Mistranslating the genetic code with leucine in yeast and mammalian cells.

Translation fidelity relies on accurate aminoacylation of transfer RNAs (tRNAs) by aminoacyl-tRNA synthetases (AARSs). AARSs specific for alanine (Ala), leucine (Leu), serine, and pyrrolysine do not recognize the anticodon bases. Single nucleotide anticodon variants in their cognate tRNAs can lead to mistranslation. Human genomes include both rare and more common mistranslating tRNA variants. We investigated three rare human tRNALeu variants that mis-incorporate Leu at phenylalanine or tryptophan codons. Expression of each tRNALeu anticodon variant in neuroblastoma cells caused defects in fluorescent protein production without significantly increased cytotoxicity under normal conditions or in the context of proteasome inhibition. Using tRNA sequencing and mass spectrometry we confirmed that each tRNALeu variant was expressed and generated mistranslation with Leu. To probe the flexibility of the entire genetic code towards Leu mis-incorporation, we created 64 yeast strains to express all possible tRNALeu anticodon variants in a doxycycline-inducible system. While some variants showed mild or no growth defects, many anticodon variants, enriched with G/C at positions 35 and 36, including those replacing Leu for proline, arginine, alanine, or glycine, caused dramatic reductions in growth. Differential phenotypic defects were observed for tRNALeu mutants with synonymous anticodons and for different tRNALeu isoacceptors with the same anticodon. A comparison to tRNAAla anticodon variants demonstrates that Ala mis-incorporation is more tolerable than Leu at nearly every codon. The data show that the nature of the amino acid substitution, the tRNA gene, and the anticodon are each important factors that influence the ability of cells to tolerate mistranslating tRNAs.

Normalizing Anxiety on Social Media Increases Self-Diagnosis of Anxiety: The Mediating Effect of Identification (But Not Stigma).

Normalizing mental health disorders in media communication can have a positive impact on the public by improving awareness. However, normalizing issues like anxiety could lead people to categorize normal anxiety as a disorder. In Study One, viewing social media posts that normalized anxiety resulted in a greater likelihood of self-diagnosis of anxiety disorder compared to social media posts that did not normalize it. This effect was through identification with and liking of the person featured in the social media post. In Study Two, those results were replicated. Additionally, we expected, but did not find, that normalizing anxiety had an impact on perceived stigma of anxiety disorders. Thus, at least in this case, normalization influenced self-diagnosis primarily through increasing identification with another person with anxiety, rather than decreasing stigma. Efforts to maximize positive impacts of normalizing disorders should examine unintended, potentially negative, consequences.

Genetic Interaction of tRNA-Dependent Mistranslation with Fused in Sarcoma Protein Aggregates.

High-fidelity protein synthesis requires properly aminoacylated transfer RNAs (tRNAs), yet diverse cell types, from bacteria to humans, show a surprising ability to tolerate errors in translation resulting from mutations in tRNAs, aminoacyl-tRNA synthetases, and other components of protein synthesis. Recently, we characterized a tRNASerAGA G35A mutant (tRNASerAAA) that occurs in 2% of the human population. The mutant tRNA decodes phenylalanine codons with serine, inhibits protein synthesis, and is defective in protein and aggregate degradation. Here, we used cell culture models to test our hypothesis that tRNA-dependent mistranslation will exacerbate toxicity caused by amyotrophic lateral sclerosis (ALS)-associated protein aggregation. Relative to wild-type tRNA, we found cells expressing tRNASerAAA showed slower but effective aggregation of the fused in sarcoma (FUS) protein. Despite reduced levels in mistranslating cells, wild-type FUS aggregates showed similar toxicity in mistranslating cells and normal cells. The aggregation kinetics of the ALS-causative FUS R521C variant were distinct and more toxic in mistranslating cells, where rapid FUS aggregation caused cells to rupture. We observed synthetic toxicity in neuroblastoma cells co-expressing the mistranslating tRNA mutant and the ALS-causative FUS R521C variant. Our data demonstrate that a naturally occurring human tRNA variant enhances cellular toxicity associated with a known causative allele for neurodegenerative disease.

Perseverance of protein homeostasis despite mistranslation of glycine codons with alanine.

