A novel alternative for pyrogen detection based on a transgenic cell line

Pyrogen, often as a contaminant, is a key indicator affecting the safety of almost all parenteral drugs (including biologicals, chemicals, traditional Chinese medicines and medical devices). It has become a goal to completely replace the in vivo rabbit pyrogen test by using the in vitro pyrogen test based on the promoted 'reduction, replacement and refinement' principle, which has been highly considered by regulatory agencies from different countries. We used NF-κB, a central signalling molecule mediating inflammatory responses, as a pyrogenic marker and the monocyte line THP-1 transfected with a luciferase reporter gene regulated by NF-κB as an in vitro model to detect pyrogens by measuring the intensity of a fluorescence signal. Here, we show that this test can quantitatively and sensitively detect endotoxin (lipopolysaccharide from different strains) and nonendotoxin (lipoteichoic acid, zymosan, peptidoglycan, lectin and glucan), has good stability in terms of NF-κB activity and cell phenotypes at 39 cell passages and can be applied to detect pyrogens in biologicals (group A & C meningococcal polysaccharide vaccine; basiliximab; rabies vaccine (Vero cells) for human use, freeze-dried; Japanese encephalitis vaccine (Vero cells), inactivated; insulin aspart injection; human albumin; recombinant human erythropoietin injection (CHO Cell)). The within-laboratory reproducibility of the test in three independent laboratories was 85%, 80% and 80% and the interlaboratory reproducibility among laboratories was 83.3%, 95.6% and 86.7%. The sensitivity (true positive rate) and specificity (true negative rate) of the test were 89.9% and 90.9%, respectively. In summary, the test provides a novel alternative for pyrogen detection.

Engineered Pyrogenic Materials as Tools to Affect Arsenic Mobility in Old Mine Site Soil of Mediterranean Region

The application of pyrogenic materials in immobilization processes of metalloids represents a burning issue in environmental and waste applications and management. The main objective of this study was to characterize the effect of biomass pretreatment by Cu, Fe and Mg blending and pyrolysis temperature on As sorption efficiency as a model of anionic metalloids from model solutions and As immobilization in old mine soil by pyrogenic materials. The physico-chemical characterization of engineered materials produced in slow pyrolysis process at 400 and 700°C from metal-blended hard wood chips (30% w/w) showed increasing of surface areas (1.4-1.8-fold), changes in pH, and more than 50% decrease in total C content. The batch sorption processes of As ions by Cu-modified pyrogenic materials (CuPM), Fe-modified pyrogenic materials (FePM), and Mg-modified pyrogenic materials (MgPM) showed increasing uptake in order CuPM700 (Q_max 2.56 mg g^-1) < CuPM400 (Q_max 3.88 mg g^-1) < FePM700 (Q_max 5.90 mg g^-1) < MgPM700 (Q_max 7.42 mg g^-1) < MgPM400 (Q_max 9.59 mg g^-1) < FePM400 (Q_max 10.55 mg g^-1). Engineered pyrogenic materials produced at 400°C showed higher immobilization effect on soluble As in soil pore water of old mine site soil from Mediterranean area. FePM400 reduced mobility of arsenic > 3.2 times and MgPM400 > 5 times compared to control. Promising pyrogenic material MgPM400 showed immobilization effect also on additional heavy metals (Cd, Cu, Fe, Mn, Pb, Sr, Zn) present in studied soil.

Self-Sterilizing Laser-Induced Graphene Bacterial Air Filter

Nosocomial infections transmitted through airborne, droplet, aerosol, and particulate-transported modes pose substantial infection risks to patients and healthcare employees. In this study, we demonstrate a self-cleaning filter comprised of laser-induced graphene (LIG), a porous conductive graphene foam formed through photothermal conversion of a polyimide film by a commercial CO₂ laser cutter. LIG was shown to capture particulates and bacteria. The bacteria cannot proliferate even when submerged in culture medium. Through a periodic Joule-heating mechanism, the filter readily reaches >300 °C. This destroys any microorganisms including bacteria, along with molecules that can cause adverse biological reactions and diseases. These molecules include pyrogens, allergens, exotoxins, endotoxins, mycotoxins, nucleic acids, and prions. Capitalizing on the high surface area and thermal stability of LIG, the utility of graphene for reduction of nosocomial infection in hospital settings is suggested.

