Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.
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PMID:Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis. 752 55

Chlamydiae possess a genus-specific epitope that is located on the lipopolysaccharide (LPS) and is composed of a 3-deoxy-D-manno-octulosonic acid (Kdo) trisaccharide of the sequence alpha Kdo-(2-->8)--alpha Kdo-(2-->4)-alpha Kdo. In Chlamydia trachomatis, this trisaccharide is biosynthetically generated through the action of a multi-functional Kdo-transferase encoded by the gene gseA. gseA of Chlamydia psittaci 6BC was cloned and expressed in a rough mutant (Re chemotype) of Escherichia coli (strain F515) that contains an LPS with only two alpha 2-->4-linked Kdo residues. Recombinant strains were able to add the immunodominant Kdo residue in alpha 2-->8-linkage to the parental LPS, as determined by SDS-PAGE and Western blot analysis using a monoclonal antibody against the genus-specific epitope. The DNA sequence of gseA was determined and aligned to that published recently for C. trachomatis serovar L2. Most surprisingly, the two deduced amino acid sequences shared only an overall homology of 67%. Thus, gseA exhibits species specificity at the DNA level, whereas its gene product results in the synthesis of a carbohydrate antigen with genus specificity.
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PMID:The genus-specific lipopolysaccharide epitope of Chlamydia is assembled in C. psittaci and C. trachomatis by glycosyltransferases of low homology. 752 26

The disaccharides allyl O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->4)-3-deoxy-a lph a-D- manno-2-octulopyranoside (8), allyl O-(3-deoxy-alpha-D-manno-2-octulopyranosyl)-(2-->8)-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosidonate) (24), and allyl O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->8)-3-deoxy-a lph a-D- manno-2-octulopyranoside (35), and the trisaccharides allyl O-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->8)-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->4)-3-deoxy-a lph a-D-manno-2-octulopyranoside (13) and allyl O-(3-deoxy-alpha-D-manno-2-octulopyranosyl)-(2-->8)-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosylonate)-(2-->4)-(sodium 3-deoxy-alpha-D-manno-2-octulopyranosidonate) (30) were prepared. The ketosidic linkages were formed in good yields and high stereoselectivity by BF3 . Et2O-catalyzed reaction of the per-O-acetylated 3-deoxy-alpha-D-manno-2-octulopyranosyl fluoride derivative (16) with 8-O-SiButMe2 derivatives 19 and 21. Coupling reactions using the Kdo monosaccharide bromide derivative 4 or the alpha-(2-->8)-linked Kdo disaccharide bromide derivatives 9 and 26 were performed under Helferich conditions in MeCN or MeNO2, respectively. The disaccharide halides were prepared in good overall yields starting from the readily available allyl beta-glycoside of Kdo. The deprotected oligosaccharides correspond to the genus-specific lipopolysaccharide epitope of Chlamydia and part structures thereof, containing the carboxyl-reduced Kdo-residues at the distal and proximal position of the Kdo trisaccharide epitope, respectively.
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PMID:Synthesis of carboxyl-reduced analogues related to the Chlamydia-specific Kdo trisaccharide epitope. 752 73

This paper reviews advances in the understanding of the pathogenesis of reactive arthritis that have occurred over the last decade. Inflammatory aseptic joint disease has been linked with prior infection initiated by many different species of microorganisms. The presence of intra-articular bacterial antigens has now been firmly established with the demonstration of bacteria, bacterial fragments, DNA, RNA, and bacterial lipopolysaccharide in joints of patients with reactive arthritis. Chlamydia trachomatis, Salmonella enteritidis, and Shigella flexneri have all been detected in the joint by immunological techniques, although there is still some doubt as to the form in which they reach the joint and whether or not they persist. A number of phlogistic bacterial components could be acting as arthritogens. Negative joint culture results from patients with reactive arthritis make it unlikely that bacteria in the joint are viable, although chlamydial DNA has been shown in the joints of patients with sexually acquired reactive arthritis using the polymerase chain reaction. The use of antimicrobial therapy in the treatment of reactive arthritis is under review; data suggests that long-term antibiotic treatment warrants further study. The role of HLA-B27 in disease pathogenesis is discussed as are possible mechanisms of interplay between germ and gene. HLA-B27 might confer disease susceptibility by affecting immune mechanisms other than classical antigen presentation. The immunopathogenesis of joint inflammation in reactive arthritis is explored with reference to studies of humoral and cellular immune responses. Serological evidence to support the concept of molecular mimicry is far from conclusive; the results of relevant studies are summarized. Lymphocyte proliferation experiments suggest that antigen presenting cells play an important role. Finally, our views on reactive arthritis in the 1990s, and areas of new and potentially fruitful future research are presented.
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PMID:Reiter's syndrome and reactive arthritis: a current view. 753 42

