Additive treatment considerations in COVID-19-The clinician's perspective on extracorporeal adjunctive purification techniques

The aim of this document was to inform the scientific community of sparse preliminary results regarding advanced supportive therapies and technology-driven systems in addition to highlighting the benefits and possibilities of performing concise research during challenging times. Advanced organ support for lung and heart offers the possibility to buy the time needed for recovery. However, remaining a bridging strategy, extracorporeal life support cannot act as the ultimate treatment for the underlying COVID-19 disease. Appropriate patient selection criteria addressed by experts and scientific organizations, such as Extracorporeal Life Support Organization and World Health Organization, may provide significant help in the difficult decision-making and to reduce mortality in patients with profound respiratory and/or cardiac failure due to COVID-19. Severe, systemic cytokine-mediated inflammation associated with the SARS-CoV-2 has also been described. Effects of crosstalk between coagulation and inflammatory pathways appear to significantly affect disease progression and lead to poor outcomes. Multiple therapeutic strategies, including antibody therapies (such as Tocilizumab, Sarilumab, Siltuximab), therapeutic plasma exchange (TPE), and blood purification techniques for direct removal of cytokines, including filtration, dialysis (diffusion), and adsorption are available. Further, we believe, that research should be facilitated and promoted, particularly under the guidance of recognized scientific societies or expert-based multicenter investigation, with rapid communication of critical and relevant information to enhance better appraisal of patient profiles, complications, and treatment modalities.

CytoResc - "CytoSorb" Rescue for critically ill patients undergoing the COVID-19 Cytokine Storm: A structured summary of a study protocol for a randomized controlled trial

OBJECTIVES

Approximately 8 - 10 % of COVID-19 patients present with a serious clinical course and need for hospitalization, 8% of hospitalized patients need ICU-treatment. Currently, no causal therapy is available and treatment is purely supportive. The main reason for death in critically ill patients is acute respiratory failure. However, in a number of patients a severe hyperinflammatory response with excessively elevated proinflammatory cytokines causes vasoplegic shock resistant to vasopressor therapy. A new polystyrene-based hemoadsorber (CytoSorb®, Cytosorbents Inc., New Jersey, USA) has been shown to adsorb effectively cytokines and other middle molecular weight toxins this way reducing their blood concentrations. This has been routinely used in clinical practice in the EU for other conditions where a cytokine storm occurs and an observational study has just been completed on COVID-19 patients. We hypothesized that the extracorporeal elimination of cytokines in critically ill COVID-19 patients with suspected hyperinflammation and shock may stabilize hemodynamics and improve outcome. The primary endpoint is time until resolution of vasoplegic shock, which is a well implemented, clinically relevant endpoint in critical care studies.

TRIAL DESIGN

Phase IIb, multicenter, prospective, open-label, randomized, 1:1 parallel group pilot study comparing the additional use of "CytoSorb" to standard of care without "CytoSorb".

PARTICIPANTS

Patients are recruited from the Intensive Care Units (ICUs) of 7 participating centers in Germany (approximately 10 ICUs). All patients aged 18- 80 with positive polymerase chain reaction (PCR) test for SARS-CoV-2, a C-reactive protein (CRP) ≥ 100 mg/l, a Procalcitonin (PCT) < 2 ng/l, and suspected cytokine storm defined via a vasoplegic shock (Norepinephrine > 0.2 μg/min/kg to achieve a Mean Arterial Pressure ≥ 65mmHg). Patients are included irrespective of indication for renal replacement therapy. Suspected or proven bacterial cause for vasoplegic shock is a contraindication.

INTERVENTION AND COMPARATOR

Within 24 hours after meeting the inclusion criteria patients will be randomized to receive either standard of care or standard of care and additional "CytoSorb" therapy via a shaldon catheter for 3-7 days. Filter exchange is done every 24 hours. If patients receive antibiotics, an additional dose of antibiotics is administered after each change of "CytoSorb" filter in order to prevent underdosing due to "CytoSorb" treatment.

MAIN OUTCOMES

Primary outcome is time to resolution of vasoplegic shock (defined as no need for vasopressors for at least 8 hours in order to sustain a MAP ≥ 65mmHg) in days. Secondary outcomes are 7 day mortality after fulfilling the inclusion criteria, mortality until hospital discharge, Interleukin-6 (IL-6) measurement on day 1 and 3, need for mechanical ventilation, duration of mechanical ventilation, duration of ICU-stay, catecholamine dose on day 1/2/3 after start of "CytoSorb" and acute kidney injury.

RANDOMIZATION

An electronic randomization will be performed using the study software secuTrial® administered by the Clinical Study Center (CSC) of the Charité - Universitätsmedizin Berlin, Germany. Randomization is done in blocks by 4 stratified by including center.

BLINDING (MASKING)

The trial will be non-blinded for the clinicians and patients. The statistician will receive a blinded data set, so that all analyses will be conducted blinded.

NUMBERS TO BE RANDOMIZED (SAMPLE SIZE)

As this is a pilot study with the goal to examine the feasibility of the study design as well as the intervention effect, no formal sample size calculation was conducted. A total number of approximately 80-100 patients is planned (40-50 patients per group). Safety assessment is done after the inclusion of each 10 patients per randomization group.

TRIAL STATUS

Please see the study protocol version from April 24 2020. Recruitment of patients is still pending.

TRIAL REGISTRATION

The study was registered on April 27 2020 in the German Registry of Clinical Trials (DRKS) under the number DRKS00021447.

FULL PROTOCOL

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Extracorporeal Blood Purification and Organ Support in the Critically Ill Patient during COVID-19 Pandemic: Expert Review and Recommendation

Critically ill COVID-19 patients are generally admitted to the ICU for respiratory insufficiency which can evolve into a multiple-organ dysfunction syndrome requiring extracorporeal organ support. Ongoing advances in technology and science and progress in information technology support the development of integrated multi-organ support platforms for personalized treatment according to the changing needs of the patient. Based on pathophysiological derangements observed in COVID-19 patients, a rationale emerges for sequential extracorporeal therapies designed to remove inflammatory mediators and support different organ systems. In the absence of vaccines or direct therapy for COVID-19, extracorporeal therapies could represent an option to prevent organ failure and improve survival. The enormous demand in care for COVID-19 patients requires an immediate response from the scientific community. Thus, a detailed review of the available technology is provided by experts followed by a series of recommendation based on current experience and opinions, while waiting for generation of robust evidence from trials.

Cytokine Removal in Critically Ill Patients Requiring Surgical Therapy for Infective Endocarditis (RECReATE): An Investigator-initiated Prospective Randomized Controlled Clinical Trial Comparing Two Established Clinical Protocols

INTRODUCTION

Infective endocarditis (IE) and other severe infections induce significant changes in the immune response in a considerable number of affected patients. Numerous IE patients develop a persistent functional immunological phenotype that can best be characterized by a profound anti-inflammation and/ or functional "anergy." This is pronounced in patients with unresolved infectious foci and was previously referred to as "injury-associated immunosuppression" (IAI). IAI can be assessed by measurement of the monocytic human leukocyte antigen-DR (mHLA-DR) expression, a global functional marker of immune competence. Persistence of IAI is associated with prolonged intensive care unit length of stay, increased secondary infection rates, and death. Immunomodulation to reverse IAI was shown beneficial in early immunostimulatory (randomized controlled) clinical trials.

METHODS

Prospective 1:1 randomized controlled clinical study to compare the course of mHLA-DR in patients scheduled for cardiac surgery for IE. Patients will receive either best standard of care plus cytokine adsorption during surgery while on cardiopulmonary bypass (protocol A) versus best standard of care alone, that is, surgery without cytokine adsorption (protocol B). A total of 54 patients will be recruited and randomized. The primary endpoint is a change in quantitative expression of mHLA-DR (antibodies per cell on CD14+ monocytes/ macrophages, assessed using a quantitative standardized assay) from baseline (preoperation [pre-OP], visit 1) to day 1 post-OP (visit 4).

