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 IgG subclasses secreted by human B cells in vitro in response to IL-2 have been analysed. B cells were prepared from tonsil, blood and spleen, and cultured with recombinant IL-2 in the presence or absence of two polyclonal activators: Staphylococcus aureus Cowan 1 (SAC) and bacterial lipopolysaccharide (LPS). Secretion of all four subclasses and of IgM was stimulated by IL-2, but the relative amounts varied according to (i) the tissue source of the B cells, and (ii) which polyclonal activator was used. The amount of IgG1 tended to be higher and IgG2 tended to be lower when SAC was the polyclonal activator (compared to LPS). This difference was most marked for tonsil B cells, and it was found that SAC had a negative effect on secretion of IgM and IgG2 in these cultures, whilst synergizing with IL-2 to stimulate the production of IgG1, 3 and 4. When the degree of stimulation of different pairs of isotypes was analysed, several interesting positive correlations emerged. In tonsil B-cell cultures, stimulation of IgM and IgG2 was linked with each other, but not with IgG1, whilst in blood B-cell cultures all isotypes appeared to be stimulated co-ordinately. Stimulation of IgG1 and IgG3 were positively correlated in cultures of B cells from all tissues. The results emphasize that the effects of a single cytokine on immunoglobulin isotype production can be influenced by the source of the B cells, and by other signals delivered to the cells.
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PMID:Immunoglobulin G subclasses secreted by human B cells in vitro in response to interleukin-2 and polyclonal activators. 237 16

We produced anti-idiotype antibodies to antibody to lipid A from Eikenella corrodens. The ALA-1 monoclonal antibody (immunoglobulin M [IgM] isotype), which had already been produced in our laboratory (T. Kato, I. Takazoe, and K. Okuda, Infect. Immun. 57:656-659, 1989), had reacted strongly with lipid A from E. corrodens, Escherichia coli, and Salmonella minnesota. Four anti-idiotype monoclonal antibodies to ALA-1 (Ab1), designated A2LA-1 (IgG1 isotype), A2LA-2 (IgG2a isotype), A2LA-3 (IgG2a isotype), and A2LA-4 (IgG3 isotype), which recognized the idiotype Ab1, were produced. A2LA-1, A2LA-2, and A2LA-3 were capable of over 61% inhibition of ALA-1 reactivity to E. coli J5 lipid A in an enzyme-linked immunosorbent assay system. The sera of mice and rabbits immunized with the anti-idiotype antibodies revealed that the internal image anti-idiotype antibody induced the production of IgG antibodies that cross-reacted with or bound to lipid A. These studies indicate that A2LA-1 and A2LA-2 contained an antigenic epitope that mimicked lipid A. Immunization of mice with A2LA-1 resulted in prevention of lethal toxicity from E. coli J5 lipopolysaccharide.
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PMID:Protection of mice against the lethal toxicity of a lipopolysaccharide (LPS) by immunization with anti-idiotype antibody to a monoclonal antibody to lipid A from Eikenella corrodens LPS. 240 70

Monoclonal antibodies were produced against Escherichia coli O111, Escherichia coli J5, and the rough (R) mutant of Salmonella typhimurium M206, and tested by enzyme-linked immunosorbent assay against lipopolysaccharides of several gram-negative strains. The monoclonal antibodies were also identified with an immunoblotting assay. Anti-Escherichia coli O111 monoclonal antibodies reacted only with homologous O antigens. Anti-J5 monoclonal antibodies cross-reacted with core lipopolysaccharide, especially with Rc lipopolysaccharide. IgM anti-J5 monoclonal antibodies showed more extensive cross-reactivity than IgG3 monoclonal antibodies. Anti-Re monoclonal antibodies cross-reacted weakly with all rough lipopolysaccharide tested. Thus, the varying specificity of these monoclonal antibodies seems to indicate that the core regions in the lipopolysaccharides of various gram-negative bacteria are not similar.
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PMID:Cross-reactivity of monoclonal antibodies against lipopolysaccharides of gram-negative bacteria. 242 54

Monoclonal antibodies against 12 of the 17 IATS serotype strains of Pseudomonas aeruginosa were produced. Eighty-seven hybridoma clones were isolated, and the antibodies secreted were found to be reactive with both Formalin-fixed whole cells and purified lipopolysaccharide of homologous strains in enzyme-linked immunosorbent assays. Among these monoclonal antibodies, the predominant antibody class was immunoglobulin M (IgM) (76%), although antibodies of the IgG2a and IgG3 isotypes were also produced. The monoclonal antibodies could further be divided into two groups based on their ability to agglutinate whole cells of homologous strains. The agglutinating monoclonal antibodies were found to immunoblot with the O side chains of homologous lipopolysaccharide, while the nonagglutinating monoclonal antibodies were found to be reactive with outer membrane protein-associated lipopolysaccharide. The applicability of monoclonal antibodies for serotyping was examined, and several antibodies were found to agglutinate whole cells and immunoblot with the O antigen of corresponding serotypes of clinical isolates from cystic fibrosis patients. In conclusion, a set of monoclonal antibodies against the IATS serotype strains of P. aeruginosa have been produced. These antibodies represent a bank of invaluable immunological reagents which may have application in serotyping, epitope mapping, lipopolysaccharide structural determination, and studies of protection against P. aeruginosa.
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PMID:Production and characterization of monoclonal antibodies against serotype strains of Pseudomonas aeruginosa. 243 30

