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)

The enzyme-linked immunosorbent assay (ELISA) was applied for immunological diagnosis of human tularemia, using lipopolysaccharide from Francisella tularensis as antigen. Sera collected from patients, healthy individuals, and vaccinated volunteers were investigated for antibodies against F. tularensis by ELISA and tube agglutination. In ELISA all sera were titrated with a polyspecific anti-immunoglobulin enzyme conjugate. A limited number of consecutive sera from individual patients were also investigated for immunoglobulin G (IgG) and IgM antibodies by means of immunoglobulin class-specific conjugates. On an average ELISA was more than 10-fold as sensitive as tube agglutination. Two weeks after onset of disease, sera from patients had significantly higher titers in ELISA than sera from healthy controls. High titers persisted after more than 2 years. Significant amounts of both IgG and IgM antibodies were present within 1 to 2 weeks after infection. The antibody activity increased during the first month, without any significant change of the relation between IgG and IgM titers. After 2.5 years the IgG/IgM titer ratio of sera from patients was significantly increased. Within 6 weeks after vaccination sera from about half of the vaccinees had significantly elevated titers in ELISA. Titers observed after vaccination were generally lower than those found after infection. An elevated ELISA titer can be of diagnostic importance by the end of the first week of illness. A significant increase of titer in consecutive serum samples indicates a diagnosis of tularemia. Determination of IgG and IgM antibodies may be of value in determing whether a positive titer of a single serum sample is of longstanding or recent origin.
 ...
PMID:Enzyme-linked immunosorbent assay for immunological diagnosis of human tularemia. 12 Aug 73

Lipopolysaccharide (LPS) from the live vaccine strain of Francisella tularensis (F. tularensis LVS) was isolated and purified. The LPS did not stimulate lymphocytes from previously tularaemia-vaccinated individuals or lymphocytes from non-primed individuals. However, serum antibodies from tularaemia vaccinees reacted with the LPS whereas virtually no reactivity was found with antibodies from individuals not exposed to F. tularensis LVS. Antibodies of immunoglobulin class M displayed the antibody reactivity predominantly. The LPS failed to induce the mononuclear cell-derived cytokine interleukin-1 and only low levels of tumour necrosis factor were detected. Furthermore, no LPS endotoxin properties were found in galactosamine-treated mice or in the Limulus amoebocyte lysate assay. From these results it can be concluded that F. tularensis LVS possesses a lipopolysaccharide-like molecule, which does not exhibit properties of a classical endotoxin.
 ...
PMID:Immunogenicity and toxicity of lipopolysaccharide from Francisella tularensis LVS. 141 18

The preventive activity of five monoclonal antibodies (McAb) in experimental tularemia was evaluated. McAb produced by hybridoma FB11-k (IgG2a), specific to F. tularensis lipopolysaccharide, prevented the death of mice and guinea pigs infected with F. tularensis virulent strain 503 of the holarctic subspecies.
 ...
PMID:[The preventive activity of monoclonal antibodies specific to the lipopolysaccharide of Francisella tularensis]. 148 10

T lymphocyte-mediated immunity is important for resistance to Francisella tularensis. To characterize the specificity of this immunity, we used membrane proteins and two lipopolysaccharide (LPS) preparations. Both membrane proteins were heat-modifiable, as indicated by their migration in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). One had an apparent molecular mass (Mm) of 120 kilodaltons (kDa) when solubilized in the SDS buffer at room temperature, but 17 kDa after heating. The respective values for the other protein were 35 kDa before and 40 kDa after heating. Both proteins were purified by a preparative SDS-PAGE. The LPS-containing preparations were isolated by aqueous phenol (WP) or PCP (phenol-chloroform-petroleum ether) extraction (LPS-R), and rendered protein-free by treatment with proteinase K. Lymphocytes from nine subjects immunized with a live tularemia vaccine from one to three years earlier responded specifically to both an F. tularensis whole cell antigen and the 17 kDa protein in the lymphocyte blast transformation test. By contrast, the 40 kDa protein and the two LPS preparations did not stimulate any detectable lymphocyte proliferation.
 ...
PMID:Membrane proteins of Francisella tularensis LVS differ in ability to induce proliferation of lymphocytes from tularemia-vaccinated individuals. 262 30

