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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Plant antigens with immunological properties. III. Separation of a biologically active fraction in a grass pollen extract].

In present paper a partial biochemical study concerning two grass pollens (Poa pratensis and Phleum pratense) is carried out. On Sephadex G-75 three fractions were detected by an extract from the grass pollens. Only the third fraction shows a biological activity and biochemical findings are in agreement with the presence of four polipeptidic subfractions of different molecular weights ranged between 10,000 and 14,500. Specific additionals trials (ultracentrifugation, disc-electrophoresis, thyn-layer electrophoresis, isoelectric-focusing, immunological studies) are carried out to confirm the observed nature of prevalent material in pollens.

Antigens↗
PubMedDate not supplied

[Plant antigens with immunological properties. II. Further studies of the chemical characteristics and immunological properties of a grass pollen extract].

This second study carried out on an extract of two grass pollens (Poa pratensis and Phleum pratense) demonstrated the presence of N-acetilglucosamine and sialic acid in the extract (RFEX). Moreover the extract has confirmed its characteristics biologic activity i.e. the inhibition of the phenomenon of immune hemolysis with a different technique too, even having the antibodies of the treated animals the complement fixing activity. No appreciable changes of the immunoelectrophoresis pattern in the serum of the immunized mice have been noticed.

Acetylglucosamine↗
PubMed1983

[Celery allergy (celery contact urticaria syndrome) and relation to allergies to other plant antigens].

Comparative study of 13 patients (group A) with severe attacks of angio-oedema and urticaria after eating celery and 143 atopics with hypersensitivity to mugwort-pollen (group B). Due to the severity of the reactions (group A) no oral provocation tests were performed. Scratch chamber tests with raw and cooked celery (and related plants) confirmed the case histories. RAST answers to celery were compared for both groups. RAST inhibition indicated that celery and mugwort-pollen and also celery and birch-pollen allergens cross-react. Whether or not the reactions (in group A) are type I allergic or non-specific reactions is discussed. The term celery-"contact urticaria syndrome" should be used (Maibach and Johnson, 1975).

Adolescent↗
PubMed1982

Quantitative studies of in situ immune complex glomerulonephritis in the rat induced by planted, cationized antigen.

Cationized human IgG can bind to the rat glomerular basement membrane (GBM), act as planted antigen, and induce in situ immune complex formation accompanied by severe glomerulonephritis. Perfusion of highly cationized human IgG (isoelectric point {more than} 9.5) via the left renal artery resulted in preferential localization within the perfused kidney (up to 56 percent of dose injected); after intravenous administration, only 4 percent was bound to the kidneys. The planted antigen was localized along the glomerular capillary walls and was accessible for antibody administered intravenously 1 h after perfusion, when virtually no antigen remained in the circulation. Persistence of cationized human IgG in the perfused kidney was markedly prolonged when complexed with antibody; one-half the cationized human IgG was still present after 12 d. There was a difference in the disappearance rates of antigen and antibody, as cationized human IgG was removed faster from the kidney than the antibody, the binding of which remained almost unchanged during the first week. Renal perfusion of a minimum of 20 mug of cationized human IgG, followed by intravenous injection of antibody, regularly induced severe glomerulonephritis with a proteinuria of at least 100 mg/24 h. The degree and the persistence of proteinuria induced depended on the dose of cationized human IgG perfused. Experiments using radiolabeled antigen and antibody showed that after renal perfusion of 20 mug cationized human IgG, 11.1 mug was kidney bound at the time of antibody injection. At the onset of proteinuria, 4.0 mug of antigen and 31.9 mug of anti-human IgG antibody were present in the perfused kidney. Immunofluorescence revealed immune deposits consisting of cationized human IgG and rabbit IgG (anti-human IgG) along the GBM. The staining pattern was linear (confluent) during the first 2 d and became granular during the course of the disease. Electronmicroscopically, a prominent finding was the accumulation of dense deposits, mainly in the subepithelial space and beneath the slit pores.

Animals↗
PubMed1998

Immunization against rabies with plant-derived antigen.

We previously demonstrated that recombinant plant virus particles containing a chimeric peptide representing two rabies virus epitopes stimulate virus neutralizing antibody synthesis in immunized mice. We show here that mice immunized intraperitoneally or orally (by gastric intubation or by feeding on virus-infected spinach leaves) with engineered plant virus particles containing rabies antigen mount a local and systemic immune response. After the third dose of antigen, given intraperitoneally, 40% of the mice were protected against challenge infection with a lethal dose of rabies virus. Oral administration of the antigen stimulated serum IgG and IgA synthesis and ameliorated the clinical signs caused by intranasal infection with an attenuated rabies virus strain.