An IgG3 murine monoclonal antibody (designated MO8) specific for the serogroup C2 Salmonella lipopolysaccharide (LPS) was generated by fusing mouse myeloma cells NS1 with spleen cells of BALB/c mice immunised with heat-killed S. manhattan. MO8 reacted with purified LPS prepared from serogroup C2 Salmonella but did not react with that prepared from other O serogroups, and its reactivity was also specifically absorbed by serogroup C2 Salmonella only. Polyacrylamide gel electrophoresis of the serogroup C2 LPS and subsequent immunoblotting with MO8 yielded multiple reactive bands giving a characteristic ladder pattern. The specificity of MO8 was further demonstrated in the slide agglutination test with 223 bacteria, of which only 25 belonging to serogroup C2 Salmonella reacted with the MO8 ascitic fluid. The specificity of MO8 makes it useful not only for the serological identification of Salmonella but also for the epitope analysis of the serogroup C2 LPS.
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PMID:Characterisation and application of a murine monoclonal antibody specific for the serogroup C2 Salmonella. 245 55

The regulation of the subclass of immunoglobulin secreted by B cells has been studied in vitro in polyclonal systems using mitogens, such as lipopolysaccharide (LPS), to bypass the requirement for cognate interaction between antigen-specific T and B cells. In these systems, interleukin-(IL)-4 induces the secretion of IgG1 (ref. 1) and IgE (ref. 2); IL-5 enhances the secretion of IgA, and interferon-gamma (IFN-gamma) enhances the secretion of IgG2a (ref. 5). Clones of murine TH cells can be divided into two subsets, TH1 and TH2 (ref. 6). Both subsets synthesize IL-3 and granulocyte-monocyte colony-stimulating factor (GM-CSF), but only TH1 clones produce IL-2, IFN-gamma, and lymphotoxin (LT) and TH2 clones produce IL-4 and IL-5 (ref. 7). We have examined the role of clones of antigen-specific TH1 and TH2 cells in the regulation of the subclasses of IgG antibody secreted by antigen-specific B cells. Our results show that both types of TH cells induce the secretion of IgM and IgG3, whereas clones of TH1 and TH2 cells specifically induce antigen-specific B cells to secrete IgG2a and IgG1, respectively. We also demonstrate that regulation of commitment to the secretion of a particular IgG isotype occurs in two distinct stages: cognate interaction between T and B cells and interaction between T-cell-derived lymphokines and B cells.
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PMID:Regulation of antibody isotype secretion by subsets of antigen-specific helper T cells. 245 66

A panel of 14 monoclonal antibodies with specificity for the O-antigenic polysaccharide chain of the lipopolysaccharide of the cell envelope of Salmonella typhimurium was established. The specificity of each antibody clone was determined against a set of Salmonella saccharide antigens, natural and synthetic, in passive hemagglutination and enzyme immunoassays. The monoclonal antibodies could be classified into at least five different groups: (i) O4 epitope specific, (ii) O4,12 specific, (iii) O4,12(2) specific, (iv) O5 specific, and (v) O12 specific. These specificities correspond to different structural and conformational domains of the polysaccharide chain, and often extend over more than one repeating unit (tetrasaccharide) of the polymer. The passive protection afforded by these antibodies was estimated in an experimental mouse typhoid model using S. typhimurium SH2201 for intraperitoneal challenge. Monoclonal antibodies of the IgG3 isotype were available for four of the epitope groups and were protective in the following order of activity O4 greater than O4,12 greater than O4,12(2) greater than or equal to O12. The difference between O4 and 012 antibodies was greater than 2500 fold in protective activity. Antibodies of the IgM class were highly protective irrespective of being of the O4,12 or O12 epitope specificity. Two IgA antibodies with O5 epitope specificity were not protective. The results show that both isotype and epitope specificity can be of importance for the protective ability of antibodies generated by the host.
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PMID:Role of monoclonal O-antigen antibody epitope specificity and isotype in protection against experimental mouse typhoid. 246 61