DISCUSSION

This randomized controlled clinical trial (RECReATE) will compare 2 clinical treatment protocols and will investigate whether cytokine adsorption restores monocytic immune competence (reflected by increased mHLA-DR expression) in patients with IE undergoing cardiac surgery.

TRIAL REGISTRATION

This protocol was registered in ClinicalTrials.gov, under number NCT03892174, first listed on March 27, 2019.

Compartmentalized profiling of amniotic fluid cytokines in women with preterm labor

Objective

Amniotic fluid cytokines have been implicated in the mechanisms of preterm labor and birth. Cytokines can be packaged within or on the surface of extracellular vesicles. The main aim of this study was to test whether the protein abundance internal to and on the surface of extracellular vesicles changes in the presence of sterile intra-amniotic inflammation and proven intra-amniotic infection in women with preterm labor as compared to the women with preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection.

Study design

Women who had an episode of preterm labor and underwent an amniocentesis for the diagnosis of intra-amniotic infection or intra-amniotic inflammation were classified into three groups: 1) preterm labor without either intra-amniotic inflammation or proven intra-amniotic infection, 2) preterm labor with sterile intra-amniotic inflammation, and 3) preterm labor with intra-amniotic infection. The concentrations of 38 proteins were determined on the extracellular vesicle surface, within the vesicles, and in the soluble fraction of amniotic fluid.

Results

1) Intra-amniotic inflammation, regardless of detected microbes, was associated with an increased abundance of amniotic fluid cytokines on the extracellular vesicle surface, within vesicles, and in the soluble fraction. These changes were most prominent in women with proven intra-amniotic infection. 2) Cytokine changes on the surface of extracellular vesicles were correlated with those determined in the soluble fraction; yet the magnitude of the increase was significantly different between these compartments. 3) The performance of prediction models of early preterm delivery based on measurements on the extracellular vesicle surface was equivalent to those based on the soluble fraction.

Conclusions

Differential packaging of amniotic fluid cytokines in extracellular vesicles during preterm labor with sterile intra-amniotic inflammation or proven intra-amniotic infection is reported herein for the first time. The current study provides insights into the biology of the intra-amniotic fluid ad may aid in the development of biomarkers for obstetrical disease.

Rationale of Hemoadsorption during Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support are increasingly used for treating various forms of shock, lung failure, protected interventions and life support including resuscitation. Most patients on ECMO are affected by a systemic inflammatory response caused by the underlying disease as well as the ECMO support itself, which contributes to vasoplegia, multi-organ failure, deterioration and death. Unfortunately, effective strategies for control of inflammation and related organ failure and shock on ECMO are lacking. Recently, a new polystyrene-based device for hemoadsorption, which aims to reduce excessive levels of inflammatory molecules such as interleukins, cytokines as well as damage- and pathogen-associated molecular patterns, has become available. Here we summarize the rationale, available data and technical aspects of polystyrene-based hemoadsorption during ECMO support, and give recommendations based on existing experience.

Pancreatitis cytosorbents (CytoSorb) inflammatory cytokine removal: A Prospective Study (PACIFIC)

BACKGROUND

Acute pancreatitis (AP) usually has a mild course with a mortality rate below 1%. However, around 10% of patients develop severe AP (SAP) involving extra-pancreatic tissues and other organ systems. The mortality of SAP is around 42%. The outcome of SAP is closely related to the development of systemic inflammation and consecutive organ failures. Most current therapies including fluid resuscitation, antimicrobial therapy, drainage procedures, and endoscopic management of complications are symptomatic rather than causative approaches, except sphincterotomy for gallstone pancreatitis. Regarding the high mortality of SAP and its close association with systemic inflammation, extracorporeal removal of inflammatory mediators is an appealing approach. Several recent studies have demonstrated that the CytoSorb adsorber effectively eliminates inflammatory cytokines, such as IL-1ß, IL-6, IL-8, IL-10, and TNF-alpha. Some of these trials suggested that therapy with CytoSorb might improve outcome, including a reduction in the vasopressor dosage and reversal of shock.Therefore, it is the objective of this study to evaluate the effectiveness of 2 consecutive 24 h-treatments with CytoSorb on hemodynamics in patients with early SAP.

METHODS

This study includes patients with early SAP (APACHE-II ≥10) and transpulmonary thermodilution hemodynamic monitoring (PiCCO; EV-1000) within a maximum of seven days from the onset of pain. Eligible patients will be treated with 2 consecutive periods of CytoSorb. A 20%-improvement in the vasopressor dependency index (VDI) - which relates is derived from mean arterial pressure (MAP) and catecholamine dosage - is the primary outcome. In addition to this clinical outcome, there are several laboratory (cytokine levels) and translational endpoints (including multiplex-ELISAs of numerous anti- and pro-inflammatory cytokines/chemokines and DNA analyses). Primary outcome analysis will compare the incidence of the primary endpoint in 30 patients from the intervention group to 60 matched controls with advanced hemodynamic monitoring recruited from recent studies in SAP within the same setting and the same centers.

DISCUSSION

A potential improvement in hemodynamics and/or other outcomes by CytoSorb would provide a new therapeutic option in the early treatment of SAP with a pathophysiological rationale.

TRIAL REGISTRATION

This study was registered on March 17, 2017 (ClinicalTrials.gov Identifier: NCT03082469). URL: https://clinicaltrials.gov/ct2/show/NCT03082469.

VERSION

V_PACIFIC_1.0 September 30, 2018.

Super High Flux Hemodialysis at High Dialysate Flows: An Ex Vivo Assessment

Background and objectives

The removal of cytokines by standard hemofiltration is limited. Super high flux membranes may significantly improve removal even when used in dialysis mode. We sought to measure cytokine clearance using a large surface super high-flux membrane and a standard hemodialysis setting.

Setting

ICU laboratory of a tertiary institution.

Subjects

Six healthy volunteers.

Methods

Blood form healthy volunteers was incubated for 4 hours with E. coli endotoxin to stimulate cytokine production. Cytokine containing blood was then circulated through a dialysis circuit at 3 different dialysate flow rates. Blood and dialysate were sampled for cytokine and albumin measurements and calculation of clearances.

Results

Super high-flux dialysis achieved high median cytokine clearances (IL-1 clearance of 106 ml/min, IL-6 clearance of 66.8 ml/min, IL-8 clearance of 61.7 ml/min and TNF clearance of 36.1 ml/min). Increasing dialysate flow rate from 300 to 500 ml/min did not significantly increase cytokine clearances. Albumin clearances however were between 2.7 and 5.4 ml/min.

Conclusions

Cytokine dialysis is feasible at high dialysate flow rates yielding high cytokine clearances. Albumin loss, however, is appreciable and may require separate supplementation in the clinical setting.

Carbon Adsorbents With Dual Porosity for Efficient Removal of Uremic Toxins and Cytokines from Human Plasma

The number of patients with chronic kidney disease increases while the number of available donor organs stays at approximately the same level. Unavoidable accumulation of the uremic toxins and cytokines for these patients comes as the result of malfunctioning kidneys and their high levels in the blood result in high morbidity and mortality. Unfortunately, the existing methods, like hemodialysis and hemofiltration, provide only partial removal of uremic toxins and/or cytokines from patients' blood. Consequently, there is an increasing need for the development of the extracorporeal treatments which will enable removal of broad spectrum of uremic toxins that are usually removed by healthy kidneys. Therefore, in this work we developed and tested ordered mesoporous carbons as new sorbents with dual porosity (micro/meso) that provide selective and efficient removal of a broad range of uremic toxins from human plasma. The new sorbents, CMK-3 are developed by nanocasting methods and have two distinct pore domains, i.e. micropores and mesopores, therefore show high adsorption capacity towards small water soluble toxins (creatinine), protein-bound molecules (indoxyl sulfate and hippuric acid), middle molecules (β-2-microglobulin) and cytokines of different size (IL-6 and IL-8). Our results show that small amounts of CMK-3 could provide selective and complete blood purification.

