He was a zealous, wise and wonder-working bishop in his birthplace, Sinope, which lies on the southern shore of the Black Sea. For bringing many idolators to faith in Christ, he was hated by the pagans. He was arrested by the governor Africanus, subjected to various tortures,and finally scalded to death in a bath-house. He contested for the Faith during the reign of the Emperor Trajan.

She was a maiden of fifteen who lived with her parents in the Christian enclave of Sinope in Pontus during the 1700s. One day, as she went to the marketplace, she passed by the house of the local Pasha (governor), who, seeing her beauty, was seized by lust for her. He ordered his servants to bring her to him, and made two attempts to defile her; each time, however, he was prevented by a mysterious power that kept him from her like an invisible wall. Determined to have his way for her, he kept her prisoner in his house; but she was able to slip away and run home to her parents' house.   Enraged that his prey had escaped, the Pasha called together the leaders of the Christian community and promised that, unless Helen were handed over to him, all the Christians in the town would be massacred. Grief-stricken and fearful, the leaders persuaded Helen's father to return the girl to the palace. The vile Pasha made several more attempts to rape the Saint, but once again he was restrained as if by an invisible wall as she recited the Six Psalms and all the prayers that she knew by heart. Realizing that he was powerless against her, the Pasha had her thrown in the common jail, then ordered that she be tortured to death. The executioners subjected the maiden to several cruel torments before killing her by driving two nails into her skull and beheading her. They then put her body in a sack and threw it in the Black Sea.   Some Greek sailors followed a heavenly light to the place where the sack had sunk, and divers retrieved the Saint's relics, which immediately revealed themselves as a source of healing for many. Her body was taken to Russia; her head was placed in the church in Sinope, where it continued to work miracles, especially for those who suffered from headaches. When the Greeks were driven from Sinope in 1924, refugees took the head with them. It is venerated today in a church near Thessalonika.

He lived during the years when Constantinople was held in captivity by the Crusaders, and the Imperial government was in exile in Nicaea. Simon fled the world at a young age and traveled to the Holy Mountain, where he submitted himself to a strict but wise Elder for many years. In time, seeking greater seclusion, he moved to a small cave on the western side of Mt Athos, near a cliff that towered a thousand feet above the sea. One night, a few days before the Feast of the Nativity, he saw a star move across the sky and come to rest above the cliff near his cave. Taking this as a demonic delusion, he ignored it; but on the Eve of Nativity, the star once again took its place above the cliff, and Simon heard a voice from heaven saying 'Be in no doubt, Simon, faithful servant of my Son! See this sign, and do not leave this spot in search of greater solitude as you have in mind, for it is here that I want you to establish your monastery, for the salvation of many souls.' Soon afterward, three young monks from wealthy Macedonian families, who had heard of the Saint's holiness, came and laid their wealth at his feet, asking that he accept them as disciples. Simon sent for builders and ordered them to construct a monastery on the very edge of the precipitous cliff. The builders at first refused, saying the work was much too dangerous; but, persuaded by a miracle worked through the Saint's prayers, they were convinced. As soon as the building was finished, the monastic community began to grow rapidly.   In his own lifetime St Simon was the source of many miracles, prophecies and healings. Once the monastery was attacked by Saracen pirates. Simon went to meet them with gifts, hoping to dissuade them from attacking. When the pirates attacked him, they were blinded, and the arm of one of them was paralyzed when he attempted to strike the Saint. All of them were healed when the holy man prayed for them, and at this wonder they all repented, received Baptism and became monks.   Saint Simon reposed in peace. A fragrant, healing balm afterwards flowed from his tomb in great quantities, so that he came to be called Myroblytis, 'Myrrh-gusher' or 'Outpourer of Myrrh.' In subsequent years, the monastery was destroyed and rebuilt more than once, and no trace now remains of the tomb.