[Biological activity of native and modified lipopolysaccharides Rahnella aquatilis]

The results of the comparative toxicity studies of native lipopolysaccharide (LPS) of Rahnella aquatilis 96U037 and that modified by tin complexes indicates that, due to the modification of LPS by tin complex with benzoylhydrazone of 4-dimethylaminobenzaldehyde, a decrease of its toxicity was observed that led to disappearance of the pyrogenic effect. All obtained derivatives lost completely the antigenic activity both in homologous and heterologous systems which may indicate to the interaction of modifying complexes with certain groups being the components of antigenic determinant. The paper is presented in Ukrainian.

A novel nasal delivery system of a Chinese traditional medicine, Radix Bupleuri, based on the concept of ion-activated in situ gel

The purpose of this study was to develop a nasal in situ gel system for Radix Bupleuri employing gellan gum as a polymer. Radix Bupleuri in situ gel containing 0.2 mL essential oil extracted from 450 g Radix Bupleuri, proper solubilizing agents and gellan gum (0.5% w/v) was prepared and characterized. The antipyretic effect produced by in situ gel formulation was investigated in fevered rabbits and compared to an intranasal solution. The resulting in situ gel was a clear and light-yellow liquid, with viscosity of 346 mPa x s and caproic acid content of 1.31 +/- 0.01 mg/mL. Intranasal administration of this preparation to fevered rabbits decreased body temperature markedly (1.1 degree C at the doses of oil from 1.5 g Bupleuri/body) and the effect could last for 20-30 h. The results suggest that Radix Bupleuri in situ gel can be greater effective than the solution in the treatment of fever.

Crystal structure of the streptococcal superantigen SpeI and functional role of a novel loop domain in T cell activation by group V superantigens

Superantigens (SAgs) are potent microbial toxins that bind simultaneously to T cell receptors (TCRs) and class II major histocompatibility complex molecules, resulting in the activation and expansion of large T cell subsets and the onset of numerous human diseases. Within the bacterial SAg family, streptococcal pyrogenic exotoxin I (SpeI) has been classified as belonging to the group V SAg subclass, which are characterized by a unique, relatively conserved approximately 15 amino acid extension (amino acid residues 154 to 170 in SpeI; herein referred to as the alpha3-beta8 loop), absent in SAg groups I through IV. Here, we report the crystal structure of SpeI at 1.56 A resolution. Although the alpha3-beta8 loop in SpeI is several residues shorter than that of another group V SAg, staphylococcal enterotoxin serotype I, the C-terminal portions of these loops, which are located adjacent to the putative TCR binding site, are structurally similar. Mutagenesis and subsequent functional analysis of SpeI indicates that TCR beta-chains are likely engaged in a similar general orientation as other characterized SAgs. We show, however, that the alpha3-beta8 loop length, and the presence of key glycine residues, are necessary for optimal activation of T cells. Based on Vbeta-skewing analysis of human T cells activated with SpeI and structural models, we propose that the alpha3-beta8 loop is positioned to form productive intermolecular contacts with the TCR beta-chain, likely in framework region 3, and that these contacts are required for optimal TCR recognition by SpeI, and likely all other group V SAgs.

Persistent organic pollutants and sedimentary organic matter properties: a case study in the Kishon River, Israel

The Kishon River, the second largest coastal river in Israel, has been severely polluted for several decades. Sediments from upstream and downstream sites of the river were analyzed, lipid-extracted and evaluated for phenanthrene uptake. Total polycyclic aromatic hydrocarbon (PAH) concentration in downstream sediments was 299 microg kg(-1), consisting mostly of petrogenic-derived PAHs. Downstream sedimentary lipids were found to be dominated by fresh and decomposed petroleum-derived n-alkanes. The total PAH concentration in upstream sediments was 173 microg kg(-1), consisting mostly of pyrogenic-derived PAHs, whereas lipids from these sediments were mostly vegetation-derived. Spectroscopic data suggested an exceptionally high aromatic content in downstream humic acid, which originated from PAHs attached to its structure. Sorption data suggested that upstream sedimentary cuticle-derived lipids function as a sorption domain, while downstream sedimentary lipids, consisting of shorter-chain-length petroleum-derived alkanes, compete with phenanthrene for sorption sites.

