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)

The factors controlling lysis of gram-negative bacteria by complement are being investigated systematically. The first question was how smooth Salmonella minnesota, which has on its surface lipopolysaccharide with long O polysaccharide side chains, avoids lysis. Rough organisms are serum sensitive. In both smooth and rough organisms, complement components are deposited on the surface and the lytic sequence proceeds to completion. However, with serum-resistant organisms the membrane attack complex (MAC), composed of late-acting complement proteins, does not successfully insert into the outer membrane to cause membrane damage. At the completion of the lytic sequence, the hydrophobic MAC is shed. C3b, which directs late component assembly, is deposited on the longest O polysaccharide side chains on these smooth organisms, where it does not direct successful insertion of the MAC into the outer membrane. Serum-resistant gonococci sequester the MAC on the organism's surface in association with specific outer membrane components, where it does no damage to the outer membrane. Antibody appears to mediate site-directed complement component deposition in a number of systems. Thus, depending on antibody specificity, complement may be deposited on the organism's surface to cause successful complement attack or may block complement attack induced by bactericidal antibody. Monoclonal antibodies of the same isotype directed at different epitopes on the same bacterial surface antigen may either induce lysis or block lytic attack.
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PMID:The function of antibody and complement in the lysis of bacteria. 331 49

A monoclonal antibody (RM3/1), raised by immunizing mice with human monocytes, is described which detects a surface antigen on about 20% of freshly isolated peripheral blood monocytes and is increasingly expressed upon cultivation, reaching a maximum between day 2 and 3. By incubation of monocytes with interferon-gamma, 12-O-tetradecanoylphorbol-13-acetate and lipopolysaccharide, antigen expression is decreased but strongly enhanced after incubation with dexamethasone. In cryostat sections of normal tissue, the antibody detects histiocytes in the skin, Kupffer cells in the liver, few alveolar macrophages in the lung, macrophages in the red pulp of the spleen and in the cortex of the thymus, and many macrophages in the placenta. In acute inflammatory tissue, e.g. gingivitis, the antigen is preferentially expressed by macrophages appearing late in the inflammatory process. In chronic inflammation, e.g. BCG granulomas and rheumatoid arthritis, RM3/1-positive macrophages are seen to varying degrees. Double-staining experiments with the antigen 25F9, specific for resting mature macrophages, revealed that RM3/1 and 25F9 are expressed by distinct populations in normal and acute inflammatory tissues. From this it is concluded that the antibody RM3/1 specifically detects a macrophage phenotype which seems to be associated with the healing phase of the inflammatory process.
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PMID:A monoclonal antibody to a novel differentiation antigen on human macrophages associated with the down-regulatory phase of the inflammatory process. 345 May 46

Active trachoma is characterized by chronic inflammation of the conjunctiva, and repeated episodes of reinfection are thought to be necessary to sustain this inflammation. It is currently believed that much of the tissue damage is immunologically mediated. To identify which antigens might be responsible for stimulating this continued inflammation, cynomolgus monkeys that had recovered from a previous ocular infection with Chlamydia trachomatis were challenged with various antigen preparations. Purified preparations of formalin- or UV-inactivated elementary bodies did not elicit any inflammation even with daily inoculation. In addition, neither purified chlamydial major outer membrane protein nor lipopolysaccharide, including recombinant organisms expressing the lipopolysaccharide group antigen, elicit inflammation. A soluble triton extract of the organism rapidly induced marked inflammation when inoculated in the eyes of immune monkeys but had no effect in naive animals. These studies suggest that the continual inflammation in trachoma may not be due to repeated exposure to chlamydial surface antigen(s) but rather to a labile product released by the living organisms.
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PMID:Pathogenesis of trachoma: the stimulus for inflammation. 357 82

Murine bone marrow (BM) cells were cultivated on bacteriological grade culture dishes (BCD) in liquid medium containing L-cell-conditioned medium (LCM). The first month of rapid exponential multiplication was always followed by an interim phase of slow growth, and then by continuous proliferation. These established lines were called Jerusalem bone marrow macrophages (JBM phi). One of these, which had been derived from a C3H/Crg1 female mouse and was designated JBM phi 1.1, was studied in more detail. Its cloning efficiency when grown in LCM-containing soft agar was 65%. Of several clones isolated, one, C1.26, was selected for further cultivation and propagated for about 600 days. Cells from all cultures were surface adherent with limited proliferative capacity on tissue culture plastic. The properties displayed by all cells in a culture or clone include a typical macrophage (M phi)-like morphology, effective ingestion of killed bacteria and zymosan, staining for nonspecific esterase, and expression of Fc receptors and of F4/80 surface antigen. Addition of lymphokine (LK) induced Ia antigen expression on a high percentage of the cells. The JBM phi 1.1 cells also secreted high levels of lysozyme, produced a zymosan-induced respiratory burst, and, upon addition of lipopolysaccharide (LPS), released interleukin-1 and tumor necrosis factor. Efficient tumoricidal activity could be induced by LK and LPS. No evidence for the production of colony-stimulating factors, even in the presence of LPS, could be found. The JBM phi 1.1 or C1.26 cells did not develop into tumors following subcutaneous injection in x-irradiated syngeneic or in nu/nu mice and were also incapable of growing in soft agar without LCM. All the properties studied were expressed at similar levels by the "young" BM-derived M phi during their first exponential growth phase, as well as by other JBM phi lines and clones. It is concluded that the established JBM phi lines consist of homogeneous cell populations which, according to all markers and functions studied, could be classified as non-activated, functional, and mature M phi, resembling in all aspects BM-derived M phi during their first few weeks of cultivation. This shows that cell lines expressing properties of normal M phi may develop spontaneously by continuous cultivation of BM cells in growth factor-containing liquid medium on BCD.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Establishment and characterization of murine bone marrow-derived spontaneously immortalized cell lines and clones expressing properties of normal macrophages. 359 67

