Polymerized whole ragweed: An improved method of immunotherapy

Allergens of honeybee venom (BV) were modified by formaldehyde treatment (F), acetoacetylation (A) or coupling to polyethylene glycol (P). The biochemical, toxicologic and immunologic properties of these modified BV preparations were analyzed. F showed strongly reduced cytotoxicity, enzymatic activity and reactivity with human BV-specific IgE antibodies but retained the reactivity to BV-specific human and rabbit IgG. In A, enzymatic activity, cytotoxicity and the reactivity with human IgE and rabbit IgG antibodies were only moderately reduced. P lacked enzymatic activity and cytotoxicity and showed only minimal reactivity with IgE and IgG antibodies to BV.

Section: Introductionmentioning

confidence: 99%

Studies of Chemically Modified Honeybee Venom I.

Muêller¹,

Reisman²,

Elliott³

et al. 1982

“…The above peculiarity of KCNO-treated allergens allows the possibility to distinguish monomeric from polymeric allergoids such as those obtained by the reaction of allergens with glutaraldehyde [19, 20]. Polymeric allergoids are characterized by a significant increase in the molecular size of their components (reaching more than 1,000 kDa) as result of inter-/intramolecular cross-linking.…”

Section: Discussionmentioning

confidence: 99%

“…Such allergoids are characterized by a significant reduction in allergenic potency (probably as the result of an alteration in IgE epitopes of allergenic molecules) while still maintaining their immunogenic properties (capacity to induce IgG antibodies able to interact with native extract). Furthermore, unlike polymeric allergoids (such as those obtained by reaction with aldehydes) which are characterized by a strong increase in molecular dimension of their components due to inter-/intramolecular cross-linking phenomena [19, 20], they maintain a native molecular (monomeric) dimension of their own components [18]. …”

Section: Introductionmentioning

confidence: 99%

Date Palm Pollen Allergoid: Characterization of Its Chemical-Physical and Immunological Properties

Mistrello

Harfi

Roncarolo

et al. 2007

Background: Date palm (DP) pollen can cause allergic symptoms in people living in different countries. Specific immunotherapy with allergenic extracts by subcutaneous route is effective to cure allergic people. However, the risk of side effects has led to explore safer therapeutic modalities. The aim of our work was to evaluate IgE cross-reactivity between DP and autochthonous palm (European fan palm, EFP) pollen extracts, to chemically modify DP extract with potassium cyanate in order to obtain an allergoid, and to characterize it. Methods: By radioallergosorbent test inhibition, immunoblotting (IB) and skin prick test, in vitro and in vivo allergenic activities of native and modified DP extracts were compared. By SDS-PAGE and IB, we compared the protein profile and IgE-binding capacity of both native and modified DP, as well as of EFP extracts. By IB inhibition, IgE cross-reactivity of native DP and EFP extracts was evaluated. By ELISA, the capacity of modified DP-induced IgG to react with native DP extract was determined. Results: Radioallergosorbent test inhibition, IB and skin prick test results demonstrated that modified DP was significantly less allergenic than native DP extract. The SDS-PAGE profile showed that potassium cyanate treatment of DP extract did not alter the molecular weight of its components. In addition, no difference was observed between native DP and EFP extracts. Subsequent IB inhibition data evidenced the existence of a strong IgE cross-reactivity between native DP and EFP extracts. ELISA results indicated that the administration of modified DP in mice was able to induce specific IgG also recognizing native DP extract. Conclusions: Modified DP extract (allergoid) seems to be a good candidate for immunotherapy of patients affected by specific allergy.

“…Although the use of GA-modified protein antigens for immuno therapy of human allergic disorders has considerably expanded in recent years, most previous studies in both humans [12][13][14][15] and animal models [16][17][18] have been carried out with preparations likely to display a high degree of molecular heterogeneity.…”

Section: Discussionmentioning

confidence: 99%

Suppression of the IgE Antibody Response by Glutaraldehyde-Modified Ovalbumin: Dissociation between Loss of Antigenic Reactivity and Ability to Induce Suppression

HayGlass¹,

Strejan²

1984

Ovalbumin (OA) was substituted with glutaraldehyde (GA) at various GA:OA ratios and several preparations were isolated by gel filtration according to molecular weight. Two GA-substituted but unpolymerized preparations (OA₁-L and OA₁H) and 3 polymerized preparations of increasing molecular weight (OA₄, OA₁₇₅ and OA-POL) were obtained and were assessed for their ability to react with IgG and IgE antibodies directed against the native OA molecule, as well as for their ability to suppress the IgE antibody response. The results show that while both polymerized and unpolymerized GA-modified preparations lost their reactivity towards antinative OA antibodies, to a considerable extent, their ability to suppress the OA/IgE antibody response was directly dependent on polymerization. Pretreatment of CBA mice with unpolymerized OA preparations was ineffective while the effect of pretreatment with three polymers (OA₄, OA₁₇₅ and OA-POL) was directly dependent on the size of the polymer. The ability to induce IgG antibodies or delayed hypersensitivity to OA was not suppressed.