The rockefeller university

Advances in human genome editing, in particular the development of the clustered regularly interspaced palindromic repeats (CRISPR)/Cas9 method, have led to increasing concerns about the ethics of editing the human genome. In response, the US National Academy of Sciences and the National Academy of Medicine constituted a multidisciplinary, international committee to review the current status and make recommendations. I was a member of that committee, and the core of this review reflects the committee's conclusions. The committee's report, issued in February 2017, recommends the application of current ethical and regulatory standards for gene therapy to somatic (nonheritable) human genome editing. It also recommends allowing experimental germline genome editing to proceed if (a) it is restricted to preventing transmission of a serious disease or condition, (b) the edit is a modification to a common DNA sequence known not to be associated with disease, and (c) the research is conducted under a stringent set of ethical and regulatory requirements. Crossing the so-called red line of germline genome editing raises important bioethical issues, most importantly, serious concern about the potential negative impact on individuals with disabilities. This review highlights some of the major ethical considerations in human genome editing in light of the report's recommendations.

Most natural product biosynthetic gene clusters identified in bacterial genomic and metagenomic sequencing efforts are silent under laboratory growth conditions. Here, we describe a scalable biosynthetic gene cluster activation method wherein the gene clusters are disassembled at interoperonic regions in vitro using CRISPR/Cas9 and then reassembled with PCR-amplified, short DNAs, carrying synthetic promoters, using transformation assisted recombination (TAR) in yeast. This simple, cost-effective, and scalable method allows for the simultaneous generation of combinatorial libraries of refactored gene clusters, eliminating the need to understand the transcriptional hierarchy of the silent genes. In two test cases, this in vitro disassembly-TAR reassembly method was used to create collections of promoter-replaced gene clusters that were tested in parallel to identify versions that enabled secondary metabolite production. Activation of the atolypene (ato) gene cluster led to the characterization of two unprecedented bacterial cyclic sesterterpenes, atolypene A (1) and B (2), which are moderately cytotoxic to human cancer cell lines. This streamlined in vitro disassembly-in vivo reassembly method offers a simplified approach for silent gene cluster refactoring that should facilitate the discovery of natural products from silent gene clusters cloned from either metagenomes or cultured bacteria.

Many cellular processes rely on precise and timely deformation of the

Background: IL-22 is potentially a pathogenic cytokine in patients with atopic dermatitis (AD), but the molecular effects of IL-22 antagonism have not been defined in human subjects. Objective: We sought to evaluate the cellular and molecular effects of IL-22 blockade in tissues from patients with moderate-to-severe AD. Methods: We assessed lesional and nonlesional skin from 59 patients with moderate-to-severe AD treated with anti-IL-22 (fezakinumab) versus placebo (2: 1) using transcriptomic and immunohistochemistry analyses. Results: Greater reversal of the AD genomic profile was seen with fezakinumab versus placebo, namely 25.3% versus 10.5% at 4 weeks (P = 1.7 x 10(-5)) and 65.5% versus 13.9% at 12 weeks (P = 9.5 3 10(-19)), respectively. Because IL-22 blockade showed clinical efficacy only in patients with severe AD, we used baseline median IL-22 mRNA expression to stratify for high (n = 30) and low (n = 29) IL-22 expression groups. Much stronger mean transcriptomic improvements were seen with fezakinumab in the IL-22-high drug-treated group (82.8% and 139.4% at 4 and 12 weeks, respectively) than in the respective IL-22-high placebo-treated group (39.6% and 56.3% at 4 and 12 weeks) or the IL-22-low groups. Significant downregulations of multiple immune pathways, including T(H)1/CXCL9, T(H)2/CCL18/CCL22, T(H)17/CCL20/DEFB4A, and T(H)22/IL22/S100A's, were restricted to the IL-22-high drug group (P <.05). Consistently, tissue predictors of clinical response were mostly genes involved in T-cell and dendritic cell activation and differentiation. Conclusions: This is the first report showing a profound effect of IL-22 blockade on multiple inflammatory pathways in AD. These data, supported by robust effects in patients with high IL-22 baseline expression, suggest a central role for IL-22 in AD, indicating the need for a precision medicine approach for improving therapeutic outcomes in patients with AD.

Many bacteria and archaea have the unique ability to heritably alter their genomes by incorporating small fragments of foreign DNA, called spacers, into CRISPR loci. Once transcribed and processed into individual CRISPR RNAs, spacer sequences guide Cas effector nucleases to destroy complementary, invading nucleic acids. Collectively, these two processes are known as the CRISPR-Cas immune response. In this Progress article, we review recent studies that have advanced our understanding of the molecular mechanisms underlying spacer acquisition and that have revealed a fundamental link between the two phases of CRISPR immunity that ensures optimal immunity from newly acquired spacers. Finally, we highlight important open questions and discuss the potential basic and applied impact of spacer acquisition research.

Inherited IL-12R beta 1 and TYK2 deficiencies impair both IL-12- and IL-23 -dependent IFN-gamma immunity and are rare monogenic causes of tuberculosis, each found in less than 1/600,000 individuals. We show that homozygosity for the common TYK2 P1104A allele, which is found in about 1/600 Europeans and between 1/1000 and 1/10,000 individuals in regions other than East Asia, is more frequent in a cohort of patients with tuberculosis from endemic areas than in ethnicity-adjusted controls (P = 8.37 x 10(-8); odds ratio, 89.31; 95% CI, 14.7 to 1725). Moreover, the frequency of P1104A in Europeans has decreased, from about 9% to 4.2%, over the past 4000 years, consistent with purging of this variant by endemic tuberculosis. Surprisingly, we also show that TYK2 P1104A impairs cellular responses to IL-23, but not to IFN-alpha, IL-10, or even IL-12, which, like IL-23, induces IFN-gamma via activation of TYK2 and JAK2. Moreover, TYK2 P1104A is properly docked on cytokine receptors and can be phosphorylated by the proximal JAK, but lacks catalytic activity. Last, we show that the catalytic activity of TYK2 is essential for IL-23, but not IL-12, responses in cells expressing wild-type JAK2. In contrast, the catalytic activity of JAK2 is redundant for both IL-12 and IL-23 responses, because the catalytically inactive P1057A JAK2, which is also docked and phosphorylated, rescues signaling in cells expressing wild-type TYK2. In conclusion, homozygosity for the catalytically inactive P1104A missense variant of TYK2 selectively disrupts the induction of IFN-gamma by IL-23 and is a common monogenic etiology of tuberculosis.

Stimulated muscarinic acetylcholine receptors (M2Rs) release G beta gamma subunits, which slow heart rate by activating a G protein-gated K+ channel (GIRK). Stimulated beta 2 adrenergic receptors (beta 2ARs) also release G beta gamma subunits, but GIRK is not activated. This study addresses the mechanism underlying this specificity of GIRK activation by M2Rs. K+ currents and bioluminescence resonance energy transfer between labelled G proteins and GIRK show that M2Rs catalyze G beta gamma subunit release at higher rates than beta 2ARs, generating higher G beta gamma concentrations that activate GIRK and regulate other targets of G beta gamma. The higher rate of G beta gamma release is attributable to a faster G protein coupled receptor - G protein trimer association rate in M2R compared to beta 2AR. Thus, a rate difference in a single kinetic step accounts for specificity.