The first ab initio aspherical structure refinement against experimental X-ray structure factors for polypeptides and proteins using a fragmentation approach to break up the protein into residues and solvent, thereby speeding up quantum-crystallographic Hirshfeld atom refinement (HAR) calculations, is described. It it found that the geometric and atomic displacement parameters from the new fragHAR method are essentially unchanged from a HAR on the complete unfragmented system when tested on dipeptides, tripeptides and hexapeptides. The largest changes are for the parameters describing H atoms involved in hydrogen-bond interactions, but it is shown that these discrepancies can be removed by including the interacting fragments as a single larger fragment in the fragmentation scheme. Significant speed-ups are observed for the larger systems. Using this approach, it is possible to perform a highly parallelized HAR in reasonable times for large systems. The method has been implemented in the TONTO software.

Sure, they happen every day, but there's so much to know about them, including that tides are just big waves.

Bioluminescent algae blooms every few years on the California coast, Australia and elsewhere.

The invention relates to a process for the preparation of oligonucleotides by the following steps: reaction of a nucleoside with a phosphine derivative, reaction of the nucleotide derivative thus obtained with a nucleoside bonded to a polymeric carrier, oxidation of the carrier-bound nucleoside-nucleotide thus obtained with formation of phosphotriester groups, blocking of free primary 5'--OH groups, elimination of a protective group from the terminal 5'--OH group, where appropriate single or multiple repetition of the abovementioned steps to introduce further nucleoside phosphate or oligonucleoside phosphate units, and cleavage of the nucleoside-carrier bond and, where appropriate, elimination of all protective groups present in the oligonucleoside phosphates. The phosphine derivative used is a compound of the general formula III ##STR1## in which X and L can react with OH groups of the sugar units in the oligonucleotides, and R3 is a protective group which can be liberated by β-elimination.

An antisense molecule capable of binding to a selected target site to induce exon skipping in the dystrophin gene, as set forth in SEQ ID NO: 1 to 202.

The invention refers to polynucleotides selected from the group consisting of a) polynucleotides encoding for the polypeptide RBM20 comprising a P638L mutation for a human polypeptide RBM20, or a P641L mutation for a rat polypeptide RBM20, b) polynucleotides with a reverse complementary sequence of the polynucleotide of a) above, and c) polynucleotides with an identity at least 50% to a polynucleotide of a) or b) above.

The present disclosure provides reagents that can be used to label synthetic oligonucleotides with rhodamine dyes or dye networks that contain rhodamine dyes.

A method of labeling a sulfenic acid (—SOH) group of a cysteine residue in a protein; or peptide, comprises contacting said protein or peptide with a beta-ketoester to covalently couple said beta-ketoester to said cysteine residue and form a beta-ketoester-labeled cysteine residue in said protein or peptide.

A polymeric dendrimer-like structure with four branches of monomethoxy-polyethylene glycol that can be represented as: The carboxylic group of the previous structure can be functionalized for the production of conjugates of pharmaceutical interest. The binding of this dendrimer-like polyethylene glycol to therapeutic proteins improves their in vitro and in vivo stability.

The invention relates to a polypeptide having a mutation at one or more position corresponding to T219 of SEQ ID NO: 55, wherein the polypeptide has at least 50% sequence identity with SEQ ID NO: 55, and wherein the polypeptide has permease activity.

Cyclic CRF antagonist peptides having improved properties of “drugability”. The peptides are 33 residues in length with a lactam bond between the residues in position 22 and 25; however, they may be N-terminally shortened by up to 3 residues.

A method of producing a molecularly-imprinted material comprises synthesizing a peptide, oligosaccharide or oligonucleotide on a disposable surface modified support to produce a support surface-attached peptide, oligosaccharide or oligonucleotide, providing a selected monomer mixture, contacting the monomer mixture with the support surface-attached peptide, oligosaccharide or oligonucleotide, initiating polymerisation or at least one crosslinking reaction, dissolving or degrading the support surface-attached peptide, oligosaccharide or oligonucleotide and support, and obtaining molecularly imprinted material.

