Nutritional Gaps and Supplementation in the First 1000 Days.

Optimized nutrition during the first 1000 days (from conception through the 2nd birthday) is critical for healthy development and a healthy life for the newborn. Pregnancy and the postpartum period are accompanied by physiological changes, increased energy needs, and changing requirements in the nutrients critical for optimal growth and development. Infants and toddlers also experience physiological changes and have specific nutritional needs. Food and nutrition experts can provide women of childbearing age with adequate dietary advice to optimize nutrition, as well as guidance on selecting appropriate dietary supplements. Considering the approaching 2020-2025 Dietary Guidelines for Americans (DGA) will be making specific recommendations for children, it is important to provide accurate scientific information to support health influencers in the field of nutrition. The purpose of this review is to summarize the nutrition and supplementation literature for the first 1000 days; to highlight nutritional and knowledge gaps; and to educate nutrition influencers to provide thoughtful guidance to mothers and families. Optimal nutrition during pregnancy through early childhood is critical for supporting a healthy life. Nutrition influencers, such as dietitians, obstetricians/gynecologists, and other relevant health professionals, should continue guiding supplement and food intake and work closely with expectant families and nutrition gatekeepers.

Interaction of ICP34.5 with Beclin 1 modulates herpes simplex virus type 1 pathogenesis through control of CD4+ T-cell responses.

Autophagy is an important component of host innate and adaptive immunity to viruses. It is critical for the degradation of intracellular pathogens and for promoting antigen presentation. Herpes simplex virus type 1 (HSV-1) infection induces an autophagy response, but this response is antagonized by the HSV-1 neurovirulence gene product, ICP34.5. This is due, in part, to its interaction with the essential autophagy protein Beclin 1 (Atg6) via the Beclin-binding domain (BBD) of ICP34.5. Using a recombinant virus lacking the BBD, we examined pathogenesis and immune responses using mouse models of infection. The BBD-deficient virus (Delta68H) replicated equivalently to its marker-rescued counterpart (Delta68HR) at early times but was cleared more rapidly than Delta68HR from all tissues at late times following corneal infection. In addition, the infection of the cornea with Delta68H induced less ocular disease than Delta68HR. These results suggested that Delta68H was attenuated due to its failure to control adaptive rather than innate immunity. In support of this idea, Delta68H stimulated a significantly stronger CD4(+) T-cell-mediated delayed-type hypersensitivity response and resulted in significantly more production of gamma interferon and interleukin-2 from HSV-specific CD4(+) T cells than Delta68HR. Taken together, these data suggest a role for the BBD of ICP34.5 in precluding autophagy-mediated class II antigen presentation, thereby enhancing the virulence and pathogenesis of HSV-1.

Interferon gamma is not required for recurrent herpetic stromal keratitis.

The role that interferon-gamma (IFNgamma) plays during herpetic stromal keratitis (HSK) has not been definitively determined. In primary HSK most reports suggest that IFNgamma may help control viral replication and contribute to corneal pathology. However, its role in recurrent HSK has not been directly addressed. The present study addresses its role in recurrent HSK by comparing HSK in latently infected normal and IFNgamma gene knockout (GKO) on the C57BL/6 background. We initially evaluated HSK following primary infection and observed that GKO mice had higher tear film virus titers, but virtually identical ocular disease as normal mice. In contrast, following reactivation of latent virus, GKO mice had a greater incidence and severity of opacity, neovascularization, and blepharitis. Interestingly, the incidence of reactivation after UV-B exposure was equivalent in GKO and normal mice, but virus shedding was increased in the GKO groups. We also observed diminished delayed-type hypersensitivity responses in GKO mice, as expected. These data indicate that IFNgamma is important for the control of virus replication in both primary and recurrent ocular HSV infection in C57BL/6 mice. The enhanced recurrent disease seen in GKO mice may be the result of increased viral titers and persistence in these mice which act to prolong the stimulation of an inflammatory response.

Herpes simplex virus virion host shutoff attenuates establishment of the antiviral state.

Herpes simplex virus mutants lacking the vhs protein are severely attenuated in animal models of pathogenesis and exhibit reduced growth in primary cell culture. As a result of these properties, viruses with vhs deleted have been proposed as live-attenuated vaccines. Despite these findings and their implications for vaccines, the mechanisms by which vhs promotes infection in cell culture and in vivo are not understood. In this study we demonstrate that vhs-deficient viruses replicate to reduced levels in interferon (IFN)-primed cells and that this deficit has both IFN-dependent and IFN-independent components. Furthermore, vhs-defective viruses induce increased and physiologically active levels of IFN, increased amounts of IFN-stimulated transcripts, and more phosphorylated eIF2alpha. In addition, we demonstrate greater accumulation of viral RNAs following infection with a vhs-deficient virus. This leads to the hypothesis that attenuation of viruses lacking vhs may be attributed to increased levels of double-stranded RNA, a potent pathogen-associated molecular pattern. Together these data show that vhs likely functions to reduce innate immune responses and thereby acts as a critical determinant of viral pathogenesis.

