Structural insights into the IgE mediated responses induced by the allergens Hev b 8 and Zea m 12 in their dimeric forms
Por:
Mares-Mejiá I., Martínez-Caballero S., Garay-Canales C., Cano-Sánchez P., Torres-Larios A., Lara-González S., Ortega E., Rodríguez-Romero A.
Publicada:
2 sep 2016
Categoría:
Multidisciplinary
Resumen:
Oligomerization of allergens plays an important role in IgE-mediated
reactions, as effective crosslinking of IgE-Fc epsilon RI complexes on
the cell membrane is dependent on the number of exposed B-cell epitopes
in a single allergen molecule or on the occurrence of identical epitopes
in a symmetrical arrangement. Few studies have attempted to
experimentally demonstrate the connection between allergen dimerization
and the ability to trigger allergic reactions. Here we studied plant
allergenic profilins rHev b 8 (rubber tree) and rZea m 12 (maize)
because they represent an important example of cross-reactivity in the
latex-pollen-food syndrome. Both allergens in their monomeric and
dimeric states were isolated and characterized by exclusion
chromatography and mass spectrometry and were used in immunological in
vitro experiments. Their crystal structures were solved, and for Hev b 8
a disulfide-linked homodimer was found. Comparing the structures we
established that the longest loop is relevant for recognition by IgE
antibodies, whereas the conserved regions are important for
cross-reactivity. We produced a novel monoclonal murine IgE (mAb 2F5),
specific for rHev b 8, which was useful to provide evidence that
profilin dimerization considerably increases the IgE-mediated
degranulation in rat basophilic leukemia cells.
Filiaciones:
Mares-Mejiá I.:
Instituto de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, 04510, Mexico
Martínez-Caballero S.:
Instituto de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, 04510, Mexico
Garay-Canales C.:
Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
Cano-Sánchez P.:
Instituto de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, 04510, Mexico
Torres-Larios A.:
Instituto de Fisiologiá Celular, Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
Lara-González S.:
Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055, San Luis Potosí, 78216, Mexico
Ortega E.:
Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, Ciudad de México, 04510, Mexico
Rodríguez-Romero A.:
Instituto de Química, Universidad Nacional Autónoma de México, Coyoacán, Ciudad de México, 04510, Mexico
All Open Access, Gold
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