She was a maiden of fifteen who lived with her parents in the Christian enclave of Sinope in Pontus during the 1700s. One day, as she went to the marketplace, she passed by the house of the local Pasha (governor), who, seeing her beauty, was seized by lust for her. He ordered his servants to bring her to him, and made two attempts to defile her; each time, however, he was prevented by a mysterious power that kept him from her like an invisible wall. Determined to have his way for her, he kept her prisoner in his house; but she was able to slip away and run home to her parents' house.   Enraged that his prey had escaped, the Pasha called together the leaders of the Christian community and promised that, unless Helen were handed over to him, all the Christians in the town would be massacred. Grief-stricken and fearful, the leaders persuaded Helen's father to return the girl to the palace. The vile Pasha made several more attempts to rape the Saint, but once again he was restrained as if by an invisible wall as she recited the Six Psalms and all the prayers that she knew by heart. Realizing that he was powerless against her, the Pasha had her thrown in the common jail, then ordered that she be tortured to death. The executioners subjected the maiden to several cruel torments before killing her by driving two nails into her skull and beheading her. They then put her body in a sack and threw it in the Black Sea.   Some Greek sailors followed a heavenly light to the place where the sack had sunk, and divers retrieved the Saint's relics, which immediately revealed themselves as a source of healing for many. Her body was taken to Russia; her head was placed in the church in Sinope, where it continued to work miracles, especially for those who suffered from headaches. When the Greeks were driven from Sinope in 1924, refugees took the head with them. It is venerated today in a church near Thessalonika.

He lived during the years when Constantinople was held in captivity by the Crusaders, and the Imperial government was in exile in Nicaea. Simon fled the world at a young age and traveled to the Holy Mountain, where he submitted himself to a strict but wise Elder for many years. In time, seeking greater seclusion, he moved to a small cave on the western side of Mt Athos, near a cliff that towered a thousand feet above the sea. One night, a few days before the Feast of the Nativity, he saw a star move across the sky and come to rest above the cliff near his cave. Taking this as a demonic delusion, he ignored it; but on the Eve of Nativity, the star once again took its place above the cliff, and Simon heard a voice from heaven saying 'Be in no doubt, Simon, faithful servant of my Son! See this sign, and do not leave this spot in search of greater solitude as you have in mind, for it is here that I want you to establish your monastery, for the salvation of many souls.' Soon afterward, three young monks from wealthy Macedonian families, who had heard of the Saint's holiness, came and laid their wealth at his feet, asking that he accept them as disciples. Simon sent for builders and ordered them to construct a monastery on the very edge of the precipitous cliff. The builders at first refused, saying the work was much too dangerous; but, persuaded by a miracle worked through the Saint's prayers, they were convinced. As soon as the building was finished, the monastic community began to grow rapidly.   In his own lifetime St Simon was the source of many miracles, prophecies and healings. Once the monastery was attacked by Saracen pirates. Simon went to meet them with gifts, hoping to dissuade them from attacking. When the pirates attacked him, they were blinded, and the arm of one of them was paralyzed when he attempted to strike the Saint. All of them were healed when the holy man prayed for them, and at this wonder they all repented, received Baptism and became monks.   Saint Simon reposed in peace. A fragrant, healing balm afterwards flowed from his tomb in great quantities, so that he came to be called Myroblytis, 'Myrrh-gusher' or 'Outpourer of Myrrh.' In subsequent years, the monastery was destroyed and rebuilt more than once, and no trace now remains of the tomb.

She was a maiden of fifteen who lived with her parents in the Christian enclave of Sinope in Pontus during the 1700s. One day, as she went to the marketplace, she passed by the house of the local Pasha (governor), who, seeing her beauty, was seized by lust for her. He ordered his servants to bring her to him, and made two attempts to defile her; each time, however, he was prevented by a mysterious power that kept him from her like an invisible wall. Determined to have his way for her, he kept her prisoner in his house; but she was able to slip away and run home to her parents' house.   Enraged that his prey had escaped, the Pasha called together the leaders of the Christian community and promised that, unless Helen were handed over to him, all the Christians in the town would be massacred. Grief-stricken and fearful, the leaders persuaded Helen's father to return the girl to the palace. The vile Pasha made several more attempts to rape the Saint, but once again he was restrained as if by an invisible wall as she recited the Six Psalms and all the prayers that she knew by heart. Realizing that he was powerless against her, the Pasha had her thrown in the common jail, then ordered that she be tortured to death. The executioners subjected the maiden to several cruel torments before killing her by driving two nails into her skull and beheading her. They then put her body in a sack and threw it in the Black Sea.   Some Greek sailors followed a heavenly light to the place where the sack had sunk, and divers retrieved the Saint's relics, which immediately revealed themselves as a source of healing for many. Her body was taken to Russia; her head was placed in the church in Sinope, where it continued to work miracles, especially for those who suffered from headaches. When the Greeks were driven from Sinope in 1924, refugees took the head with them. It is venerated today in a church near Thessalonika.

