Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An in vitro blood-brain barrier (BBB) model consisting of primary cultures of bovine brain microvascular endothelial cells was used to examine the effect of Haemophilus influenzae type b (Hib) on the BBB. Whole bacteria and purified lipopolysaccharide (LPS; greater than 10 ng/ml) caused marked cytotoxicity on the bovine brain endothelial cells. This effect could be completely blocked by polymyxin B. Similar cytotoxic effects were observed with a cultured bovine pulmonary endothelial cell line. Serum was essential for the LPS-mediated cytotoxic effect, and human, horse, bovine, or fetal calf serum all had similar effects. The serum factor was not a complement component. A monoclonal antibody against CD14, a receptor involved in mediating the effect of LPS in monocytes, completely blocked the cytotoxic effect in both brain and pulmonary endothelial cells. These results suggest that Hib LPS disrupts an in vitro BBB model via a serum- and CD14-dependent pathway and that LPS has cytotoxic effects on bovine endothelial cells without the involvement of monocytic cells, an effect that may be important in gram-negative meningitis and in endotoxic shock.
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PMID:Haemophilus influenzae lipopolysaccharide disrupts confluent monolayers of bovine brain endothelial cells via a serum-dependent cytotoxic pathway. 137 54

The phenomenon of spontaneous fusion between myeloma cells and splenocytes from mice immunized with formalin-inactivated Haemophilus paragallinarum cells, has been reported on recently (1). The identity and properties of the bacterial inducer of fusogenicity of splenocytes have been further investigated with the aid of a monoclonal antibody VF3 against H. paragallinarum (2), which has a bacterial strain specificity correlating with the ability of the strains to induce spontaneous fusion between splenocytes of immunized mice and myeloma cells. It was shown that the lipopolysaccharide fraction of the bacteria was required for the induction of fusogenicity. LPS involvement was clearly indicated by the parallel effects on VF3 antigenicity and fusogenic inductivity of various treatments such as proteolytic digestion, periodate oxidation and sensitivity towards alkali, acid or freezing.
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PMID:Spontaneous hybridoma formation induced by immunization with Haemophilus paragallinarum: evidence for a lipopolysaccharide fusion inducer. 160 14

The rapid quantitation of bacteria in blood was achieved by using a novel assay method for gram-negative bacterial lipopolysaccharide (endotoxin, LPS). The assay involves the capture of specific LPS onto microtiter plates by means of monoclonal antibodies directed against the oligosaccharide region of the LPS, followed by detection of the bound LPS by a chromogenic Limulus amebocyte lysate (LAL) system. This immunolimulus (IML) assay combines the specificity of monoclonal antibodies with the sensitivity of the LAL system to achieve the first specific, sensitive quantitation of bioactive endotoxin in plasma. In the animal model tested, Haemophilus influenzae type b (Hib) bacteremia in infant rats, there was a strong correlation between IML results and the concentration of Hib colony-forming units in blood samples (r = .845, P less than .001). Using antibodies with appropriate specificities, this approach should be useful for rapid detection of a wide range of gram-negative bacteria and endotoxins in blood.
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PMID:Detection of experimental Haemophilus influenzae type b bacteremia and endotoxemia by means of an immunolimulus assay. 185 84

Polysaccharide-protein conjugate vaccines made with different carriers vary in their ability to elicit antipolysaccharide IgG antibody responses in young infants and an adult mouse model, suggesting that the carrier proteins used in the conjugate vaccines differ in their ability to act as carriers, or that additional mechanisms of immunogenicity play a role. A conjugate vaccine of Haemophilus influenzae PRP coupled to the outer membrane protein complex (OMPC) of Neisseria meningitidis serogroup B is immunogenic in children as young as 2 mo of age and is immunogenic in infant rhesus monkeys, an animal model for infant humans. In the present study, PRP-OMPC was found to induce efficient IgM to IgG switching of anti-PRP serum antibody in adult mice, whereas PRP conjugated to two other protein carriers did not. Thus the PRP-OMPC conjugate was examined in order to determine why PRP coupled to OMPC was so immunogenic, even more immunogenic than conjugates made with other carrier proteins. The OMPC carrier differs from the other protein carriers in that the proteins are present in a liposomal form containing lipids (including LPS) derived from the outer membrane of N. meningitidis. We studied the OMPC to see whether the different components or the nature of the OMPC carrier could contribute to its enhanced immunogenicity. Specifically we evaluated the OMPC for both classic Th cell carrier activity and adjuvanticity, and the LPS component of OMPC for systemic polyclonal B cell activation. Carrier recognition of the OMPC moiety of PRP-OMPC was demonstrated. In addition the PRP-OMPC conjugate vaccine was observed to have adjuvant properties for both T cell-dependent and T cell-independent Ag in the absence of LPS-induced systemic polyclonal B cell activation. These observations suggest that in addition to functioning as a classic protein carrier whereby the proteins in OMPC provide Th cell epitopes, the OMPC also has adjuvant activity that distinguishes it from other protein carriers and may contribute to the increased immunogenicity of PRP-OMPC conjugates in animal models.
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PMID:Immunogenicity of a Haemophilus influenzae polysaccharide-Neisseria meningitidis outer membrane protein complex conjugate vaccine. 212 Mar 44