The present invention relates to CX3CR1-binding polypeptides, in particular polypeptides comprising specific immunoglobulin domains. The invention also relates to nucleic acids encoding such polypeptides; to methods for preparing such polypeptides; to host cells expressing or capable of expressing such polypeptides; to compositions comprising such polypeptides; and to uses of such polypeptides or such compositions, in particular for prophylactic, therapeutic and diagnostic purposes.

The invention relates to melanocortin receptor-specific cyclic peptides of Formula (I) or a pharmaceutically acceptable salt thereof, where R1, R2, R3, R4a, R4b, R4c, R5, x and y are as defined in the specification. These compounds are particularly useful in the treatments of energy homeostasis and metabolism related (e.g. diabetes), food intake related and/or energy balance and body weight related diseases, disorders and/or conditions, including obesity, overweight and diseases, disorders and/or conditions associated with obesity and/or overweight, such as type 2 diabetes and metabolic syndrome.

A method for reducing or substantially preventing formation of a trisulfide derivative of a polypeptide in a liquid medium containing the polypeptide ijn question comprises stripping the liquid medium with a gas, suitably a chemically unreactive gas such as nitrogen or argon.

The present invention relates to methods for producing a polypeptide having biological activity, comprising: (a) cultivating a fungal host cell in a medium conducive for the production of the polypeptide, wherein the fungal host cell comprises a first polynucleotide encoding the polypeptide operably linked to a second polynucleotide encoding a variant signal peptide or a variant prepropeptide; and (b) isolating the secreted polypeptide having biological activity from the cultivation medium.

The present invention relates to novel compounds having a function of a peptide in the amylin family, related nucleic acids, expression constructs, host cells, and processes production of the compounds. The compounds of the invention include one or more amino acid sequence modifications. In addition, methods and compositions are disclosed to treat and prevent metabolic disorders such as obesity, diabetes, and increased cardiovascular risk.

A biosensor and method of making are disclosed. The biosensor is configured to detect a target and may include a peptide immobilized on a sensing component, the sensing component having an anode and a cathode. The immobilized peptide may comprise an antimicrobial peptide binding motif for the target. The sensing component has an electrical conductivity that changes in response to binding of the immobilized peptide to the target. The immobilized peptide may bind one or more targets selected from the list consisting of: bacteria, Gram-negative bacteria, Gram-positive bacteria, pathogens, protozoa, fungi, viruses, and cancerous cells. The biosensor may have a display with a readout that is responsive to changes in electrical conductivity of the sensing component. The display unit may be wirelessly coupled to the sensing component. A resonant circuit with an inductive coil may be electrically coupled to the sensing component. A planar coil antenna may be disposed in proximity to the resonant circuit, the planar coil antenna being configured to provide power to the sensing component.

Compositions and methods for inhibiting and controlling the growth of microbes are disclosed. The composition comprises at least one chemically-modified peptide with antimicrobial activity and at least one carrier. The method comprises of administering an amount, effective for the prevention, inhibition and termination of microbial growth for industrial, pharmaceutical, household and personal care use.

Isolated polynucleotides and polypeptides and recombinant DNA constructs particularly useful for altering agronomic characteristics of plants under nitrogen limiting conditions, compositions (such as plants or seeds) comprising these recombinant DNA constructs, and methods utilizing these recombinant DNA constructs. The recombinant DNA construct comprises a polynucleotide operably linked to a promoter functional in a plant, wherein said polynucleotide encodes an LNT1 polypeptide.

