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Biomedical subjects

G Peltre

Publications and source records attributed to G Peltre.

63 records · Page 4Linked to original sources
PubMed1983

Inhibition of the passive cutaneous anaphylaxis reaction to Dactylis glomerata pollen allergens by a purified component of this pollen.

By isoelectric focusing a protein fraction of pI 4.6 was isolated from a crude water-soluble extract of Dactylis glomerata pollen (SE). This fraction was neither immunogenic nor allergenic in BALB/c mice. In one week, this protein inhibited the mouse IgE-specific antibodies to the soluble extract as measured by PCA in rats and was therefore called Dactylis inhibitory protein (DIP). Two experimental approaches which lowered IgE anti-SE titer were undertaken. Pretreatment with DIP as well as injection of DIP after the last sensitizing injection with SE resulted in an inhibition of the circulating IgE antibody level to SE. For both experiments the regulation of the immune response touched only the IgE class, whereas the titers of anti-SE IgG, IgM, IgA antibodies were not modified. DIP treatment did not alter the IgE titers, measured by PCA, in the immune response to ovalbumin.

Allergens↗
PubMed1982

Heterogeneity of grass pollen allergens (Dactylis glomerata) recognized by IgE antibodies in human patients sera by a new nitrocellulose immunoprint technique.

A new nitrocellulose immunoprint technique has been developed to detect specific antigens or/and allergens present among a heterogeneous solution such as a water-soluble crude extract of a grass pollen (Dactylis glomerata). The antigens are separated by isoelectric focusing (IEF) in an agarose gel and characterized by their isoelectric point (pI). These antigens are transferred and immobilized on a nitrocellulose sheet. They are recognized by the binding of specific antibodies contained in an unfractionated serum to be studied. Finally, the binding of these antibodies is visualized by species- or/and class-specific antibodies themselves labeled by an enzyme or by radioactivity. So one can detect the allergens recognized by the specific serum IgE antibodies and also the other antigens recognized by specific IgG, IgA or IgM antibodies.

Allergens↗
PubMed1967

The immune response to a hybrid protein molecule; specificity of secondary stimulation and of tolerance induction.

Upon immunization with LDH-III (subunit composition AABB) rabbits produce anti-A and anti-B antibodies in comparable amounts. These antibodies fit equally well to the hybrid enzyme and to LDH-V (AAAA) or LDH-I (BBBB) respectively, as tested by passive hemagglutination inhibition. No antibodies reacting with both LDH-I and LDH-V were detected. A minority of hybrid-specific antibodies was, however, present in the sera. Animals primed with LDH-III respond regularly to a boosting injection of LDH-V with the production of large amounts of anti-A (but not anti-B) antibodies. A similar injection of LDH-I stimulates (if it has any effect at all) the production of anti-B antibodies only. Stimulation with one of the pure types does not impair a subsequent response to the other. The majority of the animals primed with LDH-III responded not at all or weakly to a boosting injection of LDH-I, though antibodies to LDH-I were present in the sera at the time of stimulation. This effect can hardly be explained on the basis of serological sepcificity. Hyporesponsiveness to LDH-III can be induced by injection of LDH-V into the newborn. Both anti-A and anti-B titers are equally depressed. Within the dose range tested, LDH-I does not exert any tolerogenic action with respect to LDH-III. The carrier property of subunit A is evident in the induction of both immunity and tolerance to LDH-III. The early phase of the immune response to the hybrid enzyme may be carrier-specific, and receptors for the haptenic subunit B may not exist at that stage.

Animals↗
PubMedDate not supplied

Molecular basis of IgE cross-reactivity between human beta-casein and bovine beta-casein, a major allergen of milk.

Twenty patients allergic to cow's milk proteins and with high levels of specific IgE directed against bovine whole casein were selected to evaluate reactivity of their IgE antibodies with human beta-casein. Highly purified human and bovine beta-caseins were prepared by selective precipitations and FPLC separation. Their identity and purity were assessed by HPLC, analysis of amino acid composition, sequencing of the five N-terminal amino acid residues and immunochemical tests. Direct and indirect ELISAs were performed using human and bovine beta-casein coated into microtiter plates and monoclonal anti-human IgE antibody AChE labelled for revelation. Seven sera contained specific IgE directed against human beta-casein. Inhibition studies using native human and bovine beta-caseins as well as bovine beta-casein-derived peptides demonstrated that, depending on the sera, one or several common epitopes located in different parts of the molecule were shared by the two homologous proteins.

Adolescent↗
PubMedDate not supplied

Production of a monoclonal antibody against a major allergen of Dactylis glomerata pollen (Dg1).

A mouse monoclonal antibody was produced against the most frequent allergen Ag Dg1ief, purified from the Dactylis glomerata grass pollen by isoelectric focusing. Using the immunoprint technique, this monoclonal antibody detected Ag Dg1ief in D. glomerata pollen and some cross-reacting molecules in four other grass pollens. This hybridoma was grown in ascitic fluid. An immunosorbent was made from it and, by affinity chromatography, was used to purify monoclonal Ag Dg1m from the pollen extract. Ag Dg1m (6,000 to 8,000 daltons) appeared to be 4 to 5 times smaller than Ag Dg1ief. It appeared as a weak allergen in passive cutaneous anaphylaxis in rats, but was more potent in triggering histamine release on human basophils from grass-pollen sensitive patients. These results suggest that Ag Dg1m could be a part of the Ag Dg1ief used to induce production of this monoclonal antibody.

Animals↗
PubMedDate not supplied

Biological effect of transferrin on mast cell mediator release during the passive cutaneous anaphylaxis reaction: a possible inhibition mechanism involving iron.

A purification procedure for passive cutaneous anaphylaxis inhibitory factor from BALB/c mouse serum has been previously described. In the present work, this inhibitory activity was found to be related to transferrin. No activity was obtained using iron-unsaturated transferrin, whereas iron-saturated transferrin appeared to be potent. The in vivo inhibition of IgE-dependent mediator release from rat mast cells was also obtained using free iron. This effect was observed when iron was injected prior to or simultaneously with mouse IgE in rat skin. Iron and iron-saturated transferrin could play a role in the mechanism of desensitization by modulating the responsiveness of mast cells.

Animals↗