He lived during the years when Constantinople was held in captivity by the Crusaders, and the Imperial government was in exile in Nicaea. Simon fled the world at a young age and traveled to the Holy Mountain, where he submitted himself to a strict but wise Elder for many years. In time, seeking greater seclusion, he moved to a small cave on the western side of Mt Athos, near a cliff that towered a thousand feet above the sea. One night, a few days before the Feast of the Nativity, he saw a star move across the sky and come to rest above the cliff near his cave. Taking this as a demonic delusion, he ignored it; but on the Eve of Nativity, the star once again took its place above the cliff, and Simon heard a voice from heaven saying 'Be in no doubt, Simon, faithful servant of my Son! See this sign, and do not leave this spot in search of greater solitude as you have in mind, for it is here that I want you to establish your monastery, for the salvation of many souls.' Soon afterward, three young monks from wealthy Macedonian families, who had heard of the Saint's holiness, came and laid their wealth at his feet, asking that he accept them as disciples. Simon sent for builders and ordered them to construct a monastery on the very edge of the precipitous cliff. The builders at first refused, saying the work was much too dangerous; but, persuaded by a miracle worked through the Saint's prayers, they were convinced. As soon as the building was finished, the monastic community began to grow rapidly.   In his own lifetime St Simon was the source of many miracles, prophecies and healings. Once the monastery was attacked by Saracen pirates. Simon went to meet them with gifts, hoping to dissuade them from attacking. When the pirates attacked him, they were blinded, and the arm of one of them was paralyzed when he attempted to strike the Saint. All of them were healed when the holy man prayed for them, and at this wonder they all repented, received Baptism and became monks.   Saint Simon reposed in peace. A fragrant, healing balm afterwards flowed from his tomb in great quantities, so that he came to be called Myroblytis, 'Myrrh-gusher' or 'Outpourer of Myrrh.' In subsequent years, the monastery was destroyed and rebuilt more than once, and no trace now remains of the tomb.

She was a maiden of fifteen who lived with her parents in the Christian enclave of Sinope in Pontus during the 1700s. One day, as she went to the marketplace, she passed by the house of the local Pasha (governor), who, seeing her beauty, was seized by lust for her. He ordered his servants to bring her to him, and made two attempts to defile her; each time, however, he was prevented by a mysterious power that kept him from her like an invisible wall. Determined to have his way for her, he kept her prisoner in his house; but she was able to slip away and run home to her parents' house.   Enraged that his prey had escaped, the Pasha called together the leaders of the Christian community and promised that, unless Helen were handed over to him, all the Christians in the town would be massacred. Grief-stricken and fearful, the leaders persuaded Helen's father to return the girl to the palace. The vile Pasha made several more attempts to rape the Saint, but once again he was restrained as if by an invisible wall as she recited the Six Psalms and all the prayers that she knew by heart. Realizing that he was powerless against her, the Pasha had her thrown in the common jail, then ordered that she be tortured to death. The executioners subjected the maiden to several cruel torments before killing her by driving two nails into her skull and beheading her. They then put her body in a sack and threw it in the Black Sea.   Some Greek sailors followed a heavenly light to the place where the sack had sunk, and divers retrieved the Saint's relics, which immediately revealed themselves as a source of healing for many. Her body was taken to Russia; her head was placed in the church in Sinope, where it continued to work miracles, especially for those who suffered from headaches. When the Greeks were driven from Sinope in 1924, refugees took the head with them. It is venerated today in a church near Thessalonika.

