Membrane-Targeting Perylenylethynylphenols Inactivate Medically Important Coronaviruses via the Singlet Oxygen Photogeneration Mechanism.

Perylenylethynyl derivatives have been recognized as broad-spectrum antivirals that target the lipid envelope of enveloped viruses. In this study, we present novel perylenylethynylphenols that exhibit nanomolar or submicromolar antiviral activity against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) and feline infectious peritonitis virus (FIPV) in vitro. Perylenylethynylphenols incorporate into viral and cellular membranes and block the entry of the virus into the host cell. Furthermore, these compounds demonstrate an ability to generate singlet oxygen when exposed to visible light. The rate of singlet oxygen production is positively correlated with antiviral activity, confirming that the inhibition of fusion is primarily due to singlet-oxygen-induced damage to the viral envelope. The unique combination of a shape that affords affinity to the lipid bilayer and the capacity to generate singlet oxygen makes perylenylethynylphenols highly effective scaffolds against enveloped viruses. The anticoronaviral activity of perylenylethynylphenols is strictly light-dependent and disappears in the absence of daylight (under red light). Moreover, these compounds exhibit negligible cytotoxicity, highlighting their significant potential for further exploration of the precise antiviral mechanism and the broader scope and limitations of this compound class.

Broad-Spectrum Antiviral Activity of 3'-Deoxy-3'-Fluoroadenosine against Emerging Flaviviruses.

Emerging flaviviruses are causative agents of severe and life-threatening diseases, against which no approved therapies are available. Among the nucleoside analogues, which represent a promising group of potentially therapeutic compounds, fluorine-substituted nucleosides are characterized by unique structural and functional properties. Despite having first been synthesized almost 5 decades ago, they still offer new therapeutic opportunities as inhibitors of essential viral or cellular enzymes active in nucleic acid replication/transcription or nucleoside/nucleotide metabolism. Here, we report evaluation of the antiflaviviral activity of 28 nucleoside analogues, each modified with a fluoro substituent at different positions of the ribose ring and/or heterocyclic nucleobase. Our antiviral screening revealed that 3'-deoxy-3'-fluoroadenosine exerted a low-micromolar antiviral effect against tick-borne encephalitis virus (TBEV), Zika virus, and West Nile virus (WNV) (EC50 values from 1.1 ± 0.1 µM to 4.7 ± 1.5 µM), which was manifested in host cell lines of neural and extraneural origin. The compound did not display any measurable cytotoxicity up to concentrations of 25 µM but had an observable cytostatic effect, resulting in suppression of cell proliferation at concentrations of >12.5 µM. Novel approaches based on quantitative phase imaging using holographic microscopy were developed for advanced characterization of antiviral and cytotoxic profiles of 3'-deoxy-3'-fluoroadenosine in vitro In addition to its antiviral activity in cell cultures, 3'-deoxy-3'-fluoroadenosine was active in vivo in mouse models of TBEV and WNV infection. Our results demonstrate that fluoro-modified nucleosides represent a group of bioactive molecules with excellent potential to serve as prospective broad-spectrum antivirals in antiviral research and drug development.

Development of a Multiplex Bead Assay To Detect Immunoglobulin G Antibodies to Babesia duncani in Human Serum.

Babesia duncani is the causative agent of babesiosis in the western United States. The indirect fluorescent antibody (IFA) assay is the diagnostic test of choice for detection of B. duncani-specific antibodies. However, this test requires parasitized red blood cells harvested from infected hamsters, and test results are often difficult to interpret. To simplify serological testing for B. duncani, a proteomics approach was employed to identify candidate immunodiagnostic antigens. Several proteins were identified by electrospray ionization mass spectrometric analysis, and four recombinant protein constructs were expressed and used in a multiplex bead assay (MBA) to detect B. duncani-specific antibodies. Two antigens, AAY83295.1 and AAY83296.1, performed well with high sensitivities and specificities. AAY83295.1 had a higher sensitivity (100%) but lower specificity (89%) than AAY83296.1, which had a sensitivity of 90% and a specificity of 96%. Combining these two antigens did not improve the performance of the assay. This MBA could be useful for diagnosis, serosurveillance, and blood donor screening for B. duncani infection.