The invention relates to compounds that specifically bind a T1R1/T1R3 or T1R2/T1R3 receptor or fragments or sub-units thereof. The present invention also relates to the use of hetero-oligomeric and chimeric taste receptors comprising T1R1/T1R3 and T1R2/T1R3 in assays to identify compounds that respectively respond to umami taste stimuli and sweet taste stimuli. Further, the invention relates to the constitutive of cell lines that stably or transiently co-express a combination of T1R1 and T1R3; or T1R2 and T1R3; under constitutive or inducible conditions. The use of these cells lines in cell-based assays to identify umami and sweet taste modulatory compounds is also provided, particularly high throughput screening assays that detect receptor activity by use of fluorometric imaging.

The present invention relates to a novel method for analyzing nucleic acid sequences based on real-time detection of DNA polymerase-catalyzed incorporation of each of the four nucleotide bases, supplied individually and serially in a microfluidic system, to a reaction cell containing a template system comprising a DNA fragment of unknown sequence and an oligonucleotide primer. Incorporation of a nucleotide base into the template system can be detected by any of a variety of methods including but not limited to fluorescence and chemiluminescence detection. Alternatively, microcalorimetic detection of the heat generated by the incorporation of a nucleotide into the extending template system using thermopile, thermistor and refractive index measurements can be used to detect extension reactions.

Polypeptides capable of binding human IL-13 and/or of binding human IL-4 in the presence of IL-4 Rα can be used in medicine, in diagnosis and in screening for agonists/antagonists of IL-13/IL-4. One such polypeptide is shown in FIG. 1.

A molecule comprising a lipid, a peptide and a linker to bind the lipid to the peptide which have specific amino acid sequence to bind to Epidermal Growth Factor Receptor (EGFR) of tumor cells, and a liposomal composition which is targeted by the molecule, and method for preparing thereof is disclosed.

In one aspect, the invention relates to a method of loading exosomes with oligonucleotide cargo, by incubating an oligonucleotide comprising one or more hydrophobic modifications with a population of exosomes for a period of time sufficient to allow loading of the exosomes with the oligonucleotide. Exosomes loaded with hydrophobic ally modified oligonucleotide cargo, and uses thereof, are also provided.

In sporadic Alzheimer's disease, neurofibrillary lesion formation is preceded by extensive post-translational modification of the microtubule associated protein tau. Immunoassays have been developed recently that detect tau in biological specimens, thus providing a means for pre-mortem diagnosis of Alzheimer's disease, which has remained elusive. These assays have been improved by the analysis of relevant post-translational modifications, such as phosphorylation, however opportunity for improvement remains. The present invention addresses this issue by disclosing synthetic methylated peptides derived from the tau protein of paired helical filaments and non-diseased control brain. Alzheimer's disease specificity is provided by the presence or absence of methyl moieties on lysine residues and differences between mono-, di-, and tri-methylation. The methylated peptide is useful as an antigen and a binding partner for identifying compounds that interact with the peptide and the methylated tau protein, including antibodies that can distinguish non-diseased brain from that affected by Alzheimer's disease. The resulting antibodies are useful diagnostically and therapeutically. The compounds that specifically bind to methylated tau proteins are useful for eliminating abnormally methylated tau.

(United States Fourth Circuit) - Held that the University of South Carolina did not violate students' First Amendment rights when it required a student leader to attend a meeting to discuss other students' complaints about a controversial campus event he had helped organize that was designed to highlight perceived threats to free expression on campus. The student, then president of the College Libertarians, and the other plaintiffs argued that the state university was chilling their free speech. Affirming summary judgment against the plaintiffs' claims, the Fourth Circuit held that the university's minimally intrusive resolution of subsequent student complaints did not rise to the level of a First Amendment violation. The panel also rejected a facial challenge to the university's general policy on harassment.

Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B–E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B–E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS–PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications.

Ignat V. Shilov
Sep 1, 2007; 6:1638-1655
Technology

Martin R. Larsen
Jul 1, 2005; 4:873-886
Technology

Yasushi Ishihama
Sep 1, 2005; 4:1265-1272
Research

Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B–E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B–E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS–PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications.