Aminopeptidase N (APN, CD13) is a transmembrane ectopeptidase involved in many crucial cellular functions. Besides its role as a peptidase, APN also mediates signal transduction and is involved in the activation of matrix metalloproteinases (MMPs). MMPs function in tissue remodeling within the extracellular space and are therefore involved in many human diseases, such as fibrosis, rheumatoid arthritis, tumor angiogenesis, and metastasis, as well as viral infections. However, the exact mechanism that leads to APN-driven MMP activation is unclear. It was previously shown that extracellular 14-3-3 adapter proteins bind to APN and thereby induce the transcription of MMPs. As a first step, we sought to identify potential 14-3-3–binding sites in the APN sequence. We constructed a set of phosphorylated peptides derived from APN to probe for interactions. We identified and characterized a canonical 14-3-3–binding site (site 1) within the flexible, structurally unresolved N-terminal APN region using direct binding fluorescence polarization assays and thermodynamic analysis. In addition, we identified a secondary, noncanonical binding site (site 2), which enhances the binding affinity in combination with site 1 by many orders of magnitude. Finally, we solved crystal structures of 14-3-3σ bound to mono- and bis-phosphorylated APN-derived peptides, which revealed atomic details of the binding mode of mono- and bivalent 14-3-3 interactions. Therefore, our findings shed some light on the first steps of APN-mediated MMP activation and open the field for further investigation of this important signaling pathway.

The investor confidence shot up in RIL because of the back-to-back strategic investments in its telecom subsidiary in the last three weeks

NOPE.

Crystals of the dimethyl sulfoxide (DMSO) solvate of [1–9-NαC]-linusorb B3 (Cyclo­linopeptide A; CLP-A; C57H84N9O9·C2H6OS), a cyclic polypeptide were obtained following peptide extraction and purification from flaxseed oil. There are four intramolecular N—H⋯O hydrogen bonds. In the crystal, the mol­ecules are linked in chains along the a axis by N—H⋯O hydrogen bonds. Each DMSO O atom accepts a hydrogen bond from an NH group at the Phe6 location in the CLP-A mol­ecule.

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Human leukocyte antigen (HLA) B*51:01 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly genetically associated with Behcet's disease (BD). Previous studies have defined two subgroups of HLA-B*51 peptidome containing proline (Pro) or alanine (Ala) at position 2 (P2). Little is known about the unconventional non-Pro/Ala2 HLA-B*51-bound peptides. We aimed to study the features of this novel subpeptidome, and investigate its regulation by ERAP1. CRISPR-Cas9 was used to generate an HLA-ABC-triple knockout HeLa cell line (HeLa.ABC-KO), which was subsequently transduced to express HLA-B*51:01 (HeLa.ABC-KO.B51). ERAP1 was silenced using lentiviral shRNA. Peptides bound to HLA-B*51:01 were eluted and analyzed by mass spectrometry. The characteristics of non-Pro/Ala2, Pro2, and Ala2 peptides and their alteration by ERAP1 silencing were investigated. Effects of ERAP1 silencing on cell surface expression of HLA-B*51:01 were studied using flow cytometry. More than 20% of peptides eluted from HLA-B*51:01 lacked Pro or Ala at P2. This unconventional group of HLA-B*51:01-bound peptides was relatively enriched for 8-mers (with relatively fewer 9-mers) compared with the Pro2 and Ala2 subpeptidomes and had similar N-terminal and C-terminal residue usages to Ala2 peptides (with the exception of the less abundant leucine at position ). Knockdown of ERAP1 increased the percentage of non-Pro/Ala2 from 20% to ~40%, increased the percentage of longer (10-mer and 11-mer) peptides eluted from HLA-B*51:01 complexes, and abrogated the predominance of leucine at P1. Interestingly knockdown of ERAP1 altered the length and N-terminal residue usage of non-Ala2&Pro2 and Ala2 but not the Pro2 peptides. Finally, ERAP1 silencing regulated the expression levels of cell surface HLA-B*51 in a cell-type-dependent manner. In conclusion, we have used a novel methodology to identify an unconventional but surprisingly abundant non-Pro/Ala2 HLA-B*51:01 subpeptidome. It is increased by knockdown of ERAP1, a gene affecting the risk of developing BD. This has implications for theories of disease pathogenesis.