A Novel Biological Role for Peptidyl-Arginine Deiminases: Citrullination of Cathelicidin LL-37 Controls the Immunostimulatory Potential of Cell-Free DNA.

LL-37, the only human cathelicidin that is released during inflammation, is a potent regulator of immune responses by facilitating delivery of oligonucleotides to intracellular TLR-9, thereby enhancing the response of human plasmacytoid dendritic cells (pDCs) to extracellular DNA. Although important for pathogen recognition, this mechanism may facilitate development of autoimmune diseases. In this article, we show that citrullination of LL-37 by peptidyl-arginine deiminases (PADs) hindered peptide-dependent DNA uptake and sensing by pDCs. In contrast, carbamylation of the peptide (homocitrullination of Lys residues) had no effect. The efficiency of LL-37 binding to oligonucleotides and activation of pDCs was found to be inversely proportional to the number of citrullinated residues in the peptide. Similarly, preincubation of carbamylated LL-37 with PAD2 abrogated the peptide's ability to bind DNA. Conversely, LL-37 with Arg residues substituted by homoarginine, which cannot be deiminated, elicited full activity of native LL-37 regardless of PAD2 treatment. Taken together, the data showed that citrullination abolished LL-37 ability to bind DNA and altered the immunomodulatory function of the peptide. Both activities were dependent on the proper distribution of guanidinium side chains in the native peptide sequence. Moreover, our data suggest that cathelicidin/LL-37 is citrullinated by PADs during NET formation, thus affecting the inflammatory potential of NETs. Together this may represent a novel mechanism for preventing the breakdown of immunotolerance, which is dependent on the response of APCs to self-molecules (including cell-free DNA); overactivation may facilitate development of autoimmunity.

Citrullination-Resistant LL-37 Is a Potent Antimicrobial Agent in the Inflammatory Environment High in Arginine Deiminase Activity.

LL-37, the only member of the mammalian cathelicidin in humans, plays an essential role in innate immunity by killing pathogens and regulating the inflammatory response. However, at an inflammatory focus, arginine residues in LL-37 can be converted to citrulline via a reaction catalyzed by peptidyl-arginine deiminases (PAD2 and PAD4), which are expressed in neutrophils and are highly active during the formation of neutrophil extracellular traps (NETs). Citrullination impairs the bactericidal activity of LL-37 and abrogates its immunomodulatory functions. Therefore, we hypothesized that citrullination-resistant LL-37 variants would retain the functionality of the native peptide in the presence of PADs. To test this hypothesis, we synthetized LL-37 in which arginine residues were substituted by homoarginine (hArg-LL-37). Bactericidal activity of hArg-LL-37 was comparable with that of native LL-37, but neither treatment with PAD4 nor exposure to NETs affected the antibacterial and immunomodulatory activities of hArg-LL-37. Importantly, the susceptibilities of LL-37 and hArg-LL-37 to degradation by proteases did not significantly differ. Collectively, we demonstrated that citrullination-resistant hArg-LL-37 is an attractive lead compound for the generation of new agents to treat bacterial infections and other inflammatory diseases associated with enhanced PAD activity. Moreover, our results provide a proof-of-concept for synthesis of therapeutic peptides using homoarginine.

Infliximab pharmacokinetics monitoring in inflammatory bowel disease.

Therapeutic drug monitoring is a strategy utilized to optimize biological therapy. It consists in the drug level measurement before the next dose is due, when the drug concentration reaches the trough level, and includes the detection of potential antidrug antibodies. The monitoring makes it possible to adjust the therapy accordingly - to intensify or change the biologics applied to secure safe and highly effective therapeutics. Therapeutic optimization is based on the nature of therapy failure, which can be caused by pharmacokinetic or pharmacodynamic factors. Pharmacokinetic monitoring can be currently classified as reactive, measuring the drug level and antidrug antibodies during therapy failure, or adverse reactions to the drug applied, and proactive, monitoring patients in clinical remission to retain remission and prevents development of a secondary failure.

Bone Metabolism in Inflammatory Bowel Diseases 2.