Measurement of Inflammatory Chemokines in Micro-dissected Tissue Biopsy Samples by Chip-Based Immunoaffinity Capillary Electrophoresis

To aid in the biochemical analysis of human skin biopsies, a chip-based immunoaffinity capillary electrophoresis (ICE) system has been developed for measuring inflammatory chemokines in micro-dissected areas of the biopsy. Following isolation of the areas of interest, the tissue was solubilized and the analytes of interest were isolated by the immunoaffinity disk within the chip. The captured analytes were labeled in situ with a 635 nm light-emitting laser dye and electro-eluted into the chip separation channel. Electrophoretic separation of all of the analytes was achieved in 2.5 min with quantification of each peak being performed by online LIF detection and integration of each peak area. The degree of accuracy and precision achieved by the chip-based system is comparable to conventional immunoassays and the system is robust enough to be applied to the analysis of clinical samples. Further, with the expanding array of antibodies that are commercially available, this chip-based system can be applied to a wide variety of different biomedical and clinical analyses.

Improvement of radiotherapy-induced lacrimal gland injury by induced pluripotent stem cell-derived conditioned medium via MDK and inhibition of the p38/JNK pathway

Radiation therapy is the most widely used and effective treatment for orbital tumors, but it causes dry eye due to lacrimal gland damage. Induced pluripotent stem cell-derived conditioned medium (iPSC-CM) has been shown to rescue different types of tissue damage. The present study investigated the mechanism of the potential radioprotective effect of IPS cell-derived conditioned medium (iPSC-CM) on gamma-irradiation-induced lacrimal gland injury (RILI) in experimental mice. In this study, we found that iPSC-CM ameliorated RILI. iPSC-CM markedly decreased radiotherapy induced inflammatory processes, predominantly through suppressing p38/JNK signaling. Further signaling pathway analyses indicated that iPSC-CM could suppress Akt (Protein Kinase B, PKB) phosphorylation. High levels of midkine (MDK) were also found in iPSC-CM and could be involved in lacrimal gland regeneration by promoting cell migration and proliferation. Thus, our study indicates that inhibiting the p38/JNK pathway or increasing the MDK level might be a therapeutic target for radiation-induced lacrimal gland injury.

[Content of some pro- and anti-inflammatory cytokines in blood sera of leptospirosis patients]

AIM

Study the content of some pro- and anti-inflammatory cytokines in blood sera of leptospirosis patients in dynamics of infectious process and the role of these cytokines in the disease immunopathogenesis.

MATERIALS AND METHODS

The content of cytokines in blood sera was determined by a method based on xMAP technology with a standard panel consisting of 9 analytes: TNF-α, MCP-1, IL-8, IL-4, IL-6, IL-10, IL-1Ra, IL-12 (p70), IFN-γ.

RESULTS

A significantly increased level of IL-8, IL-10, TNF-α was confirmed and the increased content of MCP-1 in leptospirosis patients compared with practically healthy donors was established for the first time. Correlations between cytokines during leptospirosis were detected.

CONCLUSION

The data obtained show that cytokines play an important role in leptospirosis immunopathogenesis.

Detection of intracellular cytokines

The intracellular cytokine method allows for a multiparametric readout by flow cytometry with precise phenotyping of the responding T cells. The intracellular cytokine staining of cells that have been fixed and permeabilized following a short-term activation and staining with antibodies to cell surface markers allows for identification of the cellular origin of the cytokine accumulated product.

Analysis of clinical and biological samples using microsphere-based multiplexing Luminex system

Immunoassays are one of the most commonly used biomedical techniques to detect the expression of an antibody or an antigen in a test sample. Enzyme-linked immunosorbent assay (ELISA) has been used for various applications including diagnostic tools and quality controls. However, one of the main limitations of ELISA is its lack of multiplexing ability, so ELISA may not be an efficient diagnostic tool when a measurement of multiple determinants is needed for samples with limited quantity such as blood or biological samples from newborns or babies. Although similar to ELISA in assay measurement, Luminex is an xMAP-based technology that combines several different technologies to provide an efficient and accurate measurement of multiple analytes from a single sample. The multiplexing can be achieved because up to 100 distinct Luminex color-coded microsphere bead sets can be coated with a reagent specific to a particular bioassay, allowing the capture and detection of specific analytes from a sample. Various biological samples can be analyzed by a Luminex system include serum, plasma, tissue and cell lysate, saliva, sputum, and bronchoalveolar lavage (BAL). The most common Luminex-based assays are used to detect a combined set of cytokines to provide a measurement of cytokine expression profiling for a diagnostic purpose.

Role of cytokine hemoadsorption in cardiopulmonary bypass-induced ventricular dysfunction in a porcine model

Little is known about the effect of cardiopulmonary bypass alone on cardiac function; in an attempt to illuminate this relationship and test a possible mechanism, we used Cytosorb, a device capable of removing virtually all types of circulating cytokines to test the hypothesis that hemoadsorption of cytokines during bypass attenuates bypass-induced acute organ dysfunction. Twelve Yorkshire pigs (50-65 kg) were instrumented with a left ventricular conductance catheter. Baseline mechanics and cytokine expression (tumor necrosis factor [TNF], interleukin-6 [IL-6], and interleukin-10) were measured before and hourly after 1 hour of normothermic cardiopulmonary bypass. Animals underwent bypass without (cardiopulmonary bypass [CPB], n = 6) or with (CPB+HA, n = 6) the CytosorbTM device. Data were compared with "historical" controls (n = 6) that were similarly instrumented but underwent observation instead of bypass. Five hours after separation from bypass (or observation), animals were euthanized. Myocardial water content was determined postmortem. Neither TNF nor IL-6 was significantly elevated in either experimental group versus controls at any time point. Preload recruitable stroke work and dP/dtmax were significantly depressed immediately after separation from bypass in both CPB+HA and CPB and remained depressed for the duration of the experiment. Although Tau remained unchanged, dP/dTmin was significantly diminished in both bypass groups at all time points after separation from bypass. Cytokine hemoadsorption had no effect on any measurable index of function. Differences in postmortem data were not evident between groups. One hour of normothermic CPB results in a significant and sustained decline in left ventricular function that appears unrelated to changes in cytokine expression. Because we did not appreciate a significant change in cytokine concentrations postbypass, the capacity of cytokine hemoadsorption to attenuate CPB-induced ventricular dysfunction could not be assessed.

A shark liver gene-derived active peptide expressed in the silkworm, Bombyx mori: preliminary studies for oral administration of the recombinant protein

Active peptide from shark liver (APSL) is a cytokine from Chiloscyllium plagiosum that can stimulate liver regeneration and protects the pancreas. To study the effect of orally administered recombinant APSL (rAPSL) on an animal model of type 2 diabetes mellitus, the APSL gene was cloned, and APSL was expressed in Bombyx mori N cells (BmN cells), silkworm larvae and silkworm pupae using the silkworm baculovirus expression vector system (BEVS). It was demonstrated that rAPSL was able to significantly reduce the blood glucose level in mice with type 2 diabetes induced by streptozotocin. The analysis of paraffin sections of mouse pancreatic tissues revealed that rAPSL could effectively protect mouse islets from streptozotocin-induced lesions. Compared with the powder prepared from normal silkworm pupae, the powder prepared from pupae expressing rAPSL exhibited greater protective effects, and these results suggest that rAPSL has potential uses as an oral drug for the treatment of diabetes mellitus in the future.

[Prokaryotic expression and polyclonal antibody preparation of human novel gene CTRP4]

AIM

To further investigate the biological function of human novel gene CTRP4 by constructing the prokaryotic expression vector of human CTRP4, inducing the expression of and purifying hCTRP4-his protein in E.coli, and preparing polyclonal antibody against human CTRP4.