Spontaneous fusion between lymphoid and carcinoma cells in vivo has been described previously. Splenocytes from mice treated with LPS or mitogen have been reported to fuse better with myeloma cells using PEG as fusion agent than splenocytes from untreated mice. We report a phenomenon where immunization of mice with formalin treated, whole Haemophilus paragallinarum bacteria induced spontaneous fusion of splenocytes with myeloma cells in vitro, without the aid of any fusion agent. Co-immunization of mice with H. paragallinarum and an unrelated antigen (hen's egg white lysozyme), followed by co-culturing of the immune splenocytes with SP2/0 myeloma cells, yielded stable hybridoma cell lines producing anti-lysozyme antibodies. H. paragallinarum may be used in adjuvants to simplify the production of monoclonal antibodies, and the discovery of a promotional activity of a gram negative bacterium on cell fusion and hybridoma formation may shed new light on spontaneous fusion as a natural immune phenomenon in cancer.
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PMID:Spontaneous fusion between splenocytes and myeloma cells induced by bacterial immunization. 225 87

Influenza A virus infections are commonly associated with symptoms that suggest involvement of TNF-alpha. In this study, we exposed human monocytes, rat alveolar macrophages, and murine PU5-1.8 macrophages to influenza A virus, strain Puerto Rico 8. We observed a productive infection that was accompanied by TNF-alpha mRNA accumulation, TNF-alpha release and subsequent cell death. TNF-alpha production was dependent on exposure to live virus, in contrast to IFN release that was also induced by UV-inactivated virus. Most strikingly, low amounts of LPS (1 to 10 ng/ml) from Escherichia coli or Haemophilus influenzae were capable of strongly potentiating TNF-alpha production from virus-infected macrophages. The potentiating effect of LPS was neither due to increased survival of macrophages nor to altered virus multiplication, enhanced TNF-alpha gene expression, discharge of intracellular TNF-alpha stores, or shifts in the kinetics of TNF-alpha release. Thus, low amounts of LPS, which could easily be present in vivo, may serve as a potent trigger signal for TNF-alpha production from macrophages that have been primed by influenza A virus infection. These data suggest that the frequently observed serious complications of combined influenza A virus and bacterial infections may be partially due to a high TNF-alpha production.
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PMID:Tumor necrosis factor-alpha production of influenza A virus-infected macrophages and potentiating effect of lipopolysaccharides. 239 23

The major surface antigens of Escherichia coli are the cell wall lipopolysaccharides (LPS; O antigens) and the capsular polysaccharides (PS; K antigens). These polysaccharides are synthesized at the cytoplasmic membrane of the bacteria; the LPS are transported to the outer membrane, where they reside, whereas the PS are secreted into capsules. The LPS consist of lipid A covalently linked to the core oligosaccharide, which itself is covalently linked to the O-specific polysaccharide. The latter, which determines the O specificity of the bacteria may be neutral or contain negative charges (carboxyl groups or phosphate). The relatedness of E. coli to other genera (e.g., Klebsiella or Shigella) frequently is borne out by structural identity. This intergeneric relation is paralleled by similar pathogenic properties of the bacteria in question. The capsular antigens of E. coli are acidic polysaccharides, which can be divided into groups (I and II) on the basis of molecular size, nature of the acidic component, coexpression with O antigens, and temperature regulation of their biosynthesis. The major acidic components are hexuronic acid (mainly of Klebsiella-like group I) as well as 2-keto-3-deoxy-D-mannooctulonic acid, N-acetylneuraminic acid, or phosphate (mainly in Neisseria- and Haemophilus-like group II). Relatedness of encapsulated E. coli to encapsulated bacteria of other genera (Neisseria, Haemophilus, Klebsiella) is based on structural identity or similarity of the respective capsules. Identity not only refers to structure and serology of these capsules but also to the pathogenicity of the respective bacteria (e.g., E. coli K1 and Neisseria meningitidis b). Bacterial pathogenicity may be caused by the host's inability to raise an immune response to bacterial capsules (E. coli K1 and K5) because of the identity of the capsular polysaccharides and the host carbohydrates. This can be described as camouflage used by the bacteria as a strategem for bacterial virulence.
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PMID:Polysaccharide antigens of Escherichia coli. 244 69

