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Novel birch pollen specific immunotherapy formulation based on contiguous overlapping peptides.

Pellaton C, Perrin Y, Boudousquié C, Barbier N, Wassenberg J, Corradin G, Thierry AC, Audran R, Reymond C, Spertini F - Clin Transl Allergy (2013)

Bottom Line: Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen.In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen.The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon, Lausanne, 1011, Switzerland. francois.spertini@chuv.ch.

ABSTRACT

Background: Synthetic contiguous overlapping peptides (COPs) may represent an alternative to allergen extracts or recombinant allergens for allergen specific immunotherapy. In combination, COPs encompass the entire allergen sequence, providing all potential T cell epitopes, while preventing IgE conformational epitopes of the native allergen.

Methods: Individual COPs were derived from the sequence of Bet v 1, the major allergen of birch pollen, and its known crystal structure, and designed to avoid IgE binding. Three sets of COPs were tested in vitro in competition ELISA and basophil degranulation assays. Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen.

Results: The combination, named AllerT, of three COPs selected for undetectable IgE binding in competition assays and for the absence of basophil activation in vitro was unable to induce anaphylaxis in sensitized mice in contrast to rBet v 1. In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen. In contrast, a second set of COPs, AllerT4-T5 displayed some residual IgE binding in competition ELISA and a weak subliminal reactivity to skin prick testing.

Conclusions: The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human.

Trial registration: ClinicalTrials.gov NCT01719133.

No MeSH data available.


Related in: MedlinePlus

BALB/c mice sensitization and in vivo challenge. Mice were sensitized to rBet v 1 by injecting 0.1 μg rBet v 1 adsorbed to 1 mg Aluminum hydroxide. rBet v 1-specific IgE (panel A), IgG1 (panel B) and IgG2a (panel C) were measured in mice serum harvested immediately before the next injection. Results were expressed as means ± SD. Panel D. Rectal temperature was recorded at indicated time points following 30 μg rBet v 1(◊) or 190 μg AllerT (■) i.p. challenge at day 84 of the immunization protocol.
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Figure 3: BALB/c mice sensitization and in vivo challenge. Mice were sensitized to rBet v 1 by injecting 0.1 μg rBet v 1 adsorbed to 1 mg Aluminum hydroxide. rBet v 1-specific IgE (panel A), IgG1 (panel B) and IgG2a (panel C) were measured in mice serum harvested immediately before the next injection. Results were expressed as means ± SD. Panel D. Rectal temperature was recorded at indicated time points following 30 μg rBet v 1(◊) or 190 μg AllerT (■) i.p. challenge at day 84 of the immunization protocol.

Mentions: Mice were sensitized by repeated injections of rBet v 1 (0.1 μg in Aluminum Hydroxide) as described previously [28]. Bet v 1 specific IgE increased markedly after the fourth injection to level thereafter (Figure 3A). IgG1 and IgG2a levels started to increase after the fourth injection and steadily increased up to the last injection (Figure 3B and C). Clinical hypersensitivity of mice was tested by injecting i.p. 30 μg rBet v 1, using rectal temperature as a surrogate marker of anaphylaxis [26]. As seen in Figure 3D, a marked temperature drop was observed within 30 minutes after i.p. injection of rBet v 1. In contrast, injection of up to 190 μg of AllerT did not lead to any temperature shift, strongly indicating the absence of clinically relevant IgE binding to AllerT.


Novel birch pollen specific immunotherapy formulation based on contiguous overlapping peptides.

Pellaton C, Perrin Y, Boudousquié C, Barbier N, Wassenberg J, Corradin G, Thierry AC, Audran R, Reymond C, Spertini F - Clin Transl Allergy (2013)

BALB/c mice sensitization and in vivo challenge. Mice were sensitized to rBet v 1 by injecting 0.1 μg rBet v 1 adsorbed to 1 mg Aluminum hydroxide. rBet v 1-specific IgE (panel A), IgG1 (panel B) and IgG2a (panel C) were measured in mice serum harvested immediately before the next injection. Results were expressed as means ± SD. Panel D. Rectal temperature was recorded at indicated time points following 30 μg rBet v 1(◊) or 190 μg AllerT (■) i.p. challenge at day 84 of the immunization protocol.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672070&req=5

Figure 3: BALB/c mice sensitization and in vivo challenge. Mice were sensitized to rBet v 1 by injecting 0.1 μg rBet v 1 adsorbed to 1 mg Aluminum hydroxide. rBet v 1-specific IgE (panel A), IgG1 (panel B) and IgG2a (panel C) were measured in mice serum harvested immediately before the next injection. Results were expressed as means ± SD. Panel D. Rectal temperature was recorded at indicated time points following 30 μg rBet v 1(◊) or 190 μg AllerT (■) i.p. challenge at day 84 of the immunization protocol.
Mentions: Mice were sensitized by repeated injections of rBet v 1 (0.1 μg in Aluminum Hydroxide) as described previously [28]. Bet v 1 specific IgE increased markedly after the fourth injection to level thereafter (Figure 3A). IgG1 and IgG2a levels started to increase after the fourth injection and steadily increased up to the last injection (Figure 3B and C). Clinical hypersensitivity of mice was tested by injecting i.p. 30 μg rBet v 1, using rectal temperature as a surrogate marker of anaphylaxis [26]. As seen in Figure 3D, a marked temperature drop was observed within 30 minutes after i.p. injection of rBet v 1. In contrast, injection of up to 190 μg of AllerT did not lead to any temperature shift, strongly indicating the absence of clinically relevant IgE binding to AllerT.

Bottom Line: Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen.In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen.The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon, Lausanne, 1011, Switzerland. francois.spertini@chuv.ch.

ABSTRACT

Background: Synthetic contiguous overlapping peptides (COPs) may represent an alternative to allergen extracts or recombinant allergens for allergen specific immunotherapy. In combination, COPs encompass the entire allergen sequence, providing all potential T cell epitopes, while preventing IgE conformational epitopes of the native allergen.

Methods: Individual COPs were derived from the sequence of Bet v 1, the major allergen of birch pollen, and its known crystal structure, and designed to avoid IgE binding. Three sets of COPs were tested in vitro in competition ELISA and basophil degranulation assays. Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen.

Results: The combination, named AllerT, of three COPs selected for undetectable IgE binding in competition assays and for the absence of basophil activation in vitro was unable to induce anaphylaxis in sensitized mice in contrast to rBet v 1. In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen. In contrast, a second set of COPs, AllerT4-T5 displayed some residual IgE binding in competition ELISA and a weak subliminal reactivity to skin prick testing.

Conclusions: The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human.

Trial registration: ClinicalTrials.gov NCT01719133.

No MeSH data available.


Related in: MedlinePlus