A monoclonal antibody is described that was generated by immunizing mice with cultured human blood monocytes. The antibody (27E10) belongs to the IgG1 subclass and detects a surface antigen at Mr 17,000 that is found on 20% of peripheral blood monocytes. The antigen is increasingly expressed upon culture of monocytes, reaching a maximum between days 2 and 3. Stimulation of monocytes with interferon-gamma (IFN-gamma), 12-O-tetradecanoyl-phorbol-13-acetate (TPA), and lipopolysaccharide (LPS) but not with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP) increased the 27E10 antigen density. The amount of 27E10-positive cells is not or is only weakly affected. The antigen is absent from platelets, lymphocytes, and all tested human cell lines, yet it cross-reacts with 15% of freshly isolated granulocytes. By using the indirect immunoperoxidase technique, the antibody is found to be negative on cryostat sections of normal human tissue (skin, lung, and colon) and positive on only a few monocyte-like cells in liver and on part of the cells of the splenic red pulp. In inflammatory tissue, however, the antibody is positive on monocytes/macrophages and sometimes on endothelial cells and epidermal cells, depending on the stage and type of inflammation, e.g., BCG granulomas are negative, whereas psoriasis vulgaris, atopic dermatitis, erythrodermia, pressure urticaria, and periodontitis contain positively staining cells. In contact eczemas at different times after elicitation (6 hr, 24 hr, and 72 hr), the 27E10 antigen is seen first after 24 hr on a few infiltrating monocytes/macrophages, which increase in numbers after 72 hr. From this it is concluded that the antibody 27E10 detects an antigen expressed by a subset of peripheral blood monocytes. In situ the antigen is found only in inflammatory tissues and is absent from normal resident mononuclear phagocytes.
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PMID:A monoclonal antibody to a subset of human monocytes found only in the peripheral blood and inflammatory tissues. 372 15

Cell surface antigens used as markers of in vivo differentiation may not be stable on monocytes maintained under different conditions of in vitro culture. Monocytes were isolated from blood by centrifugation over Percoll or by adherence to plastic dishes, and the cells cultured in suspension or as adherent monolayers. Initially, monocytes obtained by both methods were similar in size, morphology, and surface antigen expression detected with the antimonocyte monoclonal antibodies OKM1, FMC17, PHM2, and PHM3. After culture, cells maintained in suspension were predominantly small, whereas those adherent to plastic rapidly increased in size; however, cytochemical staining for nonspecific esterase and acid phosphatase showed increased enzymic activity by monocytes in both systems, possibly reflecting increased cell maturation. The most striking difference was a substantial loss of FMC17 antigen by most monocytes within four hours in suspension culture, as compared with a qualitative and quantitative increase in expression by plastic adherent cells within two hours. These changes occurred even if the cells were first reacted with lipopolysaccharide. Monocytes taken from suspension culture and allowed to adhere to plastic rapidly synthesized the antigen, a process inhibited by cycloheximide, and conversely, cells removed from plastic progressively displayed decreased FMC17 antigen expression when transferred to suspension culture. No functional role in adherence or phagocytosis has been found for the FMC17 antigen. The results suggest that antigen expression may depend as much on the physical state of the cells as on apparent activation or maturation events.
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PMID:Rapid changes in surface antigen expression by blood monocytes cultured in suspension or adherent to plastic. 397 34

