The rockefeller university

We are just beginning to understand how translational control affects tumour initiation and malignancy. Here we use an epidermis-specific, in vivo ribosome profiling strategy to investigate the translational landscape during the transition from normal homeostasis to malignancy. Using a mouse model of inducible SOX2, which is broadly expressed in oncogenic RAS-associated cancers, we show that despite widespread reductions in translation and protein synthesis, certain oncogenic mRNAs are spared. During tumour initiation, the translational apparatus is redirected towards unconventional upstream initiation sites, enhancing the translational efficiency of oncogenic mRNAs. An in vivo RNA interference screen of translational regulators revealed that depletion of conventional eIF2 complexes has adverse effects on normal but not oncogenic growth. Conversely, the alternative initiation factor eIF2A is essential for cancer progression, during which it mediates initiation at these upstream sites, differentially skewing translation and protein expression. Our findings unveil a role for the translation of 5' untranslated regions in cancer, and expose new targets for therapeutic intervention.

Objectives: A CD1d-binding invariant natural killer T (iNKT)-cell stimulatory glycolipid, namely 7DW8-5, is shown to enhance the efficacy of radiation-attenuated sporozoites (RAS)-based malaria vaccine in mice. In the current study, we aim to determine whether 7DW8-5 can display a potent adjuvant effect in human immune system (HIS) mice.Methods: HIS-A2/hCD1d mice, which possess both functional human iNKT cells and CD8+T cells, were generated by the transduction of NSG mice with adeno-associated virus serotype 9 expressing genes that encode human CD1d molecules and HLA-A*0201, followed by the engraftment of human hematopoietic stem cells. The magnitudes of human iNKT-cell response against 7DW8-5 and HLA-A*0201-restricted human CD8+T-cell response against a human malaria antigen in HIS-A2/hCD1d mice were determined by using human CD1d tetramer and human HLA-A*0201 tetramer, respectively.Results: We found that 7DW8-5 stimulates human iNKT cells in HIS-A2/hCD1d mice, as well as those derived from HIS-A2/hCD1d mice in vitro. We also found that 7DW8-5 significantly increases the level of a human malarial antigen-specific HLA-A*0201-restricted human CD8+T-cell response in HIS-A2/hCD1d mice.Conclusions: Our study indicates that 7DW8-5 can display a potent adjuvant effect on RAS vaccine-induced anti-malarial immunity by augmenting malaria-specific human CD8+T-cell response.

CRISPR loci and their associated (Cas) proteins encode a prokaryotic immune system that protects against viruses and plasmids. Upon infection, a low fraction of cells acquire short DNA sequences from the invader. These sequences (spacers) are integrated in between the repeats of the CRISPR locus and immunize the host against the matching invader. Spacers specify the targets of the CRISPR immune response through transcription into short RNA guides that direct Cas nucleases to the invading DNA molecules. Here we performed random mutagenesis of the RNA-guided Cas9 nuclease to look for variants that provide enhanced immunity against viral infection. We identified a mutation, I473F, that increases the rate of spacer acquisition by more than two orders of magnitude. Our results highlight the role of Cas9 during CRISPR immunization and provide a useful tool to study this rare process and develop it as a biotechnological application.

Historically, many of the classical organic fluorescent dyes were developed as laser dyes and characterized and optimized in organic solvents. Since then, fluorescence has, however, found a vast range of applications in the life sciences in which the fluorophores are usually surrounded by water and not by organic solvents. The omnipresence of water in biomolecular fluorescence spectroscopy and imaging leads to some unwanted but nonetheless unavoidable consequences on the photophysical properties of the dyes, which may impact the quality and complicate quantitative interpretation of the experiments. This paper discusses and illustrates with examples two such water-induced phenomena, namely chromophore aggregation in water and fluorescence quenching by water, as well as some ways to overcome them.

