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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to determine the extent of the repertoire of the immunoglobulin light chain V-region locus (Igl-V) in the laboratory rat (Rattus norvegicus), we constructed a specifically primed cDNA library from lipopolysaccharide-stimulated DA strain rat spleens. The library was screened with a rat Igl-C2-specific probe, and 33 clones containing identifiable V regions were sequenced, of which 19 sequences are presented here. In addition to one sequence (Igl-V1) which was already known, and is closely related to the two known mouse V lambda gene segments, clones encoding representatives of three new, distantly related, rat Igl-V subfamilies were found, namely Igl-V2, Igl-V3, and Igl-V4. At least two of these sub-families, Igl-V2 and Igl-V3, contain multiple members as well as restriction fragment length polymorphism variants, indicating the presence of at least 10-15 Igl-V gene segments (including some pseudogenes) in the rat genome. An additional ten clones contained no rearranged V region, although they showed a correct J-C splice, suggesting the presence of cryptic transcriptional promoters between J lambda and the 3'-most Igl-V gene segment. Phylogenetic tree reconstruction based on amino acid sequence alignments showed at least three of the four rat Igl-V sequences clustering with distinct human Igl-V genes. Thus, although rats express lambda-bearing Ig at levels no higher than mice, the rat Igl-V locus is considerably more complex than that of laboratory mice, and its diversity reflects the products of gene duplications which predate the time of primate/rodent divergence.
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PMID:Transcription and diversity of immunoglobulin lambda chain variable genes in the rat. 142 10

The lipopolysaccharide (LPS) of a rough mutant (95R) of Vibrio cholerae Ogawa has been investigated chemically and serologically. D-Fructose was released from LPS under conditions (10mM trifluoroacetic acid, 60 degrees, 1 h) that liberated no other sugar constituent of the LPS (2-amino-2-deoxy-D-glucose, D-glucose, L-glycero-D-manno-heptose). Upon periodate oxidation, D-fructose and D-glucose were oxidised quantitatively, whereas approximately 50% of heptose was periodate-resistant. The data indicate that D-fructose does not link the polysaccharide and lipid A portion as proposed earlier, and suggest that D-fructose is present as a branch. By passive hemolysis inhibition, it was shown that the release of D-fructose paralleled the exposure of an antigenic determinant cryptic in LPS.
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PMID:The effect of removal of D-fructose on the antigenicity of the lipopolysaccharide from a rough mutant of Vibrio cholerae Ogawa. 242 94

The antigenic properties of the lipopolysaccharide (LPS) of Chlamydia trachomatis L2 were investigated. By means of passive hemolysis, passive hemolysis inhibition, and absorption experiments, it was shown that antiserum raised against chlamydial elementary bodies contained at least two different antibody specificities which reacted with different antigenic determinants of chlamydial LPS. One of these antibodies cross-reacted with enterobacterial Re LPS, recognizing a structure which is shared by both LPSs, whereas the reactivity of the second antibody was restricted to chlamydial LPS. The former antibody could be absorbed with Salmonella minnesota Re LPS, whereas the latter was not affected by this absorption. Therefore, chlamydial LPS possesses two distinct antigenic determinants, one of which is C. trachomatis specific, the other of which is responsible for the cross-reactivity with enterobacterial Re-type LPS. Both antigenic determinants were destroyed during mild acid-catalyzed hydrolysis. It was further shown that free chlamydial lipid A exhibits antigenicity that cross-reacts with free enterobacterial lipid A. This antigenicity, however, as in enterobacterial LPS, is present in a cryptic form, i.e., it is unmasked only after acid hydrolysis of LPS.
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PMID:Antigenic properties of Chlamydia trachomatis lipopolysaccharide. 258 Jul 95