Inflammatory Bowel Disease encompasses Crohns Disease, which is capable of affecting the entire GI tract, although usually favors the ileocolonic and perianal areas, and Ulcerative Colitis, which is limited to the colon. The pathophysiology is not fully understood but is thought to be caused by a complex interplay among gut microbiota, dysregulation of the hosts immune system, genetic susceptibility and environmental factors. Osteopenia and osteoporosis are considered to be extraintestinal manifestations of inflammatory bowel disease. Osteoporosis is usually diagnosed by dual-energy X-ray absortiometry. Early interventions to treat active CD and preventative treatment strategies to reduce excessive bone loss might prevent long term consequences of bone loss, including fractures. The immune response in IBD includes increased production of variety of proinflammatory cytokines such as IL1β, TNFα, IL6 a IL1 from T cells and macrophages. These have both direct and indirect effects on bone turnover. Vitamin D is vital in mantenance of bone strenght, mineralisation and fracture prevention. Vitamin Ds physiological importance has also been implicated in a number of inflammatory diseases, mainly asthma, atherosclerosis and autoimmune disease.

Bone metabolism in inflammatory bowel diseases 1.

Inflammatory Bowel Disease encompasses Crohns Disease, which is capable of affecting the entire GI tract, although usually favors the ileocolonic and perianal areas, and Ulcerative Colitis, which is limited to the colon. The pathophysiology is not fully understood but is thought to be caused by a complex interplay among gut microbiota, dysregulation of the hosts immune system, genetic susceptibility and environmental factors. Osteopenia and osteoporosis are considered to be extraintestinal manifestations of inflammatory bowel disease. Osteoporosis is usually diagnosed by dual-energy X-ray absortiometry. Early interventions to treat active CD and preventative treatment strategies to reduce excessive bone loss might prevent long term consequences of bone loss, including fractures. The immune response in IBD includes increased production of variety of proinflammatory cytokines such as IL1β, TNFα, IL6 a IL1 from T cells and macrophages. These have both direct and indirect effects on bone turnover. Vitamin D is vital in mantenance of bone strenght, mineralisation and fracture prevention. Vitamin Ds physiological importance has also been implicated in a number of inflammatory diseases, mainly asthma, atherosclerosis and autoimmune disease.

The molecular mechanism of induction of unfolded protein response by Chlamydia.

The unfolded protein response (UPR) contributes to chlamydial pathogenesis, as a source of lipids and ATP during replication, and for establishing the initial anti-apoptotic state of host cell that ensures successful inclusion development. The molecular mechanism(s) of UPR induction by Chlamydia is unknown. Chlamydia use type III secretion system (T3SS) effector proteins (e.g, the Translocated Actin-Recruiting Phosphoprotein (Tarp) to stimulate host cell's cytoskeletal reorganization that facilitates invasion and inclusion development. We investigated the hypothesis that T3SS effector-mediated assembly of myosin-II complex produces activated non-muscle myosin heavy chain II (NMMHC-II), which then binds the UPR master regulator (BiP) and/or transducers to induce UPR. Our results revealed the interaction of the chlamydial effector proteins (CT228 and Tarp) with components of the myosin II complex and UPR regulator and transducer during infection. These interactions caused the activation and binding of NMMHC-II to BiP and IRE1α leading to UPR induction. In addition, specific inhibitors of myosin light chain kinase, Tarp oligomerization and myosin ATPase significantly reduced UPR activation and Chlamydia replication. Thus, Chlamydia induce UPR through T3SS effector-mediated activation of NMMHC-II components of the myosin complex to facilitate infectivity. The finding provides greater insights into chlamydial pathogenesis with the potential to identify therapeutic targets and formulations.

Changes in cytokine and chemokine profiles in mouse serum and brain, and in human neural cells, upon tick-borne encephalitis virus infection.

