Characterization of the allergic T-cell response to Pru p 3, the nonspecific lipid transfer protein in peach.
BACKGROUND
Pru p 3, the nonspecific lipid transfer protein from peach, is an important plant food allergen that frequently induces systemic reactions.


OBJECTIVE
We sought to analyze the allergic T-cell response to Pru p 3.


METHODS
PBMCs from Italian and Spanish patients with peach allergy were stimulated with purified natural Pru p 3. Allergen-specific T-cell lines were used to identify T-cell epitopes of Pru p 3. Pru p 3-specific T-cell clones (TCCs) were analyzed for allergen-induced secretion of IL-4, IFN-gamma, and IL-10 and expression of the integrin beta7, a receptor critical for gut homing.


RESULTS
No difference in T-cell responses of Italian and Spanish patients was found. Among several T cell-activating regions, Pru p 3(13-27), Pru p 3(34-48), Pru p 3(43-57), and Pru p 3(61-75) were most frequently recognized in 18 Pru p 3-specific T-cell lines. The majority of 32 Pru p 3-specific TCCs belonged to the T(H)2 subset. In contrast to TCCs specific for other plant food and pollen allergens, only a limited number of Pru p 3-specific TCCs produced significant amounts of IL-10. The expression of integrin beta7 on Pru p 3-specific TCCs was comparable with that observed on peanut-specific TCCs and higher compared with that seen in different pollen-specific TCCs.


CONCLUSIONS
The T-cell response to Pru p 3 is dominated by T(H)2 cells presumably primed in the gut. The identification of relevant T cell-activating regions provides a basis for engineering hypoallergenic variants of Pru p 3 with less IgE binding and retained T-cell stimulatory capacity for safe immunotherapy of peach allergy.
Department of Pathophysiology, Center for Physiology, Pathophysiology and Immunology, Medical University of Vienna, Vienna, Austria.
Véronique
V
Schulten
Astrid
A
Radakovics
Christina
C
Hartz
Adriano
A
Mari
Sonia
S
Vazquez-Cortes
Montserrat
M
Fernandez-Rivas
Iris
I
Lauer
Beatrice
B
Jahn-Schmid
Thomas
T
Eiwegger
Stephan
S
Scheurer
Barbara
B
Bohle
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000145:classification*; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D002352:Carrier Proteins; D018984:Epitopes, T-Lymphocyte / Q000145:classification; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D039641:Integrin beta Chains / Q000378:metabolism; D016753:Interleukin-10; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010641:Phenotype; D010940:Plant Proteins; D027861:Prunus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D018418:Th2 Cells; D055815:Young Adult
D000485:Allergens; D052179:Antigens, Plant; D002352:Carrier Proteins; D018984:Epitopes, T-Lymphocyte; D039641:Integrin beta Chains; D010940:Plant Proteins; C463181:Pru p 3 allergen; C091368:integrin beta7; C030363:lipid transfer protein; D016753:Interleukin-10