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

Mouse spleen cells were cultured for 4 days in RPMI 1640 medium with 5% fetal calf serum. The neutral proteinases trypsin and plasmin, and bacterial lipopolysaccharide LPS, all polyclonal B lymphocyte activators, stimulated the development of immunoglobulin producing cells as detected by the protein A plaque assay. At the same time, direct plaque forming cells reacting with mouse, human and rabbit IgG and the Fc fragment of human IgG were induced by the stimulants. The plaques could be inhibited by free IgG or Fc fragment. In the culture supernatants, IgM and IgM anti-IgG antibodies were detected by enzyme linked immunosorbent assays. Both general IgM and IgM anti-IgG antibodies increased under the influence of the proteinases and of LPS. The results are discussed in relation to rheumatoid factor production during inflammatory diseases.
 ...
PMID:Neutral proteinases induce rheumatoid factor production in mouse spleen cell cultures. 622 74

The involvement of rheumatoid factor (RF)-secreting cells in normal immune responses was examined by screening hybridomas derived from 129/Sv mice during primary and secondary immune responses against foreign proteins. No RF-secreting cells were detected during primary responses, but up to 10% of the total number of clones obtained during secondary responses produced IgM with anti-IgG activity. Like typical mouse RF, these anti-IgG autoantibodies had a strict isotypic specificity, mostly for IgG1, and a much stronger avidity for immune complexes than for native IgG. The selective activation of IgG1-specific RF during these secondary immune reactions was not due to fortuitous antigenic similarities between mouse IgG1 and the antigens used for immunization, nor did it result from the use of adjuvants for priming, or from contamination of antigen preparations with lipopolysaccharide. It is therefore concluded that, in the 129/Sv mouse, RF production during secondary immune responses is a physiological phenomenon.
 ...
PMID:Rheumatoid factors and secondary immune responses in the mouse. I. Frequent occurrence of hybridomas secreting IgM anti-IgG1 autoantibodies after immunization with protein antigens. 660 60

Polymorphonuclear leukocytes (PMN) chemotaxis and serum chemoattractant ability were studied in patients with rheumatoid arthritis (RA) employing the agarose plate technique. No statistically significant differences were observed in random migration of unstimulated cells compared to the controls. Moreover, there were no statistically significant differences between the chemotactic migration of control and patient cells in response to a number of non-treated sera. The chemotactic responsiveness of normal PMN cells to treated rheumatoid serum was significantly less than that observed using treated control serum with Escherichia coli lipopolysaccharide. The possible explanation for this abnormality may be due to the presence of chemotactic inhibitors in some RA serum. No correlation was detected between chemoattractant activity of rheumatoid arthritis serum, circulating immune complexes or rheumatoid factor. There were no statistically significant differences in the adhesiveness of RA-PMNs compared to normal PMNs.
 ...
PMID:Defective serum chemotactic capacity in rheumatoid arthritis. 683 25