BACKGROUND: Tick-borne encephalitis (TBE) is a severe neuropathological disorder caused by tick-borne encephalitis virus (TBEV). Brain TBEV infection is characterized by extensive pathological neuroinflammation. The mechanism by which TBEV causes CNS destruction remains unclear, but growing evidence suggests that it involves both direct neuronal damage by the virus infection and indirect damage caused by the immune response. Here, we aimed to examine the TBEV-infection-induced innate immune response in mice and in human neural cells. We also compared cytokine/chemokine communication between naïve and infected neuronal cells and astrocytes. METHODS: We used a multiplexed Luminex system to measure multiple cytokines/chemokines and growth factors in mouse serum samples and brain tissue, and in human neuroblastoma cells (SK-N-SH) and primary cortical astrocytes (HBCA), which were infected with the highly pathogenic TBEV strain Hypr. We also investigated changes in cytokine/chemokine production in naïve HBCA cells treated with virus-free supernatants from TBEV-infected SK-N-SH cells and in naïve SK-N-SH cells treated with virus-free supernatants from TBEV-infected HBCA cells. Additionally, a plaque assay was performed to assess how cytokine/chemokine treatment influenced viral growth following TBEV infection. RESULTS: TBEV-infected mice exhibited time-dependent increases in serum and brain tissue concentrations of multiple cytokines/chemokines (mainly CXCL10/IP-10, and also CXCL1, G-CSF, IL-6, and others). TBEV-infected SK-N-SH cells exhibited increased production of IL-8 and RANTES and downregulated MCP-1 and HGF. TBEV infection of HBCA cells activated production of a broad spectrum of pro-inflammatory cytokines, chemokines, and growth factors (mainly IL-6, IL-8, CXCL10, RANTES, and G-CSF) and downregulated the expression of VEGF. Treatment of SK-N-SH with supernatants from infected HBCA induced expression of a variety of chemokines and pro-inflammatory cytokines, reduced SK-N-SH mortality after TBEV infection, and decreased virus growth in these cells. Treatment of HBCA with supernatants from infected SK-N-SH had little effect on cytokine/chemokine/growth factor expression but reduced TBEV growth in these cells after infection. CONCLUSIONS: Our results indicated that both neurons and astrocytes are potential sources of pro-inflammatory cytokines in TBEV-infected brain tissue. Infected/activated astrocytes produce cytokines/chemokines that stimulate the innate neuronal immune response, limiting virus replication, and increasing survival of infected neurons.

Pancreatic Solid Focal Lesions: Differential Diagnosis between Autoimmune Pancreatitis and Pancreatic Cancer.

BACKGROUND: Diagnosis of pancreatic cancer (PC) in early stages is still challenging for gastroenterologists. The early detection of cancer is one of the utmost importance for the successful therapy of this malignancy. An accurate differential diagnosis of focal pancreatic lesions plays also an important role, whether it is differential diagnosis of chronic pancreatitis from PC or autoimmune pancreatitis (AIP) from PC. Raised serum immunoglobulin G4 (IgG4) levels to twice the normal value are considered one of significant diagnostic features of type 1 AIP. However, IgG4 can be increased also in patients with PC, but levels usually do not exceed twice the normal value. METHODS: In years 2012-2017, IgG4 serum levels were examined in 115 patients with histologically confirmed PC. Patients with PC and elevated IgG4 level (above 135 mg/dL) had tested their histological resection specimens or bioptic specimens from pancreatic lesion, with targeted detection of the presence of IgG4 and plasmocytes in the pancreatic tissue and changes characteristic for type 1 AIP. RESULTS: A plasmatic IgG4 level in 115 patients with diagnosed PC was higher than 135 mg/dL in 14 patients (12.2%). Out of them, 2 patients (1.7%) revealed a serum IgG4 level higher than double the normal value, that is, higher than 270.0 mg/dL (suggestive of AIP). One patient met histological criteria for diagnosis of AIP in the simultaneous presence of PC. CONCLUSION: Diagnosis of early cancer stages, particularly differentiating AIP from PC can be sometimes problematic. IgG4 levels can be slightly elevated also in case of PC. A targeted biopsy of the pancreas is the method of choice in cases suspected from a focal form of AIP and we recommend to prefer it over other modalities, such as, for example, response to steroid therapy.

Carbon Nanoparticles Inhibit the Antimicrobial Activities of the Human Cathelicidin LL-37 through Structural Alteration.