By linking amino acids to their codon assignments, transfer RNAs (tRNAs) are essential for protein synthesis and translation fidelity. Some human tRNA variants cause amino acid mis-incorporation at a codon or set of codons. We recently found that a naturally occurring tRNASer variant decodes phenylalanine codons with serine and inhibits protein synthesis. Here, we hypothesized that human tRNA variants that misread glycine (Gly) codons with alanine (Ala) will also disrupt protein homeostasis. The A3G mutation occurs naturally in tRNAGly variants (tRNAGlyCCC, tRNAGlyGCC) and creates an alanyl-tRNA synthetase (AlaRS) identity element (G3 : U70). Because AlaRS does not recognize the anticodon, the human tRNAAlaAGC G35C (tRNAAlaACC) variant may function similarly to mis-incorporate Ala at Gly codons. The tRNAGly and tRNAAla variants had no effect on protein synthesis in mammalian cells under normal growth conditions; however, tRNAGlyGCC A3G depressed protein synthesis in the context of proteasome inhibition. Mass spectrometry confirmed Ala mistranslation at multiple Gly codons caused by the tRNAGlyGCC A3G and tRNAAlaAGC G35C mutants, and in some cases, we observed multiple mistranslation events in the same peptide. The data reveal mistranslation of Ala at Gly codons and defects in protein homeostasis generated by natural human tRNA variants that are tolerated under normal conditions. This article is part of the theme issue 'Reactivity and mechanism in chemical and synthetic biology'.

The British Athletics Muscle Injury Classification grading system as a predictor of return to play following hamstrings injury in professional football players.

OBJECTIVES: Investigate the British Athletics Muscle Injury Classification (BAMIC) grading system as a predictor of return to play (RTP) following primary hamstring strain injury (HSI) and its agreement with the Peetron's classification system in professional footballers. METHODS: A retrospective cohort study of 39 hamstrings strains in a professional English football club were identified. Two musculoskeletal radiologists reviewed historical MRI's and classified them against the BAMIC and Peetron's grading system. Classification, oedema length and cross-sectional area were compared against RTP. RESULTS: Pearson's correlation coefficient demonstrated a weak but statistically significant correlation between BAMIC and RTP (r = 0.32; 95%CI 0.01 to 0.58; p = 0.05). Maximum length of intramuscular oedema demonstrated weak correlations with RTP (r = 0.3; 95%CI -0.02 to 0.56; p = 0.06). Percentage cross sectional demonstrated a weak correlation with RTP (r = 0.02; 95%CI -0.3 to 0.33; p = 0.91). Multiple regression demonstrated that 16% of the variance in RTP was explained by the model. Kappa for the agreement between BAMIC and Peetron's was 0.21 (95%CI 0 to 0.42). CONCLUSIONS: A significant association between the grade of HSI on the BAMIC system and RTP was found. Findings suggest BAMIC could provide valuable prognostic information on the RTP.

Mindfulness-Based Interventions for Surgical Patients and Impact on Postoperative Outcomes, Patient Wellbeing, and Satisfaction.

Several psychosocial factors can impact surgical outcomes and overall patient wellbeing following surgery. Although advances in surgical interventions and pain management protocols can reduce surgical trauma and enhance recovery from surgery, additional intervention is warranted to optimize surgical outcomes and patient quality of life (QoL) in the short- and long-term. Research on mindfulness techniques suggests that mindfulness-based interventions (MBI) effectively promote health behaviors, reduce pain, and improve psychological wellbeing and QoL. Thus, there has been an increase in research evaluating the use of MBIs to improve postoperative outcomes and wellbeing in surgical patients. The authors provide a brief overview of psychosocial outcomes of surgery and MBIs and review the literature on the impact of MBIs on postoperative outcomes. The extant literature indicates that MBIs are feasible and acceptable for use in surgical patient populations and provides preliminary evidence of the benefits of mindfulness across a range of surgical patient populations. However, more research is needed to assess the long-term efficacy of MBIs delivered online and in-person across the perioperative continuum.

De novo endocytic clathrin coats develop curvature at early stages of their formation.