METHODS

Human CTRP4 gene was amplified by PCR, digested with enzymes, and subcloned into a his-tagged prokaryotic expression vector to generate a recombinant plasmid named pET-32a-hCTRP4. The pET-32a-hCTRP4 was transformed into E.coli BL21(DE3). The hCTRP4-his fusion protein was induced by IPTG, purified by Ni-NTA purification system, and analyzed by SDS-PAGE. The recombinant vector pcDNA3.1-myc/his(-)B-hCTRP4 expressing full-length human CTRP4 and purified prokaryotic protein hCTRP4 were used to immunize BALB/c mice to produce polyclonal antibody. The anti-serum was purified and the characteristics of the antibody were identified by ELISA, Western blotting, immunofluorescence cytochemistry and immunohistochemistry.

RESULTS

The prokaryotic expression vector of pET-32a-hCTRP4 was constructed successfully. hCTRP4-his fusion protein was expressed in E.coli BL21(DE3) after IPTG induction. The titer of the anti-serum reached 1:20 000, and its specificity was proved by Western blotting. The results of immunofluorescence cytochemistry and immunohistochemistry indicated that CTRP4 was mainly localized in the cytoplasm of hepatic cells.

CONCLUSION

hCTRP4-his fusion protein can be successfully expressed in E.coli. A specific polyclonal antibody against human CTRP4 has been successfully prepared.

Characteristics common to a cytokine family spanning five orders of insects

Growth-blocking peptide (GBP) is a member of an insect cytokine family with diverse functions including growth and immunity controls. Members of this cytokine family have been reported in 15 species of Lepidoptera, and we have recently identified GBP-like peptides in Diptera such as Lucilia cuprina and Drosophila melanogaster, indicating that this peptide family is not specific to Lepidoptera. In order to extend our knowledge of this peptide family, we purified the same family peptide from one of the tenebrionids, Zophobas atratus,(1) isolated its cDNA, and sequenced it. The Z. atratus GBP sequence together with reported sequence data of peptides from the same family enabled us to perform BLAST searches against EST and genome databases of several insect species including Coleoptera, Diptera, Hymenoptera, and Hemiptera and identify homologous peptide genes. Here we report conserved structural features in these sequence data. They consist of 19-30 amino acid residues encoded at the C terminus of a 73-152 amino acid precursor and contain the motif C-x(2)-G-x(4,6)-G-x(1,2)-C-[KR], which shares a certain similarity with the motif in the mammalian EGF peptide family. These data indicate that these small cytokines belonging to one family are present in at least five insect orders.

Collection of aerosolized human cytokines using Teflon® filters

BACKGROUND

Collection of exhaled breath samples for the analysis of inflammatory biomarkers is an important area of research aimed at improving our ability to diagnose, treat and understand the mechanisms of chronic pulmonary disease. Current collection methods based on condensation of water vapor from exhaled breath yield biomarker levels at or near the detection limits of immunoassays contributing to problems with reproducibility and validity of biomarker measurements. In this study, we compare the collection efficiency of two aerosol-to-liquid sampling devices to a filter-based collection method for recovery of dilute laboratory generated aerosols of human cytokines so as to identify potential alternatives to exhaled breath condensate collection.

METHODOLOGY/PRINCIPAL FINDINGS

Two aerosol-to-liquid sampling devices, the SKC® Biosampler and Omni 3000™, as well as Teflon® filters were used to collect aerosols of human cytokines generated using a HEART nebulizer and single-pass aerosol chamber setup in order to compare the collection efficiencies of these sampling methods. Additionally, methods for the use of Teflon® filters to collect and measure cytokines recovered from aerosols were developed and evaluated through use of a high-sensitivity multiplex immunoassay. Our results show successful collection of cytokines from pg/m(3) aerosol concentrations using Teflon® filters and measurement of cytokine levels in the sub-picogram/mL concentration range using a multiplex immunoassay with sampling times less than 30 minutes. Significant degradation of cytokines was observed due to storage of cytokines in concentrated filter extract solutions as compared to storage of dry filters.

CONCLUSIONS

Use of filter collection methods resulted in significantly higher efficiency of collection than the two aerosol-to-liquid samplers evaluated in our study. The results of this study provide the foundation for a potential new technique to evaluate biomarkers of inflammation in exhaled breath samples.

Quantitative and semiquantitative immunoassay of growth factors and cytokines in the conditioned medium of STO and CF-1 mouse feeder cells

Feeder cells of irradiated mouse fibroblasts are commonly used for, and are generally necessary for, the in vitro maintenance and growth of many fastidious cell types, particularly embryonic stem cells or induced pluripotent stem cells. Quantitative and semiquantitative immunoassays of conditioned media were performed to identify some of the soluble cytokines, chemokines, protein hormones, and cell matrix/adhesion molecules that are elaborated from two commonly used feeder cells, STO and CF-1. Among those quantitatively assayed, the most abundant cytokine proteins expressed by the feeder cells were activin A, hepatocyte growth factor (HGF), insulin-like growth factor 1, insulin-like growth factor 2, insulin-like growth factor binding protein (IGFBP)-6, macrophage colony-stimulating factor (a.k.a. CSF-1), and pigment epithelium-derived factor (a.k.a. serine protease inhibitor, clade F, member 1). CF-1 cells expressed ten times more activin A than STO cells and also produced larger amounts of interleukin-6 and IGFBP-2, IGFBP-3, IGFBP-4, and IGFBP-5. Conversely, STO cell produced almost ten times more HGF and five times more stem cell factor (a.k.a. c-kit ligand) than CF-1 cells. Assayed semiquantitatively, relatively large amounts of chemokines were produced by both feeder cells including fractalkine (CX3CL1), interferon-inducible protein 10 (a.k.a. CXCL10 and cytokine-responsive gene-2, CRG-2), monocyte chemotactic protein (MCP)-1 (a.k.a. CCL2 and junctional epithelium chemokine (JE), MCP-5/CCL12), keratinocyte-derived chemokine (a.k.a. CXCL1 and growth-related oncogene alpha, GROα), nephroblastoma overexpressed gene (CCN3, IGFBP-9), stromal cell-derived factor 1 (CXCL12), and serpin E1 (PAI-1). In contrast to one another, STO produced more CXCL16 than CF-1 cells, and CF-1 cell produced more MCP-5 (CCL12), macrophage inflammatory protein (MIP)-1α (CCL3), MIP-1β (CCL4), pentraxin-3 (TSG-14), and platelet factor-4 (CXCL4) than STO cells. Soluble adhesion molecule, sICAM (ICAM-1, CD54), was expressed by CF-1 cells, but not STO cells, and similarly, the cell matrix-associated molecules endocan (endothelial cell-specific molecule 1), endostatin (collagen XVIII), and matrix metalloproteinase 3 were expressed more by CF-1 cells. Tissue inhibitor of metalloproteinases 1 was robustly expressed by both feeder cells. Other proteins primarily detected from CF-1 cells included retinol-binding protein 4 and FGF21, while STO cells secreted more interferon gamma. Both feeder cells produced no or low amounts of LIF, tumor necrosis factor alpha, vascular endothelial growth factor (VEGF), VEGF-B, prolactin, various interleukins, fibroblast growth factor (FGF)-1, FGF-2, FGF-7, EGF, HB-EGF, and amphiregulin. The results may explain some of the cell growth and maintenance responses by various types of cells co-cultured on STO or CF-1 feeder cells.

[Enzymatic activities of recombinant human NAMPT and NAMPT (H247A) proteins]

OBJECTIVE

To prepare and purify recombinant human NAMPT and NAMPT (H247A) proteins and to detect their enzymatic activity.