Chlamydia trachomatis is a major etiologic agent of sexually transmitted diseases. Although C. trachomatis is a gram-negative pathogen, chlamydial infections are not generally thought of as endotoxin-mediated diseases. A molecular characterization of the acute immune response to chlamydia, especially with regard to the role of its lipopolysaccharide (LPS), remains to be undertaken. We extracted 15 mg of LPS from 5 x 10(12) C. trachomatis elementary bodies (EB) for analysis of structure and biological activity. When methylated lipid A was subjected to high-pressure liquid chromatography followed by mass spectrometry, the majority of the lipid A was found to be pentaacyl. The endotoxin activities of whole C. trachomatis EB and purified LPS were characterized in comparison with whole Salmonella minnesota R595 and with S. minnesota R595 LPS and lipooligosaccharide from Neisseria gonorrhoeae. Both C. trachomatis LPS and whole EB induced the release of tumor necrosis factor alpha from whole blood ex vivo, and C. trachomatis LPS was capable of inducing the translocation of nuclear factor kappa B in a Chinese hamster ovary fibroblast cell line transfected with the LPS receptor CD14. In both assays, however, C. trachomatis was approximately 100-fold less potent than S. minnesota and N. gonorrhoeae. The observation that C. trachomatis is a weak inducer of the inflammatory cytokine response correlates with the clinical observation that, unlike N. gonorrhoeae infection, genital tract infection with C. trachomatis is often asymptomatic. The ability of specific LPS antagonists to completely inhibit the tumor necrosis factor alpha-inducing activity of whole C. trachomatis EB suggests that the inflammatory cytokine response to chlamydia infection may be mediated primarily through LPS. This implies that the role of other surface protein antigens, at least in terms of eliciting the proinflammatory cytokine response, is likely to be minor.
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PMID:The inflammatory cytokine response to Chlamydia trachomatis infection is endotoxin mediated. 754 38

A healthy female bird fancier developed progressive follicular keratoconjunctivitis despite topical treatment with antibiotics and steroids. Although bacterial, viral, and chlamydial cultures were negative, direct fluorescent antibody staining of conjunctival scrapings revealed chlamydial lipopolysaccharide; however, this procedure failed to detect the major outer membrane protein (MOMP) of Chlamydia trachomatis. The polymerase chain reaction (PCR) used with species-specific primers to the MOMP gene detected DNA of Chlamydia psittaci. Genotype analysis of the infecting strain revealed a nucleotide homology of 96% with C. psittaci avian strain 6-BC. Serum IgG titers were measured at 1:512 by microimmunofluorescence at 6 weeks, and they remained elevated for 3 months. A 10-week course of treatment with doxycycline was required for eradication of the infection. This case illustrates the importance of PCR/genotyping for direct detection and typing of Chlamydia species when chlamydial infections are suspected. To our knowledge, this is the first report of a naturally occurring ocular infection due to an avian strain of C. psittaci.
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PMID:Molecular identification of an avian strain of Chlamydia psittaci causing severe keratoconjunctivitis in a bird fancier. 761 97