James A. Wilkins
Apr 13, 2020; 0:RA120.001944v1-mcp.RA120.001944
Research

Mona Radwan
Apr 1, 2020; 19:640-654
Research

Qingbo Shu
Apr 1, 2020; 19:672-689
Research

Chronic hyperglycemia is known to disrupt the proteolytic milieu, initiating compensatory and maladaptive pathways in the diabetic kidney. Such changes in intrarenal proteolysis are captured by the urinary peptidome. To elucidate the early kidney response to chronic hyperglycemia, we conducted a peptidomic investigation into urines from otherwise healthy youths with type 1 diabetes and their non-diabetic peers using unbiased and targeted mass spectrometry-based techniques. This cross-sectional study included two separate cohorts for the discovery (n = 30) and internal validation (n = 30) of differential peptide excretion. Peptide bioactivity was predicted using PeptideRanker and subsequently verified in vitro. Proteasix and the Nephroseq database were used to identify putative proteases responsible for peptide generation and examine their expression in diabetic nephropathy. A total of 6550 urinary peptides were identified in the discovery analysis. We further examined the subset of 162 peptides, which were quantified across all thirty samples. Of the 15 differentially excreted peptides (p < 0.05), seven derived from a C-terminal region (⁵⁸⁹SGSVIDQSRVLNLGPITRK⁶⁰⁷) of uromodulin, a kidney-specific protein. Increased excretion of five uromodulin peptides was replicated in the validation cohort using parallel reaction monitoring (p < 0.05). One of the validated peptides (SGSVIDQSRVLNLGPI) activated NFB and AP-1 signaling, stimulated cytokine release, and enhanced neutrophil migration in vitro. In silico analyses highlighted several potential proteases such as hepsin, meprin A, and cathepsin B to be responsible for generating these peptides. In summary, we identified a urinary signature of uromodulin peptides associated with early type 1 diabetes before clinical manifestations of kidney disease and discovered novel bioactivity of uromodulin peptides in vitro. Our present findings lay the groundwork for future studies to validate peptide excretion in larger and broader populations, to investigate the role of bioactive uromodulin peptides in high glucose conditions, and to examine proteases that cleave uromodulin.

Large-scale identification of N-linked intact glycopeptides by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in human serum is challenging because of the wide dynamic range of serum protein abundances, the lack of a complete serum N-glycan database and the existence of proteoforms. In this regard, a spectral library search method was presented for the identification of N-linked intact glycopeptides from N-linked glycoproteins in human serum with target-decoy and motif-specific false discovery rate (FDR) control. Serum proteins were firstly separated into low-abundance and high-abundance proteins by acetonitrile (ACN) precipitation. After digestion, the N-linked intact glycopeptides were enriched by hydrophilic interaction liquid chromatography (HILIC) and a portion of the enriched N-linked intact glycopeptides were processed by Peptide-N-Glycosidase F (PNGase F) to generate N-linked deglycopeptides. Both N-linked intact glycopeptides and deglycopeptides were analyzed by LC-MS/MS. From N-linked deglycopeptides data sets, 764 N-linked glycoproteins, 1699 N-linked glycosites and 3328 unique N-linked deglycopeptides were identified. Four types of N-linked glycosylation motifs (NXS/T/C/V, X=P) were used to recognize the N-linked deglycopeptides. The spectra of these N-linked deglycopeptides were utilized for N-linked deglycopeptides library construction and identification of N-linked intact glycopeptides. A database containing 739 N-glycan masses was constructed and utilized during spectral library search for the identification of N-linked intact glycopeptides. In total, 526 N-linked glycoproteins, 1036 N-linked glycosites, 22,677 N-linked intact glycopeptides and 738 N-glycan masses were identified under 1% FDR, representing the most in-depth serum N-glycoproteome identified by LC-MS/MS at N-linked intact glycopeptide level.

