Protein with negative surface charge distribution, Bnr1, shows characteristics of a DNA-mimic protein and may be involved in the adaptation of Burkholderia cenocepacia.

Adaptation of opportunistic pathogens to their host environment requires reprogramming of a vast array of genes to facilitate survival in the host. Burkholderia cenocepacia, a Gram-negative bacterium with a large genome of ∼8 Mb that colonizes environmental niches, is exquisitely adaptable to the hypoxic environment of the cystic fibrosis lung and survives in macrophages. We previously identified an immunoreactive acidic protein encoded on replicon 3, BCAS0292. Deletion of the BCAS0292 gene significantly altered the abundance of 979 proteins by 1.5-fold or more; 19 proteins became undetectable while 545 proteins showed ≥1.5-fold reduced abundance, suggesting the BCAS0292 protein is a global regulator. Moreover, the ∆BCAS0292 mutant showed a range of pleiotropic effects: virulence and host-cell attachment were reduced, antibiotic susceptibility was altered, and biofilm formation enhanced. Its growth and survival were impaired in 6% oxygen. In silico prediction of its three-dimensional structure revealed BCAS0292 presents a dimeric ß-structure with a negative surface charge. The ΔBCAS0292 mutant displayed altered DNA supercoiling, implicated in global regulation of gene expression. Three proteins were identified in pull-downs with FLAG-tagged BCAS0292, including the Histone H1-like protein, HctB, which is recognized as a global transcriptional regulator. We propose that BCAS0292 protein, which we have named Burkholderia negatively surface-charged regulatory protein 1 (Bnr1), acts as a DNA-mimic and binds to DNA-binding proteins, altering DNA topology and regulating the expression of multiple genes, thereby enabling the adaptation of B. cenocepacia to highly diverse environments.

Primordial mimicry induces morphological change in Escherichia coli.

The morphology of primitive cells has been the subject of extensive research. A spherical form was commonly presumed in prebiotic studies but lacked experimental evidence in living cells. Whether and how the shape of living cells changed are unclear. Here we exposed the rod-shaped bacterium Escherichia coli to a resource utilization regime mimicking a primordial environment. Oleate was given as an easy-to-use model prebiotic nutrient, as fatty acid vesicles were likely present on the prebiotic Earth and might have been used as an energy resource. Six evolutionary lineages were generated under glucose-free but oleic acid vesicle (OAV)-rich conditions. Intriguingly, fitness increase was commonly associated with the morphological change from rod to sphere and the decreases in both the size and the area-to-volume ratio of the cell. The changed cell shape was conserved in either OAVs or glucose, regardless of the trade-offs in carbon utilization and protein abundance. Highly differentiated mutations present in the genome revealed two distinct strategies of adaption to OAV-rich conditions, i.e., either directly targeting the cell wall or not. The change in cell morphology of Escherichia coli for adapting to fatty acid availability supports the assumption of the primitive spherical form.

Effective tools for RNA-derived therapeutics: siRNA interference or miRNA mimicry.

The approval of the first small interfering RNA (siRNA) drug Patisiran by FDA in 2018 marks a new era of RNA interference (RNAi) therapeutics. MicroRNAs (miRNA), an important post-transcriptional gene regulator, are also the subject of both basic research and clinical trials. Both siRNA and miRNA mimics are ~21 nucleotides RNA duplexes inducing mRNA silencing. Given the well performance of siRNA, researchers ask whether miRNA mimics are unnecessary or developed siRNA technology can pave the way for the emergence of miRNA mimic drugs. Through comprehensive comparison of siRNA and miRNA, we focus on (1) the common features and lessons learnt from the success of siRNAs; (2) the unique characteristics of miRNA that potentially offer additional therapeutic advantages and opportunities; (3) key areas of ongoing research that will contribute to clinical application of miRNA mimics. In conclusion, miRNA mimics have unique properties and advantages which cannot be fully matched by siRNA in clinical applications. MiRNAs are endogenous molecules and the gene silencing effects of miRNA mimics can be regulated or buffered to ameliorate or eliminate off-target effects. An in-depth understanding of the differences between siRNA and miRNA mimics will facilitate the development of miRNA mimic drugs.