Administration, Oral↗
PubMed1986

Antibody, antigen, and glomerular capillary wall charge interactions: influence of antigen location on in situ immune complex formation.

These studies examined the charge interactions between the glomerular capillary wall, antibody and antigen at different sites in the glomerulus. Sheep IgG was separated into differently charged subclasses and immunologically placed in one of two glomerular locations (subepithelial or subendothelial) to serve as planted antigen. Single kidneys with planted antigen were transplanted into uninephrectomized recipients that received affinity-purified, cationic and anionic rat anti-sheep IgG labelled with 125I and 131I, respectively. Glomerular bound antibody was determined and corrected for antibody delivery. Specificity of antibody binding was confirmed by comparison of kidneys with or without planted antigen. The results indicate that the influence of charge on glomerular antibody binding depends on the site of the antigen. When antigen was planted in the subepithelial space, significantly more (15 to 25%) cationic than anionic antibody bound despite the fact that the antigen was cationic. Conversely, when the antigen was planted subendothelially, significantly more anionic (13 to 22%) antibody bound when the antigen was cationic, and significantly more cationic (7 to 16%) antibody bound when the antigen was anionic. Thus, the negatively-charged glomerular filtration barrier retards the permeation of anionic antibodies that complex with antigens located in the subepithelial space, but antigen-antibody charge interactions appear to predominate when the antigen is more proximally located.

Animals↗
PubMed1980

A model of in situ immune complex glomerulonephritis in the rat employing cationized ferritin.

In the model described here the ability of cationized (basic) ferritin to bind to the glomerular basement membrane and act as a planted antigen was exploited. This planted antigen was accessible to circulating antibody resulting in in situ immune complex formation. Perfusion of cationized ferritin (isoelectric point greater than 9.5) directly into the renal arteries, followed by intravenous injection of anti-ferritin antibody resulted in induction of glomerulonephritis with heavy proteinuria lasting for about 3 weeks. Fine granular deposition of antigen, antibody and rat C3 along the glomerular capillary walls was seen by immunofluorescence. Electron microscopy revealed the presence of subepithelial deposits containing ferritin; the foot processes were fused. This demonstrates the potential role of basic antigens in the pathogenesis of in situ immune complex glomerulonephritis.

Animals↗
PubMed2006

Superexpression of tuberculosis antigens in plant leaves.

Recent developments in genetic engineering allow the employment of plants as factories for 1/foreign protein production. Thus, tuberculosis (TB) ESAT6 antigen was expressed in different plant systems, but the level of vaccine protein accumulation was extremely low. We describe the technology for superexpression of TB vaccine proteins (Ag85B, ESAT6, and ESAT6:Ag85B fusion) in plant leaves which involves: (i) construction of tobacco mosaic virus-based vectors with the coat protein genes substituted by those for TB antigens; (ii) Agrobacterium-mediated delivery to plant leaf tissues of binary vectors containing the cDNA copy of the vector virus genome; and (iii) replication of virus vectors in plant cells under conditions suppressing the virus-induced gene silencing. This technology enables efficient production of the TB vaccine proteins in plants; in particular, the level of Ag85B antigen accumulation was not less than 800 mg/kg of fresh leaves. Expression of TB antigens in plant cells as His(6)-tagged proteins promoted their isolation and purification by Ni-NTA affinity chromatography. Deletion of transmembrane domains from Ag85B caused a dramatic increase in its intracellular stability. We propose that the strategy of TB antigens superproduction in a plant might be used as a basis for the creation of prophylactic and therapeutic vaccine against TB.

Agrobacterium tumefaciens↗
PubMed2000

Staphylococcal acid phosphatase binds to endothelial cells via charge interaction; a pathogenic role in Wegener's granulomatosis?