Xenophagy in herpes simplex virus replication and pathogenesis.

Autophagy functions in part as an important host defense mechanism to engulf and degrade intracellular pathogens, a process that has been termed xenophagy. Xenophagy is detrimental to the invading microbe in terms of replication and pathogenesis and many pathogens either dampen the autophagic response, or utilize the pathway to enhance their life cycle. Herpes simplex virus type 1 (HSV-1) counteracts the induction of xenophagy through its neurovirulence protein, ICP34.5. ICP34.5 binds protein phosphatase 1alpha to counter PKR-mediated phosphorylation of eIF2alpha, and also binds the autophagy-promoting protein Beclin 1. Through these interactions, ICP34.5 prevents translational arrest and down-regulates the formation of autophagosomes. Whereas autophagy antagonism promotes neurovirulence, it has no impact on the replication of HSV-1 in permissive cultured cells. As discussed in this article, this work raises a number of questions as to the mechanism of ICP34.5-mediated inhibition of autophagy, as well as to the role of autophagy antagonism in the lifecycle of HSV-1.

Analysis of the role of autophagy in replication of herpes simplex virus in cell culture.

The herpes simplex virus type 1 (HSV-1) neurovirulence gene encoding ICP34.5 controls the autophagy pathway. HSV-1 strains lacking ICP34.5 are attenuated in growth and pathogenesis in animal models and in primary cultured cells. While this growth defect has been attributed to the inability of an ICP34.5-null virus to counteract the induction of translational arrest through the PKR antiviral pathway, the role of autophagy in the regulation of HSV-1 replication is unknown. Here we show that HSV-1 infection induces autophagy in primary murine embryonic fibroblasts and that autophagosome formation is increased to a greater extent following infection with an ICP34.5-deficient virus. Elimination of the autophagic pathway did not significantly alter the replication of wild-type HSV-1 or ICP34.5 mutants. The phosphorylation state of eIF2alpha and viral protein accumulation were unchanged in HSV-1-infected cells unable to undergo autophagy. These data show that while ICP34.5 regulates autophagy, it is the prevention of translational arrest by ICP34.5 rather than its control of autophagy that is the pivotal determinant of efficient HSV-1 replication in primary cell culture.

The Snf1 protein kinase and Sit4 protein phosphatase have opposing functions in regulating TATA-binding protein association with the Saccharomyces cerevisiae INO1 promoter.

To identify the mechanisms by which multiple signaling pathways coordinately affect gene expression, we investigated regulation of the S. cerevisiae INO1 gene. Full activation of INO1 transcription occurs in the absence of inositol and requires the Snf1 protein kinase in addition to other signaling molecules and transcription factors. Here, we present evidence that the Sit4 protein phosphatase negatively regulates INO1 transcription. A mutation in SIT4 was uncovered as a suppressor of the inositol auxotrophy of snf1Delta strains. We found that sit4 mutant strains exhibit an Spt(-) phenotype, suggesting a more general role for Sit4 in transcription. In fact, like the gene-specific regulators of INO1 transcription, Opi1, Ino2, and Ino4, both Snf1 and Sit4 regulate binding of TBP to the INO1 promoter, as determined by chromatin immunoprecipitation analysis. Experiments involving double-mutant strains indicate that the negative effect of Sit4 on INO1 transcription is unlikely to occur through dephosphorylation of histone H3 or Opi1. Sit4 is a known component of the target of rapamycin (TOR) signaling pathway, and treatment of cells with rapamycin reduces INO1 activation. However, analysis of rapamycin-treated cells suggests that Sit4 represses INO1 transcription through multiple mechanisms, only one of which may involve inhibition of TOR signaling.

Inhibition of TATA binding protein dimerization by RNA polymerase III transcription initiation factor Brf1.

The Brf1 subunit of TFIIIB plays an important role in recruiting the TATA-binding protein (TBP) to the up-stream region of genes transcribed by RNA polymerase III. When TBP is not bound to promoters, it sequesters its DNA binding domain through dimerization. Promoter assembly factors therefore might be required to dissociate TBP into productively binding monomers. Here we show that Saccharomyces cerevisiae Brf1 induces TBP dimers to dissociate. The high affinity TBP binding domain of Brf1 is not sufficient to promote TBP dimer dissociation but in addition requires the TFIIB homology domain of Brf1. A model is proposed to explain how two distinct functional domains of Brf1 work in concert to dissociate TBP into monomers.