The analysis on the human protein domain targets and host-like interacting motifs for the MERS-CoV and SARS-CoV/CoV-2 infers the molecular mimicry of coronavirus.

The MERS-CoV, SARS-CoV, and SARS-CoV-2 are highly pathogenic viruses that can cause severe pneumonic diseases in humans. Unfortunately, there is a non-available effective treatment to combat these viruses. Domain-motif interactions (DMIs) are an essential means by which viruses mimic and hijack the biological processes of host cells. To disentangle how viruses achieve this process can help to develop new rational therapies. Data mining was performed to obtain DMIs stored as regular expressions (regexp) in 3DID and ELM databases. The mined regexp information was mapped on the coronaviruses' proteomes. Most motifs on viral protein that could interact with human proteins are shared across the coronavirus species, indicating that molecular mimicry is a common strategy for coronavirus infection. Enrichment ontology analysis for protein domains showed a shared biological process and molecular function terms related to carbon source utilization and potassium channel regulation. Some of the mapped motifs were nested on B, and T cell epitopes, suggesting that it could be as an alternative way for reverse vaccinology. The information obtained in this study could be used for further theoretic and experimental explorations on coronavirus infection mechanism and development of medicines for treatment.

Molecular Mimicry between Betaine Aldehyde Dehydrogenase of Leptospira and Retinal Dehydrogenase 1 of Human Lens: A Potential Trigger for Cataract Formation in Leptospiral Uveitis Patients.

Purpose: Rapidly progressing cataract is one of the ocular manifestations in leptospiral uveitis patients. We examined whether molecular mimicry between the leptospira antigens and lens proteins exists that could result in cataract in these patients.Methods: Immunoblot analysis using patient sera was done with proteins from normal lens and cataract lens from leptospiral uveitis patients and the cross-reacting lens proteins were identified by mass spectrometry analysis.Results: Retinal dehydrogenase 1 and crystallins (α-B, α-A2, ß-B2), were recognized by the antibodies in the serum of leptospiral uveitis patients. And, retinal dehydrogenase 1 is homologous to the leptospiral protein, betaine aldehyde dehydrogenase.Conclusions: Leptospiral uveitis patient serum contains antibodies that cross-react with multiple lens proteins that have a role in maintaining lens transparency. And, these antibodies could act as a potential trigger for cataractogenesis.

Both d- and l-Glucose Polyphosphates Mimic d-myo-Inositol 1,4,5-Trisphosphate: New Synthetic Agonists and Partial Agonists at the Ins(1,4,5)P3 Receptor.

Chiral sugar derivatives are potential cyclitol surrogates of the Ca2+-mobilizing intracellular messenger d-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. Six novel polyphosphorylated analogues derived from both d- and l-glucose were synthesized. Binding to Ins(1,4,5)P3 receptors [Ins(1,4,5)P3R] and the ability to release Ca2+ from intracellular stores via type 1 Ins(1,4,5)P3Rs were investigated. ß-d-Glucopyranosyl 1,3,4-tris-phosphate, with similar phosphate regiochemistry and stereochemistry to Ins(1,4,5)P3, and α-d-glucopyranosyl 1,3,4-tris-phosphate are full agonists, being equipotent and 23-fold less potent than Ins(1,4,5)P3, respectively, in Ca2+-release assays and similar to Ins(1,4,5)P3 and 15-fold weaker in binding assays. They can be viewed as truncated analogues of adenophostin A and refine understanding of structure-activity relationships for this Ins(1,4,5)P3R agonist. l-Glucose-derived ligands, methyl α-l-glucopyranoside 2,3,6-trisphosphate and methyl α-l-glucopyranoside 2,4,6-trisphosphate, are also active, while their corresponding d-enantiomers, methyl α-d-glucopyranoside 2,3,6-trisphosphate and methyl α-d-glucopyranoside 2,4,6-trisphosphate, are inactive. Interestingly, both l-glucose-derived ligands are partial agonists: they are among the least efficacious agonists of Ins(1,4,5)P3R yet identified, providing new leads for antagonist development.

microRNA-21 Aggravates Lipopolysaccharide-Induced Inflammation in MH7A Cells Through Targeting SNF5.

