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)

Haemophilus influenzae type b polysaccharide-conjugate vaccines elicit protective antibody responses in young infants. One of these conjugates, polysaccharide linked to outer membrane protein complex (PRP-OMPC), is produced by linking the capsular polysaccharide to an outer membrane protein complex derived from group B Neisseria meningitidis. The outer membrane protein complex contains T cell carrier epitopes that elicit T cell-dependent antibody responses. OMPC also has been shown to increase the antibody response to other proteins administered concurrently that are not covalently linked (i.e., acts as an adjuvant). In this study PRP-OMPC immunized mice demonstrated significant increases in spleen size as well as in splenocyte number as compared to saline controls (p < 0.01, p < 0.001, respectively). No such increase was noted after immunization with another H. influenzae type b-conjugate vaccine, oligosaccharide linked to a variant of diphtheria toxin. By analytic flow cytometry, the mice immunized with PRP-OMPC demonstrated an increase in large splenocytes expressing the Ag Mac-1 (CD11b, CR3). Furthermore, the spleens on histologic examination were characterized by an increase in the red pulp area consisting predominantly of cells of macrophage morphology. By immunohistochemical staining, the cells were identified as macrophages due to expression of Mac-1 and p150,95 (CD11C) Ag. After PRP-OMPC immunization, severe combined immunodeficient mice also demonstrated significant splenomegaly with an increase in macrophages identified by expression of Mac-1 and MHC class II Ag. Thus PRP-OMPC vaccine resulted in T cell-independent splenomegaly with an increase number of macrophages. We propose that this unique property may confer increased immunogenicity to PRP-OMPC through macrophage activation and cytokine release. Furthermore, the effect on macrophages may explain the "adjuvant" capacity of OMPC.
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PMID:Effect of Haemophilus influenzae polysaccharide outer membrane protein complex conjugate vaccine on macrophages. 146 Feb 86

Although antibiotics have reduced mortality, the most recent clinical trials in sepsis and meningitis have been directed at the host inflammatory response in an attempt to improve outcome. Endotoxin, cell wall constituents and toxins are potent inducers of small molecular weight proteins (cytokines) from a variety of host cells. Several lines of investigation have implicated tumor necrosis factor-alpha (TNF-alpha) as a cytokine mediator of sepsis and septic shock. A recent study has been able to measure plasma TNF-alpha concentrations in patients with meningococcemia and demonstrated a correlation with prognostic groups related to mortality. Therefore, TNF-alpha, probably through its effects on other mediators, has an effect in sepsis. New speculation regarding morbidity in bacterial meningitis focuses on cytokine activity in the central nervous system. Cerebrospinal fluid (CSF) from experimental animals with meningitis contains increased amounts of interleukin-1 beta (IL-1 beta) and TNF alpha. These IL-1 beta levels correlated directly with duration of fever and neurological sequelae. Children with Haemophilus influenzae, type b meningitis treated with dexamethasone had significantly reduced levels of CSF IL-1 beta compared to placebo-treated controls.
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PMID:The immunology of sepsis and meningitis--cytokine biology. 209 Dec 57

Pentoxifylline has been shown to decrease endotoxin-induced tumor necrosis factor alpha production and reverse the inflammatory actions of interleukin-1 (IL-1) and tumor necrosis factor on leukocyte function. Because of the potential role of this cytokine-leukocyte interaction in the pathogenesis of bacterial meningitis, we investigated the ability of pentoxifylline to modulate meningeal inflammation in the rabbit meningitis model. Pentoxifylline treatment (initially an intravenous injection of 20 mg/kg followed by 6 mg/kg per h) started 20 min before intracisternal injection of 20 ng of Haemophilus influenzae type b lipooligosaccharide (endotoxin) reduced significantly concentrations in cerebrospinal fluid of leukocytes (P less than 0.0001), protein (P less than 0.001), and lactate (P less than 0.001) during the 9-h infusion compared with values in intravenous-saline-treated rabbits. When pentoxifylline was given 1 h after H. influenzae type b endotoxin, the mean peak lactate and leukocyte concentrations in cerebrospinal fluid were significantly lower than those in control animals. Pentoxifylline also significantly decreased lactate and protein concentrations (P less than 0.05) and tended to diminish leukocyte counts (P = 0.08) compared with results in control animals after antibiotic-induced release of endotoxin in animals with H. influenzae meningitis. In this regard, dexamethasone was superior to pentoxifylline and no synergism was observed when the drugs were combined. Additionally, pentoxifylline attenuated meningeal inflammatory changes induced by intracisternal inoculation of 10 ng of rabbit recombinant IL-1 beta compared with results in either dexamethasone- or saline-treated animals. We conclude that pentoxifylline is effective in this animal model in modulating the meningeal inflammatory response following intracisternal inoculation of H. influenzae type b endotoxin or organisms or rabbit recombinant IL-1beta.
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PMID:Pentoxifylline modulates meningeal inflammation in experimental bacterial meningitis. 236 Aug 22