In some colonies, 129/Sv mice produce, upon aging, a rheumatoid factor (RF) that is specific for mouse IgG2a but fails to react with IgG2a of the b allotype. It is not known whether this narrow specificity is due to the absence of other RF specificities in the repertoire of these mice or to the selective activation of the production of anti-IgG2a autoantibodies by a specific stimulus. To analyze the RF repertoire of 129/Sv mice, we have derived hybridomas from their spleen cells 3 d after an intraperitoneal injection of lipopolysaccharide. We have obtained 68 hybridomas secreting a monoclonal IgM with RF activity. This represents approximately 3 percent of the total number of hybridomas generated in four hybridizations. In addition, one monoclonal IgA RF was derived from unstimulated 129/Sv spleen cells. The specificities of these monoclonal RF were examined by testing their ability to bind to a panel of homologous and heterologous IgG preparations. The majority of the IgM RF reacted exclusively with a single mouse IgG subclass: 58 with IgG1, and 1 with IgG2a. Eight bound preferentially to IgG1 but cross-reacted to some extent with IgG2a and one was specific for a determinant shared by IgG1, IgG2a, and IgG3. The IgA RF derived from unstimulated spleen cells was primarily directed against IgG2a but cross- reacted somewhat with IgG2b. Identical results were obtained with two different monoclonal IgG1 and IgG2a proteins of the a allotype. No allotypic specificity was found for the anti-IgG1 RF, which all reacted well with IgG1 of the b allotype. In contrast, the IgM anti-IgG2a antibody exhibited such allotypic specificity because it failed to react with IgG2a of the b allotype. When tested on heterologous IgG preparations, all anti-IgG1 RF reacted better with rat IgG1, rat IgG2c, bovine IgG2, goat IgG2, and rabbit IgG than with mouse IgG1, demonstrating a particular homology between these Ig. On the basis of additional cross-reactions with other IgG, including rat IgG2a, rat IgG2b, bovine IgG1, goat IgG1, human IgG, and chicken IgG, seven different anti-IgG1 clonotypes could be identified. However, despite their heterogeneity, nearly all antigenic determinants recognized by anti-IgG 1 RF appeared to be located in the hinge region of the molecule. Total lack of binding to IgG1 Fab fragments was indeed observed, and only one antibody reacted with IgG1 Fc fragments. Unlike the anti-IgG1 RF, the IgM and the IgA anti-IgG2a antibodies did not cross-react with any heterologous IgG of the same panel. Altogether, t 1 different RF clonotypes could be distinguished on the basis of their fine specificity. The anti-IgG2a specificity of the RF spontaneously produced by 129/ Sv mice is thus not due to the absence of other RF specificities in the repertoire of these mice.
 ...
PMID:Monoclonal anti-IgG autoantibodies derived from lipopolysaccharide-activated spleen cells of 129/Sv mice. 697 13

We investigated the ability of various polyclonal B-cell activators (PBA) to induce immunoglobulin synthesis, circulating immune complexes, and rheumatoid-factor-like autoantibodies. We found that, following the injection of a PBA--bacterial lipopolysaccharide, dextran sulfate, polyriboinosinic-polyribocytidilic acid, or purified protein derivative of tubercle bacteria--a transitory formation of circulating immune complexes occurred simultaneously with an increase in immunoglobulin production. The presence of circulating immune complexes after PBA administration was documented by the 125I-Clq-binding assay and the conglutinin-binding assay, and a partial characterization of this material was achieved. Although the kinetic properties, size, and composition of the immune complexes tested varied with the PBA used, the complexes detected in each group were inactivated by mild reduction and alkylation with 2-mercaptoethanol and were unaffected by DNase treatment. In the mice injected with bacterial lipopolysaccharide, the induction of circulating immune complexes correlated significantly with the presence of rheumatoid-factor-like antibodies, suggesting that this autoantibody may be present within the detected immune complexes. In tissues, glomerular deposits of IgM, IgG, and C3 were observed in a pattern compatible with the deposition of immune complexes. These deposits were progressively associated with marked glomerular abnormalities in mice chronically injected with LPS during 1 year. These data suggest that the induction of polyclonal antibody synthesis, which occurs in a variety of infectious or autoimmune diseases, may be responsible for the high incidence and persistence of immune complexes in these diseases. Such complexes would involve primarily autoantigens and corresponding autoantibodies, such as rheumatoid factor IgG complexes, without the participation of any specific bacterial, viral, or parasitic antigen.
 ...
PMID:Induction of circulating immune complexes and their renal localization after acute or chronic polyclonal B-cell activation in mice. 698 26