METHODS

Using pcDNA3.1-hnampt as template, full-length hnampt was sub-cloned into pET-11a(+) plasmid. The hnampt (H247A) mutant was obtained by site-directed mutagenesis. The plasmids were introduced in Escherichia coli BL21star for protein expression. The recombined NAMPT and NAMPT (H247A) proteins were purified by flowing through nickel column and size-exclusion column. The target proteins were confirmed by SDS-PAGE and mass spectrometry detection. The enzymatic activities of recombinant proteins were assessed by solution NMR.

RESULT

The DNA sequences showed that hnampt (wild type) and hnampt (H247A) (mutation) were cloned into pET-11a(+). The recombinant proteins were expressed in Escherichia coli BL21star in soluble form. The purified protein was confirmed to be NAMPT with a molecular weight of 56 KD. The enzyme activity of NAMPT (H247A) was dramatically decreased compared to wild-type NAMPT.

CONCLUSION

The recombinant hNAMPT and hNAMPT (H247A) proteins have been successful prepared and purified. The H247A mutation dramatically decreases the enzymatic activity of NAMPT.

In vitro and in vivo affinity microdialysis sampling of cytokines using heparin-immobilized microspheres

Heparin-immobilized microspheres were included in microdialysis sampling perfusion fluids under both in vitro and in vivo conditions to improve the recovery of different cytokines, acidic fibroblast growth factor, vascular endothelial growth factor, monocyte chemoattractant protein-1 (or CCL2), and regulation upon activation normal T cell express sequence (or CCL5). Different strategies to dissociate captured CCL2 and CCL5 from the immobilized heparin were attempted, and both cytokines could be quantitatively eluted from the beads using a phosphate buffer (pH 7.4) containing 25% (v/v) acetonitrile which did not interfere with the subsequent detection of cytokine using an ELISA assay. Using these heparin-immobilized microspheres, a two to fivefold increase of microdialysis relative recovery (RR) was achieved for the four cytokines from a quiescent solution. Enhanced microdialysis RR of CCL2 using the heparin-immobilized microspheres from microdialysis probes implanted into the peritoneal cavity of a rat was performed to test the in vivo application. This work suggests that the heparin-immobilized microspheres provide an alternative affinity agent to the previously used antibody-immobilized microspheres for enhanced microdialysis sampling of cytokines.

Heparin-immobilized microspheres for the capture of cytokines

The preparation and characterization of heparin-immobilized microspheres which were used to bind acidic fibroblast growth factor (aFGF), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein 1 (MCP-1/CCL2), and regulation upon activation normal T cell express sequence (RANTES/CCL5) is described. These beads were used as trapping agents in microdialysis sampling experiments in a separate study. Both free heparin and a synthesized heparin-albumin conjugate were immobilized onto microspheres and compared for their effectiveness. The heparin-albumin conjugate microspheres exhibited significant nonspecific adsorption which appeared to be due to the albumin content. The prepared heparin-immobilized microspheres were stable for 3 months at 4 °C. A bead-based flow cytometric assay was developed to study the binding capacity and specificity of the heparin-immobilized microspheres to cytokines. These heparin-immobilized microspheres exhibited broad dynamic ranges for binding to the four cytokines (aFGF, 1.0-1,000 ng/mL; VEGF, 0.5-1,000 ng/mL; CCL2, 1.95-1,000 ng/mL; CCL5, 1.95-500 ng/mL). Fast binding kinetics of the cytokines to the heparin-immobilized beads suggests that these beads may be useful as affinity agents in microfluidic flow systems.

Blood purification in sepsis: a new paradigm

Sepsis is one of the main causes of death in critically ill patients. The pathophysiology of sepsis is complex and not completely understood. The proinflammatory and anti-inflammatory response leads to cell and organ dysfunction and, in many cases, death. Thus, the goal of the intervention is to restore the homeostasis of circulating mediators rather than to inhibit selectively the proinflammatory or anti-inflammatory mediators. Blood purification has been reported to remove a wide array of inflammatory mediators. The effects are broad-spectrum and auto-regulating. Blood purification has also been demonstrated to restore immune function through improving antigen-presenting capability, adjusting leukocyte recruitment, oxidative burst and phagocytosis, and improving leukocyte responsiveness. A great deal of work has to be done in order to find and optimize the best extracorporeal blood purification therapy for sepsis. New devices specifically target the pathophysiological mechanisms involved in these conditions. High-volume hemofiltration, hemoadsorption, coupled plasma filtration adsorption, and high cutoff membrane are now being tested in septic patients. Preliminary data indicate the feasibility of these modified techniques in sepsis. Their impact on patient prognosis, however, still needs proof by large randomized clinical trials. Finally, the emerging paradigm of sepsis-induced immune suppression provides additional rationale for the development of extracorporeal blood purification therapy for sepsis.

Expression and purification of bioactive high-purity human midkine in Escherichia coli

Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine (rhMK) is therefore required to facilitate its functional studies of this important growth factor. In the present work, rhMK was expressed in Escherichia coli (E. coli) BL21 (DE3). The expression of midkine was efficiently induced by isopropyl-beta-D-thiogalactopyranoside (IPTG). After sonication, midkine was recovered in an insoluble form, and was dissolved in guanidine hydrochloride buffer. Renaturation of the denatured protein was carried out in the defined protein refolding buffer, and the refolded protein was purified using S-Sepharose ion-exchange chromatography. The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis (SDS-PAGE) and reverse phase high performance liquid chromatography (RP-HPLC). The purified rhMK enhanced the proliferation of NIH3T3 cells.

[Expression, purification of tetanus toxin C fragment/cardiotrophin-1 recombinant fusion protein, target delivery to CNS and neurotrophy biology ability]

OBJECTIVE

Expression, purification of tetanus toxin C fragment/cardiotrophin-1 recombinant fusion protein (CT-1/TTC) in BL21 (DE3) E. coli, examined whether tetanus toxin C fragment mediate the cardiotrophin-1 target delivery to the central nervous system and the cardiotrophin-1 has the neurotrophic ability.

METHODS

Induction by IPTG, the fusion protein was expressed and then purified by GST affinity agarose. The interest protein was viewed by SDS-PAGE, further characterized by Western Blot Rat sciatic nerve transected model was selected. Using drug by nerve-regeneration-chamber and intramuscular injection. Execute these animals one week after the operation. The L4-L6 segments of the spinal cord were harvested after transaortic perfusion with 4% paraformaldehyde. The freeze sections of spinal tissues were stained with immunohistochemistry method. And select the new born SD rat sciatic nerve transected model, using CT-1/TTC fusion protein by muscle injection. Execute these animals one week after the operation. The L4-L6 segments of the spinal cord were harvested after transaortic perfusion with 4% paraformaldehyde. The freeze sections of spinal tissues were stained by Nissl's staining.

RESULTS

After induction, the fusion protein was about 15% of the total protein and the soluble part was predominant. Purified by GST fusion protein column, the interest protein's concentration is 2.7 g/L. The CT-1/TTC fusion protein was found in lumbar intumescentia by immunohistochemistry method. And after sciatic nerve transected, the numbers of cornu anterius medullae spinalis motoneurons in L4-L6 segments, compared to CT-1/TTC protein grope, have a lower survival rate.

CONCLUSIONS

The recombinant CT-1/TTC protein can be expressed and purified in BL21 (DE3) E. coli. This fusion protein has two biological activities of targeting delivery to central nervous system and protecting the cornu anterius medullae spinalis motoneurons.

[Preparation of fractions and characteristic of neutrophilokines complex induced by Yersinia pestis EV]

Biochemical and immunobiologic characteristics of fractions of neutrophilokines during primary and secondary immune response against plague infection are presented. Fractions were obtained using gel chromatography from neutrophilokines complex induced by vaccine strain of Yersinia pestis. It was revealed that fractions of neutrophilokines regulate IL-2 synthesis by Th1-helpers, IL-4 and IL-5 synthesis by Th2-helpers and also expression of IL-2 receptors by immunocompetent cells. Helper effect of neutrophilokines' fractions was more pronounced during secondary immune response.