Although previous studies using human cytokines in rabbits and rats have provided evidence of the participation of tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) in the meningeal inflammatory cascade, the results obtained by several groups of investigators have been discordant or, at times, contradictory. In the present study, homologous cytokines were applied to the rabbit meningitis model. Intracisternal administration of 10(2)-10(5) IU of purified rabbit TNF-alpha (RaTNF-alpha) produced significant cerebrospinal fluid (CSF) inflammation. A similar response was observed after intracisternal inoculation of 5-200 ng of rabbit recombinant IL-1 beta (rrIL-1 beta). Preincubation of these two mediators with their specific antibodies resulted in an almost complete suppression of the CSF inflammatory response. In animals with Haemophilus influenzae type b lipooligosaccharide-induced meningitis, intracisternal administration of anti-rrIL-1 beta, anti-RaTNF-alpha, or both resulted in a significant modulation of meningeal inflammation. Simultaneous administration of 10(3) IU of RaTNF-alpha and 5 ng of rrIL-1 beta resulted in a synergistic inflammatory response manifested by a more rapid and significantly increased influx of white blood cells into the CSF compared with results after each cytokine given alone. These data provide evidence for a seminal role of TNF-alpha and IL-1 beta in the initial events of meningeal inflammation.
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PMID:Tumor necrosis factor alpha/cachectin and interleukin 1 beta initiate meningeal inflammation. 237 90

We have studies the role that interleukin-1 (IL-1) and IL-1-like cytokine play in the mechanism of bone resorption that occurs in periodontal disease. To determine whether the bone cell itself produces IL-1-like cytokine, we examined bone cells migrating from fragments of newborn mouse calvaria. These bone cells were cultured in alpha-MEM with of without fetal calf serum. IL-1-like cytokine activity was measured by incorporation of [3H] thymidine into C3H/HeJ thymocytes treated with lipopolysaccharide (LPS) from Haemophilus actinomycetemcomitans, a bacterium found in juvenile periodontopathy. The bone cells produced a significant amount of IL-1-like cytokine. The maximum production of IL-1-like cytokine was observed at 24 hours with the LPS in serum-free alpha-MEM. IL-1-like cytokine production stimulated by LPS was marked in the bone cells from LPS high-responder C3H/HeN mice, but not in those from low-responder C3H/HeJ mice. Peak of IL-1-like cytokine activity in culture supernatants of the bone cells was detected in fractions with a molecular weight corresponding to 15,000 daltons.
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PMID:[Production of IL-1 like cytokine by cultured bone cells: inducing effect of Haemophilus actinomycetemcomitans lipopolysaccharide on the cytokine production]. 248 80

Previous studies have suggested that, in vivo, activated T lymphocytes and neutrophils are important in immunity to nontypable Haemophilus influenzae. We now extend this work by showing that neutrophils pretreated with products of activated T lymphocytes or activated macrophages show significantly enhanced killing of nontypable H. influenzae. Lymphotoxin, a product of activated T lymphocytes, significantly enhanced the neutrophil-mediated killing of nontypable H. influenzae, and tumor necrosis factor, produced by activated T lymphocytes as well as macrophages stimulated by activated T lymphocytes, also significantly increased the bactericidal activity of neutrophils. These cytokine-induced effects were seen with short pretreatment times of neutrophils and were maximal by 30 min. The killing of H. influenzae by neutrophils required the presence of heat-labile opsonins. In the absence of these opsonins, both tumor necrosis factor and lymphotoxin were unable to promote the killing of the bacteria by neutrophils. Furthermore, the results showed that tumor necrosis factor-primed neutrophils displayed significantly increased expression of CR3 and CR4 that was associated with increased phagocytosis of complement-opsonized nontypable H. influenzae. These cytokines may play an important role in immunity toward nontypable H. influenzae by stimulating neutrophil bactericidal activity.
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PMID:Activation of the neutrophil bactericidal activity for nontypable Haemophilus influenzae by tumor necrosis factor and lymphotoxin. 773 51

Intracisternal or intraarticular inoculation of rabbit recombinant interleukin (IL)-1 beta and rabbit tumor necrosis factor-alpha combined with IL-1 receptor antagonist (IL-1RA) and soluble tumor necrosis factor receptor (sTNFR), respectively, produced significantly less inflammation in rabbits than after inoculation of these cytokines alone. In contrast, when Haemophilus influenzae type b (Hib) or Hib lipooligosaccharide (LOS) was given intraarticularly with IL-1RA, sTNFR, or the combination, there was no significant or consistent modulation of synovial inflammation and cartilage proteoglycan degradation. In the experimental meningitis model, IL-1RA and sTNFR did not significantly reduce the meningeal inflammatory response associated with intracisternal inoculation of Hib LOS. These data indicate that specific cytokine inhibitors (sTNFR and IL-1RA) may not be effective in modulating inflammation induced by a broad inflammatory stimulus such as gram-negative bacteria or their products and suggest caution in using them to treat these infectious conditions in humans.
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PMID:Effect of interleukin-1 receptor antagonist and soluble tumor necrosis factor receptor in animal models of infection. 779 56