Host defense peptides, also known as antimicrobial peptides, are key elements of innate host defense. One host defense peptide with well-characterized antimicrobial activity is the human cathelicidin, LL-37. LL-37 has been shown to be upregulated at sites of infection and inflammation and is regarded as one of the primary innate defense molecules against bacterial and viral infection. Human exposure to combustion-derived or engineered nanoparticles is of increasing concern, and the implications of nanomaterial exposure on the human immune response is poorly understood. However, it is widely acknowledged that nanoparticles can interact strongly with several immune proteins of biological significance, with these interactions resulting in structural and functional changes of the proteins involved. This study investigated whether the potent antibacterial and antiviral functions of LL-37 were inhibited by exposure to, and interaction with, carbon nanoparticles, together with characterizing the nature of the interaction. LL-37 was exposed to carbon black nanoparticles in vitro, and the antibacterial and antiviral functions of the peptide were subsequently assessed. We demonstrate a substantial loss of antimicrobial function when the peptide was exposed to low concentrations of nanomaterials, and we further show that the nanomaterial-peptide interaction resulted in a significant change in the structure of the peptide. The human health implications of these findings are significant, as, to our knowledge, this is the first evidence that nanoparticles can alter host defense peptide structure and function, indicating a new role for nanoparticle exposure in increased disease susceptibility.

The dehydration stress of couch grass is associated with its lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA.

BACKGROUND: The wild relatives of crop species represent a potentially valuable source of novel genetic variation, particularly in the context of improving the crop's level of tolerance to abiotic stress. The mechanistic basis of these tolerances remains largely unexplored. Here, the focus was to characterize the transcriptomic response of the nodes (meristematic tissue) of couch grass (a relative of barley) to dehydration stress, and to compare it to that of the barley crown formed by both a drought tolerant and a drought sensitive barley cultivar. RESULTS: Many of the genes up-regulated in the nodes by the stress were homologs of genes known to be mediated by abscisic acid during the response to drought, or were linked to either development or lipid metabolism. Transporters also featured prominently, as did genes acting on root architecture. The resilience of the couch grass node arise from both their capacity to develop an altered, more effective root architecture, but also from their formation of a lipid barrier on their outer surface and their ability to modify both their lipid metabolism and transporter activity when challenged by dehydration stress. CONCLUSIONS: Our analysis revealed the nature of dehydration stress response in couch grass. We suggested the tolerance is associated with lipid metabolism, the induction of transporters and the re-programming of development coordinated by ABA. We also proved the applicability of barley microarray for couch grass stress-response analysis.

Ecological and biogeographical drivers of freshwater green algae biodiversity: from local communities to large-scale species pools of desmids.

Dispersal limitation, niche-based processes as well as historical legacies shape microbial biodiversity, but their respective influences remain unknown for many groups of microbes. We analysed metacommunity structure and functional trait variation in 148 communities of desmids, freshwater green algae, distributed throughout Europe. We delineated biogeographic modules for both taxa and sites using bipartite network analysis given that the taxa of a module co-occurred more often than expected by chance in sites of the same module. The network analysis distinguished two main acidic and neutral habitats, reflecting environmental filtering, and within each habitat separated species pools with distinct geographic locations, representing a plausible influence of historical biogeography. The geographic differentiation was consistent with a hypothesis of glacial refugia on Atlantic coast. Distance decay in community composition in addition to environmental influence further suggested a role of dispersal limitation. Next, we quantified the variation in cell volume and surface-to-volume of taxa within and among communities, to examine morphological and physiological adaptations of desmids in varying environments. Communities from continental climate contained larger desmids. Conversely, we found a functional convergence of smaller, fast-growing, desmids in oceanic regions. Overall, our findings suggest that niche-based processes, dispersal limitation, and historical legacy together drive the distribution and structure of desmid communities. Combining trait- and network-based analyses can resolve long-lasting questions in microbial ecology and biogeography, and could be successfully used in macrobial ecology too.

The Roles of Unfolded Protein Response Pathways in Chlamydia Pathogenesis.

Chlamydia is an obligate intracellular bacterium that relies on host cells for essential nutrients and adenosine triphosphate (ATP) for a productive infection. Although the unfolded protein response (UPR) plays a major role in certain microbial infectivity, its role in chlamydial pathogenesis is unknown. We hypothesized that Chlamydia induces UPR and exploits it to upregulate host cell uptake and metabolism of glucose, production of ATP, phospholipids, and other molecules required for its replicative development and host survival. Using a combination of biochemical and pathway inhibition assays, we showed that the 3 UPR pathway transducers-protein kinase RNA-activated (PKR)-like ER kinase (PERK), inositol-requiring enzyme-1α (IRE1α), and activating transcription factor-6α (ATF6α)-were activated during Chlamydia infection. The kinase activity of PERK and ribonuclease (RNase) of IRE1α mediated the upregulation of hexokinase II and production of ATP via substrate-level phosphorylation. In addition, the activation of PERK and IRE1α promoted autophagy formation and apoptosis resistance for host survival. Moreover, the activation of IRE1α resulted in the generation of spliced X-box binding protein 1 (sXBP1) and upregulation of lipid production. The vital role of UPR pathways in Chlamydia development and pathogenesis could lead to the identification of potential molecular targets for therapeutics against Chlamydia.