BACKGROUND--Infection caused by Chlamydia trachomatis is now recognised as the most prevalent sexually transmitted disease in many parts of the world. Anorectal infections caused by C. trachomatis is not uncommon. Enzyme-linked immunoassay (EIA) detects an antigen lipopolysaccharide (LPS) of C. trachomatis directly in clinical specimens. OBJECTIVE--Our aim was to compare an enzyme immunoassay, Wellcozyme Chlamydia (WZ04) with cell culture for the diagnosis of chlamydial infection of the anogenital tract. METHOD--Rectal swabs were taken from 100 prostitutes (80 females and 20 males) for chlamydia culture, WZ04 and direct immunofluorescence (DIF). In addition, endocervical specimens were obtained from the females for the above three tests. MAIN FINDINGS--All the positive rectal specimens were from females. Nine patients had a positive chlamydia culture from the rectum but negative WZ04 and DIF. Two patients had false positive results by WZ04 but negative culture and DIF. For cervical specimens, WZ04 identified 43% (3/7) of the culture positive cases. Specificity was 98.6%. WZ04 identified an additional specimen as positive which was also confirmed as positive by DIF. CONCLUSION--Our study shows that in our hands enzyme-linked immunoassays such as Wellcozyme Chlamydia are neither sensitive nor specific in detecting C. trachomatis infection of the rectum. For cervical infections, the sensitivity of WZ04 was 43% and the specificity 98.6% as compared to culture, with a positive predictive value of 75% and a negative predictive value of 94.7%.
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PMID:Evaluation of enzyme immunoassay for the detection of anogenital infections caused by Chlamydia trachomatis. 767 62

Western-blot analysis was used to study the reaction of koala antisera, two specific polyclonal antibodies and one monoclonal antibody, with chlamydial antigens in koalas infected with Chlamydia psittaci. The koala sera recognized four C. psittaci surface antigens, corresponding to the major outer membrane protein (39.5 kDa), 31 kDa protein, 18 kDa protein and lipopolysaccharide. The S25-23 LPS specific monoclonal antibody inhibited chlamydial infection (55-67%) with both koala strains (type I and type II). Both koala antiserum and rabbit polyclonal antibodies against either type of chlamydia significantly reduced the number of infected cells resulting from type II infections at a dilution of 1 in 20. Rabbit antiserum against type II was effective in neutralizing infection by type II elementary bodies, but was less effective against type I infection. In addition, no koala antiserum was effective in neutralizing type I infection.
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PMID:Some aspects of the immune response of koalas (Phascolarctos cinereus) and in vitro neutralization of Chlamydia psittaci (koala strains). 768 65

The replication of Chlamydia trachomatis serovar K was studied in human peripheral blood monocytes (PBMo). The intracellular fate of the bacteria was examined by determining the presence of chlamydial major outer-membrane protein (MOMP), lipopolysaccharide (LPS) and ribosomal RNA (rRNA). In-vitro infection of PBMo with C. trachomatis serovar K was not productive. However, chlamydial MOMP antigen, demonstrated by immunofluorescence, was present in PBMo for up to 14 days. Infected monocytes also contained chlamydial rRNA, measured by in-vitro hybridisation, and LPS, measured by enzyme immunoassay, for up to 14 days. These data are compatible with the hypothesis that the infection of PBMo with C. trachomatis may play a role in the systemic distribution of chlamydial antigens, leading to systemic manifestations of urogenital chlamydial infection.
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PMID:Intracellular persistence of chlamydial major outer-membrane protein, lipopolysaccharide and ribosomal RNA after non-productive infection of human monocytes with Chlamydia trachomatis serovar K. 768 22

The lipopolysaccharide of the recombinant strain Escherichia coli F515-207, expressing the genus-specific epitope of Chlamydia lipopolysaccharide, was sequentially de-O- and de-N-acylated by mild hydrazinolysis and treatment with 4 M KOH, respectively, yielding two oligosaccharide bisphosphates which were isolated by high-performance anion-exchange chromatography and gel-permeation chromatography. Their structures were determined by chemical analysis, NMR spectroscopy, and mass spectrometry as alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcN-(1-6)-alpha-D-GlcN 1,4'-P2 (tetrasaccharide bisphosphate) and alpha-Kdo-(2-8)-alpha-Kdo-(2-4)-alpha-Kdo-(2-6)-beta-D-GlcN-(1-6)-alpha- D-GlcN 1,4'-P2 (pentasaccharide bisphosphate).
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PMID:Structural analysis of two oligosaccharide bisphosphates isolated from the lipopolysaccharide of a recombinant strain of Escherichia coli F515 (Re chemotype) expressing the genus-specific epitope of Chlamydia lipopolysaccharide. 768 88


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