[Development of sandwich ELISA for equine interferon-gamma detection]

AIM

To develop a quantitative ELISA by measuring interferon (IFN-gamma) of equine lymphocytes.

METHODS

Sandwich ELISA for equine IFN-gamma was developed using mAb A5 as a capture antibody and biotinylated mAb SB10 as a detection antibody.

RESULTS

The detection limit of the sandwich ELISA for equine IFN-gamma was 1 microg/L and did not show cross-reactivity with recombinant equine IL-18. Equine IFN-gamma was detected by ELISA in culture medium of the peripheral blood mononuclear cells (PBMCs) stimulated with ConA or PMA/Ionomycin.

CONCLUSION

This method can be used to help understand the role of this cytokine in various equine diseases and develop specific cell-mediated immunity assay.

Expression, purification, crystallization and preliminary X-ray crystallographic analysis of a resuscitation-promoting factor from Mycobacterium tuberculosis

The resuscitation-promoting factor RpfB, the most complex of the five resuscitation-promoting factors produced by M. tuberculosis, is devoted to bacterial reactivation from the dormant state. RpfB consists of 362 residues predicted to form five domains. An RpfB fragment containing the protein catalytic domain and a G5 domain has been successfully crystallized using vapour-diffusion methods. This is the first crystallographic study of a resuscitation-promoting factor. Crystals of this protein belong to space group I422, with unit-cell parameters a = 97.63, b = 97.63, c = 114.87 A. Diffraction data have also been collected from a selenomethionine derivative at 2.9 A resolution. Model building using the phases derived from the multiwavelength anomalous dispersion experiment is in progress.

Cytokine profiles in the respiratory tract during primary infection with human metapneumovirus, respiratory syncytial virus, or influenza virus in infants

OBJECTIVES

We characterized the T helper cytokine profiles in the respiratory tract of infants infected with influenza virus, human metapneumovirus, and respiratory syncytial virus to examine whether these agents elicit similar cytokine responses and whether T helper type 2 polarization is associated with wheezing and severe disease.

METHODS

A prospective study of infants who were seeking medical help for acute upper and/or lower respiratory tract infection symptoms for the first time and were found to be infected with influenza, human metapneumovirus, or respiratory syncytial virus was performed. Respiratory viruses were detected in nasal secretions with reverse transcriptase-polymerase chain reaction assays. The study was performed in emergency departments and outpatient clinics in Buenos Aires, Argentina. T cell cytokine responses were determined in nasal secretions with immunoassays and reverse transcriptase-polymerase chain reaction assays.

RESULTS

Influenza elicited higher levels of interferon-gamma, interleukin-4, and interleukin-2 than did the other agents. Human metapneumovirus had the lowest interferon-gamma/interleukin-4 ratio (T helper type 2 bias). However, no association was found between T helper type 2 bias and overall wheezing or hospitalization rates.

CONCLUSIONS

These findings show that viral respiratory infections in infants elicit different cytokine responses and that the pathogeneses of these agents should be studied individually.

Purification and characterization of prokaryotically expressed human interferon-lambda2

A system for the production of soluble interferon (IFN)-lambda2 was developed by fusing the IFN-lambda2, NusA protein, polyhistidine and S peptide genes and then expressing the fused product (Nus-His-S-tagged IFN-lambda2) in Escherichia coli. The expressed fusion protein was purified by Ni-NTA affinity chromatography. The fusion tag was removed from recombinant IFN-lambda2 by cleavage with enterokinase. N-Terminal sequencing confirmed the identity of the purified protein. When compared with commercial IFN-alpha2b, IFN-lambda2 had similar antiviral activity. The production and characterization of biologically active IFN-lambda2 will be beneficial for its potential role in clinical applications.

A method to enable the investigation of murine bronchial immune cells, their cytokines and mediators

Innovative therapies for severe lung diseases (such as allergic and chronic asthma, chronic obstructive pulmonary disease or any type of lung cancer) require a detailed understanding of the cellular and immune processes in the lung. This protocol details a method to obtain the immune cells of the bronchi as well as the cytokines and mediators produced by these cells for further investigation. The broncho-alveolar lavage fluid (BALF) is taken by injecting physiological solution through the tracheal tube into the murine airways and carefully regained by winding up the connected syringe. After centrifugation, the resulting BALF supernatant can be stored for detection of cytokines or other mediators by enzyme-linked immunosorbent assay or other methods; the resuspended cell pellet can also be used for flow cytometric analyses, to check cell viability and the level of apoptosis, as well as other applications. In addition, CD4+ T cells isolated from wild-type and genetically modified mice alone or along with other immunologically important cells such as T regulatory cells, which can be used to reconstitute immunodeficient mice, may be retrieved from the airways with this method. This protocol can be completed within 35 min.

Omentin plasma levels and gene expression are decreased in obesity

Central obesity and the accumulation of visceral fat are risk factors for the development of type 2 diabetes and cardiovascular disease. Omentin is a protein expressed and secreted from visceral but not subcutaneous adipose tissue that increases insulin sensitivity in human adipocytes. To determine the impact of obesity-dependent insulin resistance on the regulation of two omentin isoforms, gene expression and plasma levels were measured in lean, overweight, and obese subjects. Omentin 1 was shown to be the major circulating isoform in human plasma. Lean subjects had significantly higher plasma omentin 1 levels than obese and overweight subjects. In addition, higher plasma omentin 1 levels were detected in women compared with men. Plasma omentin 1 levels were inversely correlated with BMI, waist circumference, leptin levels, and insulin resistance as measured by homeostasis model assessment and positively correlated with adiponectin and HDL levels. Both omentin 1 and omentin 2 gene expression were decreased with obesity and were highly correlated with each other in visceral adipose tissue. In summary, decreased omentin levels are associated with increasing obesity and insulin resistance. Therefore, omentin levels may be predictive of the metabolic consequences or co-morbidities associated with obesity.

Decreased selenoprotein expression alters the immune response during influenza virus infection in mice

Previous work from our laboratory demonstrated that host selenium (Se) deficiency results in greater lung pathology and altered immune function in mice infected with influenza virus. Because selenoproteins play a key role in determining the oxidant status of the host, we utilized a transgenic mouse line carrying a mutant selenocysteine (Sec) tRNA ([Ser]Sec) transgene (t-trspi(6)A(-)). The levels of selenoproteins are decreased in these mice in a protein- and tissue-specific manner. Male t-trspi(6)A(-) and wild-type (WT) mice were infected with influenza and killed at various time points postinfection (p.i.). Lung mRNA levels for innate and pro-inflammatory cytokines increased with infection but did not differ between groups. However, at d 2 p.i., chemokine levels were greater in the t-trspi(6)A(-) mice compared with WT mice. Additionally, IFN-gamma was higher at d 7 p.i. in the t-trspi(6)A(-) mice and viral clearance slower. Despite these immune system changes, lung pathology was similar in t-trspi(6)A(-) and WT mice. (75)Se labeling experiments demonstrated that glutathione peroxidase (GPX)-1 and thioredoxin reductase, although greatly diminished in the lungs of t-trspi(6)A(-) mice, were not altered as a result of infection. GPX-1 activity in the lungs of the t-trspi(6)A(-) mice was approximately 82% of the WT mice. In addition, the GPX-1 activity in the lungs of Se-deficient mice was 125% less than in the t-trspi(6)A(-) mice. These results suggest that although selenoproteins are important for immune function, there is a threshold of GPX-1 activity that can prevent an increase in lung pathology during influenza infection.