The research aims to explore the roles and underlying mechanisms of microRNA-21 (miR-21) in lipopolysaccharide (LPS)-induced inflammation in MH7A cells. Cells were treated with LPS and/or transfected with miR-21 mimic/inhibitor or pc-sucrose nonfermentable 5 (SNF5). Cell viability was detected by CCK-8. ELISA and western blot were respectively conducted to measure the protein levels of pro-inflammatory factors, NF-κB or PTEN/PI3K/AKT key proteins and SNF5. miR-21/U6 was measured by qRT-PCR. The association between miR-21 and SNF5 was determined by luciferase reporter assay. Cell viability and the protein expression levels of interleukin-1ß (IL-1ß), IL-6, and p/t-p65, p/t-IκBα, p/t-PI3K, and p/t-AKT were significantly elevated by LPS, but with an inhibition of p-PTEN. Besides, LPS upregulated miR-21, whose overproduction or silence enhanced or alleviated the LPS stimulation on those elements above, respectively. miR-21 mimic notably inhibited SNF5, which was accelerated by miR-21 inhibitor, and abundant SNF5 abolished the effect of miR-21 mimic on cell viability, pro-inflammatory mediators, and sensitivity of signaling pathways, representing a negative relationship between them. miR-21 augmented LPS-induced inflammation response through activating NF-κB and PTEN/PI3K/AKT pathways by silencing SNF5 in MH7A cell line.

MicroRNA let-7g-5p alleviates murine collagen-induced arthritis by inhibiting Th17 cell differentiation.

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease with complicated pathogenesis. IL-17-producing T helper cells (Th17) are important players in the RA process. Despite numerous researches have proven that microRNAs (miRNAs) are crucial to regulate autoimmune diseases including RA, the effect of miRNAs on Th17 cell differentiation and function in the RA progress is not clear. Here, our results showed that the expression of miRNA let-7g-5p was substantially lower in RA patients and CIA mice compared with healthy controls, accompanied by the increased Th17 cell population. Furthermore, the inhibition of let-7g-5p on Th17 cell differentiation and function were verified in vitro. Notably, the disease severity in CIA mice was significantly alleviated after the treatment of let-7g-5p mimics. In addition, let-7g-5p mimics treatment markedly down-regulated the frequency of Th17 cells in CIA mice. Taken together, our findings indicate that let-7g-5p can ameliorate CIA through blocking the differentiation of Th17 cells, which may be a novel strategy to treat autoimmune diseases such as RA.

MicroRNA-588 regulates migration capacity and invasiveness of renal cancer cells by targeting EIF5A2.