Hybridoma-derived monoclonal antibodies (MAB) against the cell surface antigens of Pasteurella haemolytica serotype 1 were obtained by the fusion of murine myeloma cells (P3 X 63 - Ag 8.653) with splenocytes of BALB/c mice immunized with crude logarithmic growth-phase culture supernatant. Initial screening was performed, using an ELISA, with the same bacterial growth culture supernatant as coating antigens. Further selection was done, using a panel of purified antigens--either capsular polysaccharide or lipopolysaccharide--as the coating antigen in an ELISA, and then performing a leukotoxin-neutralization assay. Two MAB, designated IIB-6 and H-2, reacted specifically with the capsular polysaccharide and the other 3, designated IVG-3, IH-3, and IIC-2, reacted with the lipopolysaccharide. One MAB, designated IH-6, did not react with leukotoxin, capsular polysaccharide, or lipopolysaccharide. The MAB to the capsular polysaccharide (IIB-6 and H-2) were characterized further; both antibodies belonged to the IgM class and were agglutinating. In addition, they promoted neutrophil-mediated opsonophagocytosis and complement-mediated immune bacteriolysis of P haemolytica serotype 1. Results from 3 studies indicated that the MAB IIB-6 and H-2 were specific only to the capsular polysaccharide of serotype 1 of P haemolytica. The MAB to the lipopolysaccharide (IVG-3, IH-3, and IIC-2) were of the IgG1, IgG3, and IgM classes, respectively and were not characterized further. The availability of a MAB identifying a serotype-specific, surface-exposed determinant on the capsule of P haemolytica serotype 1 should facilitate and expand studies concerning the role of the capsular material and lipopolysaccharide in the pathogenicity of P haemolytica infection in cattle.
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PMID:Production and partial characterization of monoclonal antibodies to Pasteurella haemolytica A1 capsular polysaccharide and lipopolysaccharide. 247 Feb 77

Previously we have demonstrated that eight out of nine IgG3 monoclonal antibodies (mAb) obtained from autoimmune MRL-lpr/lpr mice were able to self-associate and to precipitate in the cold (Gyotoku et al., J. Immunol. 1987. 138:3785). To determine whether the cryoprecipitation of IgG3 mAb is enhanced or inhibited in the presence of specific ligand, we have established eight IgG3 mAb reactive with 2,4-dinitrophenol (DNP) hapten: four mAb were obtained from fusion of spleen cells of C57BL/6 mice immunized with 2,4,6-trinitrophenylated keyhole limpet hemocyanin, three from 129/Sv and one from BALB/c immunized with DNP-lipopolysaccharide. Five of them induced cryoglobulins composed exclusively of the IgG3 mAb. The binding of negatively charged monomeric DNP-amino acid conjugates completely inhibited the cryoprecipitation of all the five cryoprecipitating anti-DNP IgG3 mAb, while the incubation with positively charged or neutral DNP-amino acid conjugates had variable effects: increase, inhibition or no change of the cryoprecipitation. In addition, positively charged DNP-amino acid conjugates were able to induce the cryoprecipitation of one of the non-cryoprecipitating anti-DNP IgG3 mAb. Our data showed that (a) IgG3 mAb derived from non-autoimmune strains of mice, similar to IgG3 mAb derived from an autoimmune MRL-lpr/lpr strain, possessed the unique property to self-associate and were able to form cryoglobulins in most cases; (b) although the Fc-Fc interactions of IgG3 mAb play a decisive role in IgG3 cold solubility, IgG3 cryoprecipitation was markedly influenced after interacting with their specific ligand, depending on the charge of the hapten-amino acid conjugate. This suggested that even minor interferences with the electrostatic equilibrium of the IgG3 by the binding of charged hapten molecules induced dramatic changes in the solubility of the IgG3 mAb at low temperature.
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PMID:Inhibition of cryoprecipitation of murine IgG3 anti-dinitrophenyl (DNP) monoclonal antibodies by anionic DNP-amino acid conjugates. 249 23

Chronic lung infection in cystic fibrosis is characteristically associated with polyagglutinable, serum-sensitive, mucoid strains of Pseudomonas aeruginosa. Enzyme-linked immunosorbent assay (ELISA) methods for standard-free quantitation of immunoglobulin G (IgG) and IgM antibodies to P. aeruginosa lipopolysaccharides (LPSs) have been developed. We now report the development of assays for quantitation of monomer and dimer total IgA and IgA anti-LPS antibodies. Use of these methods in diagnosis of early chronic P. aeruginosa lung infection was assessed. IgG and IgA anti-LPS levels increased significantly at the onset of chronic infection and continued to increase to very high levels in the later stages of infection. IgM anti-LPS levels also rose at the onset of chronic infection but did not increase further. The function of true- and false-positive rates was illustrated by using various concentrations of IgG, IgA, and IgM anti-LPS for discrimination of patients. Values that gave optimum separations were used for statistical evaluation of the diagnostic sensitivities and specificities of anti-LPS antibody concentrations. The results obtained in these assays were compared with a diagnosis, based on the number of precipitins in crossed immunoelectrophoresis, of serum samples from cystic fibrosis patients. In 64 paired serum samples taken before and immediately after the onset of chronic infection, as defined by crossed immunoelectrophoresis precipitins, the predictive values of a positive ELISA were 86% for IgG and 89% for IgA. The predictive values for a negative ELISA were 98% for IgG and 97% for IgA. Results of the IgM anti-LPS ELISA had a lower predictive value. Immunoblotting and absorption studies showed that IgG anti-LPS antibodies were directed specifically against LPS of P. aeuruginosa. ELISAs were developed to determine the specific IgG sublclasses involved. The increase in IgG anti-LPS involved all four subclasses. Highest anti-LPS titers were seen with IgG1 and IgG4, but the largest relative increases were seen with IgG2 and IgG3.
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PMID:Antilipopolysaccharide antibodies and differential diagnosis of chronic Pseudomonas aeruginosa lung infection in cystic fibrosis. 250 58


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