Elena Lorente
Apr 7, 2020; 0:RA120.002014v1-mcp.RA120.002014
Research

Liye Chen
May 1, 2020; 19:871-883
Research

The presentation of peptides on class I human leukocyte antigen (HLA-I) molecules plays a central role in immune recognition of infected or malignant cells. In cancer, non-self HLA-I ligands can arise from many different alterations, including non-synonymous mutations, gene fusion, cancer-specific alternative mRNA splicing or aberrant post-translational modifications. Identifying HLA-I ligands remains a challenging task that requires either heavy experimental work for in vivo identification or optimized bioinformatics tools for accurate predictions. To date, no HLA-I ligand predictor includes post-translational modifications. To fill this gap, we curated phosphorylated HLA-I ligands from several immunopeptidomics studies (including six newly measured samples) covering 72 HLA-I alleles and retrieved a total of 2,066 unique phosphorylated peptides. We then expanded our motif deconvolution tool to identify precise binding motifs of phosphorylated HLA-I ligands. Our results reveal a clear enrichment of phosphorylated peptides among HLA-C ligands and demonstrate a prevalent role of both HLA-I motifs and kinase motifs on the presentation of phosphorylated peptides. These data further enabled us to develop and validate the first predictor of interactions between HLA-I molecules and phosphorylated peptides.

For more than two decades naturally presented, human leukocyte antigen (HLA)-restricted peptides (immunopeptidome) have been eluted and sequenced using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Since, identified disease-associated HLA ligands have been characterized and evaluated as potential active substances. Treatments based on HLA-presented peptides have shown promising results in clinical application as personalized T cell-based immunotherapy. Peptide vaccination cocktails are produced as investigational medicinal products under GMP conditions. To support clinical trials based on HLA-presented tumor-associated antigens, in this study the sensitive LC-MS/MS HLA class I antigen identification pipeline was fully validated for our technical equipment according to the current US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines.

The immunopeptidomes of JY cells with or without spiked-in, isotope labeled peptides, of peripheral blood mononuclear cells of healthy volunteers as well as a chronic lymphocytic leukemia and a bladder cancer sample were reliably identified using a data-dependent acquisition method. As the LC-MS/MS pipeline is used for identification purposes, the validation parameters include accuracy, precision, specificity, limit of detection and robustness.

Human leukocyte antigen (HLA) B*51:01 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly genetically associated with Behcet's disease (BD). Previous studies have defined two subgroups of HLA-B*51 peptidome containing proline (Pro) or alanine (Ala) at position 2 (P2). Little is known about the unconventional non-Pro/Ala2 HLA-B*51-bound peptides. We aimed to study the features of this novel subpeptidome, and investigate its regulation by ERAP1. CRISPR-Cas9 was used to generate an HLA-ABC-triple knockout HeLa cell line (HeLa.ABC-KO), which was subsequently transduced to express HLA-B*51:01 (HeLa.ABC-KO.B51). ERAP1 was silenced using lentiviral shRNA. Peptides bound to HLA-B*51:01 were eluted and analyzed by mass spectrometry. The characteristics of non-Pro/Ala2, Pro2, and Ala2 peptides and their alteration by ERAP1 silencing were investigated. Effects of ERAP1 silencing on cell surface expression of HLA-B*51:01 were studied using flow cytometry. More than 20% of peptides eluted from HLA-B*51:01 lacked Pro or Ala at P2. This unconventional group of HLA-B*51:01-bound peptides was relatively enriched for 8-mers (with relatively fewer 9-mers) compared with the Pro2 and Ala2 subpeptidomes and had similar N-terminal and C-terminal residue usages to Ala2 peptides (with the exception of the less abundant leucine at position ). Knockdown of ERAP1 increased the percentage of non-Pro/Ala2 from 20% to ~40%, increased the percentage of longer (10-mer and 11-mer) peptides eluted from HLA-B*51:01 complexes, and abrogated the predominance of leucine at P1. Interestingly knockdown of ERAP1 altered the length and N-terminal residue usage of non-Ala2&Pro2 and Ala2 but not the Pro2 peptides. Finally, ERAP1 silencing regulated the expression levels of cell surface HLA-B*51 in a cell-type-dependent manner. In conclusion, we have used a novel methodology to identify an unconventional but surprisingly abundant non-Pro/Ala2 HLA-B*51:01 subpeptidome. It is increased by knockdown of ERAP1, a gene affecting the risk of developing BD. This has implications for theories of disease pathogenesis.

Join Henry Burrell as he asks Davids Price why Snopes, the fact checking website, has run into trouble and how crowdfunding could save the day. Is it still important in this age of fake news? Then Scott Carey commentates on the bout between Mark Zuckerberg and Elon Musk. Who knows the most about AI? When will the killer robots descend upon us? Does Mark do all his online Q & A’s in front of a cooking brisket? All this answered and more.  