OBJECTIVE: To investigate whether microRNA-588 was involved in the development and progression of renal cancer, and to explore its possible regulatory mechanisms. PATIENTS AND METHODS: Tumor tissues excised from renal carcinoma and adjacent normal tissues were selected for the experiment. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to analyze the expression level of microRNA-588 in tissue specimens. The relationship between the expression of microRNA-588 and the prognosis of patients with renal cell carcinoma was also evaluated. Subsequently, two renal cancer cell lines, including769-P and 786-O, were selected for functional experiments in vitro. Eukaryotic initiation factor 5A2 (pcDNA-EIF5A2) or microRNA-588 mimics was transfected into 769-P cells, respectively. Meanwhile, si-EIF5A2 or microRNA-588 inhibitor was transfected into 786-O cells. After that, the mRNA expression level of EIF5A2 was detected by qRT-PCR. The invasiveness and metastasis abilities of the two cell lines were evaluated via transwell assay. Furthermore, the levels of EIF5A2 and epithelial-mesenchymal transition (EMT)-related proteins were analyzed using Western blot. Luciferase reporter gene assay was used to confirm that microRNA-588 could directly regulate EIF5A2 expression. QRT-PCR and Western blot were performed to explore the mRNA and protein expressions of EIF5A2 in patients with highly or lowly-expressed microRNA-588. The correlation between the two molecules was evaluated using linear analysis. Through the above experiments, it was verified whether microRNA-588 could enhance the invasiveness and metastasis of renal cancer by targeting EIF5A2. RESULTS: MicroRNA-588 expression in tumor tissues of patients with renal carcinoma was significantly decreased with the increase of tumor diameter and stage. A higher level of microRNA-588 indicated significantly longer overall survival of patients. This suggested that microRNA-588 expression was negatively correlated with the prognosis of patients. Overexpression of microRNA-588 remarkably reduced the invasion and metastasis abilities of 769-P cells, as well as the expressions of EMT-related proteins. However, opposite results were observed in 786-O cells after knockdown of microRNA-588. Reporter gene assay confirmed that microRNA-588 could target bind to EIF5A2. In 769-P cells, up-regulated microRNA-588 significantly inhibited the mRNA and protein expressions of EIF5A2. However, down-regulated microRNA-588 in 786-O cells significantly enhanced the expressions of EIF5A2 at both mRNA and protein levels. Linear analysis verified that microRNA-588 was negatively correlated with EIF5A2 at the mRNA level. Additionally, the up-regulation of EIF5A2 in 769-P cells enhanced the malignancy of cancer cells and the expressions of EMT-related proteins. However, in 786-O cells, opposite results were observed after knockdown of EIF5A2. CONCLUSIONS: MicroRNA-588 was lowly expressed in renal cancer tissues and cell lines. This might lead to an increase in the protein level of EIF5A2, eventually promoting tumor invasion and metastasis.

MiR-16 inhibits hepatocellular carcinoma progression by targeting FEAT through NF-κB signaling pathway.

OBJECTIVE: MicroRNA-16 (miR-16) expression has been proved to take part in the initiation and development of several cancers, including hepatocellular carcinoma (HCC). However, its role and its molecular mechanism in HCC cells remain unclear. Our study aimed to elucidate miR-16 probable role and potential mechanism in HCC cells. PATIENTS AND METHODS: MiR-16 expression in HCC was measured by Real Time-Polymerase Chain Reaction (RT-PCR). MiR-16 mimic or inhibitor was applied to increase or decrease miR-16 expression in Huh7 cells separately. The cell viability was measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide). The invaded cells and migrated cells were detected by the transwell assay. The epithelial-mesenchymal transition (EMT) and the nuclear factor-κB (NF-κB) were performed using Western blot. The tumor growth was measured via xenograft tumor formation assay. Moreover, bioinformatical methods and luciferase reporter assay were carried out to confirm the miR-16 target gene. RESULTS: MiR-16 expression was downregulated in HCC tissues and cells. Furthermore, the increasing miR-16 expression was suppressed, whereas the decreasing miR-16 expression promoted cell proliferation, invasion, and migration in Huh7 cells. Moreover, miR-16 targeted FEAT in regulating HCC progression. FEAT was associated with a poor prognosis of HCC patients. Especially, miR-16 suppressed EMT and NF-κB pathway in HCC and inhibited the tumor growth in vivo. CONCLUSIONS: We stated that miR-16 suppressed HCC cell progression by targeting FEAT and inhibiting EMT and NF-κB pathway. MiR-16 may be clinically utilized as a factor for the clinical diagnosis and prognosis of HCC.

MiR-203 regulates proliferation and apoptosis of ovarian cancer cells by targeting SOCS3.