C9ORF72-associated Motor Neuron Disease patients feature abnormal expression of 5 dipeptide repeat (DPR) polymers. Here we used quantitative proteomics in a mouse neuronal-like cell line (Neuro2a) to demonstrate that the Arg residues in the most toxic DPRS, PR and GR, leads to a promiscuous binding to the proteome compared with a relative sparse binding of the more inert AP and GA. Notable targets included ribosomal proteins, translation initiation factors and translation elongation factors. PR and GR comprising more than 10 repeats appeared to robustly stall on ribosomes during translation suggesting Arg-rich peptide domains can electrostatically jam the ribosome exit tunnel during synthesis. Poly-GR also recruited arginine methylases, induced hypomethylation of endogenous proteins, and induced a profound destabilization of the actin cytoskeleton. Our findings point to arginine in GR and PR polymers as multivalent toxins to translation as well as arginine methylation that may explain the dysfunction of biological processes including ribosome biogenesis, mRNA splicing and cytoskeleton assembly.

Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B–E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B–E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS–PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications.

Niemann-Pick disease, type C1 (NPC1) is a lipid storage disorder in which cholesterol and glycosphingolipids accumulate in late endosomal/lysosomal compartments because of mutations in the NPC1 gene. A hallmark of NPC1 is progressive neurodegeneration of the cerebellum as well as visceral organ damage; however, the mechanisms driving this disease pathology are not fully understood. Phosphoinositides are phospholipids that play distinct roles in signal transduction and vesicle trafficking. Here, we utilized consensus spectra analysis of MS imaging datasets and orthogonal LC–MS analyses to evaluate the spatial distribution of phosphoinositides and quantify them in cerebellar tissue from Npc1-null mice. Our results suggest significant depletion of multiple phosphoinositide species, including phosphatidylinositol (PI), phosphatidylinositol monophosphate (PIP), and bisphosphate (PIP2), in the cerebellum of the Npc1-null mice in both whole-tissue lysates and myelin-enriched fractions. Additionally, we observed altered levels of the regulatory enzyme phosphatidylinositol 4-kinase type 2 α (PI4K2A) in Npc1-null mice. In contrast, the levels of related kinases, phosphatases, and transfer proteins were unaltered in the Npc1-null mouse model as observed by Western blot analysis. Our discovery of phosphoinositide lipid biomarkers for NPC1 opens new perspectives on the pathophysiology underlying this fatal neurodegenerative disease.

Post-translational modifications play a critical and diverse role in regulating cellular activities. Despite their fundamentally important role in cellular function, there has been no report to date of an effective generalized approach to the targeting, extraction and characterization of the critical c-terminal regions of natively prenylated proteins. Various chemical modification and metabolic labelling strategies in cell culture have been reported. However, their applicability is limited to cell culture systems and does not allow for analysis of tissue samples. The chemical characteristics (hydrophobicity, low abundance, highly basic charge) of many of the c-terminal regions of prenylated proteins have impaired the use of standard proteomic workflows. In this context, we sought a direct approach to the problem in order to examine these proteins in tissue without the use of labelling.  Here we demonstrate that prenylated proteins can be captured on chromatographic resins functionalized with mixed disulfide functions. Protease treatment of resin-bound proteins using chymotryptic digestion revealed peptides from many known prenylated proteins. Exposure of the protease-treated resin to reducing agents and hydro organic mixtures released c-terminal peptides with intact prenyl groups along with other enzymatic modifications expected in this protein family. Database and search parameters were selected to allow for c-terminal modifications unique to these molecules such as CAAX box processing and c-terminal methylation. In summary, we present a direct approach to enrich and obtain information at a molecular level of detail about prenylation of proteins from tissue and cell extracts using high performance LCMS without the need for metabolic labeling and derivatization.