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The human leucocyte antigen (HLA)-B*27:05 allele and the endoplasmic reticulum-resident aminopeptidases are strongly associated with ankylosing spondylitis (AS), a chronic inflammatory spondyloarthropathy. This study examined the effect of endoplasmic reticulum aminopeptidase 2 (ERAP2) in the generation of the natural HLA-B*27:05 ligandome in live cells. Complexes of HLA-B*27:05-bound peptide pools were isolated from human ERAP2-edited cell clones and the peptides were identified using high throughput mass spectrometry analyses. The relative abundance of thousand ligands was established by quantitative tandem mass spectrometry and bioinformatics analysis. The residue frequencies at different peptide position, identified in presence or absence of ERAP2, determined structural features of ligands and their interactions with specific pockets of antigen binding site of HLA-B*27:05 molecule. Sequence alignment of ligands identified with species of bacteria associated with HLA-B*27-dependent reactive arthritis was performed. In the absence of ERAP2, peptides with N-terminal basic residues, and minority canonical P2 residues are enriched in the natural ligandome. Further, alterations of residue frequencies and hydrophobicity profile at P3, P7, and P positions were detected. In addition, several ERAP2-dependent cellular peptides were highly similar to protein sequences of arthritogenic bacteria, including one human HLA-B*27:05 ligand fully conserved in a protein from Campylobacter jejuni. These findings highlight the pathogenic role of this aminopeptidase in the triggering of AS autoimmune disease.

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.

The signal peptide of preproinsulin is a major source for HLA class I autoantigen epitopes implicated in CD8 T cell (CTL)–mediated β-cell destruction in type 1 diabetes (T1D). Among them, the 10-mer epitope located at the C-terminal end of the signal peptide was found to be the most prevalent in patients with recent-onset T1D. While the combined action of signal peptide peptidase and endoplasmic reticulum (ER) aminopeptidase 1 (ERAP1) is required for processing of the signal peptide, the mechanisms controlling signal peptide trimming and the contribution of the T1D inflammatory milieu on these mechanisms are unknown. Here, we show in human β-cells that ER stress regulates ERAP1 gene expression at posttranscriptional level via the IRE1α/miR-17-5p axis and demonstrate that inhibition of the IRE1α activity impairs processing of preproinsulin signal peptide antigen and its recognition by specific autoreactive CTLs during inflammation. These results underscore the impact of ER stress in the increased visibility of β-cells to the immune system and position the IRE1α/miR-17 pathway as a central component in β-cell destruction processes and as a potential target for the treatment of autoimmune T1D.

Wien : Toeplitz & Deuticke, 1886.

Berlin : G. Reimer, 1899.

Leishmania major is the causative agent of cutaneous leishmaniasis (CL). No human vaccine is available for CL and current drug regimens present several drawbacks such as emerging resistance, severe toxicity, medium effectiveness, and/or high cost. Thus, the need for better treatment options against CL is a priority. In the present study, we validate the enzyme methionine aminopeptidase-1 (MetAP1), a metalloprotease that catalyzes the removal of N-terminal methionine from peptides and proteins, as a chemotherapeutic target against CL infection. The in vitro antileishmanial activity of eight novel MetAP1 inhibitors (OJT001-OJT008) were investigated. Three compounds OJT006, OJT007, and OJT008 demonstrated potent anti-proliferative effect in macrophages infected with L. major amastigotes and promastigotes at submicromolar concentrations, with no cytotoxicity against host cells. Importantly, the leishmanicidal effect was diminished by almost 10-fold in transgenic L. major promastigotes overexpressing MetAP1_LM in comparison to wild-type promastigotes. Furthermore, the in vivo activity of OJT006, OJT007, and OJT008 were investigated in L. major-infected BALB/c mice. In comparison to the control group, OJT008 significantly decreased footpad parasite load by 86%, and exhibited no toxicity against in treated mice. We propose MetAP1 inhibitor OJT008 as a potential chemotherapeutic candidate against CL infection caused by L. major infection.

The hackers have been using files and emails that warn about a new coronavirus strain to trick users into opening them. Doing so can secretly deliver malware to the victim's machine.

