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The associative links between base concentration of C-reactive protein (hsCRP), levels of serum antiendotoxin antibodies of different classes and endotoxin-binding capacity of monocytes and granulocytes of healthy volunteers were investigated by cluster analysis. In the group of healthy volunteers with increased base concentration of hsCRP in blood the levels of serum antiendotoxin antibodies of different classes and endotoxin-binding capacity of monocytes and granulocytes were reduced. Thus, the disbalance of detoxification and clearance of endotoxin by humoral and cellular mechanisms can be one of the possible causes of development of low intensity inflammation and increase of hsCRP concentration in blood.

In the review the new information about a participation of immune mechanisms in a pathogenesis of a chronic heart failure (CHF) is presented. Significance of a bacterial endotoxin, as inductor of activation of immune system at CHF, and factors of a system inflammation in a pathogenesis of the disease, breaking balance of matrix metalloproteinases and tissue inhibitors of metalloproteinases system, leading to change of structure of an extracellular matrix of a myocardium, are discussed.

Current knowledge of immunocellular and lipoprotein mechanisms of the liver-induced anti-endotoxin tolerance has been summarized. The role of T regulatory cells, different macrophage phenotypes, high density lipoproteins, oxidized low density lipoproteins and their receptors as the key players in mechanism of tolerance to endotoxin has been discussed.

Aim: To assess the effect of systemic endotoxinemia and LPS-induced immune response on severity of community-acquired pneumonia (CAP)., Materials and Methods: Clinico-immunological follow-up of 60 patients with CAP of different severity was conducted. LPS was quantitatively measured by ENDOSAFE ENDOCHROME (0.015-0.12 EU/ml), LBP--by Hbt Human LBP ELISA (min 1 ng/ml), IgG to core region of LPS--by Hbt EndoCAb ELISA (min 0.125 MU/ml) ("HyCult biotechnology", Netherlands)., Results: Level of LPS in blood was not increased, whereas there was increase of antiendotoxin proteins in patients with more severe CAP with Gram-negative or mixed bacterial flora identified. Correlation between levels of LBP, IgG to core-region of LPS, IL-6, TNF-alpha, IL-4 and immune response abnormalities during severe forms of disease was demonstrated., Conclusion: State of antiendotoxin immunity is an etiologic marker of CAP and its severity.

There were examined 34 children, in whom systemic inflammatory answer syndrome (SIAS) was diagnosed. In 16 children pathogenetically substantiated immunocorrection, using donor's plasma, enhanced by antibodies (AB) to endotoxin (ET), was conducted; in 18 children--the conventional complex therapy. While presence of gram-negative infection in children, suffering SIAS, the activation o the inborn nonspeciphic factors (LBP, sCD14) and speciphic low-affinic AB (anti-ET-IgM, anti-ET-IgA) the antiendotoxin immunity in combination with selective immunodeficiency of anti-ET-IgG were revealed. While the donor's plasm application, enhanced by AB to ET, the titer of anti-ET-IgG, anti-ET-IgM, anti-ET-IgA and LBP have had achieved normal values and did not differ from such in the control on the 14th day.

