deficiency disrupts V(D)J recombination to cause SCID and Omenn syndrome.

Inborn errors of T cell development present a pediatric emergency in which timely curative therapy is informed by molecular diagnosis. In 11 affected patients across four consanguineous kindreds, we detected homozygosity for a single deleterious missense variant in the gene NudC domain-containing 3 () Two infants had severe combined immunodeficiency with the complete absence of T and B cells (TB SCID), whereas nine showed classical features of Omenn syndrome (OS). Restricted antigen receptor gene usage by residual T lymphocytes suggested impaired V(D)J recombination.

YY1 Binding to Regulatory Elements That Lack Enhancer Activity Promotes Locus Folding and Gene Activation.

Enhancers activate their cognate promoters over huge distances but how enhancer/promoter interactions become established is not completely understood. There is strong evidence that cohesin-mediated loop extrusion is involved but this does not appear to be a universal mechanism. Here, we identify an element within the mouse immunoglobulin lambda (Igλ) light chain locus, HSCλ1, that has characteristics of active regulatory elements but lacks intrinsic enhancer or promoter activity.

Temporal analyses reveal a pivotal role for sense and antisense enhancer RNAs in coordinate immunoglobulin lambda locus activation.

Transcription enhancers are essential activators of V(D)J recombination that orchestrate non-coding transcription through complementary, unrearranged gene segments. How transcription is coordinately increased at spatially distinct promoters, however, remains poorly understood. Using the murine immunoglobulin lambda (Igλ) locus as model, we find that three enhancer-like elements in the 3' Igλ domain, Eλ3-1, HSCλ1 and HSE-1, show strikingly similar transcription factor binding dynamics and close spatial proximity, suggesting that they form an active enhancer hub.

A bovine antibody possessing an ultralong complementarity-determining region CDRH3 targets a highly conserved epitope in sarbecovirus spike proteins.

Broadly neutralizing antibodies have huge potential as novel antiviral therapeutics due to their ability to recognize highly conserved epitopes that are seldom mutated in viral variants. A subset of bovine antibodies possess an ultralong complementarity-determining region (CDR)H3 that is highly adept at recognizing such conserved epitopes, but their reactivity against Sarbecovirus Spike proteins has not been explored previously. Here, we use a SARS-naïve library to isolate a broadly reactive bovine CDRH3 that binds the receptor-binding domain of SARS-CoV, SARS-CoV-2, and all SARS-CoV-2 variants.

Association between self-reported signs and symptoms and SARS-CoV-2 antibody detection in UK key workers.

Background: Screening for SARS-CoV-2 antibodies is under way in some key worker groups; how this adds to self-reported COVID-19 illness is unclear. In this study, we investigate the association between self-reported belief of COVID-19 illness and seropositivity.

Methods: Cross-sectional study of three key worker streams comprising (A) Police and Fire & Rescue (2 sites) (B) healthcare workers (1 site) and (C) healthcare workers with previously positive PCR result (5 sites).

Broadly Neutralizing Bovine Antibodies: Highly Effective New Tools against Evasive Pathogens?

Potent antibody-mediated neutralization is critical for an organism to combat the vast array of pathogens it will face during its lifetime. Due to the potential genetic diversity of some viruses, such as HIV-1 and influenza, standard neutralizing antibodies are often ineffective or easily evaded as their targets are masked or rapidly mutated. This has thwarted efforts to both prevent and treat HIV-1 infections and means that entirely new formulations are required to vaccinate against influenza each year.

Acute ischaemic stroke in meningoencephalitis.

is the third most frequent cause of bacterial meningitis and has a predilection for elderly patients and the immunosuppressed. A small number of patients with meningoencephalitis have previously been reported to experience stroke-like symptoms that were attributed to microabscess formation and the mass effect of collections of infection in the brain. These infections led to temporary neurological deficits that resolved with antimicrobial treatment, rather than to true strokes with permanent neurological deficits.

Teaching Basic Knowledge on Substance Use Disorders: The Impact of e-Learning on Health Professionals.

Purpose: Recent evolution toward a medical perspective on patients with substance use disorders (SUDs) has led to a lack of medical training in substance abuse. To increase this knowledge, a distance learning course ("e-learning") was implemented to teach the general concepts of SUDs to medical residents and health professionals before delivering on-campus courses. The purpose was to evaluate the impact on participants' basic knowledge.

The ESC: The Dangerous By-Product of V(D)J Recombination.

V(D)J recombination generates antigen receptor diversity by mixing and matching individual variable (V), diversity (D), and joining (J) gene segments. An obligate by-product of many of these reactions is the excised signal circle (ESC), generated by excision of the DNA from between the gene segments. Initially, the ESC was believed to be inert and formed to protect the genome from reactive broken DNA ends but more recent work suggests that the ESC poses a substantial threat to genome stability.

Genome instability triggered by the V(D)J recombination by-product.

A newly identified process by which mistargeted V(D)J recombination could cause genome instability in childhood leukemia has been discovered. In this mechanism, called cut-and-run, the excised DNA by-products of V(D)J recombination are re-bound by the recombinase proteins and erroneously trigger double-strand breaks at multiple locations throughout the genome. Many of these breakpoints co-localize with known chromosome alterations in acute lymphoblastic leukemia (ALL).

Combined Immunodeficiency With Late-Onset Progressive Hypogammaglobulinemia and Normal B Cell Count in a Patient With RAG2 Deficiency.

Proteins expressed by recombination activating genes 1 and 2 (RAG1/2) are essential in the process of V(D)J recombination that leads to generation of the T and B cell repertoires. Clinical and immunological phenotypes of patients with RAG deficiencies correlate well to the degree of impaired RAG activity and this has been expanding to variants of combined immunodeficiency (CID) or even milder antibody deficiency syndromes. Pathogenic variants that severely impair recombinase activity of RAG1/2 determine a severe combined immunodeficiency (SCID) phenotype, whereas hypomorphic variants result in leaky (partial) SCID and other immunodeficiencies.