ABSTRACT

The global stress response controlled by the alternative sigma factor RpoS protects enteric bacteria from a variety of environmental stressors. The role of RpoS in other, nonenteric bacteria, such as the opportunistic pathogen Pseudomonas aeruginosa, is less well understood. Here, we employed experimental social evolution to reveal that cooperative behavior via secreted public goods is an important function in the RpoS response of P. aeruginosa. Using whole-genome sequencing, we identified rpoS loss-of-function mutants among isolates evolved in a protein growth medium that requires extracellular proteolysis. We found that rpoS mutants comprise up to 25% of the evolved population and that they behave as social cheaters, with low fitness in isolation but high fitness in mixed culture with the cooperating wild type. We conclude that rpoS mutants cheat because they exploit an RpoS-controlled public good produced by the wild type, the secreted aminopeptidase PaAP, and because they do not carry the metabolic costs of expressing PaAP and many other gene products in the large RpoS regulon. Our results suggest that PaAP is an integral part of a proteolytic sequence in P. aeruginosa that permits the utilization of protein as a nutrient source. Our work broadens the scope of stress response functions in bacteria.

IMPORTANCE Bacterial stress responses are generally considered protective measures taken by individual cells. Enabled by an experimental evolution approach, we describe a contrasting property, collective nutrient acquisition, in the RpoS-dependent stress response of the opportunistic human pathogen P. aeruginosa. Specifically, we identify the secreted P. aeruginosa aminopeptidase (PaAP) as an essential RpoS-controlled function in extracellular proteolysis. As a secreted "public good," PaAP permits cheating by rpoS mutants that save the metabolic costs of expressing RpoS-controlled genes dispensable under the given growth conditions. Proteolytic enzymes are important virulence factors in P. aeruginosa pathogenesis and constitute a potential target for antimicrobial therapy. More broadly, our work contributes to recent findings in higher organisms that stress affects not only individual fitness and competitiveness but also cooperative behavior.

ABSTRACT

Cold seeps and hydrothermal vents deliver large amounts of methane and other gaseous alkanes into marine surface sediments. Consortia of archaea and partner bacteria thrive on the oxidation of these alkanes and its coupling to sulfate reduction. The inherently slow growth of the involved organisms and the lack of pure cultures have impeded the understanding of the molecular mechanisms of archaeal alkane degradation. Here, using hydrothermal sediments of the Guaymas Basin (Gulf of California) and ethane as the substrate, we cultured microbial consortia of a novel anaerobic ethane oxidizer, "Candidatus Ethanoperedens thermophilum" (GoM-Arc1 clade), and its partner bacterium "Candidatus Desulfofervidus auxilii," previously known from methane-oxidizing consortia. The sulfate reduction activity of the culture doubled within one week, indicating a much faster growth than in any other alkane-oxidizing archaea described before. The dominance of a single archaeal phylotype in this culture allowed retrieval of a closed genome of "Ca. Ethanoperedens," a sister genus of the recently reported ethane oxidizer "Candidatus Argoarchaeum." The metagenome-assembled genome of "Ca. Ethanoperedens" encoded a complete methanogenesis pathway including a methyl-coenzyme M reductase (MCR) that is highly divergent from those of methanogens and methanotrophs. Combined substrate and metabolite analysis showed ethane as the sole growth substrate and production of ethyl-coenzyme M as the activation product. Stable isotope probing demonstrated that the enzymatic mechanism of ethane oxidation in "Ca. Ethanoperedens" is fully reversible; thus, its enzymatic machinery has potential for the biotechnological development of microbial ethane production from carbon dioxide.

IMPORTANCE In the seabed, gaseous alkanes are oxidized by syntrophic microbial consortia that thereby reduce fluxes of these compounds into the water column. Because of the immense quantities of seabed alkane fluxes, these consortia are key catalysts of the global carbon cycle. Due to their obligate syntrophic lifestyle, the physiology of alkane-degrading archaea remains poorly understood. We have now cultivated a thermophilic, relatively fast-growing ethane oxidizer in partnership with a sulfate-reducing bacterium known to aid in methane oxidation and have retrieved the first complete genome of a short-chain alkane-degrading archaeon. This will greatly enhance the understanding of nonmethane alkane activation by noncanonical methyl-coenzyme M reductase enzymes and provide insights into additional metabolic steps and the mechanisms underlying syntrophic partnerships. Ultimately, this knowledge could lead to the biotechnological development of alkanogenic microorganisms to support the carbon neutrality of industrial processes.

A new study shows that in fact, if you build them, people use them and drive less.