The composition, structure, and certain biological properties of lipopolysaccharides (LPS) isolated from six strains of bacteria Pseudomonas syringae pv. atrofaciens pathogenic for grain-crops (wheat, rye) are presented. The LPS-protein complexes were isolated by a sparing procedure (extraction from microbial cells with a weak salt solution). They reacted with the homologous O sera and contained one to three antigenic determinants. Against the cells of warm-blooded animals (mice, humans) they exhibited the biological activity typical of endotoxins (stimulation of cytokine production, mitogenetic activity, etc.). The LCD of the biovar type strain was highly toxic to mice sensitized with D-galactosamine. The structural components of LPS macromolecules obtained by mild acidic degradation were characterized: lipid A, core oligosaccharide, and O-specific polysaccharide (OPS). Fatty acids 3-HO-C10:0, C12:0, 2-HO-C12:0, 3-HO-C12:0, C16:0, C16:1, C18:0, and C18:1 were identified in lipid A of all the strains, as well as the components of the hydrophilic part: glucosamine (GlcN), ethanolamine (EtN), phosphate, and phosphoethanolamine (EtN-P). In the core LPS, glucose (Glc), rhamnose (Rha), L-glycero-D-manno-heptose (Hep), GlcN, galactosamine (GalN), 2-keto-3-deoxy-D-mannooctonic acid (KDO), alanine (Ala), and phosphate were present. The O chain of all the strains consisted of repeated elements containing a linear chain of three to four L- (two strains) or D-Rha (four strains) residues supplemented with a single residue of 3-acetamido-3,6-dideoxy-D-galactose (D-Fucp3Nac), N-acetyl-D-glucosamine (D-GlcpNAc), D-fucose (D-Fucf), or D-Rhap (strain-dependent) as a side substitute. In different strains the substitution position for Rha residues in the repeated components of the major rhamnan chain was also different. One strain exhibited a unique type of O-chain heterogeneity. Immunochemical investigation of the LPS antigenic properties revealed the absence of close serological relations between the strains of one pathovar; this finding correlates with the differences in their OPS structure. Resemblance between the investigated strains and other P. syringae strains with similar LPS structures was revealed. The results of LPS analysis indicate the absence of correlation between the OPS structure and the pathovar affiliation of the strains.

Aim: To study microbiocenosis of the parietal layer of the colon and feces, concentrations of endotoxin and proinflammatory cytokines in patients with chronic heart failure (CHF) of different functional classes vs. healthy subjects of the same age., Material and Methods: The trial includes 37 patients with ischemic CHF and 13 healthy volunteers. The examination comprised 6-min walking test, echocardiographic evaluation of the left ventricular ejection fraction, clinical state by a special scale, assay for C-reactive protein, endotoxin, fecal seeding, colonoscopy with biopsy and seeding., Results: Gram-negative flora in the colon and parietal layer occurred in high concentrations correlating with severity of CHF. The examinees with CHF of functional class III-IV had elevated levels of circulating endotoxin and serum C-reactive protein.

Immune inflammation is an important link in pathogenesis of chronic heart failure (CHF). It has been proven that hyperproduction of proinflammatory cytokines (TNFa, IL-6, IL-1, etc) with associated endothelial dysfunction and oxidative stress affect unfavorably clinico-hemodynamic parameters and prognosis of life of patients. However attempt to augment efficacy of treatment of CHF by means of inclusion of TNFa activity inhibitors in the complex of main remedies turned out unsuccessful. At present under discussion are perspectives of application in this category of patients of statins--lipid lowering drugs with pleiotropic properties most important of which is antiinflammatory action. Theoretical obstacles for the use of statins constitute available epidemiological data on reverse relationship between cholesterol level and mortality of patients with CHF in a framework of endotoxin-lipoprotein theory. At the same time preclinical and clinical experience has been accumulated evidencing for perspectiveness of such approach. Final solution of the problem of safety and feasibility of application of statins in CHF is expected after completion of prospective randomized trials GISSI-HF and CORONA.

The content of endotoxin of Gram-negative bacteria and humoral and granulocytic immunity indices to endotoxin in sportsmen and untrained persons before and after undergoing physical load were studied. The study revealed that prior to physical load the content of intestinal microflora endotoxin in the blood stream of volunteer students increased and the humoral immunity indices to endotoxin decreased. Judging by the content of cortisol in the blood, the state of stress increased after a physical load. In the groups with good adaptation a decreased endotoxin content in the blood stream was noted, especially 24 hours after load. On the contrary, in the groups with dysadaptation the content of endotoxin in blood plasma increased after a load and was accompanied by a decrease in antibody titers and in the reserve of leukocytes capable of binding endotoxin.