OBJECTIVE: Cytokine signal transduction inhibitor 3 (SOCS3) negatively regulates Janus kinases (JAK) - signal transducer and activator of transcription (STAT) pathway. Bioinformatics analysis revealed a targeted relationship between miR-203 and SOCS3 mRNA. This study investigated the role of miR-203 in ovarian cancer cell proliferation and apoptosis. PATIENTS AND METHODS: Ovarian cancer tissues and adjacent tissues were collected to detect the expression of miR-203 and SOCS3. Ovarian cancer HO8910 cells were divided into miR-NC group, miR-203 inhibitor group, and miR-203 mimic group followed by the analysis of the expression of miR-203 and SOCS3 mRNA by quantitative Reverse Transcription-PCR (qRT-PCR), protein expression of p-JAK2 and p-STAT3 by Western blot, cell apoptosis by flow cytometry, and proliferation by 5-Ethynyl-2'-deoxyuridine (EdU) staining chronologically. RESULTS: Compared with adjacent tissues, miR-203 expression was significantly increased in tumor tissues and SCOS3 mRNA expression was decreased. Compared with those with lower miR-203 expression, the prognosis of patients with higher expression of miR-203 was significantly worse. There was a targeted regulatory relationship between miR-203 and SOCS3 mRNA. Compared with IOSE80 cells, miR-203 expression in HO8910 and SKOV3 cells was increased, and its expressions of SOCS3 mRNA and protein were decreased. Compared with miR-NC group, the transfection of miR-203 inhibitor significantly increased SOCS3 expression, and decreased the expression of p-JAK2 and p-STAT3 protein. We draw the conclusion that miR-203 increased cell apoptosis and decreased cell proliferation. However, opposite results were observed after the transfection of miR-203 mimic. CONCLUSIONS: Abnormal miR-203 and SOCS3 expression are related to the pathogenesis of ovarian cancer. MiR-203 affects the proliferation of JAK-STAT pathway and regulates the proliferation and apoptosis of ovarian cancer cells by targeting the inhibition of SOCS3 expression.

Syntenies Between Cohosted Mitochondrial, Chloroplast, and Phycodnavirus Genomes: Functional Mimicry and/or Common Ancestry?

Recent analyses suggest bacterial and/or mitochondrion-like ancestry for giant viruses (Megavirales sensu latu): amoeban mitochondrial gene arrangements resemble those of their candidate homologs in megaviral genomes. This presumed ancestral synteny decreases with genome size across megaviral families at large and within Poxviridae. In this study, analyses focus on Phycodnaviridae, a polyphyletic group of giant viruses infecting Haplophyta, Stramenopiles, and other algae, using syntenies between algal mitogene arrangements and chloroplast genomes and Rickettsia prowazekii as positive controls. Mitogene alignment qualities with Rickettsia are much higher than with viral genomes. Mitogenome synteny with some viruses is higher, for others lower than with Rickettsia, despite lower alignments qualities. In some algae, syntenies among cohosted chloroplast, virus, and mitochondrion are higher, in others lower than expected. This suggests gene order coevolution in cohosted genomes, different coregulations of organelle metabolisms for different algae, and viral mitogenome mimicry, to hijack organelle-committed cellular resources and/or escape cellular defenses/genetic immunity systems. This principle might explain high synteny between human mitochondria and the pathogenic endocellular alphaproteobacterium R. prowazekii beyond common ancestry. Results indicate that putative bacteria/mitochondrion-like genomic ancestors of Phycodnaviridae originated before or at the mitochondrion-bacteria split, and ulterior functional constraints on gene arrangements of cohosted genomes.

Apolipoprotein E binds to and reduces serum levels of DNA-mimicking, pyrrolated proteins.

Lysine N-pyrrolation, converting lysine residues to Nϵ-pyrrole-l-lysine, is a recently discovered post-translational modification. This naturally occurring reaction confers electrochemical properties onto proteins that potentially produce an electrical mimic to DNA and result in specificity toward DNA-binding molecules such as anti-DNA autoantibodies. The discovery of this unique covalent protein modification provides a rationale for establishing the molecular mechanism and broad functional significance of the formation and regulation of Nϵ-pyrrole-l-lysine-containing proteins. In this study, we used microbeads coupled to pyrrolated or nonpyrrolated protein to screen for binding activities of human serum-resident nonimmunoglobin proteins to the pyrrolated proteins. This screen identified apolipoprotein E (apoE) as a protein that innately binds the DNA-mimicking proteins in serum. Using an array of biochemical assays, we observed that the pyrrolated proteins bind to the N-terminal domain of apoE and that oligomeric apoE binds these proteins better than does monomeric apoE. Employing surface plasmon resonance and confocal microscopy, we further observed that apoE deficiency leads to significant accumulation of pyrrolated serum albumin and is associated with an enhanced immune response. These results, along with the observation that apoE facilitates the binding of pyrrolated proteins to cells, suggest that apoE may contribute to the clearance of pyrrolated serum proteins. Our findings uncover apoE as a binding target of pyrrolated proteins, providing a key link connecting covalent protein modification, lipoprotein metabolism, and innate immunity.