An enzyme immunoassay, with phenol-water extracted lipopolysaccharide (LPS) from Brucella abortus as antigen, was used to detect the class-specific antibody response in sera from 173 patients with B. abortus, B. melitensis or B. suis infection. Sera from 30 patients with salmonellosis, yersiniosis or tularaemia and from 25 healthy individuals served as controls. The B. abortus LPS antigen permitted a safe diagnosis of acute and chronic brucellosis with high IgM and rising IgG titres in sera collected in the acute stage of the disease, and with elevated IgG titres only in the chronic stage. The B. abortus LPS antigen also permitted a specific diagnosis with the exception of the high titres estimated in sera from patients with Yersinia enterocolitica 09 infection. The problem with that well-known reciprocal cross-reactivity was overcome by using two additional antigens: Y. enterocolitica 09 native and periodate oxidized and borohydride reduced LPS preparations. In sera from patients with brucellosis high titres were estimated against all three antigens, whereas in sera from patients with yersiniosis caused by serotype 09 high titres were measurable only with the B. abortus and the Y. enterocolitica native LPS antigens. These data suggest that the B. abortus and Y. enterocolitica 09 LPS share one antigenic determinant resistant to periodate oxidation and borohydride reduction, and that in addition the Y. enterocolitica 09 LPS has a determinant which is sensitive to periodate oxidation and borohydride reduction.
 ...
PMID:Enzyme immunoassay of the antibody response to Brucella and Yersinia enterocolitica 09 infections in humans. 617 1

An enzyme-linked immunosorbent assay (ELISA) with bacterial sonicate (S) as antigen developed for determining the presence of IgM, IgA, and IgG antibodies to Francisella tularensis was compared with the bacterial agglutination (BA) test and a corresponding ELISA using lipopolysaccharide (LPS) antigen. Of the organisms tested, F tularensis was the only one to cause significant inhibition, indicating the specificity of the S-ELISA. BA test titers correlated significantly with antibody levels in all three immunoglobulin classes and most closely with IgM antibodies (r = 0.83). With some minor exceptions, the S-ELISA and the LPS-ELISA gave identical results, and the correlations between the tests were very close (r = 0.94-0.99). The S-ELISA confirmed the tularemia diagnosis with the first serum specimens from 43% of patients with tularemia vs 17% of the BA test. In addition, no seroconversion was observed by the BA test in 4% of the patients, although large increases were observed in S-ELISA titers.
 ...
PMID:Enzyme-linked immunosorbent assay (ELISA) with bacterial sonicate antigen for IgM, IgA, and IgG antibodies to Francisella tularensis: comparison with bacterial agglutination test and ELISA with lipopolysaccharide antigen. 663 Oct 62

Approximately 8 years after treatment for tularemia, 14 of 22 (63.6%) individuals tested still had a positive microagglutination test for Francisella tularensis antibodies. An enzyme-linked immunosorbent assay for anti-F. tularensis outer membrane antibodies was positive for 55% (immunoglobulin A [IgA]), 95% (IgG), and 27% (IgM) of the late-phase sera, but with antibody levels significantly reduced from those in the acute-phase sera. IgG and IgA antibody levels in the late-phase sera showed significant correlation with levels in the acute-phase sera. The IgG/IgM ratio calculation discriminated between acute-phase and persistent antibodies for most sera, but Western blot (immunoblot) patterns did not. Immunoblotting indicated that the F. tularensis lipopolysaccharide is a major target for antibodies in both groups of sera. Our results substantiate the need for caution in the interpretation of positive serological test results for tularemia, which could result from disease occurring years earlier.
 ...
PMID:Comparative analysis of antibodies to Francisella tularensis antigens during the acute phase of tularemia and eight years later. 749 53