The functional state of cell-mediated and humoral antiendotoxin factors in patients with chronic viral hepatitides B and C has been studied. A decreased content of antibodies to glycolipid of chemotype Re and to Escherichia coli O14 with common enterobacterial antigen was shown to occur in these diseases. In addition, a decreased number of neutrophils, eosinophils and thrombocytes has been noted. The conclusion has been made that patients with chronic hepatitides are not protected from the pathogenic action of endotoxin penetrating from the intestines into the systemic blood stream.

Endotoxin is a biologically active substance that has a lipopolysaccharide structure. It is found in the cell walls of microorganisms, principally gram-negative bacteria. By contacting with the cell, endotoxin enhances immunity. The findings suggest that acute myocardial infarction (AMI) occurs due to low immunity that remains the same at week 3 of the disease, thus the levels of antiendotoxin agents may be used in predicting AMI.

Hemosplenoperfusion (HSP) through the donor porcine spleen was used in complex treatment of 75 patients aged from 16 to 75 with pyo-septic complications of diseases and traumas of the abdominal cavity. The influence of HSP on the state of humoral immunity was estimated by the level of antibacterial antibodies to the antigens of E. coli, Ps. aeruginosa, Pr. mirabilis, St. aureus, Bact. fragilis, Bact. bifidum and antiendotoxin antibodies to glycolipid S. Minnesota RE 595, general cortical part of the lipopolysaccharide of Gram-negative bacteria. The use of HPS promoted the resolving of endogenous intoxication, elevation of the strain of humoral antibacterial immunity and is characterized by a reliable increase of the level of antibacterial antibodies in the dynamics of treatment.

The examination of 52 patients with different forms of intestinal dysbacteriosis revealed a considerable decrease in the indices of immunity to endotoxin of gram-negative bacteria. In particular, a decrease in the content of antibodies to chemotype Re glycolipid, as well as in the content of polymorphonuclear leukocytes binding antibodies in the blood stream of the examined patients and leukocytes capable of binding endotoxin in endotoxin-treated blood smears, was registered, which was indicative of the loss of endotoxin binding reserves by leukocytes.

The development of intestinal dysbacteriosis in white mice, caused by the administration of ampyox in large doses, was shown to be accompanied by a considerable decrease in cell-mediated and humoral antiendotoxin immunity, which was manifested by a decrease in the titers of antiendotoxin antibodies and in the content of polymorphonuclear leukocytes, capable of binding endotoxin.

The content of antibodies to soluble lipid A detritus was studied with the use of the enzyme immunoassay techniques. Some regularities of anti-endotoxic immunity were established: the elevated level of anti-lipid A antibodies in chronic bronchial tree diseases of bacterial etiology. On the other hand, cases of severe purulent septic infections in young children were found to be accompanied by a considerable decrease in the titer of anti-endotoxic antibodies. The approaches to the therapy of diseases caused by Gram-negative bacteria by means of specific immunoglobulins are discussed.

The levels of bacterial blood endotoxin, antiendotoxin antibodies and the overall immunity were studied in 48 females with inflammatory genital diseases complicated by pelvioperitonitis. The severest pelvioperitonitis-complicated abnormality was shown to characterized by high concentrations of endotoxin and low levels of antibodies. Endotoxinemia was found to be of diagnostic and prognostic value.

The crush syndrome developing in casualties in mass catastrophes is the cause of their high mortality rates. We examined 18 children aged from 9 to 14 years with the crush syndrome who suffered during the earthquake in Armenia. Besides other laboratory studies, the test for the titer of antibodies (TA) to endotoxin was performed. Despite the applied complex therapy, the children's condition grew worse on day 8. The TA level reduced threefold. Six patients received a single infusion of plasma with naturally increased TA titer in a dose of 10 ml/kg. On the following day after TA infusion, the condition of children in the experimental group improved, the clinical picture of endotoxemia in the control group persisted for 10-12 days.