Release of TNF-alpha and IL-1beta from porcine brain endothelium corresponds to the pyrogenic potential of three marketed formulations of amphotericin

BACKGROUND

Formulations of amphotericin include a deoxycholate suspension (d-Amph), an amphotericin-B lipid complex (Ablc), and a liposomal product (L-Amph). Fever is most frequent with d-Amph, intermediate with Ablc, and lowest with L-Amph.

OBJECTIVE

To determine if the release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1) from brain endothelium corresponds to the incidence of amphotericin fever.

RESULTS

Release of TNF-alpha and IL-1beta after L-Amph treatment was similar to negative controls while after d-Amph treatment release was similar to lipopolysaccharide. Ablc treatment produced intermediate pyrogen release.NF-kappaB expression, a transcriptional regulator for TNF-alpha and IL-1beta genes, corresponded to this secretion pattern. TNF-alpha release was elevated 2 hours (p = 0.0021) after treatment while significant elevations in IL-1beta required 6 hours (p = 0.0009).

CONCLUSION

Results from this in vitro study suggest that amphotericin fever may be directly mediated by brain endothelium. These experiments also suggest that amphotericin fever is initially mediated by TNF-alpha.

Comparison of the rabbit pyrogen test and Limulus amoebocyte lysate (LAL) assay for endotoxin in hepatitis B vaccines and the effect of aluminum hydroxide

The rabbit pyrogen test and Limulus amoebocyte lysate (LAL) assay have been used to detect endotoxins in vaccines, but interactions between the endotoxins and proteins or aluminum hydroxide can interfere with the results. Currently, the rabbit pyrogen test is used to detect endotoxin in hepatitis B (HB) vaccines even though the HB surface protein, the active ingredient, is over-expressed in and purified from eukaryotic cells which lack endotoxin. Therefore, we examined the possibility of replacing the animal tests with the more efficient LAL test. To this end, we determined whether the aluminum hydroxide in the HB vaccines affects the rabbit pyrogen test and the LAL assay. HB vaccines and HB protein solutions spiked with lipopolysaccharide (LPS) produced almost the same dose-dependent temperature rise in rabbits, indicating that the aluminum hydroxide in the HB vaccine does not interfere with the pyrogenic response in rabbit. In contrast, a spike recovery study showed that aluminum hydroxide interfered with the LAL clot and kinetic assays; however, the LAL clot assay was effective at detecting endotoxin without loss of LAL activity after serial dilution of the samples. Furthermore, there was good correlation in the LAL clot assay between the amount of LPS added and the amount recovered. However, both turbidimetric and chromogenic kinetic assays displayed no correlation between the LPS amount added and recovered. Our results suggest that the LAL clot assay is sensitive and reliable when samples are properly prepared, and can be used to replace the rabbit pyrogen test for the detection of endotoxin in HB vaccines.

[Characterization of the lipopolysaccharide from Rahnella aquatilis 1-95]

The lipopolysaccharide from the freshwater bacterium Rahnella aquatilis 1-95 has been isolated and investigated for the first time. The structural components of the lipopolysaccharide molecule: lipid A, core oligosaccharide, and O-specific polysaccharide were isolated by mild acidic hydrolysis. In lipid A, 3-hydroxytetradecanoic and tetradecanoic acids were found to be the predominant fatty acids. In the core oligosaccharide, galactose, arabinose, fucose, and an unidentified component were shown to be the major monosaccharides. The O-specific polysaccharide consists of a regularly repeating trisaccharide unit with the acyl and phosphate following structure: [structure: see text] groups have been shown to be responsible for the toxic and pyrogenic properties of the lipopolysaccharide of R. aquatilis.