A monoclonal antibody (MAb)-based enzyme immunoassay was developed for detection of Haemophilus influenzae type b (Hib) lipooligosaccharides (LOS). The high affinity of polymyxin B for lipid A was used to bind the Hib LOS to microtiter wells. The immobilized LOS was detected with MAbs directed against the oligosaccharide component of Hib endotoxin. Hib LOS concentrations were measured in in vitro samples and in cerebrospinal fluid (CSF) sample obtained from rabbits with experimental Hib meningitis. The sensitivity of the assay was 1 ng LOS/ml sample and the results obtained with this assay correlated significantly with those obtained with the standard Limulus amebocyte lysate assay. This new assay provides a method for specific detection of Hib LOS in CSF samples and in aqueous laboratory fluids. This general methodology should also be useful for experimental research involving specific LPS/LOS molecules.
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PMID:Specific detection of Haemophilus influenzae type b lipooligosaccharide by a polymyxin B monoclonal antibody assay. 255 67

Periodontal disease is thought to be initiated by a bacterial infection and subsequently developed by immunopathological mechanisms thorough host-parasite interactions. The macrophage and lymphocyte are the major functional cell types in the lesion of the disease and participate in tissue destruction and alteration of the periodontal connective tissue as well as in host defense mechanisms. However, the detailed implications of macrophages in development of the disease is still unclear. The aim of this study was to gain more understanding of the functional role of macrophages in periodontal disease. In this study, we examined the inducing effects of sonicated extracts from some gram-negative and gram-positive bacteria associated with the pathogenesis of periodontal disease, including Bacteroides gingivalis, Fusobacterium nucleatum, Haemophilus actinomycetemcomitans, and Actinomyces viscosus, on activation of macrophage functions and IL-1 production by the macrophages from the mouse peritoneum. At a dose as low as 1 microgram/ml (dry weight) sonicated extracts from B. gingivalis induced an increase in acid phosphatase activity and in glucose consumption of mouse peritoneal macrophages in vitro. A significant increase in the acid phosphatase and in glucose consumption was observed in the cultures at 24 h and 48 h, respectively, after the addition of the sonicate. Sonicated extracts from A. viscosus, a gram-positive bacterium, as well as B. gingivalis, F. nucleatum, and H. actinomycetemcomitans, gram-negative ones, were able to induce the increase in acid phosphatase activity and in glucose consumption of the macrophages. These periodontopathic bacteria were found to strongly induce IL-1 production by the macrophages as early as 24 h after addition of the sonicates. A significant increase in the IL-1 production was observed at a dose of 1 microgram/ml of the sonicates. The inducing ability was equivalent to 1 microgram/ml Escherichia coli lipopolysaccharide. The highest production of IL-1 was observed in the macrophages treated with H. actinomycetemcomitans among these sonicates. Sonicated extracts from both gram-negative and gram-positive bacteria were able to induce the IL-1 production by macrophages from C3H/HeJ mice, which are LPS low-responders. These results suggest that periodontopathic bacteria have potent ability to induce macrophage activation and IL-1 production and that the activated macrophages may play an important role in development of periodontal disease.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Inducing effect of periodontopathic bacteria on activation of macrophage functions and production of interleukin-1 by mouse peritoneal macrophages]. 260 96

In order to obtain specific tools for studying the alterations of the immunochemical structure of Yersinia enterocolitica lipopolysaccharide in various conditions, we have produced monoclonal antibodies reacting with core and O-polysaccharide chains of Yersinia enterocolitica O:3 LPS. Immunizations were made with whole bacterial cells and outer membrane preparation, respectively. Monoclonal antibody 2B5 reacted in enzyme immunoassay with purified core-lipid A complex, and its binding was not inhibited by Polymyxin B, suggesting that the target determinant is in the outer core. 2B5 recognized 100% of all tested Y. enterocolitica O:3 strains (n = 152) and reacted to some extent also with many other gram-negative bacteria. In immunoblotting with 2B5, a band corresponding to core-lipid A complex was visualized both with Y. enterocolitica, Brucella abortus and Haemophilus influenzae. In immunofluorescence assay, the only positive reaction was seen with Y. enterocolitica. Monoclonal antibody A6 reacted in enzyme immunoassay with purified O-polysaccharide chains, recognized 100% of tested Y. enterocolitica O:3 strains, and showed no cross-reactions with other bacteria. A typical ladder pattern was not seen in the immunoblotting analysis with A6. This suggests that the O-chain of Y. enterocolitica O:3 may be different from those in other gram-negative bacteria. These two antibodies will make it possible to study the structural variations of Yersinia enterocolitica LPS more precisely than described before, because of their fine specificity against important immunogenic components of LPS. They will also be useful in serology measuring the immune response against the target determinants of these antibodies.
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PMID:Monoclonal antibodies reacting selectively with core and O-polysaccharide of Yersinia enterocolitica O:3 lipopolysaccharide. 355 94


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