceptible to HCMV infection in vivo are in a growth-arrested state, the vast majority of these studies have utilized rapidly dividing cell cultures rather than cultures of quiescent cells (29,48).A critical step in HCMV replication is the synthesis of the major immediate-early (MIE) proteins IE1 and IE2, which regulate subsequent early (E) and late (L) gene expression during lytic infections and manipulate a variety of cellular functions to optimize the cellular environment for viral replication (28,29,42). Failure to express a robust IE program, as observed in undifferentiated cell types, results in a latent outcome of HCMV infection (37). The expression of MIE genes is under the control of the major immediate-early promoter (MIEP) region, which contains one of the most powerful transcriptional enhancers identified to date (28,29,41). The MIEP enhancer spans the region between approximately Ϫ550 and Ϫ39 relative to the MIE transcription start sites at ϩ1, and it displays a characteristic array of repetitive binding sites for various cellular transcription factors that may act as positive or negative regulatory factors of MIEP activity (28,29,41). The MIEP enhancer has two components that are proximal (Ϫ39 to Ϫ300) and distal (Ϫ300 to Ϫ550) relative to the transcription start site of the MIE promoter. The proximal and distal enhancer portions both are required for efficient MIE gene expression and viral replication (17,27,41). However, the reason why the MIEP enhancer should contain a multitude of diverse transcription binding sites is unclear. Comparative analyses have shown that the arrangement and number of binding sites

Gerbera plants were grown in semi-closed rockwool culture under greenhouse conditions in different seasons in a Mediterranean climate. The plants were irrigated using either fresh (FW; 1.0 mol m−3NaCl)or moderately saline (SW; 9.0 mol m−3NaCl) water. In autumn, NaCl concentration did not influence significantly plant growth, flower production and transpiration (E), which instead were reduced in springin the plants irrigated with SW. In both seasons, water salinity did not affect leaf stomatal resistance (rl),which was determined by the inversion of the Penman–Monteith (PM) equation or measured with a diffusion porometer. The PM formula and two regression equations were calibrated and validated for estimating the hourly rate of daytime transpiration (Ed); a regression model was also fit to nocturnal transpiration (En). Regression models predicted Edas a function of vapour pressure deficit (VPD) and/or the radiation intercepted by the canopy. Leaf area index (LAI), which is required by all the equations, was modelled as function of crop thermal time (i.e. growing degree days). The PM model predicted Ed using a constant value of rl. Model calibration and validation were performed using independent data sets. The irrigation with FW or SW did not require a different calibration of transpiration models. Both PM formula and regression equations provided accurate estimates of Ed; fitted equations explained between 80% and96% of the variance in measured Ed. A linear regression of En against (LAI·VPD) accounted for 92% of measured En

Multiple sclerosis (MS) is a multifactorial neurological disease characterized by chronic inflammation and immune-driven demyelination of the central nervous system (CNS). The rising number of MS cases in the last decade could be partially attributed to environmental changes, among which the alteration of the gut microbiome driven by novel dietary habits is now of particular interest. The intent of this review is to describe how diet can impact the development and course of MS by feeding the gut microbiome. We discuss the role of nutrition and the gut microbiota in MS disease, describing preclinical studies on experimental autoimmune encephalomyelitis (EAE) and clinical studies on dietary interventions in MS, with particular attention to gut metabolites–immune system interactions. Possible tools that target the gut microbiome in MS, such as the use of probiotics, prebiotics and postbiotics, are analyzed as well. Finally, we discuss the open questions and the prospects of these microbiome-targeted therapies for people with MS and for future research.

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