Bacterial endotoxins (BE) that are lipopolysaccharide complexes (LPS) are a structural component of the external membrane of gram-negative bacteria. In normalcy, BE interact with many types of cells in the mammals. In terms of the concentration, BE may cause cell damage or stimulate the production of many biological mediators, such as interleukins, prostaglandinds, alpha-TNF. Many gastrointestinal bacteria in humans are gram-negative and BE constantly enter the blood. In health, the absence of a toxic response to BE is explained by the presence of natural humoral and cellular antiendotoxic systems and the hepatic absorption of LPS. In patients with hepatitis A and B, the following indices of the blood antiendotoxic systems were determined: the level of antiendotoxic antibodies to Re-chemotype glycolipids was assessed by the passive hemagglutination reaction in the "Antiendotox-1-test"; the count of polymorphonuclear leukocyte (PMNL) fixating LPS on their own surface and endotoxin binding function of PMNL was in vitro measured by the strain ELISA and sandwich ELISA with Re-glycolipids, respectively (LPS-test); the endotoxin fixation function of serum high density lipoproteins (HDL) was also assessed. The humoral and cellular antiendotoxic systems in patients with mild advanced hepatitis A and B was studied when the disease was most clinically significant, at an early convalescence, and at convalescence itself. Finally, the findings indicate that there is a significant decrease in Re-antibody levels and there is a greater absorption ability of HDL than that in the control. Six different types of an antiendotoxic fixation reaction of PMNL were identified in patients with viral hepatitis in the different periods of the disease. The alterations observed may play an important role in the pathogenesis of toxemia in patients with viral hepatitis.

The ultraviolet (UV) irradiation of donor blood plasma with an elevated level of natural antibodies to Re-glycolipid with doses ranging from 100 to 200 J/m2 has been found to lead to a statistically significant rise in its protective activity. The use of such plasma in clinical practice has made it possible to decrease the frequency of lethal outcomes from 24.3% to 16.5% (p < 0.01), the occurrence of secondary infectious complications from 62% to 44.4% (p < 0.01) and the duration of patients' stay in a hospital by 6-8 days. These data make it possible to regard the use of UV-irradiated plasma with an elevated level of Re-antibodies as an effective method of the immunotherapy of septic complications caused by gram-negative bacteria.

The authors propose an original approach to the problem of intoxication syndrome observed in patients with acute intestinal infections (AII). They focus on such endogenic humoral antiendotoxic systems as Re-hemotype glycolipid antibodies and high-density lipoproteins. The titers of Re-antibodies in patients with light and moderate AII at the height of intoxication remained within control levels, whereas in patients with a severe AII course the titers values remained low throughout 7 days of the follow-up. Indometac administration induced changes in the antibodies formation. Lipoprotein endotoxin-binding activity persisted at low levels to the end of 7-day follow-up. Mechanisms involved in changing functional activity of the body antiendotoxic systems are considered.

The isolation and properties of endotoxin protein, or lipid A-associated protein (LAP), from Shigella sonnei were described earlier (Zh. mikrobiol. epidemiol. immunobiol., 1991, No. 4, pp. 11-17, and No. 7). In this report the data on its protective activity are presented. In experiments on mice one nanogram of LAP injected i. v. protected 50% of the animals against i. p. challenge with 40 LD50 of virulent S. sonnei. Guinea pigs injected s. c. with 10 micrograms of LAP were protected against local (keratoconjunctival) challenge with S. sonnei, the efficiency of immunization being 58%. LAP preparations containing no detectable amounts of O-antigen (less than 0.003%) were found to have a protective effect. Hyperimmune anti-LAP rabbit serum prevented local infection when incubated with S. sonnei challenge inoculum before injection into guinea pigs. Both active and passive protection induced by LAP was specific since no effect was observed in animals challenged with Shigella flexneri. In the homologous system the protective effect of anti-LAP serum was abolished by the addition of protein-free LPS. These results are compatible with the hypothesis that the protective activity of LAP depends on the presence of minute amounts of O-antigen whose immunogenic effect is greatly amplified by the protein component of the natural endotoxin complex.

