Hev b 8, the <i>Hevea brasiliensis</i> Latex Profilin, Is a Cross-Reactive Allergen of Latex, Plant Foods and Pollen

Abstract

Background: Plant profilins are important pan-allergens. They are responsible for a significant percentage of pollen-related allergies. Limited information is available about their involvement in the latex-fruit syndrome and the cross-reactivities between latex and pollen. We aimed to clone and express the Hevea brasiliensis latex profilin to investigate its allergological significance and serological cross-reactivities to profilins from plant foods and pollens. Methods: A DNA complementary to messenger RNA (cDNA) coding for the Hevea latex profilin, Hev b 8, was amplified by polymerase chain reaction from latex RNA. Recombinant (r)Hev b 8 was produced in Escherichia coli and used to screen sera from 50 latex- allergic health care workers (HCWs) with well-documented histories of food and pollen allergy and 34 latex-allergic spina bifida (SB) patients. The cross-reactivity of natural Hev b 8 and rHev b 8 with other plant profilins was determined by ELISA inhibition assays. A three-dimensional homology model of Hev b 8 was constructed based on known profilin structures. Results: The cDNA of Hev b 8 encoded a protein of 131 amino acids with a predicted molecular mass of 14 kD. Twelve of the 50 HCWs and 2 of the 34 SB patients were sensitized to Hev b 8. All Hev b 8-sensitized patients showed allergic symptoms to pollen or plant foods. Cross-reactivities between profilins of latex, pollen and plant food were illustrated by their ability to inhibit IgE binding to rHev b 8. Homology modeling of Hev b 8 yielded a structure highly similar to Bet v 2, the birch pollen profilin, with the most distinct differences located at the N-terminus. Conclusions: We conclude that primary sensitization to latex profilin in the majority of cases takes place via pollen or food profilins. Additionally, pollinosis and food-allergic patients with profilin-specific IgE can be at risk of developing latex allergy.

Structural, Functional, and Immunological Characterization of Profilin Panallergens Amb a 8, Art v 4, and Bet v 2

“…The recombinant profilins were recognized by IgE from some allergic patients, which is consistent with previous reports (21,27,45,46). Several studies have demonstrated that IgE from patients sensitized to one profilin binds to profilins from all other sources (40,41).…”

“…The major cluster of sequences may be divided into two subclusters, and one of them contains all plant profilins, including all currently registered profilin allergens. Taking into account the high sequence similarity of plant profilins, it is not surprising that these allergens are highly crossreactive (14,(21)(22)(23). However, it is quite surprising that currently the only source of allergenic profilins is from plants.…”

A Hypoallergenic Vaccine Obtained by Tail-to-Head Restructuring of Timothy Grass Pollen Profilin, Phl p 12, for the Treatment of Cross-Sensitization to Profilin

“…The model is based on highly homologous profilin structures of Hevea brasiliensis profilin (29), the birch pollen profilin (30), and the profilin from Arabidopsis thaliana (31). Loop regions were built automatically and the model was energy minimized with the program Gromos96 (32).…”

“…The peptides are indicated in a model of the Phl p 12 structure that was generated according to the three-dimensional structure of the birch pollen profilin Bet v 2, the A. thaliana profilin, and the H. brasiliensis latex profilin Hev b 8 ( Fig. 2A) (29,30). Because the IgE epitopes of the highly cross-reactive birch profilin primarily map to the N-and C-terminal portions of Bet v 2 (30), it was expected that the restructuring will lead to a strong reduction of IgE recognition.…”

Features and Mode of Action of Cross-reactive Plant Allergens Relevant to Latex-fruit Syndrome

“…What, then, is the pan-allergen responsible for latex-fruit syndrome? One possibility is profilin, which is present in both natural rubber latex and vegetable foods (Ganglberger et al, 2001). Latex profilin was actually registered as a latex allergen (Hev b 8).…”