Sculpting a flat patch of membrane into an endocytic vesicle requires curvature generation on the cell surface, which is the primary function of the endocytosis machinery. Using super-resolved live cell fluorescence imaging, we demonstrate that curvature generation by individual clathrin-coated pits can be detected in real time within cultured cells and tissues of developing organisms. Our analyses demonstrate that the footprint of clathrin coats increases monotonically during the formation of pits at different levels of plasma membrane tension. These findings are only compatible with models that predict curvature generation at the early stages of endocytic clathrin pit formation. We also found that CALM adaptors associated with clathrin plaques form clusters, whereas AP2 distribution is more homogenous. Considering the curvature sensing and driving roles of CALM, we propose that CALM clusters may increase the strain on clathrin lattices locally, eventually giving rise to rupture and subsequent pit completion at the edges of plaques.

ASSOCIATION OF GENETIC POLYMORPHISM AND EXPRESSION OF UMOD GENE AND CHRONIC KIDNEY DISEASE.

OBJECTIVE: The aim: This study is designed to investigate the possible association of genetic polymorphism expression of UMOD gene and chronic kidney disease in population. PATIENTS AND METHODS: Materials and methods: In the current study, the single-nucleotide polymorphisms (SNPs) were genotyped in the promoter region of the UMOD gene in CKD patients to assess its association with the kidney outcome of CKD. So 50 patients' blood samples suffered from CKD were collected. Among these patients, 21 were men and 29 women, aged 35 - 85 years old. Another group included 50 healthy subjects. DNA was extracted from all blood samples with EDTA using Quick DNA miniprep Kit ZYMO, (Cat№ D3025) according to manufacturer's instructions. Genotyping of 1 common polymorphisms (rs4293393) of the UMOD gene was done and the RNA was extracted and converted to cDNA and a set of primers was used to amplify specific region within the UMOD gene; another set was used to amplify the GAPDH gene to use it in calculation as a reference gene. RESULTS: Results and conclusions: After statistical analysis, the results showed that there could be association between having CC mutant polymorphism in UMOD gene and having CKD.

Hypoxia acts as an environmental cue for the human tissue-resident memory T cell differentiation program.

Tissue-resident memory T cells (TRM) provide frontline defense against infectious diseases and contribute to antitumor immunity; however, aside from the necessity of TGF-ß, knowledge regarding TRM-inductive cues remains incomplete, particularly for human cells. Oxygen tension is an environmental cue that distinguishes peripheral tissues from the circulation, and here, we demonstrate that differentiation of human CD8+ T cells in the presence of hypoxia and TGF-ß1 led to the development of a TRM phenotype, characterized by a greater than 5-fold increase in CD69+CD103+ cells expressing human TRM hallmarks and enrichment for endogenous human TRM gene signatures, including increased adhesion molecule expression and decreased expression of genes involved in recirculation. Hypoxia and TGF-ß1 synergized to produce a significantly larger population of TRM phenotype cells than either condition alone, and comparison of these cells from the individual and combination conditions revealed distinct phenotypic and transcriptional profiles, indicating a programming response to milieu rather than a mere expansion. Our findings identify a likely previously unreported cue for the TRM differentiation program and can enable facile generation of human TRM phenotype cells in vitro for basic studies and translational applications such as adoptive cellular therapy.

Histone Deacetylase Inhibitors and IL21 Cooperate to Reprogram Human Effector CD8+ T Cells to Memory T Cells.

Clinical response rates after adoptive cell therapy (ACT) are highly correlated with in vivo persistence of the infused T cells. However, antigen-specific T cells found in tumor sites are often well-differentiated effector cells with limited persistence. Central memory CD8+ T cells, capable of self-renewal, represent desirable ACT products. We report here that exposure to a histone deacetylase inhibitor (HDACi) and IL21 could reprogram differentiated human CD8+ T cells into central memory-like T cells. Dedifferentiation of CD8+ T cells was initiated by increased H3 acetylation and chromatin accessibility at the CD28 promoter region. This led to IL21-mediated pSTAT3 binding to the CD28 region, and subsequent upregulation of surface CD28 and CD62L (markers of central memory T cells). The reprogrammed cells exhibited enhanced proliferation in response to both IL2 and IL15, and a stable memory-associated transcriptional signature (increased Lef1 and Tcf7). Our findings support the application of IL21 and HDACi for the in vitro generation of highly persistent T-cell populations that can augment the efficacy of adoptively transferred T cells.

