The rockefeller university

Background: Psoriasis is a chronic inflammatory skin disease

It is extremely expensive to conduct large sample size array- or sequencing based genome scale association studies. For a quantitative trait, an extreme case-control study design may improve the power and reduce the cost of variant calling. We investigated the performance of extreme study design when various proportions of samples are selected from the tails of phenotype distribution. Using simulations, we show that when risk genotypes become rare in the population and effect size is relatively small, it is beneficial to carry out an extreme sampling study. In particular, the number of selected cases and controls can even be unbalanced such that power is further increased, compared with a balanced selection. Our application to two data sets: methadone dose data and yearling weight data, demonstrated that similar results for full data analysis can be obtained using extreme sampling with only a fraction of the data. Using power analysis with simulated data and an experimental data application, we conclude that when full data is unavailable due to restricted budget, it is rewarding to employ an extreme sampling design in the sense that there can be immense cost reductions and qualitatively similar power as in the full data analysis.

The identification of loss-of-function mutations of the IL36RN gene encoding the interleukin-36 receptor antagonist (IL-36Ra) in generalized pustular psoriasis (GPP) emphasized the key role of this pathway in skin innate immunity and systemic inflammation. It has been previously shown in vitro that removal of the N-terminal amino acid IL36Ra (M1) is critical to its biological activity, but the in vivo contribution of this processing remains unknown. We report herein a new homozygous (c4G>T, pV2F) missense IL36RN mutation segregating in a family with three GPP-affected patients. The V2F mutation does not alter IL-36Ra protein expression but was devoid of any antagonist activity. Mass spectrometry showed that the V2F IL-36Ra mutant retains its first N-terminal methionine. These results provide the first in vivo demonstration that removal of N-terminal methionine of native IL-36Ra is a mandatory step to reach optimal antagonist activity and to prevent sustained skin and systemic inflammation in humans.

Allostatic load reflects the cumulative effects of stressful experiences

Mesenchymal stem/stromal cells (MSCs) are self-renewing multipotent

Soon after exposure to genotoxic reagents, mammalian cells inhibit transcription to prevent collisions with repair machinery and to mount a proper DNA damage response. However, mechanisms underlying early transcriptional inhibition are poorly understood. In this report, we show that site-specific acetylation of super elongation complex (SEC) subunit AFF1 by p300 reduces its interaction with other SEC components and impairs P-TEFb-mediated C-terminal domain phosphorylation of RNA polymerase II both in vitro and in vivo. Reexpression of wild-type AFF1, but not an acetylation mimic mutant, restores SEC component recruitment and target gene expression in AFF1 knockdown cells. Physiologically, we show that, upon genotoxic exposure, p300-mediated AFF1 acetylation is dynamic and strongly correlated with concomitant global down-regulation of transcription-and that this can be reversed by over-expression of an acetylation-defective AFF1 mutant. Therefore, we describe a mechanism of dynamic transcriptional regulation involving p300-mediated acetylation of a key elongation factor during genotoxic stress.

Numerous challenges have impeded HIV-1 vaccine development. Among these is the lack of a convenient small animal model in which to study antibody elicitation and efficacy. We describe a chimeric Rhabdo-Immunodeficiency virus (RhIV) murine model that recapitulates key features of HIV-1 entry, tropism and antibody sensitivity. RhIVs are based on vesicular stomatitis viruses (VSV), but viral entry is mediated by HIV-1 Env proteins from diverse HIV-1 strains. RhIV infection of transgenic mice expressing human CD4 and CCR5, exclusively on mouse CD4+ cells, at levels mimicking those on human CD4+ T-cells, resulted in acute, resolving viremia and CD4+ T-cell depletion. RhIV infection elicited protective immunity, and antibodies to HIV-1 Env that were primarily non-neutralizing and had modest protective efficacy following passive transfer. The RhIV model enables the convenient in vivo study of HIV-1 Env-receptor interactions, antiviral activity of antibodies and humoral responses against HIV-1 Env, in a genetically manipulatable host.

Voltage-gated potassium channels (K(v)s) are gated by transmembrane

Stewart Cole and colleagues determined the complete genome sequence of

Cooperative binding of transcription factors (TFs) to chromatin