The Allergenic Activity of Blo t 2, a Blomia tropicalis IgE-Binding Molecule

Abstract

Only few allergens derived from house dust mite (HDM) species have been evaluated in terms of their potential to induce allergic inflammation. In this study, we aimed to evaluate different aspects of the allergenicity and allergenic activity of Blo t 2, a Blomia tropicalis allergen. Blo t 2 was produced as a recombinant protein in Escherichia coli. Its allergenic activity was tested in humans by skin prick test and basophil activation assays, and in mice, by passive cutaneous anaphylaxis and a model of allergic airway inflammation. Sensitization rate to Blo t 2 (54.3%) was similar to that found to Blo t 21 (57.2%) and higher than to Der p 2 (37.5%). Most Blo t 2-sensitized patients showed a low intensity response (99.5%). Blo t 2 elicited CD203c upregulation and allergen induced skin inflammation. Additionally, immunized animals produced anti-Blo t 2 IgE antibodies and passive transfer of their serum to non-immunized animals induced skin inflammation after allergen exposure. Immunized animals developed bronchial hyperreactivity and a strong inflammatory lung reaction (eosinophils and neutrophils). These results confirm the allergenic activity of Blo t 2 and supports its clinical relevance.

Comparison of Antibody Responses against Two Molecules from Ascaris lumbricoides: The Allergen Asc l 5 and the Immunomodulatory Protein Al-CPI

“…Third, although rAl-CPI induced low IgE production in mice under routinary protocols for immunization, we cannot rule out the fact that it could take place after longer exposure or in the presence of other parasite components that serve as adjuvants. Our conclusions are limited to the statement that, under the same protocol of immunization, rAl-CPI induced lower IgE production than rAsc l 5 [18] as well as other allergens tested in our lab [57]. Fourth, IgE/IgG ratios may be better estimated from titration curves using standards and further assays should be performed in this regard.…”

Allergenic Activity of Individual Cat Allergen Molecules

“…However, thus far, there are no exposure-chamber-based approaches for the evaluation of individual allergen molecules, and it is also a technical challenge to expose patients to allergen-containing aerosols. Alternatively, basophil and/or mast cell activation tests can be performed which have been shown to mirror to some extent provocation test results (e.g., skin-prick testing) and in vivo allergenic activity [39][40][41][42]. Of course, there are several limitations of in vitro basophil activation tests, but it is a major advantage that effector cell activation tests allow one to test several allergens in different concentrations on different patients to compare the allergenic potency of the individual allergen molecules under controlled conditions.…”