Cancer vaccine formulation dictates synergy with CTLA-4 and PD-L1 checkpoint blockade therapy.

Anticancer vaccination is a promising approach to increase the efficacy of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed death ligand 1 (PD-L1) checkpoint blockade therapies. However, the landmark FDA registration trial for anti-CTLA-4 therapy (ipilimumab) revealed a complete lack of benefit of adding vaccination with gp100 peptide formulated in incomplete Freund's adjuvant (IFA). Here, using a mouse model of melanoma, we found that gp100 vaccination induced gp100-specific effector T cells (Teffs), which dominantly forced trafficking of anti-CTLA-4-induced, non-gp100-specific Teffs away from the tumor, reducing tumor control. The inflamed vaccination site subsequently also sequestered and destroyed anti-CTLA-4-induced Teffs with specificities for tumor antigens other than gp100, reducing the antitumor efficacy of anti-CTLA-4 therapy. Mechanistically, Teffs at the vaccination site recruited inflammatory monocytes, which in turn attracted additional Teffs in a vicious cycle mediated by IFN-γ, CXCR3, ICAM-1, and CCL2, dependent on IFA formulation. In contrast, nonpersistent vaccine formulations based on dendritic cells, viral vectors, or water-soluble peptides potently synergized with checkpoint blockade of both CTLA-4 and PD-L1 and induced complete tumor regression, including in settings of primary resistance to dual checkpoint blockade. We conclude that cancer vaccine formulation can dominantly determine synergy, or lack thereof, with CTLA-4 and PD-L1 checkpoint blockade therapy for cancer.

Resiquimod as an immunologic adjuvant for NY-ESO-1 protein vaccination in patients with high-risk melanoma.

The Toll-like receptor (TLR) 7/8 agonist resiquimod has been used as an immune adjuvant in cancer vaccines. We evaluated the safety and immunogenicity of the cancer testis antigen NY-ESO-1 given in combination with Montanide (Seppic) with or without resiquimod in patients with high-risk melanoma. In part I of the study, patients received 100 µg of full-length NY-ESO-1 protein emulsified in 1.25 mL of Montanide (day 1) followed by topical application of 1,000 mg of 0.2% resiquimod gel on days 1 and 3 (cohort 1) versus days 1, 3, and 5 (cohort 2) of a 21-day cycle. In part II, patients were randomized to receive 100-µg NY-ESO-1 protein plus Montanide (day 1) followed by topical application of placebo gel [(arm A; n = 8) or 1,000 mg of 0.2% resiquimod gel (arm B; n = 12)] using the dosing regimen established in part I. The vaccine regimens were generally well tolerated. NY-ESO-1-specific humoral responses were induced or boosted in all patients, many of whom had high titer antibodies. In part II, 16 of 20 patients in both arms had NY-ESO-1-specific CD4⁺ T-cell responses. CD8⁺ T-cell responses were only seen in 3 of 12 patients in arm B. Patients with TLR7 SNP rs179008 had a greater likelihood of developing NY-ESO-1-specific CD8⁺ responses. In conclusion, NY-ESO-1 protein in combination with Montanide with or without topical resiquimod is safe and induces both antibody and CD4⁺ T-cell responses in the majority of patients; the small proportion of CD8⁺ T-cell responses suggests that the addition of topical resiquimod to Montanide is not sufficient to induce consistent NY-ESO-1-specific CD8⁺ T-cell responses.

MAGE-specific T cells detected directly ex-vivo correlate with complete remission in metastatic breast cancer patients after sequential immune-endocrine therapy.

Studies suggest that conventional cancer therapies given after immunotherapy (IT) can boost antitumor immunity and possibly improve response rates and progression-free survival. We report two cases of metastatic breast cancer with durable complete responses (CRs) after sequential IT and endocrine therapy. Immune analyses of these long-term disease-free breast cancer patients previously treated with imiquimod (IMQ) suggest in-situ vaccination is achieved by topical application of the TLR-7 agonist directly onto tumors. Furthermore, IT-induced antigen-specific T cells were expanded by subsequent endocrine therapy and correlated with response, persisting > 2 years. Our findings therefore suggest that the induction/boosting of polyfunctional tumor antigen-specific T in response to sequential immune endocrine therapy and detected directly ex-vivo can serve as a peripheral blood biomarker for true clinical benefit.