Endotoxin protein or lipid A-associated protein (LAP) from Shigella sonnei was isolated and characterized earlier (Zh. mikrobiol. epidemiol. immunobiol., 1991, No. 4, pp. 47-50). In this investigation serum antibodies against LAP were studied in ELISA Anti-LAP antibodies were detected in high titers in the sera of nonimmunized mice, guinea pigs, rabbits, monkeys and healthy adults. We suppose that normal anti-LAP antibodies resulted from interaction between the immune system and environmental endotoxin. Parenteral injections of LAP to different animals induced intensive antibody response with a 100- to 1000-fold increase in the serum anti-LAP antibody level and a significant rise in the serum O-antibody level. The latter is seemingly due to the contamination of LAP with minute amounts of O-antigen (0.12% or less) and to the amplification of its immunogenicity by LAP. Both antigenic and amplifying activity of LAP was destroyed by proteinase K. The biological function of LAP and its possible use as a component of bacterial vaccines are briefly discussed.

The electrophoretic analysis of lipid A-associated protein (LAP), obtained from S. sonnei, in polyacrylamide gel in the presence of sodium dodecyl sulfate and urea has revealed the heterogeneity of the preparation; it has found to contain three main components with molecular weights of 43, 38 and 18 KD and some minor components with molecular weights of 49, 45 35, 30, 29, 27, 5, 21 and 14 KD. The electrophoretic mobility of the main protein components in the isolated preparation of LAP coincides with that of endotoxin components. The dissociation of proteins and lipopolysaccharide in the process of boiling the endotoxin in 2% sodium dodecyl sulfate is indicative of the noncovalent binding of these components. LAP contained in the endotoxin, in contrast to isolated LAP, is resistant to trypsin and proteinase K. The enzyme immunoassay (EIA) system with the use of LAP as a component of its solid phase has been developed, which makes it possible to carry out the quantitative determination of antibodies to this protein. The EIA system shows high sensitivity in the determination of anti-LAP IgG antibodies: in hyperimmune rabbit sera their titer is 1:250,000-1:800,000. As shown by the method of competitive EIA, the antigenic affinity of LAP of different origin corresponds to the degree of taxonomic propinquity of microorganisms: the maximal degree of cross reactions is observed between LAP obtained from S. sonnei, S. flexneri and Escherichia coli, while their affinity to Salmonella typhi is considerably less; remote microbial species (Bacterium bifidum and Sarcina marcescens) give practically no cross reactions.

The proteins of parasporal crystals of 9 strains of entomopathogenic bacteria of the Bacillus thuringiensis group of different H-serotypes were studied by different methods. Electrophoresis showed that crystals from the bacteria of 1, 3, 4, 5, 8, and 10 serotypes contained 1-2 proteins with a molecular weight of 130-145 kD and an additional fraction with a molecular weight of 55-120 kD. Double-radial immunodiffusion revealed that the crystals of all the serotypes studied are immunologically related. The proteins contained at least 3 types of antigens that can be detected either separately or all together when being tested with different antisera. The ELISA technique showed that the crystal proteins homologous with respect of antigens gave, as a rule, similar titration results.

The preparations of the blood plasma of humans and the sera of animals immunized with enterobacterial vaccine proved to have elevated titers of antibodies to deep determinants of the core of the gram-negative bacterial endotoxin molecule (to glycolipid of chemotype Re) and protected animals from infection with live cultures or serogroup A, B, or C meningococcal endotoxins. Sera from nonimmunized animals and normal donor blood plasma showed no protective activity. In experiments carried out on different models immune plasma possessed both a pronounced protective activity and a curative effect. The efficacy of protection depended not on the serogroup of the infective agent, but on the virulence of the strain used in the experiment, being statistically significant in all cases.

The effect of typhoid lipopolysaccharide (LPS) and polysaccharide (PS) on immunological memory in the system of IgM and IgG synthesis and rosette-forming cells was studied. When introduced into animals previously immunized with SRBC, PS stimulated, under certain conditions, immunological memory in the system of IgM synthesis and rosette-forming cells, while the injection of LPS induced only an insignificant stimulation of immunological memory. No stimulation in the system of IgG synthesis was observed after the injection of both LPS and PS. The suppression of immunological memory was noted in the animals receiving LPS as well as in those receiving PS the immunosuppressing effect produced by LPS was more pronounced.