Peptidoglycan (PG) and lipopolysaccharide (LPS) are bacterial cell wall components that are B cell mitogens and activators of polyclonal antibodies. Using the hemolytic plaque assay and its modifications with protein A-, IgG-, or DNA-coated erythrocytes, we determined the proportions of cells that secrete antibodies specific to various autologous and heterologous antigens in PG- and LPS-stimulated cultures of mouse splenic lymphocytes. Of all PG- and LPS-activated IgM-secreting cells, 47 to 75% produced antibodies specific to mouse IgG; 2.7 to 21% produced IgM antibodies that reacted with bovine IgG; 4.4 to 17%, with single-stranded (ss) DNA; 0.18 to 5.9% with double-stranded (ds) DNA; 0.16 top 3.3%, with bromelin-treated mouse red cells; 0.006 to 0.02%, with intact mouse red cells; and 0.35 to 1.9%, with sheep red cells. A similar distribution of cells secreting these antibodies was observed in unstimulated cultures. However, the absolute numbers of cells secreting these antibodies were substantially higher in the PG- and LPS-stimulated cultures. Similar results were obtained in BALB/c, CBA/H, and C57BL/6 mice. Since these strains of mice have different H-2 types, there was no association of a single H-2 type with the ability to form hgh numbers of autoantibody-secreting cells in vitro. The production of autoantibodies closely resembled polyclonal activation of all immunoglobulin-secreting cells in terms of the kinetics and dose-response. It did not involve any substantial specific anti-PG or anti-LPS response. Further studies on the specificities of polyclonally induced antibodies confirmed the specificity of anti-mouse IgG and anti-ssDNA antibodies. However, the formation of plaques with bovine IgG- or dsDNA-sensitized red cells was due to the cross-reacting anti-mouse IgG or anti-ssDNA antibodies, respectively. These results do not support the popular hypothesis of an equal polyclonal activation of lymphocytes secreting antibodies of all different specificities. Also, if preferential activation of cells secreting rheumatoid factor and anti-ssDNA antibodies occurs in vivo, it may have important pathologic consequences.
 ...
PMID:Preferential induction of autoantibody secretion in polyclonal activation by peptidoglycan and lipopolysaccharide. I. In vitro studies. 703 53

We previously purified a 55 kDa protein that preferentially expands anti-DNA antibody production both in vitro and in vivo across the H-2 barrier from culture supernatants of KML1-7 cells, cloned from a lupus-prone MRL/lpr mouse. By using the purified protein, termed nucleobindin (Nuc), we cloned cDNA and produced recombinant(r) Nuc in Escherichia coli. To elucidate the function of rNuc in vivo, we initially injected intraperitoneally 5 micrograms of rNuc without adjuvant into female MRL/n mice at 8 weeks of age and continued injection twice a week. As early as 5 weeks after administration, all mice treated showed an increase in IgG anti-double stranded (ds) DNA antibodies accompanied by IgG hypergammaglobulinemia (HG). Of particular interest was that these mice also produced anti-U1RNP antibodies and rheumatoid factor (RF) of IgG class, but not anti-Sm antibodies. Histopathologically, hypercellularity with occasional crescents in the glomeruli was observed, but evidence for lupus nephritis was lacking, indicating that some factors other than Nuc are necessary for the development of a lupus syndrome observed in MRL/lpr mice. Similar administration of lipopolysaccharide into MRL/n mice failed to induce autoantibodies except for a slight increase in serum IgG, suggesting that these autoimmune responses are not due simply to polyclonal B-cell activation. The presence of rNuc will give us a clue for further understanding of autoimmunity.
 ...
PMID:Novel autoimmune phenomena induced in vivo by a new DNA binding protein Nuc: a study on MRL/n mice. 814 93