The use of thermal lensing for the determination of pyrogens

Based on the optimized spectrophotometric determination of pyrogens (of various classes ( p-aminophenol and endotoxins), thermal lensing was applied to the determination of these substances at the submicrogram level. The limit of detection of p-aminophenol, a pyrogenic impurity in pharmaceutical formulations of paracetamol, by reaction with resorcinol in alkaline solutions is 100 ng mL(-1). Phloroglucinol was considered as an analog of resorcinol as a reagent in this reaction. The conditions of spectrophotometric determination of pyrogenic lipopolysaccharides (endotoxins) by ion-pair formation with methylene blue (the limit of detection is 100 ng mL(-1)), by ion-pair formation with Stains-All (1-ethyl-2-[3-(1-ethylnaphtho[1,2-d]thiazolin-2-ylidene)-2-methylpropenyl]naphtho[1,2-d]thiazolium bromide) (the limit of detection is 500 ng mL(-1)), and by reaction of 2-keto-3-deoxyoctonic acid with thiobarbituric acid (the limit of detection is 800 ng mL(-1)) were proposed. The optimized procedure for 2-keto-3-deoxyoctonic acid was applied for thermal lensing that provided a decrease in the limit of detection to 70 ng mL(-1) and was also used for lipopolysaccharide determination in the endotoxin standard from E. coli.

Characterization of two novel pyrogenic toxin superantigens made by an acute rheumatic fever clone of Streptococcus pyogenes associated with multiple disease outbreaks

The pathogenesis of acute rheumatic fever (ARF) is poorly understood. We identified two contiguous bacteriophage genes, designated speL and speM, encoding novel inferred superantigens in the genome sequence of an ARF strain of serotype M18 group A streptococcus (GAS). speL and speM were located at the same genomic site in 33 serotype M18 isolates, and no nucleotide sequence diversity was observed in the 33 strains analyzed. Furthermore, the genes were absent in 13 non-M18 strains tested. These data indicate a recent acquisition event by a distinct clone of serotype M18 GAS. speL and speM were transcribed in vitro and upregulated in the exponential phase of growth. Purified SpeL and SpeM were pyrogenic and mitogenic for rabbit splenocytes and human peripheral blood mononuclear cells in picogram amounts. SpeL preferentially expanded human T cells expressing T-cell receptors Vbeta1, Vbeta5.1, and Vbeta23, and SpeM had specificity for Vbeta1 and Vbeta23 subsets, indicating that both proteins had superantigen activity. SpeL was lethal in two animal models of streptococcal toxic shock, and SpeM was lethal in one model. Serologic studies indicated that ARF patients were exposed to serotype M18 GAS, SpeL, and SpeM. The data demonstrate that SpeL and SpeM are pyrogenic toxin superantigens and suggest that they may participate in the host-pathogen interactions in some ARF patients.

Characterization of a novel staphylococcal enterotoxin-like superantigen, a member of the group V subfamily of pyrogenic toxins

Staphylococcus aureus is an important human pathogen, causing a variety of diseases. Major virulence factors of this organism include staphylococcal enterotoxins (SEs) that cause food poisoning and toxic shock syndrome. Our study identified a novel enterotoxin-like protein that is a member of the new subfamily (group V) of pyrogenic toxin superantigens (PTSAgs) and examined its biochemical and immunobiological properties. The gene encoding the SE-like protein is directly 5' of another recently identified PTSAg, SEK. The SE-like protein had a molecular weight of 26000 and an experimentally determined isoelectric point between 7.5 and 8.0. We demonstrated that the PTSAg had many of the biological activities associated with SEs, including superantigenicity, pyrogenicity, and ability to enhance endotoxin shock, but lacked both lethality in rabbits when administered in subcutaneous miniosmotic pumps and emetic activity in monkeys. Recombinant protein stimulated human CD4 and CD8 T cells in a T cell receptor variable region, beta chain (TCRVbeta) specific manner. T cells bearing TCRVbeta 2, 5.1, and 21.3 were significantly stimulated.

Characterization and immunogenicity of pyrogenic mitogens SePE-H and SePE-I of Streptococcus equi

Two pyrogenic mitogens, SePE-H and SePE-I, were characterized in Streptococcus equi, the cause of equine strangles. SePE-H and SePE-I have molecular masses of 27.5 and 29.5 kDa, respectively, and each is almost identical to its counterpart in Streptococcus pyogenes M1. Both genes are adjacent to a gene encoding a phage muramidase of 49.7 kDa and are located immediately downstream from a phage genomic sequence almost identical to a similar phage sequence in S. pyogenes M1. Strong mitogenic responses were elicited by both proteins from horse peripheral blood mononuclear cells. However, although both were pyrogenic for rabbits, only SePE-I was pyrogenic in ponies. Convalescent sera contained antibody to each mitogen and horses recovered from strangles or immunized with SePE-I were resistant to the pyrogenic effect of SePE-I. The immunogenicity of SePE-I suggests that it should be included in new generation strangles vaccines. In isolates of S. equi sepe-I and sepe-H were consistently present but they were absent from the closely related Streptococcus zooepidemicus, suggesting that phage mediated transfer was an important event in the formation of the clonal, more virulent, S. equi from its putative S. zooepidemicus ancestor.