Cut-and-Run: A Distinct Mechanism by which V(D)J Recombination Causes Genome Instability.

V(D)J recombination is essential to generate antigen receptor diversity but is also a potent cause of genome instability. Many chromosome alterations that result from aberrant V(D)J recombination involve breaks at single recombination signal sequences (RSSs). A long-standing question, however, is how such breaks occur.

A novel mutation reveals a critical in vivo role for HMGB1/2 during V(D)J recombination.

The Recombination Activating Genes, and , are essential for V(D)J recombination and adaptive immunity. Mutations in these genes often cause immunodeficiency, the severity of which reflects the importance of the altered residue or residues during recombination. Here, we describe a novel mutation that causes immunodeficiency in an unexpected way: The mutated protein severely disrupts binding of the accessory protein, HMGB1.

The use of an online Epworth Sleepiness Scale to assess excessive daytime sleepiness.

Purpose: Excessive daytime sleepiness is the most common complaint reported in sleep clinics. We hypothesised that utilising modern media to deliver an online Epworth Sleepiness Scale, age- and gender-related differences in subjective daytime sleepiness could be assessed.

Methods: Age, gender and online Epworth Sleepiness Scale (range 0-24 points) of 39,448 subjects were recorded between January 2013 and November 2015.

Targeted genome regulation and modification using transcription activator-like effectors.

Transcription activator-like effectors (TALEs) are immensely powerful new tools for genome engineering that can be directed to bind to almost any DNA sequence of choice. They originate from the Xanthomonas species of plant pathogenic bacteria and, in nature, these proteins increase the virulence of Xanthomonas. However, in 2009, the DNA binding code of TALEs was deciphered and, subsequently, TALE proteins have been exploited for many diverse applications.

Oncogene dependency and the potential of targeted RNAi-based anti-cancer therapy.

Cancers arise through the progression of multiple genetic and epigenetic defects that lead to deregulation of numerous signalling networks. However, the last decade has seen the development of the concept of 'oncogene addiction', where tumours appear to depend on a single oncogene for survival. RNAi has provided an invaluable tool in the identification of these oncogenes and oncogene-dependent cancers, and also presents great potential as a novel therapeutic strategy against them.

TALE proteins bind to both active and inactive chromatin.

TALE (transcription activator-like effector) proteins can be tailored to bind to any DNA sequence of choice and thus are of immense utility for genome editing and the specific delivery of transcription activators. However, to perform these functions, they need to occupy their sites in chromatin. In the present study, we have systematically assessed TALE binding to chromatin substrates and find that in vitro TALEs bind to their target site on nucleosomes at the more accessible entry/exit sites, but not at the nucleosome dyad.

The Eλ(3-1) enhancer is essential for V(D)J recombination of the murine immunoglobulin lambda light chain locus.

Enhancers are essential for long range chromatin opening and the activation of V(D)J recombination at the antigen receptor loci. The murine immunoglobulin lambda light chain locus is a duplicated locus and, using a bacterial artificial chromosome spanning the 3' half of the locus to generate transgenic mice, we have identified a critical enhancer element for lambda locus recombination. Four hypersensitive sites had been previously mapped downstream of the JCλ1 gene segment (HS1-4).

Transcription-coupled eviction of histones H2A/H2B governs V(D)J recombination.

Initiation of V(D)J recombination critically relies on the formation of an accessible chromatin structure at recombination signal sequences (RSSs) but how this accessibility is generated is poorly understood. Immunoglobulin light-chain loci normally undergo recombination in pre-B cells. We show here that equipping (earlier) pro-B cells with the increased pre-B-cell levels of just one transcription factor, IRF4, triggers the entire cascade of events leading to premature light-chain recombination.

Technical note: Hapten synthesis, antibody production and development of an enzyme-linked immunosorbent assay for detection of the natural steroidal alkaloid Dendrogenin A.

We have recently discovered the existence of 5α-Hydroxy-6β-[2-(1H-imidazol-4-yl)ethylamino]cholestan-3β-ol, called Dendrogenin A (DDA), as the first endogenous steroidal alkaloid ever described in mammals. We found that the DDA content of tumors and cancer cell lines was low or absent compared with normal cells showing that a deregulation in DDA biosynthesis was associated with cancer and therefore suggesting that DDA could represent a metabolomic cancer biomarker. This prompted us to produce antibodies that selectively recognize DDA.

Molecular epidemiology and antimicrobial resistance pattern of extended-spectrum-β-lactamase-producing Enterobacteriaceae in Glasgow, Scotland.

Objectives: To establish the molecular epidemiology and antimicrobial resistance pattern of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae harbouring bla(CTX-M) in Glasgow, Scotland.

Methods: During a 12 week period, Enterobacteriaceae isolates obtained from urine samples were collected and susceptibility testing performed. Isolates were screened for the presence of bla(CTX-M) by multiplex PCR and selected Escherichia coli genes were subsequently sequenced.

Interplay between DNA methylation and transcription factor availability: implications for developmental activation of the mouse Myogenin gene.

During development, gene activation is stringently regulated to restrict expression only to the correct cell type and correct developmental stage. Here, we present mechanistic evidence that suggests DNA methylation contributes to this regulation by suppressing premature gene activation. Using the mouse Myogenin promoter as an example of the weak CpG island class of promoters, we find that it is initially methylated but becomes demethylated as development proceeds.

HSP27 controls GATA-1 protein level during erythroid cell differentiation.

Heat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34(+) human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation.