Hev b 8, the Hevea brasiliensis latex profilin, is a cross-reactive allergen of latex, plant foods and pollen.
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.
Ganglberger
E
E
Department of Pathophysiology, University of Vienna, Vienna, Austria.
Radauer
C
C
Wagner
S
S
Ríordáin
G
G
Beezhold
D H
DH
Brehler
R
R
Niggemann
B
B
Scheiner
O
O
Jensen-Jarolim
E
E
Breiteneder
H
H
D000485:Allergens / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D003285:Contractile Proteins; D003429:Cross Reactions; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis / Q000276:immunology; D007840:Latex / Q000276:immunology*; D020315:Latex Hypersensitivity / Q000097:blood / Q000276:immunology; D008297:Male; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D010945:Plants, Edible / Q000276:immunology*; D011058:Pollen / Q000276:immunology*; D051304:Profilins; D011994:Recombinant Proteins / Q000276:immunology; D016415:Sequence Alignment; D016135:Spinal Dysraphism / Q000276:immunology
D000485:Allergens; D003285:Contractile Proteins; D007840:Latex; D008840:Microfilament Proteins; D010940:Plant Proteins; D051304:Profilins; D011994:Recombinant Proteins; D007073:Immunoglobulin E