Ultrasonication of pyrogenic microorganisms improves the detection of pyrogens in the Mono Mac 6 assay

The monocytic cell line Mono Mac 6 is sensitive to pyrogens. When exposed to pyrogens secretion of interleukin-6 is induced. However, some eukaryotic pyrogenic microorganisms are not detectable. The aim of this study is to introduce a pretreatment of samples to expand the detection range of the assay. The interleukin-6 inducing capacity of a broad spectrum of UV-killed and ultrasonicated microorganisms is examined in Mono Mac 6 cells. The interleukin-6 secretion is determined in a sandwich immunoassay (DELFIA). The Mono Mac 6 assay is able to detect UV-killed Bacillus subtilis, Staphylococcus aureus and Salmonella typhimurium, but neither Candida albicans nor Aspergillus niger. After ultrasonication of the microorganisms it is possible to detect C. albicans and A. niger. The interleukin-6 inducing ability of the examined microorganisms is in no case reduced after ultrasonic treatment. However, ultrasonication of S. aureus results in a 100-fold increase in the interleukin-6 response. Even after ultrasonication Streptococcus faecalis can not be detected. Ultrasonication is an easy and simple method for expanding the detection range in the Mono Mac 6 assay.

Calcified microspheres as biological entities and their isolation from bone

Calcified microspheres, about 1 microm in diameter, appear at sites of bone formation where they invest the collagenous matrix, become confluent and disappear. Evidence that the particle boundaries are not lost with compaction but merely deformed is supported in section by the granular histochemical staining of the inorganic phase for bone salt, lipid, fibronectin and acid phosphatase in osteomalacic, acid-etched and normal human bone. Their persistence as discrete objects is confirmed by the application of methods for their isolation from the collagenous matrix of immature mouse calvarium and mature bovine femur. Five methods have been used to extract them and include (i) biochemical, (ii) chemical, (iii) mechanical, (iv) pyrogenous and (v) biological separation. Under the optical microscope, all isolates consisted of similar discrete objects and bridged assemblies, whose birefringence varied with treatment. After decalcification, their organic 'ghosts' remained. Each isolated microsphere had a complex substructure of clusters of non-collagenous calcified filaments surrounding a less dense centre. The filaments were 5 nm in diameter with a 5 nm periodicity and regular fine interfilamentous connections. It is concluded that the microspheres are independent, complex, pervasive and central to the containment (i.e. packaging) of calcium phosphate in bone. Their extraction will enable further analysis.

Structural basis for the recognition of superantigen streptococcal pyrogenic exotoxin A (SpeA1) by MHC class II molecules and T-cell receptors

Streptococcal pyrogenic exotoxin A (SpeA) is a superantigen produced by Streptococcus pyogenes and is associated with severe infections characterized by rash, hypotension, multiorgan failure and a high mortality rate. In this study, an allelic form of this toxin, SpeA1, was crystallized with four molecules in the crystallographic asymmetric unit and its crystal structure was determined at 2.6 A resolution. The crystallographic R-factor was 19.4% (33 497 reflections) for 7031 protein atoms and 88 water molecules. The overall structure of SpeA1 is considerably similar to that of other prototype microbial superantigens, either of staphylococcal or streptococcal origin, but has greatest similarity to staphylococcal enterotoxin C (SEC). Based on structural and mutagenesis data, we have mapped several important residues on the toxin molecule, which are involved in the recognition of major histocompatibility complex (MHC) class II molecules and T-cell receptors. Also, the toxin appears to possess a potential zinc-binding site which may have implications in binding to particular MHC class II molecules. Finally, we propose models for SpeA1-MHC class II and SpeA1-T-cell receptor association and the relevance of this phenomenon to the superantigenic action of this toxin is considered.

