Olive pollen allergy: searching for immunodominant T-cell epitopes on the Ole e 1 molecule.
BACKGROUND
The amino-acid and nucleotide sequence of Ole e 1 (the major antigen of olive pollen) has been described and the IgE antibody response to this major allergen was associated with DR7/DQ2 antigens. With this previous data we try to define the T-cell epitopes implicated in Ole e 1 reactivity.


OBJECTIVE
To study the recognition of T cells (derived from allergic and non-allergic Ole e 1 patients) to Ole e 1 synthetic peptides in order to define immunodominant T-cell epitopes.


METHODS
We have compared the proliferative response of the peripheral blood mononuclear cells from Ole e 1 sensitized patients vs. non-sensitized controls, induced by 14 Ole e 1 synthetic peptides. Thirty subjects were classified in two groups: group 1 (non-responders against Ole e 1, n=16) and group 2 (Ole e 1 responders, n=14), according to their clinical parameters and the presence or not in their sera of the significant Ole e 1 IgE antibody levels.


RESULTS
Our results shown that it is possible to find T cells reactive to Ole e 1 peptides in patients with and without significant levels of Ole e 1 IgE antibodies. However, the percentage of response was higher in patients with IgE antibodies 71.4% vs 25%), and the recognition profile was different: the control group showed a broad reactivity pattern, in contrast, the response by the 'Ole e 1 responders' group was mainly directed against three peptides of the carboxi-terminal region, peptides 10 (91-102), 12 (109-120) and 13 (119-130), with a response frequency of 35.7, 28.5 and 28.5%, respectively. By direct and inhibition test no antibody response was found against the synthetic peptides.


CONCLUSIONS
Our data suggest that the regions between 91 and 102 and 109-130 aminoacids on the Ole e 1 molecule are immunodominant T-cell epitopes. These epitopes are not recognized by IgE antibodies.
Cárdaba
B
B
Department of Immunology, Fundación Jiménez Díaz, Madrid, Spain.
Del Pozo
V
V
Jurado
A
A
Gallardo
S
S
Cortegano
I
I
Arrieta
I
I
Del Amo
A
A
Tramón
P
P
Florido
F
F
Sastre
J
J
Palomino
P
P
Lahoz
C
C
D000293:Adolescent; D000328:Adult; D000485:Allergens; D000595:Amino Acid Sequence; D000888:Antibodies, Anti-Idiotypic / Q000097:blood / Q000187:drug effects; D000917:Antibody Formation / Q000187:drug effects / Q000276:immunology; D052179:Antigens, Plant; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D000939:Epitopes / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D005260:Female; D006681:HLA-D Antigens / Q000097:blood; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood / Q000187:drug effects; D007074:Immunoglobulin G / Q000097:blood / Q000187:drug effects; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000276:immunology / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D011058:Pollen / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology*; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology; D014197:Trees / Q000737:chemistry / Q000276:immunology*
D000485:Allergens; D000888:Antibodies, Anti-Idiotypic; D052179:Antigens, Plant; D000939:Epitopes; D006681:HLA-D Antigens; D007074:Immunoglobulin G; C081946:Ole e I protein, Olea europaea; D009842:Oligopeptides; D010940:Plant Proteins; C026408:anti-IgE antibodies; C048844:anti-IgG; D007073:Immunoglobulin E