We examined the isolation of fimbriae from Bacteroides nodosus. It was found that the best preparations were obtained from the supernatant of washed cells cultured on solid medium, from which fimbriae could be recovered in high yield and purity by a simple one-step procedure. Analysis of such preparations by sodium dodecyl sulfate gel electrophoresis showed that greater than 98% of the protein consisted of fimbrial structural subunits whose molecular weight was ca. 17,000. These preparations also usually exhibited minor contamination with a polypeptide of ca. 80,000 molecular weight, as well as trace amounts of lipopolysaccharide. Attempts to release additional fimbriae by the traditional means of subjecting the bacterial cells to physical stress, such as shearing or heating, resulted primarily in an increase in the level of contamination, without significant gain in the yield of fimbriae. Removal of the 80,000-dalton component could not be achieved by any of a variety of techniques normally used in fimbriae purification, including isoelectric precipitation, MgCl2 precipitation, and CsCl gradient ultracentrifugation, implying a direct physical association with the fimbrial strand. Electron micrographs of fractions containing this protein show cap-shaped structures attached to the ends of what appeared to be fimbrial stubs. These observations suggest that the 80,000-dalton polypeptide may actually constitute the basal attachment site which anchors the fimbria to the outer membrane, analogous to a similar protein recently described in enterotoxigenic strains of Escherichia coli. In B. nodosus, this 80,000-dalton protein is a major surface antigen, and like the fimbrial subunit, exhibited variation in electrophoretic mobility between serotypically different isolates.
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PMID:Isolation and characterization of Bacteroides nodosus fimbriae: structural subunit and basal protein antigens. 615 24

By using monoclonal antibodies, a tumor-specific antigen (TSA 41.5) was detected on the cell surface of a B lymphoma CH-1 tumor variant, CH-1.1. This antigen is not expressed by normal lymphocytes (spleen cells, lymph node cells, thymocytes, bone marrow cells, or blast cells) of B10.A mice, the host strain of CH-1.1, or by the CH-1 lymphoma. Immunoprecipitation and biochemical characterization of TSA 41.5 with the use of two-dimensional gel electrophoresis showed this antigen to be a surface protein of CH-1.1 cells with an Mr of 80k and pI of 4.6. TSA 41.5 is not related to the murine transferrin receptor, and not to gp70, a viral envelope protein expressed by CH-1.1 cells, shown by comparative peptide map analysis of these three proteins. TSA 41.5 is a surface antigen unique to the CH-1.1 tumor, which is not expressed by the 19 different murine tumor lines that were tested nor by spleen cells of 15 independent mouse strains. In addition, treatment of spleen cells with bacterial lipopolysaccharide did not induce the expression of TSA 41.5. These characteristics of TSA 41.5 make it unlikely to be a product of viruses. Additional evidence against TSA 41.5 being a viral protein was obtained by the observation that antisera against viral proteins could not block the binding of the anti-TSA monoclonal antibody to its antigen. In vitro treatment of CH-1.1 cells with anti-TSA monoclonal antibody specifically inhibited the in vitro growth of the tumor cells in a dose-dependent fashion. The CH-1.1 tumor and monoclonal antibodies could be a useful murine model system for the exploration of the use of monoclonal antibodies for the in vivo treatment of cancer.
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PMID:Description of a murine B lymphoma tumor-specific antigen. 620 65

Surface markers of human gingival fibroblasts in vitro were investigated using monoclonal and heterologous antisera against a range of cell surface antigens, together with rosetting techniques to characterize surface receptors for IgG and C3. WI-38 fibroblasts and human peripheral blood monocytes were used as control cells. Human gingival fibroblasts exhibited complement receptors and beta2-microglobulin, as did WI-38 cells. Ten per cent of the human gingival fibroblasts were positive for HLA-DR antigens and additionally exhibited a granulocyte antigen not apparent on WI-38 cells. Monolayers of the gingival fibroblasts were further exposed for short periods to varying concentrations of enzymes (trypsin, collagenase and neuraminidase), bacterial extracts (lipopolysaccharide and lipoteichoic acid) and crude supra- and subgingival plaque sonicates. Surface-marker analysis was then carried out. The most noticeable effects were obtained with Vibrio cholerae neuraminidase which enhanced C3 receptor and surface antigen expression, and supragingival plaque sonicate which depressed the expression of HLA-DR and granulocyte antigens while not affecting beta2-microglobulin expression. Trypsin reduced antigen expression to a degree, but its effects were mainly on cell adherence.
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PMID:Surface markers of human gingival fibroblasts in vitro. Characterization and modulation by enzymes and bacterial products. 633 Mar 32

Two murine monoclonal antibodies of the IgG3 class have been isolated after immunization with Brucella abortus. An indirect immunofluorescence test was used to screen hybridoma supernatants and subsequently to determine the cross-reactivity of the monoclonal antibodies with other bacteria. One monoclonal antibody reacted with all the smooth Brucella biotypes tried and with Yersinia enterocolitica serogroup 0:9, though not with rough Br. ovis or with strains of Escherichia, Proteus, Salmonella, Pseudomonas, Francisella and Bordetella. The other monoclonal antibody displayed a high degree of specificity for brucellae carrying the A lipopolysaccharide-protein surface antigen. The implications for the diagnosis of brucellosis are discussed.
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PMID:A monoclonal antibody specific for the A antigen of Brucella spp. 643 72


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