Studies on the pathogenesis of fever. VII. Preliminary chemical characterization of leucocytic pyrogen

Study of the chemical properties of the pyrogenic component of rabbit polymorphonuclear leucocytes reveals it to contain an essential, non-dialyzable protein which: (a) is precipitated by perchloric acid, (b) is removed by extraction with phenol, (c) is soluble in 50 per cent methanol and 33 per cent saturated ammonium sulfate, and (d) is destroyed by the proteolytic action of both trypsin and pepsin. By combined chemical and chromatographic techniques the leucocytic pyrogen has been purified approximately 50-fold. The partially purified material contains less than 1 per cent carbohydrate, is resistant to periodate oxidation, is unaffected by extraction with butanol and contains at least two immunologically active components when tested by the Ouchterlony gel-diffusion technique. Its chemical properties distinguish it from other known pyrogenic substances which have been implicated in the pathogenesis of fever.

Identification of domains involved in superantigenicity of streptococcal pyrogenic exotoxin F (SpeF)

A series of 11 synthetic peptides of 30 amino acids, each with 10 amino acids overlap which spanned the entire sequence of streptococcal pyrogenic exotoxin F (SpeF), were employed in proliferation studies on human peripheral blood mononuclear cells (PBMCs). Regions 41-70, 141-170 and 181-210 were identified as important for SpeF-induced lymphocyte activation. Secondary structure predictions of these peptides showed similarities to regions in other superantigens known to be important for T cell mitogenicity. Furthermore, antisera specific to peptides covering amino acids 1-70 and 181-228 were able to inhibit SpeF-induced mitogenicity by 25% when pre-incubated with SpeF prior to PBMC activation.

The superantigen streptococcal pyrogenic exotoxin C (SPE-C) exhibits a novel mode of action

Recombinant streptococcal pyrogenic exotoxin C (SPE-C) is a potent superantigen that stimulates Vbeta2-bearing human T cells, but is inactive in mice. SPE-C binds with high affinity to both human HLA-DR and murine I-E molecules, but not to murine I-A molecules in a zinc-dependent fashion. Competition binding studies with other recombinant toxins revealed that SPE-C lacks the generic low affinity major histocompatibility complex (MHC) class II alpha-chain binding site common to all other bacterial superantigens. Despite this, SPE-C cross-links MHC class II to induce homotypic aggregation of class II-bearing B cells. Nondenaturing sodium dodecyl sulfate electrophoresis and size exclusion chromatography revealed that both wild-type and recombinant SPE-C exist in a stable dimer at neutral or alkaline pH. These data support a recent crystal structure of SPE-C and reveal yet another mechanism by which bacterial superantigens ligate and cross-link MHC class II.

Removal of endotoxin from aqueous solutions by affinity membrane

Endotoxin was removed by affinity membranes with histidine immobilized as affinity ligand. Macropore cellulose membrane was prepared from filter paper by alkaline treatment and chemical crosslinking, and was used as matrix for the immobilization of affinity ligand. The matrix membrane was derived by hexamethylenediamine and activated by glutaraldehyde before histidine was immobilized. Membrane cartridges containing 40 or 80 sheets of affinity membrane were also prepared, which can be used to remove pyrogen from aqueous solutions. Using a cartridge with 40 sheets of affinity membrane, the endotoxin content in solution can be reduced to a minimum of 0.12 EU/mL.

Definition of the mitogenic factor (MF) as a novel streptococcal superantigen that is different from streptococcal pyrogenic exotoxins A, B, and C

Human T cell activation by recombinant mitogenic factor (rMF) was investigated in comparison with that by recombinant streptococcal pyrogenic exotoxins (rSPE) A, B, and C. Recombinant MF, rSPEA, and rSPEC were mitogenic for peripheral blood mononuclear cells (PBMC), whereas rSPEB was not. Recombinant MF required only HLA-DR for the stimulation of PBMC, as determined using monoclonal antibodies (mAb) to HLA class II molecules and the mouse L cells transfected with HLA class II molecules. Recombinant SPEA and rSPEC required HLA-DR or HLA-DQ molecule. Recombinant MF selectively stimulated V beta 2, V beta 7, V beta 8, V beta 18 and V beta 21-bearing T cells, whereas rSPEA and rSPEC activated V beta 2 and V beta 6-bearing T cells as evaluated by the quantitative T cell receptor (TCR) analytical method. No clonality was observed in the nucleotide sequences of complementarity determining region 3 of TCR V beta in T cells responding to rMF. The profiles of cytokine production by PBMC in response to rMF, rSPEA, and rSPEC were quite similar. In summary, these results demonstrate that both HLA class II molecules and the TCR V beta required for rMF-mediated T cell activation are distinct from those required for rSPEA or rSPEC-mediated activation. Therefore, the MF is a novel streptococcal super-antigen which is different from SPEA, SPEB, and SPEC.