[Adiponectin in patients with metabolic syndrome and diseases of the liver, bile ducts and pancreas]. / Adiponektin u nemocných s metabolickým syndromem a chorobami jater, zlucových cest a pankreatu.

Epidemiological data show that the metabolic syndrome can be diagnosed in up to 30 % of the population. Regarding 5 components of the metabolic syndrome, three of them, in case of positivity (visceral obesity, arterial hypertension, hypertriglyceridemia, changes of HDL-cholesterol levels and type 2 diabetes mellitus), are pathogenic factors which are the most frequently related to cardiovascular diseases, but currently they are also the focus of interest for gastroenterologists. The relationship between non-alcoholic hepatic steatosis, including non-alcoholic steatohepatitis, has been described. Less is known so far about the relation to the pancreas disease, particularly with respect to the status referred to as non-alcoholic fatty pancreas disease. The hormone selectively produced by adipose tissue is adiponectin. This protein is studied as a possible biomarker in people with metabolic syndrome, including obesity. Besides that, there is a question studied whether adiponectin can also play a significant role in the pathogenesis of diseases associated with fat building up in parenchymatous organs. Finding a reliable biomarker for patients with metabolic syndrome or diseases of the liver, biliary system and pancreas in relation to metabolic syndrome, presents a big challenge. And adiponectin is one of the promising biomarkers.Key words: adiponectin - biliary disease - metabolic syndrome - pancreatic steatosis - steatohepatitis.

[A contribution to the differential diagnostics of sclerosing cholangitides]. / Príspevek k diferenciální diagnostice sklerozujících cholangitid.

Sclerosing cholangitides represent a group of chronic biliary obstructive diseases which include primary sclerosing cholangitis (PSC), IgG4 associated sclerosing cholangitis (IgG4-SC) and secondary sclerosing cholangitis (SSC). The manifestations of the diseases are similar, but their asymptomatic course is also frequent. IgG4-SC belongs to the group of IgG4 associated diseases and it is the most frequently related to type 1 autoimmune pancreatitis. Diagnosing of IgG4-SC is based on typical histopathological images, shape changes revealed by diagnostic imaging, serological tests, concurrent impairment of other organs and response to therapy, where IgG4-SC responds well to treatment with corticoids, whereas the only possibility for the remaining units is endoscopic intervention or liver transplantation. Secondary sclerosing cholangitis may develop as a result of many different insults affecting the biliary tree. Among them, the most frequently described include long-lasting biliary obstruction, surgical injury of the biliary tree, and ischemic cholangitis in liver allotransplants or recurrent pancreatitis. We use serological and imaging examination in PSC diagnostics, sometimes we have to resort to liver biopsy. PSC is to a significant degree accompanied by the presence of idiopathic bowel disease, typically ulcerative colitis. As a result, PSC may lead to cirrhosis of the liver and it is a precancerous condition of several malignancies. With regard to variable locations of the biliary tree injuries concerning the aforementioned units, also certain malignancies in subhepatic landscape need to be considered in the differential diagnosis: pancreatic cancer and cholangiogenous carcinoma.Key words: genetic factors - IBD - IgG4 cholangitis - liver transplantation - bile duct cancer - ursodeoxycholic acid - primary sclerosing cholangitis - secondary cholangitis - sclerosing cholangitis.

Clinical monitoring: infliximab biosimilar CT-P13 in the treatment of Crohn's disease and ulcerative colitis.