The presentation of post-translationally modified (PTM) peptides by cell surface HLA molecules has the potential to increase the diversity of targets for surveilling T cells. Whilst immunopeptidomics studies routinely identify thousands of HLA-bound peptides from cell lines and tissue samples, in-depth analyses of the proportion and nature of peptides bearing one or more PTMs remains challenging. Here we have analyzed HLA-bound peptides from a variety of allotypes and assessed the distribution of mass spectrometry-detected PTMs, finding deamidation of asparagine or glutamine to be highly prevalent. Given that asparagine deamidation may arise either spontaneously or through enzymatic reaction, we assessed allele-specific and global motifs flanking the modified residues. Notably, we found that the N-linked glycosylation motif NX(S/T) was highly abundant across asparagine-deamidated HLA-bound peptides. This finding, demonstrated previously for a handful of deamidated T cell epitopes, implicates a more global role for the retrograde transport of nascently N-glycosylated polypeptides from the ER and their subsequent degradation within the cytosol to form HLA-ligand precursors. Chemical inhibition of Peptide:N-Glycanase (PNGase), the endoglycosidase responsible for the removal of glycans from misfolded and retrotranslocated glycoproteins, greatly reduced presentation of this subset of deamidated HLA-bound peptides. Importantly, there was no impact of PNGase inhibition on peptides not containing a consensus NX(S/T) motif. This indicates that a large proportion of HLA-I bound asparagine deamidated peptides are generated from formerly glycosylated proteins that have undergone deglycosylation via the ER-associated protein degradation (ERAD) pathway. The information herein will help train deamidation prediction models for HLA-peptide repertoires and aid in the design of novel T cell therapeutic targets derived from glycoprotein antigens.

T cells isolated from the pancreatic infiltrates of non-obese diabetic mice have been shown to recognize epitopes formed by the covalent cross-linking of proinsulin and secretory granule peptides. Formation of such hybrid insulin peptides (HIPs) was confirmed through mass spectrometry and responses to HIPs were observed among the islet-infiltrating T cells of pancreatic organ donors and in the peripheral blood of individuals with type 1 diabetes (T1D). However, questions remain about the prevalence of HIP-specific T cells in humans, the sequences they recognize, and their role in disease. We identified six novel HIPs that are recognized in the context of DRB1*04:01, discovered by utilizing a library of theoretical HIP sequences derived from insulin fragments covalently linked to one another or to fragments of secretory granule proteins or other islet-derived proteins. We demonstrate that T cells that recognize these HIPs are detectable in the peripheral blood of subjects with T1D and exhibit an effector memory phenotype. HIP-reactive T cell clones produced Th1-associated cytokines and proliferated in response to human islet preparations. These results support the relevance of HIPs in human disease, further establishing a novel post-translational modification that may contribute to the loss of peripheral tolerance in T1D.

Long a country of emigration—13 million Italians went abroad between 1880 and 1915—Italy has also experienced significant inflows of Middle Eastern and sub-Saharan African workers in recent decades. Italy has also been on the frontlines of Europe's refugee crisis. This country profile examines Italy's shifting migration patterns, policy responses over time, and debates.

CJ Pike
Apr 1, 1993; 13:1676-1687
Articles

This article, published ahead of print on 28 July 2008, has been withdrawn by the authors. Although moderate synergy between P2-RANTES and C peptides can be observed with high statistical significance in cell fusion assays, this synergy was not able to be verified in HIV viral assays. The authors regret the overstatement of synergy and will revise the paper for publication at a later date.

Introduction: This study was performed to evaluate the impacts of vanA-positivity of Enterococcus faecium (EFM) exhibiting diverse susceptibility phenotypes to glycopeptides on clinical outcomes in patients with a bloodstream infection (BSI) through a prospective, multicenter, observational study.

Methods: A total of 509 patients with an EFM BSI from eight sentinel hospitals in South Korea during a two-year period were enrolled in this study. Risk factors of the hosts and causative EFM isolates were assessed to determine associations with the 30-day mortality of EFM BSI patients via multivariable logistic regression analyses.