Glycosylated human recombinant interleukin-1 alpha, neo interleukin-1 alpha, with D-mannose dimer exhibits selective activities in vivo

To investigate the effect of carbohydrate-introduction on IL-1 activity, especially in vivo, and to develop IL-1 with less deleterious effects, recombinant human IL-1 alpha was coupled with mannose dimer, alpha-D-Man-1-6-D-Man [Man2 alpha(1-6)] by an acyl azide method. Previous studies demonstrated that the glycosylated IL-1 exhibited reduced activities compared with original IL-1 in all the experiments performed in vitro. In this study, we investigated the in vivo activities of Man2 alpha(1-6)-conjugated IL-1 alpha. The glycosylated IL-1 alpha exhibited very low pyrogenic activity and alpha 1-acid glycoprotein induction compared with untreated IL-1 alpha. Untreated IL-1 alpha increased the serum level of IL-6, but the glycosylated IL-1 alpha did not. However, the glycosylated IL-1 alpha possessed the same potency as untreated IL-1 alpha in reduction of serum levels of glucose and triglyceride and in recovery of peripheral white blood cells in 5-fluorouracil-treated mice. Therefore, glycosylation of IL-1 appeared to be useful for the development of neoIL-1 with selective activity in vivo.

Biological and serological characterization of Campylobacter jejuni lipopolysaccharides with deviating core and lipid A structures

Lipopolysaccharides from Campylobacter jejuni were tested for their ability to induce toxic lethality in galactosamine-sensitized mice, pyrogenicity in rabbits and tumour necrosis factor (TNF) secretion from mouse peritoneal macrophages. Compared with those of Salmonella LPS, lethal toxicity was 50% lower, pyrogenicity was 30- to 50-fold lower, and ability to induce TNF was 100-fold lower. C. jejuni LPS and lipid A exhibited higher phase-transition temperatures than those of Salmonella preparations, and thus the former have lower fluidity at 37 degrees C. This lower fluidity of acyl chains may influence the biological activities of C. jejuni LPS, but acyl chain characteristics and diaminoglucose replacing glucosamine in the hydrophilic lipid A backbone may also influence the supramolecular structure of lipid A, thereby affecting biological activities. Although diaminoglucose is present in the backbone of C. jejuni lipid A, antigenically the latter resembled classical lipid A of the Enterobacteriaceae when tested with anti-lipid A antibodies. Chemical investigations suggested the presence of glucuronic acid in an acid labile linkage in the inner core region, thus producing a structurally unusual region in C. jejuni LPS.

Dissociation of endotoxic activities in a chemically synthesized lipid A precursor after acetylation

In a previous study, a chemically synthesized disaccharide precursor of lipid A (406; identical to lipid IVA) was shown to have dramatically reduced lethality, B-cell mitogenicity, and tumor necrosis factor induction in macrophages when its hydroxyl groups were replaced with either succinyl or acetyl residues (K. Tanamoto, FEBS Lett. 351:325-329, 1994). Succinylated 406 was found to lose Limulus amoebocyte lysate gelation activity completely as a result of the modification (about 10(5)-fold), too, as expected. However, acetyl 406, surprisingly, exhibited activity comparable to that of the original 406. Both succinylated and acetylated 406 lost pyrogenicity completely. These results indicate that one of the typical endotoxic activities was dissociated from the others and that the ability to induce Limulus amoebocyte lysate gelation is not always representative of endotoxin activity.