OBJECTIVE: The infliximab biosimilar CT-P13 (Remsima(®), Inflectra(®)) was approved in Europe for the treatment of inflammatory bowel disease (IBD) based on extrapolation of data from patients with rheumatic disease. Because there are limited published reports on clinical outcomes for IBD patients treated with CT-P13, we monitored responses to induction treatment with this biosimilar in patients with Crohn's disease (CD) or ulcerative colitis (UC) in centres across the Czech Republic. MATERIAL AND METHODS: Fifty-two patients with CD (n = 30) or UC (n = 22) were treated with 5 mg/kg CT-P13 for up to 14 weeks. Effectiveness of therapy was evaluated with the Crohn's Disease Activity Index (CDAI) or the Mayo Scoring System (MSS) in patients with CD or UC, respectively, before and after 14 weeks. Additional goals were to evaluate weight changes, serum C-reactive protein (CRP) levels, and complications/adverse events. RESULTS: In patients with CD, remission (CDAI <150) was achieved in 50.0% of cases, and partial response (≥70-point decrease in CDAI score from baseline) in the remaining 50.0%. In patients with UC, remission (total score on partial Mayo index ≤2 points) was achieved in 40.9% of cases, partial response (≥2-point decrease in partial Mayo score from baseline) in 54.5%, and no response in 4.5%. There were statistically significant improvements in CDAI, MSS and CRP serum levels after 14 weeks of therapy, and body weight increased. Four adverse events were identified (n = 1 each): lower-extremity phlebothrombosis, herpes labialis, pneumonia and allergic reaction. CONCLUSIONS: This prospective observational study provides evidence of the effectiveness of CT-P13 in IBD.

Citrullination alters immunomodulatory function of LL-37 essential for prevention of endotoxin-induced sepsis.

Cathelicidin LL-37 plays an essential role in innate immunity by killing invading microorganisms and regulating the inflammatory response. These activities depend on the cationic character of the peptide, which is conferred by arginine and lysine residues. At inflammatory foci in vivo, LL-37 is exposed to peptidyl arginine deiminase (PAD), an enzyme released by inflammatory cells. Therefore, we hypothesized that PAD-mediated citrullination of the arginine residues within LL-37 will abrogate its immunomodulatory functions. We found that, when citrullinated, LL-37 was at least 40 times less efficient at neutralizing the proinflammatory activity of LPS due to a marked decrease in its affinity for endotoxin. Also, the ability of citrullinated LL-37 to quench macrophage responses to lipoteichoic acid and poly(I:C) signaling via TLR2 and TLR3, respectively, was significantly reduced. Furthermore, in stark contrast to native LL-37, the modified peptide completely lost the ability to prevent morbidity and mortality in a mouse model of d-galactosamine-sensitized endotoxin shock. In fact, administration of citrullinated LL-37 plus endotoxin actually exacerbated sepsis due to the inability of LL-37 to neutralize LPS and the subsequent enhancement of systemic inflammation due to increased serum levels of IL-6. Importantly, serum from septic mice showed increased PAD activity, which strongly correlated with the level of citrullination, indicating that PAD-driven protein modification occurs in vivo. Because LL-37 is a potential treatment for sepsis, its administration should be preceded by a careful analysis to ensure that the citrullinated peptide is not generated in treated patients.

[Chronic pancreatitis diagnosed after the first attack of acute pancreatitis]. / Chronická pankreatitida diagnostikovaná po první atace akutní pankreatitidy.

INTRODUCTION: One of the diseases involving a potential risk of developing chronic pancreatitis is acute pancreatitis. MATERIAL: Of the overall number of 231 individuals followed with a diagnosis of chronic pancreatitis, 56 patients were initially treated for acute pancreatitis (24.2 %). Within an interval of 12- 24 months from the first attack of acute pancreatitis, their condition gradually progressed to reached the picture of chronic pancreatitis. The individuals included in the study abstained (from alcohol) following the first attack of acute pancreatitis and no relapse of acute pancreatitis was proven during the period of their monitoring. RESULTS: The etiology of acute pancreatitis identified alcohol as the predominant cause (55.3 %), biliary etiology was proven in 35.7 %. According to the revised Atlanta classification, severe pancreatitis was established in 69.6 % of the patients, the others met the criterion for intermediate form, those with the light form were not included. CONCLUSION: Significant risk factors present among the patients were smoking, obesity and 18 %, resp. 25.8 % had pancreatogenous diabetes mellitus identified. 88.1 % of the patients with acute pancreatitis were smokers. The majority of individuals with chronic pancreatitis following an attack of acute pancreatitis were of a productive age from 25 to 50 years. It is not only acute alcoholic pancreatitis which evolves into chronic pancreatitis, we have also identified this transition for pancreatitis of biliary etiology.