The specific humoral and cell-mediated immune responses of human volunteers vaccinated with the Francisella tularensis live vaccine strain (LVS) were evaluated. In the search for an optimal antigen to measure the immunogenicity of the vaccine in an enzyme-linked immunosorbent assay, we tested irradiation-killed LVS, an aqueous ether extract of the LVS (EEx), lipopolysaccharide (LPS) from LVS, and a virulent strain (SCHU4). Volunteers were immunized with LVS by scarification. Immunoglobulin G (IgG) responses to LVS and LPS gave the highest background titers when tested with sera from unimmunized volunteers, whereas IgA, IgG, and IgM background titers to EEx and SCHU4 were low. Vaccination caused a significant rise (P < 0.01) in IgA, IgG, and IgM titers to all antigens tested, except for the IgG response to LPS. Eighty percent of vaccinated volunteers developed a positive IgG response to EEx 14 days postvaccination, while 50% were positive to LVS. By day 14 after vaccination, 70% of immunized volunteers exhibited a positive response to EEx in an in vitro peripheral blood lymphocyte proliferation assay. EEx, a specific and sensitive antigen for evaluating immune responses of vaccinated volunteers, may be a superior antigen for the diagnosis of tularemia.
 ...
PMID:Cell-mediated and humoral immune responses after vaccination of human volunteers with the live vaccine strain of Francisella tularensis. 769 21

The relative role that humoral immunity plays in protection against infection with the intracellular bacterium, Francisella tularensis, remains controversial. Cellular immunity is thought to play the major and perhaps only role. The authors, in this article, investigate the immunologic and protective properties of immune serum collected from human recipients of the live tularemia vaccine (LVS). Sera of recipients of the vaccine demonstrated reactivity with the vaccine strain by enzyme-linked immunosorbent assay and Western blot analysis. This reactivity appeared to be directed primarily against the lipopolysaccharide of LVS and demonstrated complete cross-reactivity with fully virulent F. tularensis (Schu4). Pooled immune sera protected mice fully against a 10,000 LD50 challenge with the LVS strain relative to non-immune sera. The protection was abrogated by dilution or preadsorption with the LVS strain but not by preadsorption with Escherichia coli, which suggests specificity of protection. The authors conclude that antibodies to the LVS strain of F. tularensis are generated by live vaccination in humans and play a significant role in protection of mice against lethal challenge with the same organism. These antibodies crossreact completely with fully virulent F. tularensis, but whether they play a role in protection against fully virulent human tularemia strains requires further experimentation.
 ...
PMID:Passive protection of mice against lethal Francisella tularensis (live tularemia vaccine strain) infection by the sera of human recipients of the live tularemia vaccine. 804 59

A new lot of Francisella tularensis live vaccine strain (LVS) was tested for immunogenicity in 19 human volunteers. Scarification vaccination induced specific cell-mediated and humoral immune responses. We noted a significant rise in antibodies against irradiation-killed LVS, formalin-killed virulent strain SCHU4, and an ether extracted antigen preparation (EEx) beginning 14 days after vaccination. A main target of the humoral immune response was lipopolysaccharide. Eighty percent of vaccinated volunteers developed a positive IgG response to EEx by day 14 and 100% of vaccinees responded positively by day 21. Background IgA titers were lower than corresponding IgG or IgM titers. No early IgM rise was noted with any antigen. By day 14 after vaccination, in vitro lymphocyte responses to LVS, the rough variant of LVS, and EEx were significantly increased compared to controls. Seventy percent of volunteers had a positive in vitro lymphocyte response to EEx within 14 days of vaccination. We predict that EEx will be a useful antigen for diagnosing tularemia and for evaluating the immunogenicity of vaccines against tularemia. We are testing this antigen using sera from human cases of tularemia and control sera.
 ...
PMID:Immunogenicity of a new lot of Francisella tularensis live vaccine strain in human volunteers. 886 Oct 30


1 2 3 4 5 6 Next >>