Tissue factor (TF) is an integral membrane glycoprotein which, as the receptor and essential cofactor for coagulation factors VII and VIIa (FVII and FVIIa, respectively), is the primary cellular activator of the coagulation protease cascade. Previous studies on the procoagulant activity of a variety of cell types (either lysed or in the intact state) have variously been interpreted as showing that TF is either stored intracellularly or is present in a cryptic form in the surface membrane. Using mAbs to TF, we have directly investigated the subcellular localization and functional activity of TF in lipopolysaccharide-stimulated blood monocytes and J82 bladder carcinoma cells. Blocking of surface TF of viable cells with inhibitory anti-TF mAbs abolished greater than 90% of TF activity of the intact cells as well as of lysed cells. Furthermore, quantitative analysis of the binding of FVII and anti-TF mAb to J82 cells demonstrated that all surface-expressed TF molecules were capable of binding the ligand, FVII. By immunoelectron microscopy, TF was present only in the surface membrane of monocytes and J82 cells, although the latter also contained apparently inactive TF antigen in multivesicular bodies. On the intact cell surface the catalytic activity of the TF-FVIIa complex was investigated and found to be markedly less relative to cell lysates. Membrane alterations that affect the cofactor activity of TF may be a means of regulating the extent of initiation of the coagulation protease cascade in various cellular settings.
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PMID:Functional tissue factor is entirely cell surface expressed on lipopolysaccharide-stimulated human blood monocytes and a constitutively tissue factor-producing neoplastic cell line. 266 80

In three distinct chronic Ig-specific suppression systems in which suppression was initiated by injection of mice with anti-idiotype (Id) or anti-allotype sera, evidence has been presented by others that the differentiation of B cells bearing surface Ig with a target marker (Id or allotype) need not be totally disrupted. Normally "silent" Id+ B cells from Id-suppressed mice could be revealed by certain procedures, one of these being to make use of the powerful stimulatory properties of bacterial lipopolysaccharide. We have employed a similar strategy to determine whether cryptic CRIA+ B cells exist in significant numbers in hyperimmune, CRI-suppressed (HIS) A/J mice. Thus, following T cell removal, the Ar-specific B cell repertoire from HIS mice was probed using Ar- Brucella abortus as a T-independent Ag. No evidence for "silent" CRIA+ B cells was found. The results, taken in conjunction with those of others, suggests that there may exist multiple forms of long-term Ig-specific suppression.
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PMID:T-independent form of azophenylarsonate fails to reveal "silent" idiotype-positive B cells in idiotype-suppressed mice. 311 94

A cosmid bank of the DNA (including cryptic plasmid DNA) of a virulent strain of Salmonella typhimurium was prepared in Escherichia coli K12, and clones that contained cryptic plasmid DNA were detected by probing. Two such clones expressed a new outer membrane protein of 11 kilodaltons (kDa) and were serum resistant (E. coli K12 is serum sensitive). The gene encoding the 11-kDa protein was subcloned in a 2.1-kilobase fragment and shown to mediate serum resistance in both E. coli K12 and a cryptic plasmid-free (serum-sensitive) strain of S. typhimurium. The cryptic plasmid-free S. typhimurium strain did not express normal lipopolysaccharide, but introduction of the 11-kDa protein gene into the strain rendered the strain serum resistant without restoration of normal lipopolysaccharide synthesis. The 11-kDa protein gene was not sufficient to restore either macrophage resistance or virulence to a cryptic plasmid-free strain of S. typhimurium.
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PMID:Mediation of serum resistance in Salmonella typhimurium by an 11-kilodalton polypeptide encoded by the cryptic plasmid. 354 57

We have previously shown that Salmonella minnesota R345 (Rb) spontaneously binds to 50 to 55% of human peripheral blood mononuclear cells (PBMC). In the present study, we have compared Rb cytoadherence to lymphoid cells from various tissues of lipopolysaccharide (LPS) hyporesponsive (Lpsd) and LPS responsive (Lpsn) mouse strains. A higher number of spleen cells from Lpsd mice (C3H/HeJ and C57BL/10ScN) bound Rb bacteria (22 to 30%) than cells from Lpsn mice (4 to 9%). Rb bound mainly to T cells, and cytoadherence occurred in both Lyt-1+ and Lyt-2+ T cell subsets. By contrast, purified splenic B cells from Lpsd and Lpsn mice gave less than 4% Rb cytoadherence. In both mouse strains, cytoadherence was mediated by the homologous LPS structure, because purified Rb-LPS blocked Rb Salmonella binding to T cells. On the other hand, smooth Salmonella typhimurium LT-2 LPS (S-LPS) and Salmonella R595 (Re) LPS (Re-LPS), which contain mainly lipid A, were without effect on Rb binding. Increased Rb binding was seen with T cells from Peyer's patches (PP), mesenteric lymph nodes (MLN), and peripheral blood than from spleen of C3H/HeN (Lpsn) mice; however, greater cytoadherence was always seen with T cells of these tissues from C3H/HeJ mice. Interestingly, treatment of whole spleen or purified T cells from C3H/HeN mice with neuraminidase enhanced cytoadherence to levels seen with C3H/HeJ cells. The observed Rb binding to PP, MLN, and PBMC cells in both mouse strains suggests that gut microbial environment may play an important role in Rb cytoadherence. This is also supported by the evidence that when spleen cells of germfree and conventional mice were tested for Rb binding, higher cytoadherence was observed in conventional mice only. Taken together, these results indicate that T cells of Lpsd mice express binding site(s) for Salmonella, whereas Lpsn mice have T cells with these structure(s) in a cryptic configuration.
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PMID:Relationship between immune system and gram-negative bacteria. IV. T lymphocytes from Lpsd mice possess binding site(s) for Rb Salmonella. 387 86