Secreted proteins serve pivotal roles in the development of multicellular organisms, acting as structural matrix, extracellular enzymes, and signal molecules. However, how the secretome is regulated remains incompletely understood. Here we demonstrate, unexpectedly, that peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 alpha), a critical transcriptional co-activator of metabolic gene expression, functions to down-regulate the expression of diverse genes encoding secreted molecules and extracellular matrix components to modulate the secretome. Using cell lines, primary cells, and mice, we show that both endogenous and exogenous PGC-1 alpha down-regulate the expression of numerous genes encoding secreted molecules. Mechanistically, results obtained using mRNA stability measurements as well as intronic RNA expression analysis are consistent with a transcriptional effect of PGC-1 alpha on the expression of genes encoding secreted proteins. Interestingly, PGC-1 alpha requires the central heat shock response regulator heat shock factor protein 1 (HSF1) to affect some of its targets, and both factors co-reside on several target genes encoding secreted molecules in cells. Finally, using a mass spectrometric analysis of secreted proteins, we demonstrate that PGC-1 alpha modulates the secretome of mouse embryonic fibroblasts. Our results define a link between a key pathway controlling metabolic regulation and the regulation of the mammalian secretome.

Dengue virus (DENV) infection in the presence of reactive, non-neutralizing immunoglobulin G (IgG) (RNNIg) is the greatest risk factor for dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Progression to DHF/DSS is attributed to antibody-dependent enhancement (ADE); however, because only a fraction of infections occurring in the presence of RNNIg advance to DHF/DSS, the presence of RNNIg alone cannot account for disease severity. We discovered that DHF/DSS patients respond to infection by producing IgGs with enhanced affinity for the activating Fc receptor Fc gamma RIIIA due to afucosylated Fc glycans and IgG1 subclass. RNNIg enriched for afucosylated IgG1 triggered platelet reduction in vivo and was a significant risk factor for thrombocytopenia. Thus, therapeutics and vaccines restricting production of afucosylated, IgG1 RNNIg during infection may prevent ADE of DENV disease.

Janus kinase (JAK) inhibitors have achieved positive responses in myeloproliferative neoplasms, but at the expense of decreased natural killer (NK) cell numbers and compromised function. Selective JAK2 inhibition may also have a role in preventing and treating graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. Although JAK inhibitors can impair monocyte-derived dendritic cell (moDC) activation and function and suppress effector T-cell responses, the effects on NK cells and the relevant mechanisms remain undefined. Using common gamma(c) cytokines and distinct human dendritic cell (DC) subtypes, we compared the effects of a JAK2-specific (TG101348) with a less selective JAK1/ 2 (ruxolitinib) inhibitor on NK-cell activation and function. Ruxolitinib treatment completely blocked IL2, IL15, and DC-mediated STAT5 phosphorylation, along with the capacity of NK cells to secrete IFN gamma or lyse NK cell-sensitive targets. Only NK-cell proliferation stimulated by moDCs resisted ruxolitinib treatment. In contrast, TG101348 treatment of stimulated NK cells resulted in far less functional compromise. TG101348 completely inhibited only soluble IL15-mediated STAT5 phosphorylation, which Langerhans-type DCs (LCs), presenting membrane-bound IL15 in trans, could salvage. These results demonstrate that ruxolitinib's nonselective inhibition of JAK1/2 results in profound NK-cell dysfunction by blocking downstream pSTAT5, hence providing a persuasive rationale for the development of selective JAK2 inhibitors for immunotherapeutic applications. (C) 2016 AACR.

We engineered covalently circularized nanodiscs (cNDs) which, compared with standard nanodiscs, exhibit enhanced stability, defined diameter sizes and tunable shapes. Reconstitution into cNDs enhanced the quality of nuclear magnetic resonance spectra for both VDAC-1, a beta-barrel membrane protein, and the G-protein-coupled receptor NTR1, an alpha-helical membrane protein. In addition, we used cNDs to visualize how simple, nonenveloped viruses translocate their genomes across membranes to initiate infection.