The host-parasite relationship in the nasopharynx of young children with bacterial colonization and antigen uptake in the mucosa and lymphatic tissue provides an opportunity to investigate infectious/inflammatory processes and responses. IL-1 beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha) were analysed in nasopharyngeal secretions and serum from children with or without recurrent episodes of acute otitis media, from healthy adults and adults with or without recurrent episodes of acute otitis media, from healthy adults and adults with hypogammaglobulinaemia or selective deficiency of IgG3. Nasopharyngeal secretions generally contained substantial amounts of IL-1 beta, IL-6 and TNF-alpha. In contrast, IL-1 beta, IL-6 and TNF-alpha were not detectable in sera on the same occasion. Children were found to have higher levels of IL-1 beta, IL-6 and TNF-alpha than healthy adults and than adults with immunodeficiency. High levels of IL-1 beta were associated with low or undetectable levels of IL-6 and TNF-alpha, whereas the opposite pattern was seen in association with low levels of IL-1 beta. This was especially true for children with recurrent episodes of acute otitis media (RAOM). In children with nasopharyngeal colonization with Haemophilus influenzae, significantly higher levels of IL-1 beta, IL-6 and TNF-alpha (P = 0.0001, respectively) were found compared with non-colonized children. Notably, the RAOM children exhibited significantly lower levels of IL-1 beta, IL-6, and TNF-alpha in nasopharyngeal secretions (P = 0.0001, 0.01 and 0.0001, respectively) than healthy children. These results demonstrate local production of inflammatory cytokines in nasopharynx, related to bacterial colonization, and suggest that children with RAOM are poor nasopharyngeal cytokine producers.
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PMID:Cytokines in nasopharyngeal secretions; evidence for defective IL-1 beta production in children with recurrent episodes of acute otitis media. 808 94

While the protective effect of IgA antibodies against infection of the mucosal surfaces is well documented, the mechanisms involved are not entirely clear. The aim of the current study is to investigate the effect of human serum IgA on the release of inflammatory cytokines in human monocytes activated with a particulate stimulus, Haemophilus influenzae type b (Hib), or soluble lipopolysaccharide (LPS) purified from Escherichia coli. Our results show that IgA downregulates tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) production, whereas IgG examined in parallel had no effect. IgA had no inhibitory effect on Hib-induced granulocyte-macrophage colony-stimulating factor release. TNF-alpha and IL-6 release were downmodulated if IgA was present during cytokine induction, and IgA was also inhibitory if added to Hib-pretreated monocytes during the phase of cytokine release. These findings indicate that there are at least two mechanisms whereby IgA antibodies can downregulate TNF-alpha and IL-6 release in human monocytes: by a mechanism acting during the time of monocyte activation, and a mechanism that downregulates the production and/or the release of these cytokines in activated monocytes. Regulation of TNF-alpha and IL-6 release by IgA may be among the antiinflammatory mechanisms preventing an uncontrolled release of potentially noxious levels of inflammatory cytokines during acute and/or chronic inflammation.
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PMID:Human serum IgA downregulates the release of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-6) in human monocytes. 811 31

Lactoferrin (LF), a cationic 80-kDa protein present in polymorphonuclear leukocytes and in mucosal secretions, is known to have antibacterial effects on gram-negative bacteria, with a concomitant release of lipopolysaccharides (LPS, endotoxin). In addition, LF is known to decrease LPS-induced cytokine release by monocytes and LPS priming of polymorphonuclear leukocytes. Its mechanism of action is incompletely understood. We have now demonstrated by in vitro-binding studies that LF binds directly to isolated lipid A and intact LPS of clinically relevant serotypes of the species which most frequently cause bacteremia (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), as well as to lipid A and LPS of mucosal pathogens (among others, Neisseria meningitides and Haemophilus influenzae). Binding to LPS was inhibitable by lipid A and polymyxin B but not by KDO (3-deoxy-D-manno-octulosonate), a glycoside residue present in the inner core of LPS. Binding of LF to lipid A was saturable, and an affinity constant of 2 x 10(9) M-1 was calculated for the LF-lipid A interaction. Our data may explain, in part, the mechanism whereby LF exerts its antibacterial and anti-endotoxic effects. Further studies on the ability of LF to block the detrimental effects of LPS, both in vitro and in vivo, are warranted.
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PMID:Lactoferrin is a lipid A-binding protein. 818 89


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