A new antigenic specificity, referred to here as common lipopolysaccharide (LPS) specificity, is described in the LPSs of gram-negative bacteria belonging to various families. The specificity is present in S- and R-form LPS but absent in Re mutants of different enterobacterial genera. By the use of purified LPS and monospecific antibodies obtained by immunoabsorption, the specificity is differentiated from the known core specificities of the genus Salmonella and the lipid A specificity by aid of the passive hemolysis and passive hemolysis inhibition test. In Salmonella minnesota R-form LPS, the specificity may be cryptic (R345, Rb2 mutant) or partly exposed in the intact molecule (R7, Rd1 mutant). The specificity is either demasked or completely exposed after mild acid hydrolysis for a short time, whereas it is destroyed after prolonged hydrolysis. Periodate oxidation, reduction, and hydrolysis under conditions that do not affect the ketosidic linkages of 2-keto-3-deoxyoctulosonic acid destroy the specificity in R4 (Rd2 mutant) LPS, but do not do so in R7 LPS. It is suggested that 2-keto-3-deoxyoctulosonic acid and a following neutral sugar are the compositional requirements for expressing the specificity.
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PMID:Common lipopolysaccharide specificity: new type of antigen residing in the inner core region of S- and R-form lipopolysaccharides from different families of gram-negative bacteria. 619 16

Macrophage stimulating protein (MSP) is a member of a family of proteins characterized by a triple disulfide loop structure (kringle). We developed antibodies to human MSP for detection in Western blots, quantification in biological fluids, and neutralization of activity. Immunogens included native MSP, reduced and alkylated alpha and beta chains, and peptides of MSP regions with minimal sequence similarity to other kringle proteins. We found three antibody categories based on interaction with the following types of epitope: primary sequence, discontinuous (dependent on disulfide bonds), and cryptic (not exposed in native MSP). None of the antibodies reacted with related kringle proteins. A specific sandwich ELISA was developed for measuring human MSP. The mean serum concentration was 4 nM. Serum MSP did not increase over a 24-h period in response to intravenous lipopolysaccharide, indicating that MSP is not an acute phase protein. These findings are consistent with the hypothesis that regulation of MSP activity is by conversion of pro-MSP to MSP rather than by rapid changes in rates of synthesis.
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PMID:Antibodies to macrophage stimulating protein (MSP): specificity, epitope interactions, and immunoassay of MSP in human serum. 769 76

Using oligomer primers based on the cDNA sequence of human interleukin 1 beta converting enzyme (ICE), we have employed the RT-PCR method and rat spleen RNA to clone and sequence rat ICE. We report here that the predicted amino acid sequence of rat ICE proenzyme consists of 402 amino acids (p45) and shares 61% and 90% identity, respectively, with human and mouse ICE amino acid sequences. The active site cysteine (Cys284) and 3 or 3 potential processing sites are conserved suggesting that their the rat ICE heterodimer consists of a p22 (Ser104-Asp296) and a p10 (Gly315-His402) subunit or a cryptic processing site creates a smaller heterodimer. Northern blot analysis has revealed a approximately 2.2 kb and a more abundant approximately 1.45 kb ICE transcript both widely expressed in the rat with the highest expression in spleen and intestine and lowest in brain. IL-1 beta mRNA was similarly distributed. Injection of the immunostimulant, lipopolysaccharide (0.2 mg/kg, i.p.), increased rICE mRNA content between 2- to 3-fold in the rat brain with smaller increases measured in testis and spleen. The structural conservation of this enzyme suggests that rat models of inflammation will be useful for evaluating the therapeutic potential of ICE inhibitors in humans.
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PMID:Cloning, tissue expression and regulation of rat interleukin 1 beta converting enzyme. 778 29


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