The content of antistaphylococcal antitoxins--antialphastaphylolysins was examined in the blood serum of three groups of blood donor volunteers. It is shown that volunteer blood donors immunized according to two schemes with prophylactic purposes may be a source of antistaphylococcal plasma. Additionally antistaphylococcal plasma may be obtained from non-immune donors showing high titers of antialphastaphylolysins revealed by the screening method.

The comparative study of the chemical composition, immunobiological activity and some physico-chemical properties of lipopolysaccharide (endotoxin) of Brucella cultures isolated from myomorph rodents in the North Caucasus has been carried out. Lipopolysaccharide obtained from these cultures has been found to be most similar to B. suis lipopolysaccharide. The authors suggest that the strains isolated from myomorph rodents outside the foci of brucellosis affecting livestock should be regarded as a separate biotype of B. suis.

The comparative study of the immunological activity of Proteus vaccine prepared from soluble antigenic complexes was made after the immunization of volunteers with this vaccine used in the form of a single preparation and in combination with pyoimmunogen (Pseudomonas aeruginosa vaccine) and/or adsorbed staphylococcal toxoid. The injection of the vaccine in the form of a single preparation and in different combinations increased the ingestion of Proteus cells by neutrophils. The injection of Proteus vaccine simultaneously with pyoimmunogen and staphylococcal toxoid ensured the intensive phagocytosis of staphylococci. All combinations with Proteus vaccine, used in this investigation, stimulated the intensive formation of antibodies to Proteus vaccine strain and Re-glycolipid. Proteus vaccine introduced in combination with adsorbed staphylococcal toxoid essentially stimulated the synthesis of anti-alpha-staphylolysin.

The immunogenicity of the preparations of phase I S. sonnei neurotoxin, determined by the keratoconjunctival test on guinea pigs, is linked mainly with the presence of a high-molecular component other than endotoxin in these preparations. The preparations of phase II S. sonnei neurotoxin do not contain the endotoxin and high-molecular antigens of S. sonnei, phase I, which protect guinea pigs from the development of experimental keratoconjunctivitis; these preparations are toxic for mice and possess low immunogenicity.

For the first time the study of the indicator system consisting of sensitized liposomes with NaF incorporated as a marker and a fluorine-selective electrode has been made and, as a result, the possibility of the potentiometric determination of the immune lysis of liposomes in the presence of complement and specific antibodies has been demonstrated. The dissolution of the lipid components (Re-chemotype glycolipid and lipid A) in the bilayer matrix obviates the necessity for converting lipid antigens into the water-soluble state in the process of serological tests. As compared with other methods, the liposomal potentiometric method for the determination of Re-chemotype glycolipid and lipid A is highly sensitive (20-40 ng/ml), rapid, technically easy to perform, cheap and does not require large volumes of samples. The disadvantages of this analytical system are the instability of liposomes and the diffusion of fluorine ions from the internal aqueous phase of vesicules. For this reason the immunoassay can be made only within 12 hours after the preparation of sensitized liposomes incorporating the marker.

The injection of 100 micrograms of salmozan (polysaccharide isolated from Salmonella typhi somatic O-antigen) or 50 micrograms of Escherichia coli lipopolysaccharide into mice induced a considerable increase in the number of antibody-forming cells in the spleen in response to the injection of sheep red blood cells (SRBC) 2-3 days later. This polyclonal effect was essentially weaker if the animals previously received 500 micrograms of salmozan (9-10 days prior to the injection of SRBC). The absence of reactivity was not linked with antibodies to salmozan or with some other serum factor. The lymphocytes of nonreactive mice proved to be capable of polyclonal response in the adoptive system, and at the same time the polyclonal response of intact lymphocytes to salmozan in the body of nonreactive irradiated mice was essentially weakened. The features making the above phenomenon similar to, as well as different from, the so-called "endotoxin tolerance" are analyzed.