Purification and properties of peditoxin and the structure of its prosthetic group, pedoxin, from the sea urchin Toxopneustes pileolus (Lamarck)

A protein toxin, termed peditoxin, containing an active prosthetic group was isolated and purified from the globiferous pedicellariae of the sea urchin Toxopneustes pileolus (Lamarck). The prosthetic group, called pedoxin, is a small molecular mass substance (206 daltons) with an empirical formula of C10H10N2O3 and is comprised of a heterocyclic lactone structure formed from pyridoxal and glycine. Administered subcutaneously or intramuscularly to mice in sublethal doses, pedoxin markedly reduced basal body temperature and led to sedation and anesthetic coma accompanied by muscular relaxation. At higher doses, it leads to convulsion and death (LD50 200 mg/kg). The apoprotein, a cytochrome b-like heme protein called pedin (molecular mass, 10,000 daltons) is itself not toxic, but the purified holoprotein is extremely toxic, causing anaphylaxis-like shock and death in experimental animals at low doses (LD50 70 micrograms/kg). Small amounts of the prosthetic group added to holoprotein preparations caused the toxicity to be greatly enhanced, suggesting that holoprotein preparations also contain apoprotein capable of being activated by the low molecular weight toxin. The structure of pedoxin was determined to be 3-hydroxy-2-methyl-5-methoxy-4-pyridineformyl-glycyliden ester and was confirmed by total synthesis.

Destruction of typical endotoxins by dry heat as determined using LAL assay and pyrogen assay

The kinetics of destruction by dry heat of two typical endotoxins, Escherichia coli 055:B5 (E. coli endotoxin) and Salmonella abortus equi (S. abortus equi endotoxin), were determined using the Limulus Amebocyte Lysate (LAL) and pyrogen assays. The efficiency of recovery of these endotoxins from carriers using a pyrogen assay was also determined simultaneously. In the LAL assay 0.1-10,000 EU was used and 10-1000 EU in the pyrogen assay. Recoveries of E. coli endotoxin and S. abortus equi endotoxin were, respectively, 49.7-92.0% and 27.0-70.1% by the LAL assay, and 31.1% and 60.6% by the pyrogen assay. Fourier transformation infrared (FT-IR) spectra demonstrated the presence of chemical structural differences between the two endotoxins. By dry heat (200 or 250 degrees C), there were no significant differences in the destruction kinetics between the two endotoxins; either endotoxin can therefore be adapted for use in the endotoxin challenge test. Destruction in the pyrogen assay was significantly quicker than that predicted by the LAL assay for each of the two endotoxins. In this endotoxin destruction system, 3 log cycle reduction (the United State Pharmacopeia (USP) recommendation for the depyrogenation process) could not be obtained by challenge with 10,000 EU of endotoxin under the depyrogenation conditions of 200 degrees C for 60 min (a set of conditions described in the European Pharmacopoeia (EP)), though little pyrogenicity remained. On the other hand, at 250 degrees C for 30 min (a set of conditions described in the EP, USP and Pharmacopoeia of Japan (JP)),a 3 log cycle reduction was achieved without any pyrogenicity remaining.

[The effects and properties of sodium nucleinate as a pyrogen working-standard. 9. Pyrogen detection with epinephrine-skin-, dactinomycin- and LAL-tests. The suitability of sodium nucleinate as a pyrogen standard]

Sodium nucleinate (NN) as well as bacterial lipopolysaccharide (LPS) can be detected by epinephrine-skin, dactinomycin and LAL tests. In the quantitative determination of two pyrogen standards for rabbit tests, consisting of NN, a smaller value was found by LAL test for the standard of greatest pyrogenic effect than for that less pyrogenically effective in rabbits. A standard consisting of NN can be used for the pyrogen test in rabbits. But in the future, if necessary a standard consisting of endotoxin will be used, due to its better comparability of results obtained by LAL and rabbit tests.

The international pyrogen reference preparation

In accordance with authorization given by the WHO Expert Committee on Biological Standardization in 1950, the National Institute for Medical Research, London, obtained samples of two bacterial pyrogens and arranged for an international study of their pyrogenic properties in rabbits. The results of this study showed that the dose response curves were flat and there was a large variation in response within and between colonies of rabbits.It was agreed that some reference preparation was needed. There was no evidence to indicate the most suitable type of preparation, and there was insufficient as regards either of the two which had been studied. It was therefore decided to make available a quantity of a preparation of the O somatic antigen of Shigella dysenteriae for the International Reference Preparation. Such a substance has been obtained for this purpose and the distribution and characteristics are described.