Angiogenic effects of human multipotent stromal cell conditioned medium activate the PI3K-Akt pathway in hypoxic endothelial cells to inhibit apoptosis, increase survival, and stimulate angiogenesis

Recent reports indicated that vascular remodeling and angiogenesis are promoted by conditioned medium from the cells referred to as multipotent stromal cells (MSCs). However, the molecular events triggered by MSC-conditioned medium (CdM) were not defined. We examined the effects of CdM from human MSCs on cultures of primary human aortic endothelial cells (HAECs). The CdM inhibited hypoxia-induced apoptosis and cell death of HAECs. It also promoted tube formation by HAECs in an assay in vitro. Conditioned medium from multipotent stromal cells incubated under hypoxic conditions in serum-free endothelial basal medium for 2 days (CdM(Hyp)) from hypoxic culture of MSCs was more effective than conditioned medium from MSCs incubated under normoxic conditions in serum-free endothelial basal medium for 2 days from normoxic cultures of MSCs, an observation in part explained by its higher content of antiapoptotic and angiogenic factors, such as interleukin (IL)-6, vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein (MCP)-1. The effects of CdM(Hyp) on hypoxic HAECs were partially duplicated by the addition of IL-6 in a dose-dependent manner; however, anti-IL-6, anti-MCP-1, and anti-VEGF blocking antibodies added independently did not attenuate the effects. Also, addition of CdM(Hyp) activated the PI3K-Akt pathway; the levels of p-Akt and several of its downstream targets were increased by CdM(Hyp), and both the increase in p-Akt and the increase in angiogenesis were blocked by an inhibitor of PI3K-Akt or by expression of a dominant negative gene for PI3K. CdM(Hyp) also increased the levels of p-extracellular signal-regulated kinase (ERK), but there was a minimal effect on p-signal transducer and activator of transcription-3, and an inhibitor of the ERK1/2 pathway had no effect on hypoxia-induced apoptosis of the HAECs. The results are consistent with suggestions that administration of MSCs or factors secreted by MSCs may provide a therapeutic method of decreasing apoptosis and enhancing angiogenesis.

Effect of extracorporeal liver support by MARS and Prometheus on serum cytokines in acute-on-chronic liver failure

Introduction

Cytokines are believed to play an important role in acute-on-chronic liver failure (ACLF). Extracorporeal liver support systems may exert beneficial effects in ACLF via removal of cytokines. At present, two systems are commercially available, the Molecular Adsorbent Recirculating System (MARS™) and Fractionated Plasma Separation, Adsorption and Dialysis (Prometheus™). The aim of this study was to compare the effects of MARS and Prometheus treatments on serum cytokine levels and their clearances.

Methods

Eight patients with ACLF underwent alternating treatments with either MARS or Prometheus in a randomized cross-over design. Thirty-four treatments (17 MARS, 17 Prometheus) were available for analysis. Serum cytokines were measured before and after each treatment, and cytokine clearance was calculated from paired arterial and venous samples and effective plasma flow one hour after the start of treatment.

Results

Baseline serum levels of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), and soluble TNF-α receptor 1 were significantly elevated in patients with ACLF. Measurable plasma clearances were detected for all cytokines tested, but no significant changes in serum levels of any cytokine were found after treatments with MARS or Prometheus. In MARS treatments, IL-10 was cleared from plasma more efficiently than IL-6. Clearance of IL-10 was higher in Prometheus than in MARS treatments.

Conclusion

Cytokines are cleared from plasma by both MARS and Prometheus, but neither system is able to change serum cytokine levels. This discrepancy is probably due to a high rate of cytokine production in patients with ACLF.

Pancreatitis-associated protein: From a lectin to an anti-inflammatory cytokine

Pancreatitis-associated protein (PAP) was discovered in the pancreatic juice of rats with acute pancreatitis. PAP is a 16 kDa secretory protein structurally related to the C-type lectins although classical lectin-related function has not been reported yet. Then, it was demonstrated that PAP expression may be activated in some tissues in a constitutive or injury- and inflammation-induced manner. More recently, it has been found that PAP acts as an anti-inflammatory factor in vitro and in vivo. PAP expression can be induced by several pro- and anti-inflammatory cytokines and by itself through a JAK/STAT3-dependent pathway. PAP is able to activate the expression of the anti-inflammatory factor SOCS3 through the JAK/STAT3-dependent pathway. The JAK/STAT3/SOCS3 pathway seems to be a common point between PAP and several cytokines. Therefore, it is reasonable to propose that PAP is a new anti-inflammatory cytokine.

Blood and plasma treatments: the rationale of high-volume hemofiltration

Since the early 1990s, experts in the field have thought that a reduction in cytokines in the blood compartment could, in theory, reduce mortality, but this is perhaps too naive as the pharmacodynamics and pharmacokinetics of cytokines throughout the body are not well known and are probably much more complicated than previously thought. This ha now led to three leading theories and concepts. Ronco and Bellomo conceived the peak concentration hypothesis in which clinicians concentrate their efforts to remove mediators and cytokines from the blood compartment at the proinflammatory phase of sepsis. By reducing the amount of free cytokines, it is hoped that the level of remote organ (associated) damages can be dramatically decreased and, as a consequence, the overall death rate. In this regard, it is still not known what will happen at the interstitial and tissue level with regard to mediators and cytokines which are obviously the most important part in terms of consequences at the tissue level. In this setting, techniques that can more rapidly and substantially remove great amounts of cytokines or mediators are privileged. Among these, there is high-volume and very high-volume hemofiltration and a number of hybrid therapies encompassing high-permeability hemofiltration, super high-flux hemofiltration, hemo-adsorption or coupled filtration and adsorption and other types of adsorption using physical or chemical forces rather than driving forces as used normally in hemofiltration-derived techniques. The second concept is called the threshold immunomodulation hypothesis, also called the Honoré concept. In this concept the view of the system is much more dynamic. In experiments when removal is occurring on the blood compartment side, the level on the interstitial side and the tissue side is also changing and, because not only mediators but also pro-mediators are being removed, some pathways have really stopped when enough pro-mediators have been removed by this technique. At this point, the cascade is blocked and this point is called the threshold point. At this level, the cascade is lost and no further harm can be done to the tissue of the organism. Obviously, it is difficult to know when this point has been reached once high-volume hemofiltration is applied. But what is known, is that hemodynamics and survival can be improved in some patients as shown by various studies using high-volume hemofiltration without any significant drop in mediators inside the blood compartment itself. This effect is obtained without a dramatic fall Honoré/Joannes-Boyau/Gressens 388 in the plasma cytokine level because the cytokine or mediator levels should fall at the tissue level and not specifically at the blood compartment level. Nevertheless, the exact mechanism by which high-volume hemofiltration increases the flow of mediators and cytokines between the interstitial compartment and the blood compartment (and back to the blood side) is not known. Before the end of 2005, it was found that this missing step is perhaps well explained by the last theory and/or concept. The third theory and concept is called the mediator delivery hypothesis and has also been called the Alexander concept. In this theory, the use of high-volume hemofiltration and especially high intakes of incoming fluids (3-5 l/h) is able to increase the lymphatic flow 20- to 40-fold, even more so for mediators and cytokine lymphatic flow (drag). This has been demonstrated by several reports and is obviously extremely important. Perhaps this can explain why some very recent studies using high-permeability hemofiltration in sepsis have not been effective in improving hemodynamics and survival in septic acute animal models. In summary various brand new theories will be reviewed here in depth.

Continuous hemodiafiltration with cytokine-adsorbing hemofilter in the treatment of severe sepsis and septic shock

Continuous hemodiafiltration (CHDF) using a polymethymethacrylate (PMMA) membrane hemofilter (PMMA-CHDF) can effectively and continuously remove various cytokines from the circulating blood. PMMA-CHDF can decrease the blood levels of various cytokines when the blood levels of cytokines are high prior to the initiation of CHDF. The main mechanism of cytokine removal with PMMA-CHDF is the adsorption of cytokines to the hemofilter membrane and this characteristic was not observed in the other membrane material. PMMA-CHDF could improve blood pressure, the depressed monocytic HLA-DR expression, and recover the delayed neutrophil apoptosis in septic patients. Thus, cytokine removal with PMMA-CHDF would be effective for the treatment of severe sepsis and septic shock.