Small molecule inhibition of DDAH1 significantly attenuates triple negative breast cancer cell vasculogenic mimicry in vitro.

Dimethylarginine dimethylaminohydrolase 1 (DDAH1) is a key enzyme involved in the metabolism of the endogenous nitric oxide synthase (NOS) inhibitors asymmetric dimethylarginine (ADMA) and monomethyl arginine (L-NMMA). Increased DDAH1 expression and subsequent increased NO production have been recently linked to cancer. Specifically, DDAH1 is implicated in establishment of a vascular network by tumour cells, vasculogenic mimicry (VM), which is strongly associated with tumour progression and poor patient prognosis. The use of DDAH1 inhibitors as potential therapeutic agents thus represents a growing field of interest. Here we describe a UPLC-MS assay to quantify stability and intracellular concentration of two small molecule DDAH1 inhibitors synthesised by our group, ZST316 and ZST152, following incubation with MDA-MB-231 breast cancer cells. In an in vitro assay of VM, both DDAH1 inhibitors significantly attenuated formation of capillary-like tube structures in a dose-dependent fashion. This was not due to cell toxicity or altered cell proliferation, but may be due in part to inhibition of cell migration. Mechanistically, we demonstrate significant modulation of the endogenous DDAH/ADMA/NO pathway following exposure of 100 µM ZST316 or ZST152: a 40% increase in the DDAH1 substrate ADMA, and a 38% decrease in the DDAH1 product l-citrulline. This study represents the first evidence for therapeutic inhibition of DDAH1 by small molecules in breast cancer.

Synthesis, 18F-labelling and radiopharmacological characterisation of the C-terminal 30mer of Clostridium perfringens enterotoxin as a potential claudin-targeting peptide.

The cell surface receptor claudin-4 (Cld-4) is upregulated in various tumours and represents an important emerging target for both diagnosis and treatment of solid tumours of epithelial origin. The C-terminal fragment of the Clostridium perfringens enterotoxin cCPE290-319 appears as a suitable ligand for targeting Cld-4. The synthesis of this 30mer peptide was attempted via several approaches, which has revealed sequential SPPS using three pseudoproline dipeptide building blocks to be the most efficient one. Labelling with fluorine-18 was achieved on solid phase using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) and 4-[18F]fluorobenzoyl chloride as 18F-acylating agents, which was the most advantageous when [18F]SFB was reacted with the resin-bound 30mer containing an N-terminal 6-aminohexanoic spacer. Binding to Cld-4 was demonstrated via surface plasmon resonance using a protein construct containing both extracellular loops of Cld-4. In addition, cell binding experiments were performed for 18F-labelled cCPE290-319 with the Cld-4 expressing tumour cell lines HT-29 and A431 that were complemented by fluorescence microscopy studies using the corresponding fluorescein isothiocyanate-conjugated peptide. The 30mer peptide proved to be sufficiently stable in blood plasma. Studying the in vivo behaviour of 18F-labelled cCPE290-319 in healthy mice and rats by dynamic PET imaging and radiometabolite analyses has revealed that the peptide is subject to substantial liver uptake and rapid metabolic degradation in vivo, which limits its suitability as imaging probe for tumour-associated Cld-4.

Beyond the vicious cycle: The role of innate osteoimmunity, automimicry and tumor-inherent changes in dictating bone metastasis.