Results: The vanA gene was detected in 35.2% (179/509) of EFM isolates; 131 EFM isolates exhibited typical VanA phenotypes (group vanA-VanA), while the remaining 48 EFM isolates exhibited atypical phenotypes (group vanA-Atypical), including VanD (n = 43) and vancomycin-variable phenotypes (n = 5). A multivariable logistic regression indicated that vanA-positivity of causative pathogens was independently associated with the increased 30-day mortality rate in the patients with an EFM BSI; however, there was no significant difference in the survival rates between the patients of the vanA-VanA and vanA-Atypical groups (log-rank test, P = 0.904).

Conclusions: A high 30-day mortality rate was observed in patients with vanA-positive EFM BSIs, and vanA-positivity of causative EFM was an independent risk factor for early mortality irrespective of the susceptibility phenotypes to glycopeptides; thus, intensified antimicrobial stewardship is needed to improve clinical outcome of patients with vanA-positive EFM BSI.

Two non-amidated host defence peptides named Pin2[G] and FA1 were evaluated against three types of pathogenic bacteria; two isolated from diabetic foot ulcer patients, Staphylococcus aureus UPD13 and Pseudomonas aeruginosa UPD3, and another from a commercial collection, Salmonella enterica serovar Typhimurium (ATCC 14028). In vitro experiments showed that the antimicrobial performance of the synthetic peptides, Pin2[G] and FA1, was modest, although FA1 was more effective than Pin2[G]. In contrast Pin2[G] had superior in vivo anti-infective activity to FA1 in rabbit wound infections by the diabetic foot ulcer pathogens S. aureus UPD13 and P. aeruginosa UPD3. Indeed, Pin2[G] reduced bacterial colony counts of both S. aureus UPD13 and P. aeruginosa UPD3 by >100,000-fold after 48-72 h on skin wounds of infected rabbits, while in similar infected wounds, FA1 had no major effects at 72-96 h of treatment. Ceftriaxone was equally effective vs. Pseudomonas but less effective vs. S. aureus infections. Additionally, the two peptides were evaluated in mice against intragastrically inoculated S. enterica ser. Typhimurium (ATCC 14028). Only Pin2[G], at 0.56 mg/kg, was effective in reducing systemic (liver) infection by >67-fold, equivalent to the effect of treatment with levofloxacin. Pin2[G] showed superior immunomodulatory activity in increasing chemokine production by a human bronchial cell line and suppressing poly(IC)-induced pro-inflammatory IL6 production. These data showed that the in vitro antimicrobial activity of these peptides was not correlated with their in vivo anti-infective activity, and suggest that other factors such as immunomodulatory activity were more important.

ABSTRACT

Staphylococcus aureus can colonize the human host and cause a variety of superficial and invasive infections. The success of S. aureus as a pathogen derives from its ability to modulate its virulence through the release, sensing of and response to cyclic signaling peptides. Here we provide, for the first time, evidence that S. aureus processes and secretes small linear peptides through a specialized pathway that converts a lipoprotein leader into an extracellular peptide signal. We have identified and confirmed the machinery for each step and demonstrate that the putative membrane metalloprotease Eep and the EcsAB transporter are required to complete the processing and secretion of the peptides. In addition, we have identified several linear peptides, including the interspecies signaling molecule staph-cAM373, that are dependent on this processing and secretion pathway. These findings are particularly important because multiple Gram-positive bacteria rely on small linear peptides to control bacterial gene expression and virulence.

IMPORTANCE Here, we provide evidence indicating that S. aureus secretes small linear peptides into the environment via a novel processing and secretion pathway. The discovery of a specialized pathway for the production of small linear peptides and the identification of these peptides leads to several important questions regarding their role in S. aureus biology, most interestingly, their potential to act as signaling molecules. The observations in this study provide a foundation for further in-depth studies into the biological activity of small linear peptides in S. aureus.