Interleukin-6 family cytokine M17 induces differentiation and nitric oxide response of goldfish (Carassius auratus L.) macrophages

Cytokines belonging to the interleukin-6 (IL-6) family function in many biological processes and display a high degree of redundancy within the family. Although a number of mRNA transcripts from teleost fish that resemble IL-6 family cytokines have been identified none have been functionally characterized to confirm their identity. We report on the identification and functional characterization of goldfish M17, a molecule possessing sequence and mRNA expression patterns similar to the mammalian and avian ciliary neurotrophic factor and mammalian leukemia inhibitory factor. Goldfish M17 was found to induce the production of nitric oxide in goldfish macrophages and stimulate the proliferation of macrophage progenitor cells when added in combination with cell-conditioned medium. Moreover, goldfish M17 was found to facilitate the differentiation of sorted monocytes into macrophages at biologically relevant concentrations.

Mesoporous carbide-derived carbon with porosity tuned for efficient adsorption of cytokines

Porous carbons can be used for the purification of various bio-fluids, including the cleansing blood of inflammatory mediators in conditions such as sepsis or auto-immune diseases. Here we show that the control of pore size in carbons is a key factor to achieving efficient removal of cytokines. In particular, the surface area accessible by the protein governs the rate and effectiveness of the adsorption process. We demonstrate that novel mesoporous carbon materials synthesized from ternary MAX-phase carbides can be optimized for efficient adsorption of large inflammatory proteins. The synthesized carbons, having tunable pore size with a large volume of slit-shaped mesopores, outperformed all other materials or methods in terms of efficiency of TNF-alpha removal and the results are comparable only with highly specific antibody-antigen interactions.

Endothelial monocyte-activating polypeptide-II and its functions in (patho)physiological processes

Endothelial monocyte-activating polypeptide-II (EMAP-II) is a pro-inflammatory cytokine with anti-angiogenic properties. Its precursor, proEMAP, is identical to the p43 auxiliary component of the tRNA multisynthetase complex and therefore involved in protein translation. Although most of the activities have been ascribed to the active form EMAP-II, also p43 has reported cytokine properties. ProEMAP/p43 and EMAP-II act on many levels and on many cell types including endothelial cells, immune cells and fibroblasts. In this review we summarize all available data on isolation, expression and functions of EMAP-II both in physiological processes as well as in pathological settings, like cancer. We also discuss the different reported mechanisms for processing of proEMAP/p43 into EMAP-II. Finally, we speculate on the possible applications of this cytokine for (cancer) therapy.

The Corynebacterium glutamicum gene pmt encoding a glycosyltransferase related to eukaryotic protein-O-mannosyltransferases is essential for glycosylation of the resuscitation promoting factor (Rpf2) and other secreted proteins

Two-dimensional gel electrophoresis and immunoassays revealed several proteins of the secretory subproteome of Corynebacterium glutamicum to be glycosylated. By genome-wide searches for genes involved in glycosylation, the C. glutamicum gene cg1014 was found to exhibit significant similarity to eukaryotic protein-O-mannosyltransferases (PMTs) and to a recently identified orthologue of Mycobacterium tuberculosis, Rv1002c, which is responsible for protein-O-mannosylation. The putative membrane protein Cg1014 showed the same predicted transmembrane topology as Saccharomyces cerevisiae PMT1 and M. tuberculosis Rv1002c along with conserved amino acid residues responsible for catalytic activity. Deletion of the C. glutamicum pmt gene (cg1014) caused a complete loss of glycosylation of secreted proteins including the resuscitation promoting factor 2 (Rpf2), which is involved in intercellular communication and growth stimulation of C. glutamicum. Because the gene pmt as well as rpf genes are present in the genomes of all actinobacteria sequenced so far, this work provides new insights into bacterial protein glycosylation and new opportunities to elucidate the molecular mechanisms of Rpf activity in pathogenic growth and infection.

Human macrophage migration inhibitory factor: a proven immunomodulatory cytokine?

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory mediator with the ability to induce various immunomodulatory responses and override glucocorticoid-driven immunosuppression. Some of these functions have been linked to the unusual enzymatic properties of the protein, namely tautomerase and oxidoreductase activities. However, there are conflicting reports regarding the functional role of these enzymatic properties in normal physiological homeostasis and disease progression. Therefore, we have produced a highly pure, virtually endotoxin-free recombinant MIF preparation and fully characterized this using a variety of biochemical and biophysical approaches. The recombinant protein, with demonstrable enzymatic activity, was then used to systematically examine the biological activity of MIF. Surprisingly, treatment with MIF alone failed to induce cytokine expression, with the exception of IL-8. However, co-treatment of lipopolysaccharide (LPS) in conjunction with MIF produced synergistic secretion of tumor necrosis factor-alpha, interleukin (IL)-1, and IL-8 compared with LPS alone. The potentiating effect of MIF was seen at physiologically relevant concentrations. These data suggest that MIF has no conventional cytokine activity but, rather, acts to modulate and amplify the response to LPS.

Multiplexed protein array platforms for analysis of autoimmune diseases

Several proteomics platforms have emerged in the past decade that show great promise for filling in the many gaps that remain from earlier studies of the genome and from the sequencing of the human genome itself. This review describes applications of proteomics technologies to the study of autoimmune diseases. We focus largely on biased technology platforms that are capable of analyzing a large panel of known analytes, as opposed to techniques such as two-dimensional gel electrophoresis (2DIGE) or mass spectroscopy that represent unbiased approaches (as reviewed in 1). At present, the main analytes that can be systematically studied in autoimmunity include autoantibodies, cytokines and chemokines, components of signaling pathways, and cell-surface receptors. We review the most commonly used platforms for such studies, citing important discoveries and limitations that exist. We conclude by reviewing advances in biomedical informatics that will eventually allow the human proteome to be deciphered.

Comparison of Vaginal Cytokine Collection Methods

OBJECTIVE

The objective of our study was to correlate the interleukin-6 (IL-6) concentrations detected in patient-collected specimens with provider-collected specimens and compare the reproducibility of the methods.

STUDY DESIGN

All enrolled participants underwent pelvic examination with collection of cytokine samples by the provider and also collected samples themselves using vaginal swabs. The order of sample collection was randomly assigned. All samples were frozen at -80 degrees C for batch analysis. A commercial enzyme-linked immunosorbent assay was used to determine the concentrations of IL-6 in all samples.

RESULTS

IL-6 concentrations from wicks and swabs were correlated in a linear fashion (r = 0.67, P < 0.001). IL-6 concentrations in the two swabs (r = 0.94, P < 0.001) and the two wicks (r = 0.71, P < 0.001) were correlated in a linear fashion, although there was more variability in wick specimens.

CONCLUSION

IL-6 concentrations can be reproducibly measured using either method. The ease of patient swab collection and the correlation with provider-collected specimens may make frequent assessment of the vaginal cytokine environment more acceptable to patients.

Purification and characterization of recombinant human interleukin-29 expressed in Escherichia coli

Human interleukin (IL)-29 is the latest member of the class II cytokine family. However, as a result of lacking efficient method to generate relatively large quantity of IL-29, little is known of its functions in man. In the present study, an Escherichia coli expression system for the rapid expression of the human IL-29 gene was developed. It involved of cloning IL-29 gene into the pET-44 Ek/LIC vector, which allowed expression of IL-29 with a fusion tag consisting of the NusA protein, polyhistidine and S peptide (Nus-His-S-tag), and introducing a thrombin recognition site between the fusion tag and IL-29. The expressed fusion protein was purified by S-protein agarose affinity chromatography, and the fusion tag was removed from recombinant IL-29 by cleavage with thrombin. The purified IL-29 appeared a single band on SDS-PAGE, and the yield of IL-29 was 60 mg from 1 l of bacterial culture. N-terminal sequencing confirmed the identity of the purified protein. The recombinant IL-29 showed specific antiviral activity that was comparable to the commercially available IFN alfa-2b preparation.