Bone metastasis is a fatal consequence of a subset of solid malignancies that fail to respond to conventional therapies. While a myriad of factors contribute to osteotropism and disseminated cell survival and outgrowth in bone, efforts to inhibit tumor cell growth in the bone-metastatic niche have largely relied on measures that disrupt the bi-directional interactions between bone resident and tumor cells. However, the targeting of isolated stromal interactions has proven ineffective to date in inhibiting bone-metastatic progression and patient mortality. Osteoimmune regulation is now emerging as a critical determinant of metastatic growth in the bone microenvironment. While this has highlighted the importance of innate immune populations in dictating the temporal development of overt bone metastases, the osteoimmunological processes that underpin tumor cell progression in bone remain severely underexplored. Along with tumor-intrinsic alterations that occur specifically within the bone microenvironment, innate osteoimmunological crosstalk poses an exciting area of future discovery and therapeutic development. Here we review current knowledge of the unique exchange that occurs between bone resident cells, innate immune populations and tumor cells that leads to the establishment of a tumor-permissive milieu.

Origin, evolution, and distribution of the molecular machinery for biosynthesis of sialylated lipooligosaccharide structures in Campylobacter coli.

Campylobacter jejuni and Campylobacter coli are the most common cause of bacterial gastroenteritis worldwide. Additionally, C. jejuni is the most common bacterial etiological agent in the autoimmune Guillain-Barré syndrome (GBS). Ganglioside mimicry by C. jejuni lipooligosaccharide (LOS) is the triggering factor of the disease. LOS-associated genes involved in the synthesis and transfer of sialic acid (glycosyltranferases belonging to family GT-42) are essential in C. jejuni to synthesize ganglioside-like LOS. Despite being isolated from GBS patients, scarce genetic evidence supports C. coli role in the disease. In this study, through data mining and bioinformatics analysis, C. coli is shown to possess a larger GT-42 glycosyltransferase repertoire than C. jejuni. Although GT-42 glycosyltransferases are widely distributed in C. coli population, only a fraction of C. coli strains (1%) are very likely able to express ganglioside mimics. Even though the activity of C. coli specific GT-42 enzymes and their role in shaping the bacterial population are yet to be explored, evidence presented herein suggest that loss of function of some LOS-associated genes occurred during agriculture niche adaptation.

Molecular mimicry modulates plant host responses to pathogens.

Background: Pathogens often secrete molecules that mimic those present in the plant host. Recent studies indicate that some of these molecules mimic plant hormones required for development and immunity. Scope and Conclusion: This Viewpoint reviews the literature on microbial molecules produced by plant pathogens that functionally mimic molecules present in the plant host. This article includes examples from nematodes, bacteria and fungi with emphasis on RaxX, a microbial protein produced by the bacterial pathogen Xanthomonas oryzae pv. oryzae. RaxX mimics a plant peptide hormone, PSY (plant peptide containing sulphated tyrosine). The rice immune receptor XA21 detects sulphated RaxX but not the endogenous peptide PSY. Studies of the RaxX/XA21 system have provided insight into both host and pathogen biology and offered a framework for future work directed at understanding how XA21 and the PSY receptor(s) can be differentially activated by RaxX and endogenous PSY peptides.

Infections, atherosclerosis, and coronary heart disease.

Atherosclerosis is a chronic inflammatory disease. Pathophysiological similarities between chronic infections and atherosclerosis triggered interest in a clinical association between these conditions. Various infectious microbes have been linked to atherosclerotic vascular disease in epidemiological studies. However, this association failed to satisfy the Koch's postulates of causation with multiple clinical trials demonstrating inefficacy of anti-infective therapies in mitigating atherosclerotic cardiovascular events. Identification of underlying pathophysiological mechanisms and experience with vaccination against various infectious agents has ushered a new avenue of efforts in the development of an anti-atherosclerotic vaccine. Studies in animal models have identified various innate and adaptive immune pathways in atherosclerosis. In this review, we discuss the patho-biological link between chronic infections and atherosclerosis, evaluate existing evidence of animal and human trials on the association between infections and cardiovascular disease and introduce the concept of an anti-atherosclerotic vaccine.