The histological changes in the ankle joints were investigated in Sprague Dawley (SD) rat immunized through intraperitoneal injection of 10 micrograms or 100 micrograms of lipopolysaccharide(LPS; extracted from Escherichia coli), or Lipid A, for 10 or 15 weeks (short term) or for 30 weeks (long term). The serum anti-IgM rheumatoid factor-like substance (RFLS) was detected by enzyme-linked immunosorbent assay (ELISA). The macroscopic arthritic changes in the rat ankles, showing redness or swelling, were observed in 17 of 64 rats immunized by LPS and in 9 of 62 rats immunized by Lipid A. Rats immunized by 10 micrograms of LPS in the long term developed synovial lining cell hyperplasia in 12 of 28 ankles (12/28), lymphoid cell infiltration in 8/28, and pannus formation in 2/28. Rats immunized by 100 micrograms of Lipid A in the long term developed synovial lining cell hyperplasia in 8/18, lymphoid cell infiltration in 7/18, and pannus formation in 2/18. SD rats immunized by LPS or Lipid A developed a significantly higher incidence rate of hyperplasia in the synovial lining cells, than controls. In each case of immunization by LPS or Lipid A, the serum RFLS levels at sacrifice were significantly higher than before immunization (p < 0.01). These findings suggest that LPS and Lipid A played important roles as trigger substances causing arthritis with RFLS elevation in rats immunized with E. coli.
 ...
PMID:[Induction of arthritis in the ankles of rat immunized by intraperitoneally-injected lipopolysaccharide (LPS) or lipid A]. 818 7

A complement fixation (CF) test, a micro-immunofluorescence (micro-IF) test and an enzyme immunoassay (EIA) using Re-lipopolysaccharide as antigen were compared in the diagnosis of chlamydial infection in 136 mainly elderly patients hospitalized with community-acquired pneumonia during a Chlamydia pneumoniae epidemic in Finland in 1986-1987. Chlamydial pneumonia was diagnosed in 58 (42.6%) of the 136 pneumonia patients; 44 (75.9%) of them could be shown by micro-IF to be caused by Chlamydia pneumoniae, three by Chlamydia psittaci and four by Chlamydia spp. Only 5 (11.4%) of 44 patients with Chlamydia pneumoniae pneumonia were IgM-positive, indicating that the majority of cases were reinfections. In this population of mainly elderly patients the CF test was insensitive, being positive in only 6 (10.3%) of 58 cases of chlamydial pneumonia. The EIA detected 72.4% of cases and micro-IF 87.9% of cases (including infections with Chlamydia pneumoniae, Chlamydia psittaci and Chlamydia spp.). In the EIA 77% of positive cases were positive in serum samples taken a week apart, whereas the corresponding figure for micro-IF was 50%. In micro-IF the measurement of IgA antibody levels is recommended and IgM-positive sera should be retested after removal of IgG antibody to avoid false-positive findings due to presence of rheumatoid factor. The collection of a third serum sample, for instance one month after onset, is also recommended, since half of the patients showed a diagnostic response in the micro-IF only in the sera taken one month apart.
 ...
PMID:Evaluation of serological methods in the diagnosis of Chlamydia pneumoniae pneumonia during an epidemic in Finland. 830 44

The clinical and immunological responses to typhoid vaccination with parenteral and oral vaccines in two groups of 30 adult male subjects were studied. Specific anti-Salmonella typhi cell-mediated immunity and total or specific anti-lipopolysaccharide faecal immunoglobulin (Ig) A titres in vaccinated subjects were monitored. Cellular antibacterial activity was significantly increased only in orally vaccinated subjects. Serum arming activity and inhibition experiments suggested an IgA-dependent cellular cytotoxicity in those orally vaccinated. In these subjects, a total and anti-lipopolysaccharide faecal IgA increase was observed lasting up to 8 months after completion of the vaccination schedule. In parenteral vaccinated subjects, an early onset transitory increase of IgM rheumatoid factor was observed. Oral vaccine was well tolerated and free of side effects, whereas 65% of parenterally vaccinated subjects reported side effects such as fever, headache, malaise and local tenderness in the injection site.
 ...
PMID:Clinical and immunological response to typhoid vaccination with parenteral or oral vaccines in two groups of 30 recruits. 848 16


<< Previous 1 2 3 Next >>