Preparation of tumor antigen-loaded mature dendritic cells for immunotherapy.

While clinical studies have established that antigen-loaded DC vaccines are safe and promising therapy for tumors, their clinical efficacy remains to be established. The method described below, prepared in accordance with Good Manufacturing Process (GMP) guidelines, is an optimization of the most common ex vivo preparation method for generating large numbers of DCs for clinical studies. Our method utilizes the synthetic TLR 3 agonist Polyinosinic-Polycytidylic Acid-poly-L-lysine Carboxymethylcellulose (Poly-ICLC) to stimulate the DCs. Our previous study established that Poly-ICLC is the most potent individual maturation stimulus for human DCs as assessed by an upregulation of CD83 and CD86, induction of interleukin-12 (IL-12), tumor necrosis factor (TNF), interferon gamma-induced protein 10 (IP-10), interleukmin 1 (IL-1), and type I interferons (IFN), and minimal interleukin 10 (IL-10) production. DCs are differentiated from frozen peripheral blood mononuclear cells (PBMCs) obtained by leukapheresis. PBMCs are isolated by Ficoll gradient centrifugation and frozen in aliquots. On Day 1, PBMCs are thawed and plated onto tissue culture flasks to select for monocytes which adhere to the plastic surface after 1-2 hr incubation at 37 °C in the tissue culture incubator. After incubation, the lymphocytes are washed off and the adherent monocytes are cultured for 5 days in the presence of interleukin-4 (IL-4) and granulocyte macrophage-colony stimulating factor (GM-CSF) to differentiate to immature DCs. On Day 6, immature DCs are pulsed with the keyhole limpet hemocyanin (KLH) protein which serves as a control for the quality of the vaccine and may boost the immunogenicity of the vaccine. The DCs are stimulated to mature, loaded with peptide antigens, and incubated overnight. On Day 7, the cells are washed, and frozen in 1 ml aliquots containing 4-20 x 10(6) cells using a controlled-rate freezer. Lot release testing for the batches of DCs is performed and must meet minimum specifications before they are injected into patients.

Allele and genotype frequencies of the polymorphic cytochrome P450 genes (CYP1A1, CYP3A4, CYP3A5, CYP2C9 and CYP2C19) in the Jordanian population.

Drug metabolizing enzymes participate in the neutralizing of xenobiotics and biotransformation of drugs. Human cytochrome P450, particularly CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5, play an important role in drug metabolism. The genes encoding the CYP enzymes are polymorphic, and extensive data have shown that certain alleles confer reduced enzymatic function. The goal of this study was to determine the frequencies of important allelic variants of CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5 in the Jordanian population and compare them with the frequency in other ethnic groups. Genotyping of CYP1A1(m1 and m2), CYP2C9 (2 and 3), CYP2C19 (2 and 3), CYP3A4 5, CYP3A5 (3 and 6), was carried out on Jordanian subjects. Different variants allele were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). CYP1A1 allele frequencies in 290 subjects were 0.764 for CYP1A1 1, 0.165 for CYP1A1 2A and 0.071 for CYP1A1 2C. CYP2C9 allele frequencies in 263 subjects were 0.797 for CYP2C9 1, 0.135 for CYP2C9 2 and 0.068 for CYP2C9 3. For CYP2C19, the frequencies of the wild type (CYP2C19 1) and the nonfunctional (2 and 3) alleles were 0.877, 0.123 and 0, respectively. Five subjects (3.16 %) were homozygous for 2/2. Regarding CYP3A4 1B, only 12 subjects out of 173 subjects (6.9 %) were heterozygote with none were mutant for this polymorphism. With respect to CYP3A5, 229 were analyzed, frequencies of CYP3A5 1, 3 and 6 were 0.071, 0.925 and 0.0022, respectively. Comparing our data with that obtained in several Caucasian, African-American and Asian populations, Jordanians are most similar to Caucasians with regard to allelic frequencies of the tested variants of CYP1A1, CYP2C9, CYP2C19, CYP3A4 and CYP3A5.