The majority of patients with Wegener's granulomatosis (WG) are chronic nasal carriers of Staphylococcus aureus. Chronic nasal carriage of S. aureus is associated with an increased risk of developing a relapse of the disease. The mechanism by which this occurs is still unknown. We hypothesized that a cationic protein of S. aureus, staphylococcal acid phosphatase (SAcP), acts as a planted antigen and initiates glomerulonephritis and vasculitis in patients with WG. In order to test the hypothesis that SAcP can act as a planted antigen in WG, we studied the ability of SAcP to bind to human umbilical vein endothelial cells (HUVEC) and human glomerular endothelial cells. We also studied whether this binding can be prevented by preincubation with an anionic protein, and whether binding of SAcP activates endothelial cells. We also evaluated whether antibodies in sera of patients with WG are able to bind to endothelial cell-bound SAcP. The results show that SAcP can act as a planted antigen by binding to both types of endothelial cells in a concentration-dependent manner. Binding of concentrations as low as 4 microg/ml can be detected on HUVEC within 5 min of incubation. Binding of SAcP to endothelial cells was charge-dependent but did not activate endothelial cells. Finally, endothelial cell-bound SAcP was recognized by sera of patients with WG. The data suggest a possible pathogenic role for SAcP by acting as a planted antigen thereby initiating glomerulonephritis and vasculitis in patients with WG.

Acid Phosphatase↗
PubMed1993

Isolation and characterization of a cDNA clone for plant nuclear antigen 21D7 associated with cell division.

A cDNA clone was isolated from a carrot (Daucus carota L.) cDNA expression library using monoclonal antibody 21D7, which recognizes a nuclear antigen associated with cell division in plant cells. To show that the isolated cDNA encodes the 21D7 antigen, a polyclonal antiserum was raised against a recombinant fusion protein specified by the cDNA. Both the polyclonal antiserum and the monoclonal antibody 21D7 recognized the same plant protein on immunoblots, in immunoprecipitation experiments, and in peptide mapping. Analysis of the cDNA revealed that the deduced amino acid sequence has 45% identity to the predicted sequence of the mouse transplantation antigen P91A from mutant tumor cells that is responsible for the immune rejection of the corresponding cell clone in a syngeneic mouse. The expression of the plant cDNA at the mRNA level was highly correlated with cell proliferation. In suspension cultures of Catharanthus roseus (L.) G Don. cells, the highest level of expression was observed during the midlogarithmic phase of growth. When auxin was added to stimulate cell division of auxin-starved cells arrested in the G1 phase, transcription was immediately enhanced, and the level of expression remained high throughout the G1 and S phases and dropped dramatically at the end of DNA replication.

Amino Acid Sequence↗
PubMed1994

Factors affecting the efficiency of immunogold labelling of plant virus antigens in thin sections.

Sections of pellets of six purified plant viruses with three different morphologies were used to examine different technical aspects of the immunogold labelling (IGL) technique. The results showed that fixation by glutaraldehyde alone was better than with osmium tetroxide post-fixation, and that Decon 75 was the best of the pretreatments tried. The study showed that different virus homologous antisera gave different results in IGL tests, and that longer incubation times with both antiserum and gold probe gave higher label densities without any increase in background label. Also, cross-absorption of the virus antisera with healthy host protein before use gave cleaner backgrounds and thus higher specificity. The work also examined the relationship between label density and amounts of visible virus. There was no correlation between the numbers of virus particles seen in sections and the numbers of gold particles; moreover, there was no apparent relationship between label density and the orientation or distribution of the virus particles in the section. The role of the embedding resin and its polymerisation temperature are also discussed.

Antigens, Viral↗
PubMed2005

Rapid, high-level production of hepatitis B core antigen in plant leaf and its immunogenicity in mice.

Hepatitis B core antigen (HBc or HBcAg) self-assembles into capsid particles and is extremely immunogenic. HBc has been extensively studied for its production in various expression systems and for the use of HBc particles for high-density, immunogenic presentation of foreign epitopes. Here we reported the high-level transient expression of HBc in plant leaf and its immunogenicity in mice. By using a novel plant viral expression system, HBc was produced in Nicotiana benthamiana leaves at levels up to 7.14% of total soluble protein (TSP) or 2.38 milligrams HBc per gram of fresh weight at 7 days post-infection (dpi). Plant-derived HBc (p-HBc) assembled into virus-like particles (VLPs) as revealed by sucrose gradients and electron microscopy. Partially purified p-HBc stimulated strong serum antibody responses in mice as Escherichia coli-derived HBc upon intraperitoneal (i.p.) injection. Furthermore, mice immunized mucosally (orally and intranasally) with p-HBc in the absence of adjuvants also developed HBc-specific serum IgG as well as intestinal IgA. Taken together, our results indicate the potential usefulness of p-HBc-VLP as a carrier for immunogenic presentation and mucosal delivery of foreign epitopes.

Animals↗